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| author | Kartik K. Agaram <vc@akkartik.com> | 2016-12-26 11:44:14 -0800 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2016-12-26 11:44:14 -0800 |
| commit | 204dae921abff0c70e017215bb3c91fa6ca11aff (patch) | |
| tree | 548788d18c881e3f6beb56133c1ca9d733ffa1e8 /html/075channel.mu.html | |
| parent | e5c11a5137d538b7713dd8708ca767c208824c06 (diff) | |
| download | mu-204dae921abff0c70e017215bb3c91fa6ca11aff.tar.gz | |
3710
Turns out we don't need to explicitly add anchors for each line. Vim's TOhtml has magic for that out of the box.
Diffstat (limited to 'html/075channel.mu.html')
| -rw-r--r-- | html/075channel.mu.html | 996 |
1 files changed, 498 insertions, 498 deletions
diff --git a/html/075channel.mu.html b/html/075channel.mu.html index c8bc3de6..4b4652dd 100644 --- a/html/075channel.mu.html +++ b/html/075channel.mu.html @@ -58,504 +58,504 @@ if ('onhashchange' in window) { </head> <body onload='JumpToLine();'> <pre id='vimCodeElement'> -<a name="L1"></a><span id="L1" class="LineNr"> 1 </span><span class="Comment"># Mu synchronizes between routines using channels rather than locks, like</span> -<a name="L2"></a><span id="L2" class="LineNr"> 2 </span><span class="Comment"># Erlang and Go.</span> -<a name="L3"></a><span id="L3" class="LineNr"> 3 </span><span class="Comment">#</span> -<a name="L4"></a><span id="L4" class="LineNr"> 4 </span><span class="Comment"># Key properties of channels:</span> -<a name="L5"></a><span id="L5" class="LineNr"> 5 </span><span class="Comment">#</span> -<a name="L6"></a><span id="L6" class="LineNr"> 6 </span><span class="Comment"># a) Writing to a full channel or reading from an empty one will put the</span> -<a name="L7"></a><span id="L7" class="LineNr"> 7 </span><span class="Comment"># current routine in 'waiting' state until the operation can be completed.</span> -<a name="L8"></a><span id="L8" class="LineNr"> 8 </span><span class="Comment">#</span> -<a name="L9"></a><span id="L9" class="LineNr"> 9 </span><span class="Comment"># b) Writing to a channel implicitly performs a deep copy. This prevents</span> -<a name="L10"></a><span id="L10" class="LineNr"> 10 </span><span class="Comment"># addresses from being shared between routines, and therefore eliminates all</span> -<a name="L11"></a><span id="L11" class="LineNr"> 11 </span><span class="Comment"># possibility of race conditions.</span> -<a name="L12"></a><span id="L12" class="LineNr"> 12 </span><span class="Comment">#</span> -<a name="L13"></a><span id="L13" class="LineNr"> 13 </span><span class="Comment"># There's still a narrow window for race conditions: the ingredients passed in</span> -<a name="L14"></a><span id="L14" class="LineNr"> 14 </span><span class="Comment"># to 'start-running'. Pass only channels into routines and you should be fine.</span> -<a name="L15"></a><span id="L15" class="LineNr"> 15 </span><span class="Comment"># Any other mutable ingredients will require locks.</span> -<a name="L16"></a><span id="L16" class="LineNr"> 16 </span> -<a name="L17"></a><span id="L17" class="LineNr"> 17 </span><span class="muScenario">scenario</span> channel [ -<a name="L18"></a><span id="L18" class="LineNr"> 18 </span> run [ -<a name="L19"></a><span id="L19" class="LineNr"> 19 </span> <span class="Constant">local-scope</span> -<a name="L20"></a><span id="L20" class="LineNr"> 20 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> -<a name="L21"></a><span id="L21" class="LineNr"> 21 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L22"></a><span id="L22" class="LineNr"> 22 </span> 10:num/<span class="Special">raw</span>, 11:bool/<span class="Special">raw</span>, source <span class="Special"><-</span> read source -<a name="L23"></a><span id="L23" class="LineNr"> 23 </span> ] -<a name="L24"></a><span id="L24" class="LineNr"> 24 </span> memory-should-contain [ -<a name="L25"></a><span id="L25" class="LineNr"> 25 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 34</span> -<a name="L26"></a><span id="L26" class="LineNr"> 26 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># read was successful</span> -<a name="L27"></a><span id="L27" class="LineNr"> 27 </span> ] -<a name="L28"></a><span id="L28" class="LineNr"> 28 </span>] -<a name="L29"></a><span id="L29" class="LineNr"> 29 </span> -<a name="L30"></a><span id="L30" class="LineNr"> 30 </span><span class="muData">container</span> channel:_elem [ -<a name="L31"></a><span id="L31" class="LineNr"> 31 </span> lock:bool <span class="Comment"># inefficient but simple: serialize all reads as well as writes</span> -<a name="L32"></a><span id="L32" class="LineNr"> 32 </span> first-full:num <span class="Comment"># for write</span> -<a name="L33"></a><span id="L33" class="LineNr"> 33 </span> first-free:num <span class="Comment"># for read</span> -<a name="L34"></a><span id="L34" class="LineNr"> 34 </span> <span class="Comment"># A circular buffer contains values from index first-full up to (but not</span> -<a name="L35"></a><span id="L35" class="LineNr"> 35 </span> <span class="Comment"># including) index first-empty. The reader always modifies it at first-full,</span> -<a name="L36"></a><span id="L36" class="LineNr"> 36 </span> <span class="Comment"># while the writer always modifies it at first-empty.</span> -<a name="L37"></a><span id="L37" class="LineNr"> 37 </span> data:&:@:_elem -<a name="L38"></a><span id="L38" class="LineNr"> 38 </span>] -<a name="L39"></a><span id="L39" class="LineNr"> 39 </span> -<a name="L40"></a><span id="L40" class="LineNr"> 40 </span><span class="Comment"># Since channels have two ends, and since it's an error to use either end from</span> -<a name="L41"></a><span id="L41" class="LineNr"> 41 </span><span class="Comment"># multiple routines, let's distinguish the ends.</span> -<a name="L42"></a><span id="L42" class="LineNr"> 42 </span> -<a name="L43"></a><span id="L43" class="LineNr"> 43 </span><span class="muData">container</span> source:_elem [ -<a name="L44"></a><span id="L44" class="LineNr"> 44 </span> chan:&:channel:_elem -<a name="L45"></a><span id="L45" class="LineNr"> 45 </span>] -<a name="L46"></a><span id="L46" class="LineNr"> 46 </span> -<a name="L47"></a><span id="L47" class="LineNr"> 47 </span><span class="muData">container</span> sink:_elem [ -<a name="L48"></a><span id="L48" class="LineNr"> 48 </span> chan:&:channel:_elem -<a name="L49"></a><span id="L49" class="LineNr"> 49 </span>] -<a name="L50"></a><span id="L50" class="LineNr"> 50 </span> -<a name="L51"></a><span id="L51" class="LineNr"> 51 </span><span class="muRecipe">def</span> new-channel capacity:num<span class="muRecipe"> -> </span>in:&:source:_elem, out:&:sink:_elem [ -<a name="L52"></a><span id="L52" class="LineNr"> 52 </span> <span class="Constant">local-scope</span> -<a name="L53"></a><span id="L53" class="LineNr"> 53 </span> <span class="Constant">load-ingredients</span> -<a name="L54"></a><span id="L54" class="LineNr"> 54 </span> result:&:channel:_elem <span class="Special"><-</span> new <span class="Delimiter">{</span>(channel _elem): type<span class="Delimiter">}</span> -<a name="L55"></a><span id="L55" class="LineNr"> 55 </span> *result <span class="Special"><-</span> put *result, <span class="Constant">first-full:offset</span>,<span class="Constant"> 0</span> -<a name="L56"></a><span id="L56" class="LineNr"> 56 </span> *result <span class="Special"><-</span> put *result, <span class="Constant">first-free:offset</span>,<span class="Constant"> 0</span> -<a name="L57"></a><span id="L57" class="LineNr"> 57 </span> capacity <span class="Special"><-</span> add capacity,<span class="Constant"> 1</span> <span class="Comment"># unused slot for 'full?' below</span> -<a name="L58"></a><span id="L58" class="LineNr"> 58 </span> data:&:@:_elem <span class="Special"><-</span> new <span class="Constant">_elem:type</span>, capacity -<a name="L59"></a><span id="L59" class="LineNr"> 59 </span> *result <span class="Special"><-</span> put *result, <span class="Constant">data:offset</span>, data -<a name="L60"></a><span id="L60" class="LineNr"> 60 </span> in <span class="Special"><-</span> new <span class="Delimiter">{</span>(source _elem): type<span class="Delimiter">}</span> -<a name="L61"></a><span id="L61" class="LineNr"> 61 </span> *in <span class="Special"><-</span> put *in, <span class="Constant">chan:offset</span>, result -<a name="L62"></a><span id="L62" class="LineNr"> 62 </span> out <span class="Special"><-</span> new <span class="Delimiter">{</span>(sink _elem): type<span class="Delimiter">}</span> -<a name="L63"></a><span id="L63" class="LineNr"> 63 </span> *out <span class="Special"><-</span> put *out, <span class="Constant">chan:offset</span>, result -<a name="L64"></a><span id="L64" class="LineNr"> 64 </span>] -<a name="L65"></a><span id="L65" class="LineNr"> 65 </span> -<a name="L66"></a><span id="L66" class="LineNr"> 66 </span><span class="muRecipe">def</span> write out:&:sink:_elem, val:_elem<span class="muRecipe"> -> </span>out:&:sink:_elem [ -<a name="L67"></a><span id="L67" class="LineNr"> 67 </span> <span class="Constant">local-scope</span> -<a name="L68"></a><span id="L68" class="LineNr"> 68 </span> <span class="Constant">load-ingredients</span> -<a name="L69"></a><span id="L69" class="LineNr"> 69 </span> assert out, <span class="Constant">[write to null channel]</span> -<a name="L70"></a><span id="L70" class="LineNr"> 70 </span> chan:&:channel:_elem <span class="Special"><-</span> get *out, <span class="Constant">chan:offset</span> -<a name="L71"></a><span id="L71" class="LineNr"> 71 </span><span class="Constant"> <channel-write-initial></span> -<a name="L72"></a><span id="L72" class="LineNr"> 72 </span> <span class="Comment"># block until lock is acquired AND queue has room</span> -<a name="L73"></a><span id="L73" class="LineNr"> 73 </span> lock:location <span class="Special"><-</span> get-location *chan, <span class="Constant">lock:offset</span> -<a name="L74"></a><span id="L74" class="LineNr"> 74 </span><span class="CommentedCode">#? $print [write], 10/newline</span> -<a name="L75"></a><span id="L75" class="LineNr"> 75 </span> <span class="Delimiter">{</span> -<a name="L76"></a><span id="L76" class="LineNr"> 76 </span><span class="CommentedCode">#? $print [trying to acquire lock for writing], 10/newline</span> -<a name="L77"></a><span id="L77" class="LineNr"> 77 </span> wait-for-reset-then-set lock -<a name="L78"></a><span id="L78" class="LineNr"> 78 </span><span class="CommentedCode">#? $print [lock acquired for writing], 10/newline</span> -<a name="L79"></a><span id="L79" class="LineNr"> 79 </span> full?:bool <span class="Special"><-</span> channel-full? chan -<a name="L80"></a><span id="L80" class="LineNr"> 80 </span> <span class="muControl">break-unless</span> full? -<a name="L81"></a><span id="L81" class="LineNr"> 81 </span><span class="CommentedCode">#? $print [but channel is full; relinquishing lock], 10/newline</span> -<a name="L82"></a><span id="L82" class="LineNr"> 82 </span> <span class="Comment"># channel is full; relinquish lock and give a reader the opportunity to</span> -<a name="L83"></a><span id="L83" class="LineNr"> 83 </span> <span class="Comment"># create room on it</span> -<a name="L84"></a><span id="L84" class="LineNr"> 84 </span> reset lock -<a name="L85"></a><span id="L85" class="LineNr"> 85 </span> current-routine-is-blocked -<a name="L86"></a><span id="L86" class="LineNr"> 86 </span> switch <span class="Comment"># avoid spinlocking</span> -<a name="L87"></a><span id="L87" class="LineNr"> 87 </span> <span class="muControl">loop</span> -<a name="L88"></a><span id="L88" class="LineNr"> 88 </span> <span class="Delimiter">}</span> -<a name="L89"></a><span id="L89" class="LineNr"> 89 </span> current-routine-is-unblocked -<a name="L90"></a><span id="L90" class="LineNr"> 90 </span><span class="CommentedCode">#? $print [performing write], 10/newline</span> -<a name="L91"></a><span id="L91" class="LineNr"> 91 </span> <span class="Comment"># store a deep copy of val</span> -<a name="L92"></a><span id="L92" class="LineNr"> 92 </span> circular-buffer:&:@:_elem <span class="Special"><-</span> get *chan, <span class="Constant">data:offset</span> -<a name="L93"></a><span id="L93" class="LineNr"> 93 </span> free:num <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L94"></a><span id="L94" class="LineNr"> 94 </span> val-copy:_elem <span class="Special"><-</span> deep-copy val <span class="Comment"># on this instruction rests all Mu's concurrency-safety</span> -<a name="L95"></a><span id="L95" class="LineNr"> 95 </span> *circular-buffer <span class="Special"><-</span> put-index *circular-buffer, free, val-copy -<a name="L96"></a><span id="L96" class="LineNr"> 96 </span> <span class="Comment"># mark its slot as filled</span> -<a name="L97"></a><span id="L97" class="LineNr"> 97 </span> free <span class="Special"><-</span> add free,<span class="Constant"> 1</span> -<a name="L98"></a><span id="L98" class="LineNr"> 98 </span> <span class="Delimiter">{</span> -<a name="L99"></a><span id="L99" class="LineNr"> 99 </span> <span class="Comment"># wrap free around to 0 if necessary</span> -<a name="L100"></a><span id="L100" class="LineNr">100 </span> len:num <span class="Special"><-</span> length *circular-buffer -<a name="L101"></a><span id="L101" class="LineNr">101 </span> at-end?:bool <span class="Special"><-</span> greater-or-equal free, len -<a name="L102"></a><span id="L102" class="LineNr">102 </span> <span class="muControl">break-unless</span> at-end? -<a name="L103"></a><span id="L103" class="LineNr">103 </span> free <span class="Special"><-</span> copy<span class="Constant"> 0</span> -<a name="L104"></a><span id="L104" class="LineNr">104 </span> <span class="Delimiter">}</span> -<a name="L105"></a><span id="L105" class="LineNr">105 </span> <span class="Comment"># write back</span> -<a name="L106"></a><span id="L106" class="LineNr">106 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">first-free:offset</span>, free -<a name="L107"></a><span id="L107" class="LineNr">107 </span><span class="CommentedCode">#? $print [relinquishing lock after writing], 10/newline</span> -<a name="L108"></a><span id="L108" class="LineNr">108 </span> reset lock -<a name="L109"></a><span id="L109" class="LineNr">109 </span>] -<a name="L110"></a><span id="L110" class="LineNr">110 </span> -<a name="L111"></a><span id="L111" class="LineNr">111 </span><span class="muRecipe">def</span> read in:&:source:_elem<span class="muRecipe"> -> </span>result:_elem, eof?:bool, in:&:source:_elem [ -<a name="L112"></a><span id="L112" class="LineNr">112 </span> <span class="Constant">local-scope</span> -<a name="L113"></a><span id="L113" class="LineNr">113 </span> <span class="Constant">load-ingredients</span> -<a name="L114"></a><span id="L114" class="LineNr">114 </span> assert in, <span class="Constant">[read on null channel]</span> -<a name="L115"></a><span id="L115" class="LineNr">115 </span> eof? <span class="Special"><-</span> copy <span class="Constant">0/false</span> <span class="Comment"># default result</span> -<a name="L116"></a><span id="L116" class="LineNr">116 </span> chan:&:channel:_elem <span class="Special"><-</span> get *in, <span class="Constant">chan:offset</span> -<a name="L117"></a><span id="L117" class="LineNr">117 </span> <span class="Comment"># block until lock is acquired AND queue has data</span> -<a name="L118"></a><span id="L118" class="LineNr">118 </span> lock:location <span class="Special"><-</span> get-location *chan, <span class="Constant">lock:offset</span> -<a name="L119"></a><span id="L119" class="LineNr">119 </span><span class="CommentedCode">#? $print [read], 10/newline</span> -<a name="L120"></a><span id="L120" class="LineNr">120 </span> <span class="Delimiter">{</span> -<a name="L121"></a><span id="L121" class="LineNr">121 </span><span class="CommentedCode">#? $print [trying to acquire lock for reading], 10/newline</span> -<a name="L122"></a><span id="L122" class="LineNr">122 </span> wait-for-reset-then-set lock -<a name="L123"></a><span id="L123" class="LineNr">123 </span><span class="CommentedCode">#? $print [lock acquired for reading], 10/newline</span> -<a name="L124"></a><span id="L124" class="LineNr">124 </span> empty?:bool <span class="Special"><-</span> channel-empty? chan -<a name="L125"></a><span id="L125" class="LineNr">125 </span> <span class="muControl">break-unless</span> empty? -<a name="L126"></a><span id="L126" class="LineNr">126 </span><span class="CommentedCode">#? $print [but channel is empty; relinquishing lock], 10/newline</span> -<a name="L127"></a><span id="L127" class="LineNr">127 </span> <span class="Comment"># channel is empty; relinquish lock and give a writer the opportunity to</span> -<a name="L128"></a><span id="L128" class="LineNr">128 </span> <span class="Comment"># add to it</span> -<a name="L129"></a><span id="L129" class="LineNr">129 </span> reset lock -<a name="L130"></a><span id="L130" class="LineNr">130 </span> current-routine-is-blocked -<a name="L131"></a><span id="L131" class="LineNr">131 </span><span class="Constant"> <channel-read-empty></span> -<a name="L132"></a><span id="L132" class="LineNr">132 </span> switch <span class="Comment"># avoid spinlocking</span> -<a name="L133"></a><span id="L133" class="LineNr">133 </span> <span class="muControl">loop</span> -<a name="L134"></a><span id="L134" class="LineNr">134 </span> <span class="Delimiter">}</span> -<a name="L135"></a><span id="L135" class="LineNr">135 </span> current-routine-is-unblocked -<a name="L136"></a><span id="L136" class="LineNr">136 </span> <span class="Comment"># pull result off</span> -<a name="L137"></a><span id="L137" class="LineNr">137 </span> full:num <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L138"></a><span id="L138" class="LineNr">138 </span> circular-buffer:&:@:_elem <span class="Special"><-</span> get *chan, <span class="Constant">data:offset</span> -<a name="L139"></a><span id="L139" class="LineNr">139 </span> result <span class="Special"><-</span> index *circular-buffer, full -<a name="L140"></a><span id="L140" class="LineNr">140 </span> <span class="Comment"># clear the slot</span> -<a name="L141"></a><span id="L141" class="LineNr">141 </span> empty:&:_elem <span class="Special"><-</span> new <span class="Constant">_elem:type</span> -<a name="L142"></a><span id="L142" class="LineNr">142 </span> *circular-buffer <span class="Special"><-</span> put-index *circular-buffer, full, *empty -<a name="L143"></a><span id="L143" class="LineNr">143 </span> <span class="Comment"># mark its slot as empty</span> -<a name="L144"></a><span id="L144" class="LineNr">144 </span> full <span class="Special"><-</span> add full,<span class="Constant"> 1</span> -<a name="L145"></a><span id="L145" class="LineNr">145 </span> <span class="Delimiter">{</span> -<a name="L146"></a><span id="L146" class="LineNr">146 </span> <span class="Comment"># wrap full around to 0 if necessary</span> -<a name="L147"></a><span id="L147" class="LineNr">147 </span> len:num <span class="Special"><-</span> length *circular-buffer -<a name="L148"></a><span id="L148" class="LineNr">148 </span> at-end?:bool <span class="Special"><-</span> greater-or-equal full, len -<a name="L149"></a><span id="L149" class="LineNr">149 </span> <span class="muControl">break-unless</span> at-end? -<a name="L150"></a><span id="L150" class="LineNr">150 </span> full <span class="Special"><-</span> copy<span class="Constant"> 0</span> -<a name="L151"></a><span id="L151" class="LineNr">151 </span> <span class="Delimiter">}</span> -<a name="L152"></a><span id="L152" class="LineNr">152 </span> <span class="Comment"># write back</span> -<a name="L153"></a><span id="L153" class="LineNr">153 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">first-full:offset</span>, full -<a name="L154"></a><span id="L154" class="LineNr">154 </span><span class="CommentedCode">#? $print [relinquishing lock after reading], 10/newline</span> -<a name="L155"></a><span id="L155" class="LineNr">155 </span> reset lock -<a name="L156"></a><span id="L156" class="LineNr">156 </span>] -<a name="L157"></a><span id="L157" class="LineNr">157 </span> -<a name="L158"></a><span id="L158" class="LineNr">158 </span><span class="Comment"># todo: create a notion of iterator and iterable so we can read/write whole</span> -<a name="L159"></a><span id="L159" class="LineNr">159 </span><span class="Comment"># aggregates (arrays, lists, ..) of _elems at once.</span> -<a name="L160"></a><span id="L160" class="LineNr">160 </span> -<a name="L161"></a><span id="L161" class="LineNr">161 </span><span class="muRecipe">def</span> clear in:&:source:_elem<span class="muRecipe"> -> </span>in:&:source:_elem [ -<a name="L162"></a><span id="L162" class="LineNr">162 </span> <span class="Constant">local-scope</span> -<a name="L163"></a><span id="L163" class="LineNr">163 </span> <span class="Constant">load-ingredients</span> -<a name="L164"></a><span id="L164" class="LineNr">164 </span> chan:&:channel:_elem <span class="Special"><-</span> get *in, <span class="Constant">chan:offset</span> -<a name="L165"></a><span id="L165" class="LineNr">165 </span> <span class="Delimiter">{</span> -<a name="L166"></a><span id="L166" class="LineNr">166 </span> empty?:bool <span class="Special"><-</span> channel-empty? chan -<a name="L167"></a><span id="L167" class="LineNr">167 </span> <span class="muControl">break-if</span> empty? -<a name="L168"></a><span id="L168" class="LineNr">168 </span> _, _, in <span class="Special"><-</span> read in -<a name="L169"></a><span id="L169" class="LineNr">169 </span> <span class="Delimiter">}</span> -<a name="L170"></a><span id="L170" class="LineNr">170 </span>] -<a name="L171"></a><span id="L171" class="LineNr">171 </span> -<a name="L172"></a><span id="L172" class="LineNr">172 </span><span class="muScenario">scenario</span> channel-initialization [ -<a name="L173"></a><span id="L173" class="LineNr">173 </span> run [ -<a name="L174"></a><span id="L174" class="LineNr">174 </span> <span class="Constant">local-scope</span> -<a name="L175"></a><span id="L175" class="LineNr">175 </span> source:&:source:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> -<a name="L176"></a><span id="L176" class="LineNr">176 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L177"></a><span id="L177" class="LineNr">177 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L178"></a><span id="L178" class="LineNr">178 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L179"></a><span id="L179" class="LineNr">179 </span> ] -<a name="L180"></a><span id="L180" class="LineNr">180 </span> memory-should-contain [ -<a name="L181"></a><span id="L181" class="LineNr">181 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-full</span> -<a name="L182"></a><span id="L182" class="LineNr">182 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-free</span> -<a name="L183"></a><span id="L183" class="LineNr">183 </span> ] -<a name="L184"></a><span id="L184" class="LineNr">184 </span>] -<a name="L185"></a><span id="L185" class="LineNr">185 </span> -<a name="L186"></a><span id="L186" class="LineNr">186 </span><span class="muScenario">scenario</span> channel-write-increments-free [ -<a name="L187"></a><span id="L187" class="LineNr">187 </span> <span class="Constant">local-scope</span> -<a name="L188"></a><span id="L188" class="LineNr">188 </span> _, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> -<a name="L189"></a><span id="L189" class="LineNr">189 </span> run [ -<a name="L190"></a><span id="L190" class="LineNr">190 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L191"></a><span id="L191" class="LineNr">191 </span> chan:&:channel:num <span class="Special"><-</span> get *sink, <span class="Constant">chan:offset</span> -<a name="L192"></a><span id="L192" class="LineNr">192 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L193"></a><span id="L193" class="LineNr">193 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L194"></a><span id="L194" class="LineNr">194 </span> ] -<a name="L195"></a><span id="L195" class="LineNr">195 </span> memory-should-contain [ -<a name="L196"></a><span id="L196" class="LineNr">196 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-full</span> -<a name="L197"></a><span id="L197" class="LineNr">197 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-free</span> -<a name="L198"></a><span id="L198" class="LineNr">198 </span> ] -<a name="L199"></a><span id="L199" class="LineNr">199 </span>] -<a name="L200"></a><span id="L200" class="LineNr">200 </span> -<a name="L201"></a><span id="L201" class="LineNr">201 </span><span class="muScenario">scenario</span> channel-read-increments-full [ -<a name="L202"></a><span id="L202" class="LineNr">202 </span> <span class="Constant">local-scope</span> -<a name="L203"></a><span id="L203" class="LineNr">203 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> -<a name="L204"></a><span id="L204" class="LineNr">204 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L205"></a><span id="L205" class="LineNr">205 </span> run [ -<a name="L206"></a><span id="L206" class="LineNr">206 </span> _, _, source <span class="Special"><-</span> read source -<a name="L207"></a><span id="L207" class="LineNr">207 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L208"></a><span id="L208" class="LineNr">208 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L209"></a><span id="L209" class="LineNr">209 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L210"></a><span id="L210" class="LineNr">210 </span> ] -<a name="L211"></a><span id="L211" class="LineNr">211 </span> memory-should-contain [ -<a name="L212"></a><span id="L212" class="LineNr">212 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-full</span> -<a name="L213"></a><span id="L213" class="LineNr">213 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-free</span> -<a name="L214"></a><span id="L214" class="LineNr">214 </span> ] -<a name="L215"></a><span id="L215" class="LineNr">215 </span>] -<a name="L216"></a><span id="L216" class="LineNr">216 </span> -<a name="L217"></a><span id="L217" class="LineNr">217 </span><span class="muScenario">scenario</span> channel-wrap [ -<a name="L218"></a><span id="L218" class="LineNr">218 </span> <span class="Constant">local-scope</span> -<a name="L219"></a><span id="L219" class="LineNr">219 </span> <span class="Comment"># channel with just 1 slot</span> -<a name="L220"></a><span id="L220" class="LineNr">220 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">1/capacity</span> -<a name="L221"></a><span id="L221" class="LineNr">221 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L222"></a><span id="L222" class="LineNr">222 </span> <span class="Comment"># write and read a value</span> -<a name="L223"></a><span id="L223" class="LineNr">223 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L224"></a><span id="L224" class="LineNr">224 </span> _, _, source <span class="Special"><-</span> read source -<a name="L225"></a><span id="L225" class="LineNr">225 </span> run [ -<a name="L226"></a><span id="L226" class="LineNr">226 </span> <span class="Comment"># first-free will now be 1</span> -<a name="L227"></a><span id="L227" class="LineNr">227 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L228"></a><span id="L228" class="LineNr">228 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L229"></a><span id="L229" class="LineNr">229 </span> <span class="Comment"># write second value, verify that first-free wraps</span> -<a name="L230"></a><span id="L230" class="LineNr">230 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L231"></a><span id="L231" class="LineNr">231 </span> 20:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L232"></a><span id="L232" class="LineNr">232 </span> <span class="Comment"># read second value, verify that first-full wraps</span> -<a name="L233"></a><span id="L233" class="LineNr">233 </span> _, _, source <span class="Special"><-</span> read source -<a name="L234"></a><span id="L234" class="LineNr">234 </span> 30:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L235"></a><span id="L235" class="LineNr">235 </span> ] -<a name="L236"></a><span id="L236" class="LineNr">236 </span> memory-should-contain [ -<a name="L237"></a><span id="L237" class="LineNr">237 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-free after first write</span> -<a name="L238"></a><span id="L238" class="LineNr">238 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-full after first read</span> -<a name="L239"></a><span id="L239" class="LineNr">239 </span> <span class="Constant"> 20</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-free after second write, wrapped</span> -<a name="L240"></a><span id="L240" class="LineNr">240 </span> <span class="Constant"> 30</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-full after second read, wrapped</span> -<a name="L241"></a><span id="L241" class="LineNr">241 </span> ] -<a name="L242"></a><span id="L242" class="LineNr">242 </span>] -<a name="L243"></a><span id="L243" class="LineNr">243 </span> -<a name="L244"></a><span id="L244" class="LineNr">244 </span><span class="muScenario">scenario</span> channel-new-empty-not-full [ -<a name="L245"></a><span id="L245" class="LineNr">245 </span> run [ -<a name="L246"></a><span id="L246" class="LineNr">246 </span> <span class="Constant">local-scope</span> -<a name="L247"></a><span id="L247" class="LineNr">247 </span> source:&:source:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> -<a name="L248"></a><span id="L248" class="LineNr">248 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L249"></a><span id="L249" class="LineNr">249 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan -<a name="L250"></a><span id="L250" class="LineNr">250 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan -<a name="L251"></a><span id="L251" class="LineNr">251 </span> ] -<a name="L252"></a><span id="L252" class="LineNr">252 </span> memory-should-contain [ -<a name="L253"></a><span id="L253" class="LineNr">253 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># empty?</span> -<a name="L254"></a><span id="L254" class="LineNr">254 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># full?</span> -<a name="L255"></a><span id="L255" class="LineNr">255 </span> ] -<a name="L256"></a><span id="L256" class="LineNr">256 </span>] -<a name="L257"></a><span id="L257" class="LineNr">257 </span> -<a name="L258"></a><span id="L258" class="LineNr">258 </span><span class="muScenario">scenario</span> channel-write-not-empty [ -<a name="L259"></a><span id="L259" class="LineNr">259 </span> <span class="Constant">local-scope</span> -<a name="L260"></a><span id="L260" class="LineNr">260 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> -<a name="L261"></a><span id="L261" class="LineNr">261 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L262"></a><span id="L262" class="LineNr">262 </span> run [ -<a name="L263"></a><span id="L263" class="LineNr">263 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L264"></a><span id="L264" class="LineNr">264 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan -<a name="L265"></a><span id="L265" class="LineNr">265 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan -<a name="L266"></a><span id="L266" class="LineNr">266 </span> ] -<a name="L267"></a><span id="L267" class="LineNr">267 </span> memory-should-contain [ -<a name="L268"></a><span id="L268" class="LineNr">268 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># empty?</span> -<a name="L269"></a><span id="L269" class="LineNr">269 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># full?</span> -<a name="L270"></a><span id="L270" class="LineNr">270 </span> ] -<a name="L271"></a><span id="L271" class="LineNr">271 </span>] -<a name="L272"></a><span id="L272" class="LineNr">272 </span> -<a name="L273"></a><span id="L273" class="LineNr">273 </span><span class="muScenario">scenario</span> channel-write-full [ -<a name="L274"></a><span id="L274" class="LineNr">274 </span> <span class="Constant">local-scope</span> -<a name="L275"></a><span id="L275" class="LineNr">275 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">1/capacity</span> -<a name="L276"></a><span id="L276" class="LineNr">276 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L277"></a><span id="L277" class="LineNr">277 </span> run [ -<a name="L278"></a><span id="L278" class="LineNr">278 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L279"></a><span id="L279" class="LineNr">279 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan -<a name="L280"></a><span id="L280" class="LineNr">280 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan -<a name="L281"></a><span id="L281" class="LineNr">281 </span> ] -<a name="L282"></a><span id="L282" class="LineNr">282 </span> memory-should-contain [ -<a name="L283"></a><span id="L283" class="LineNr">283 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># empty?</span> -<a name="L284"></a><span id="L284" class="LineNr">284 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># full?</span> -<a name="L285"></a><span id="L285" class="LineNr">285 </span> ] -<a name="L286"></a><span id="L286" class="LineNr">286 </span>] -<a name="L287"></a><span id="L287" class="LineNr">287 </span> -<a name="L288"></a><span id="L288" class="LineNr">288 </span><span class="muScenario">scenario</span> channel-read-not-full [ -<a name="L289"></a><span id="L289" class="LineNr">289 </span> <span class="Constant">local-scope</span> -<a name="L290"></a><span id="L290" class="LineNr">290 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">1/capacity</span> -<a name="L291"></a><span id="L291" class="LineNr">291 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> -<a name="L292"></a><span id="L292" class="LineNr">292 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> -<a name="L293"></a><span id="L293" class="LineNr">293 </span> run [ -<a name="L294"></a><span id="L294" class="LineNr">294 </span> _, _, source <span class="Special"><-</span> read source -<a name="L295"></a><span id="L295" class="LineNr">295 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan -<a name="L296"></a><span id="L296" class="LineNr">296 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan -<a name="L297"></a><span id="L297" class="LineNr">297 </span> ] -<a name="L298"></a><span id="L298" class="LineNr">298 </span> memory-should-contain [ -<a name="L299"></a><span id="L299" class="LineNr">299 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># empty?</span> -<a name="L300"></a><span id="L300" class="LineNr">300 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># full?</span> -<a name="L301"></a><span id="L301" class="LineNr">301 </span> ] -<a name="L302"></a><span id="L302" class="LineNr">302 </span>] -<a name="L303"></a><span id="L303" class="LineNr">303 </span> -<a name="L304"></a><span id="L304" class="LineNr">304 </span><span class="SalientComment">## cancelling channels</span> -<a name="L305"></a><span id="L305" class="LineNr">305 </span> -<a name="L306"></a><span id="L306" class="LineNr">306 </span><span class="Comment"># every channel comes with a boolean signifying if it's been closed</span> -<a name="L307"></a><span id="L307" class="LineNr">307 </span><span class="Comment"># initially this boolean is false</span> -<a name="L308"></a><span id="L308" class="LineNr">308 </span><span class="muData">container</span> channel:_elem [ -<a name="L309"></a><span id="L309" class="LineNr">309 </span> closed?:bool -<a name="L310"></a><span id="L310" class="LineNr">310 </span>] -<a name="L311"></a><span id="L311" class="LineNr">311 </span> -<a name="L312"></a><span id="L312" class="LineNr">312 </span><span class="Comment"># a channel can be closed from either the source or the sink</span> -<a name="L313"></a><span id="L313" class="LineNr">313 </span><span class="Comment"># both routines can modify the 'closed?' bit, but they can only ever set it, so this is a benign race</span> -<a name="L314"></a><span id="L314" class="LineNr">314 </span><span class="muRecipe">def</span> close x:&:source:_elem<span class="muRecipe"> -> </span>x:&:source:_elem [ -<a name="L315"></a><span id="L315" class="LineNr">315 </span> <span class="Constant">local-scope</span> -<a name="L316"></a><span id="L316" class="LineNr">316 </span> <span class="Constant">load-ingredients</span> -<a name="L317"></a><span id="L317" class="LineNr">317 </span> chan:&:channel:_elem <span class="Special"><-</span> get *x, <span class="Constant">chan:offset</span> -<a name="L318"></a><span id="L318" class="LineNr">318 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">closed?:offset</span>, <span class="Constant">1/true</span> -<a name="L319"></a><span id="L319" class="LineNr">319 </span>] -<a name="L320"></a><span id="L320" class="LineNr">320 </span><span class="muRecipe">def</span> close x:&:sink:_elem<span class="muRecipe"> -> </span>x:&:sink:_elem [ -<a name="L321"></a><span id="L321" class="LineNr">321 </span> <span class="Constant">local-scope</span> -<a name="L322"></a><span id="L322" class="LineNr">322 </span> <span class="Constant">load-ingredients</span> -<a name="L323"></a><span id="L323" class="LineNr">323 </span> chan:&:channel:_elem <span class="Special"><-</span> get *x, <span class="Constant">chan:offset</span> -<a name="L324"></a><span id="L324" class="LineNr">324 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">closed?:offset</span>, <span class="Constant">1/true</span> -<a name="L325"></a><span id="L325" class="LineNr">325 </span>] -<a name="L326"></a><span id="L326" class="LineNr">326 </span> -<a name="L327"></a><span id="L327" class="LineNr">327 </span><span class="Comment"># once a channel is closed from one side, no further operations are expected from that side</span> -<a name="L328"></a><span id="L328" class="LineNr">328 </span><span class="Comment"># if a channel is closed for reading,</span> -<a name="L329"></a><span id="L329" class="LineNr">329 </span><span class="Comment"># no further writes will be let through</span> -<a name="L330"></a><span id="L330" class="LineNr">330 </span><span class="Comment"># if a channel is closed for writing,</span> -<a name="L331"></a><span id="L331" class="LineNr">331 </span><span class="Comment"># future reads continue until the channel empties,</span> -<a name="L332"></a><span id="L332" class="LineNr">332 </span><span class="Comment"># then the channel is also closed for reading</span> -<a name="L333"></a><span id="L333" class="LineNr">333 </span><span class="muRecipe">after</span> <span class="Constant"><channel-write-initial></span> [ -<a name="L334"></a><span id="L334" class="LineNr">334 </span> closed?:bool <span class="Special"><-</span> get *chan, <span class="Constant">closed?:offset</span> -<a name="L335"></a><span id="L335" class="LineNr">335 </span> <span class="muControl">return-if</span> closed? -<a name="L336"></a><span id="L336" class="LineNr">336 </span>] -<a name="L337"></a><span id="L337" class="LineNr">337 </span><span class="muRecipe">after</span> <span class="Constant"><channel-read-empty></span> [ -<a name="L338"></a><span id="L338" class="LineNr">338 </span> closed?:bool <span class="Special"><-</span> get *chan, <span class="Constant">closed?:offset</span> -<a name="L339"></a><span id="L339" class="LineNr">339 </span> <span class="Delimiter">{</span> -<a name="L340"></a><span id="L340" class="LineNr">340 </span> <span class="muControl">break-unless</span> closed? -<a name="L341"></a><span id="L341" class="LineNr">341 </span> empty-result:&:_elem <span class="Special"><-</span> new <span class="Constant">_elem:type</span> -<a name="L342"></a><span id="L342" class="LineNr">342 </span> current-routine-is-unblocked -<a name="L343"></a><span id="L343" class="LineNr">343 </span> <span class="muControl">return</span> *empty-result, <span class="Constant">1/true</span> -<a name="L344"></a><span id="L344" class="LineNr">344 </span> <span class="Delimiter">}</span> -<a name="L345"></a><span id="L345" class="LineNr">345 </span>] -<a name="L346"></a><span id="L346" class="LineNr">346 </span> -<a name="L347"></a><span id="L347" class="LineNr">347 </span><span class="SalientComment">## helpers</span> -<a name="L348"></a><span id="L348" class="LineNr">348 </span> -<a name="L349"></a><span id="L349" class="LineNr">349 </span><span class="Comment"># An empty channel has first-empty and first-full both at the same value.</span> -<a name="L350"></a><span id="L350" class="LineNr">350 </span><span class="muRecipe">def</span> channel-empty? chan:&:channel:_elem<span class="muRecipe"> -> </span>result:bool [ -<a name="L351"></a><span id="L351" class="LineNr">351 </span> <span class="Constant">local-scope</span> -<a name="L352"></a><span id="L352" class="LineNr">352 </span> <span class="Constant">load-ingredients</span> -<a name="L353"></a><span id="L353" class="LineNr">353 </span> <span class="Comment"># return chan.first-full == chan.first-free</span> -<a name="L354"></a><span id="L354" class="LineNr">354 </span> full:num <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L355"></a><span id="L355" class="LineNr">355 </span> free:num <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L356"></a><span id="L356" class="LineNr">356 </span> result <span class="Special"><-</span> equal full, free -<a name="L357"></a><span id="L357" class="LineNr">357 </span>] -<a name="L358"></a><span id="L358" class="LineNr">358 </span> -<a name="L359"></a><span id="L359" class="LineNr">359 </span><span class="Comment"># A full channel has first-empty just before first-full, wasting one slot.</span> -<a name="L360"></a><span id="L360" class="LineNr">360 </span><span class="Comment"># (Other alternatives: <a href="https://en.wikipedia.org/wiki/Circular_buffer#Full_.2F_Empty_Buffer_Distinction)">https://en.wikipedia.org/wiki/Circular_buffer#Full_.2F_Empty_Buffer_Distinction)</a></span> -<a name="L361"></a><span id="L361" class="LineNr">361 </span><span class="muRecipe">def</span> channel-full? chan:&:channel:_elem<span class="muRecipe"> -> </span>result:bool [ -<a name="L362"></a><span id="L362" class="LineNr">362 </span> <span class="Constant">local-scope</span> -<a name="L363"></a><span id="L363" class="LineNr">363 </span> <span class="Constant">load-ingredients</span> -<a name="L364"></a><span id="L364" class="LineNr">364 </span> <span class="Comment"># tmp = chan.first-free + 1</span> -<a name="L365"></a><span id="L365" class="LineNr">365 </span> tmp:num <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> -<a name="L366"></a><span id="L366" class="LineNr">366 </span> tmp <span class="Special"><-</span> add tmp,<span class="Constant"> 1</span> -<a name="L367"></a><span id="L367" class="LineNr">367 </span> <span class="Delimiter">{</span> -<a name="L368"></a><span id="L368" class="LineNr">368 </span> <span class="Comment"># if tmp == chan.capacity, tmp = 0</span> -<a name="L369"></a><span id="L369" class="LineNr">369 </span> len:num <span class="Special"><-</span> capacity chan -<a name="L370"></a><span id="L370" class="LineNr">370 </span> at-end?:bool <span class="Special"><-</span> greater-or-equal tmp, len -<a name="L371"></a><span id="L371" class="LineNr">371 </span> <span class="muControl">break-unless</span> at-end? -<a name="L372"></a><span id="L372" class="LineNr">372 </span> tmp <span class="Special"><-</span> copy<span class="Constant"> 0</span> -<a name="L373"></a><span id="L373" class="LineNr">373 </span> <span class="Delimiter">}</span> -<a name="L374"></a><span id="L374" class="LineNr">374 </span> <span class="Comment"># return chan.first-full == tmp</span> -<a name="L375"></a><span id="L375" class="LineNr">375 </span> full:num <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> -<a name="L376"></a><span id="L376" class="LineNr">376 </span> result <span class="Special"><-</span> equal full, tmp -<a name="L377"></a><span id="L377" class="LineNr">377 </span>] -<a name="L378"></a><span id="L378" class="LineNr">378 </span> -<a name="L379"></a><span id="L379" class="LineNr">379 </span><span class="muRecipe">def</span> capacity chan:&:channel:_elem<span class="muRecipe"> -> </span>result:num [ -<a name="L380"></a><span id="L380" class="LineNr">380 </span> <span class="Constant">local-scope</span> -<a name="L381"></a><span id="L381" class="LineNr">381 </span> <span class="Constant">load-ingredients</span> -<a name="L382"></a><span id="L382" class="LineNr">382 </span> q:&:@:_elem <span class="Special"><-</span> get *chan, <span class="Constant">data:offset</span> -<a name="L383"></a><span id="L383" class="LineNr">383 </span> result <span class="Special"><-</span> length *q -<a name="L384"></a><span id="L384" class="LineNr">384 </span>] -<a name="L385"></a><span id="L385" class="LineNr">385 </span> -<a name="L386"></a><span id="L386" class="LineNr">386 </span><span class="SalientComment">## helpers for channels of characters in particular</span> -<a name="L387"></a><span id="L387" class="LineNr">387 </span> -<a name="L388"></a><span id="L388" class="LineNr">388 </span><span class="muRecipe">def</span> buffer-lines in:&:source:char, buffered-out:&:sink:char<span class="muRecipe"> -> </span>buffered-out:&:sink:char, in:&:source:char [ -<a name="L389"></a><span id="L389" class="LineNr">389 </span> <span class="Constant">local-scope</span> -<a name="L390"></a><span id="L390" class="LineNr">390 </span> <span class="Constant">load-ingredients</span> -<a name="L391"></a><span id="L391" class="LineNr">391 </span> <span class="Comment"># repeat forever</span> -<a name="L392"></a><span id="L392" class="LineNr">392 </span> eof?:bool <span class="Special"><-</span> copy <span class="Constant">0/false</span> -<a name="L393"></a><span id="L393" class="LineNr">393 </span> <span class="Delimiter">{</span> -<a name="L394"></a><span id="L394" class="LineNr">394 </span> line:&:buffer <span class="Special"><-</span> new-buffer<span class="Constant"> 30</span> -<a name="L395"></a><span id="L395" class="LineNr">395 </span> <span class="Comment"># read characters from 'in' until newline, copy into line</span> -<a name="L396"></a><span id="L396" class="LineNr">396 </span> <span class="Delimiter">{</span> -<a name="L397"></a><span id="L397" class="LineNr">397 </span><span class="Constant"> +next-character</span> -<a name="L398"></a><span id="L398" class="LineNr">398 </span> c:char, eof?:bool, in <span class="Special"><-</span> read in -<a name="L399"></a><span id="L399" class="LineNr">399 </span> <span class="muControl">break-if</span> eof? -<a name="L400"></a><span id="L400" class="LineNr">400 </span> <span class="Comment"># drop a character on backspace</span> -<a name="L401"></a><span id="L401" class="LineNr">401 </span> <span class="Delimiter">{</span> -<a name="L402"></a><span id="L402" class="LineNr">402 </span> <span class="Comment"># special-case: if it's a backspace</span> -<a name="L403"></a><span id="L403" class="LineNr">403 </span> backspace?:bool <span class="Special"><-</span> equal c,<span class="Constant"> 8</span> -<a name="L404"></a><span id="L404" class="LineNr">404 </span> <span class="muControl">break-unless</span> backspace? -<a name="L405"></a><span id="L405" class="LineNr">405 </span> <span class="Comment"># drop previous character</span> -<a name="L406"></a><span id="L406" class="LineNr">406 </span> <span class="Delimiter">{</span> -<a name="L407"></a><span id="L407" class="LineNr">407 </span> buffer-length:num <span class="Special"><-</span> get *line, <span class="Constant">length:offset</span> -<a name="L408"></a><span id="L408" class="LineNr">408 </span> buffer-empty?:bool <span class="Special"><-</span> equal buffer-length,<span class="Constant"> 0</span> -<a name="L409"></a><span id="L409" class="LineNr">409 </span> <span class="muControl">break-if</span> buffer-empty? -<a name="L410"></a><span id="L410" class="LineNr">410 </span> buffer-length <span class="Special"><-</span> subtract buffer-length,<span class="Constant"> 1</span> -<a name="L411"></a><span id="L411" class="LineNr">411 </span> *line <span class="Special"><-</span> put *line, <span class="Constant">length:offset</span>, buffer-length -<a name="L412"></a><span id="L412" class="LineNr">412 </span> <span class="Delimiter">}</span> -<a name="L413"></a><span id="L413" class="LineNr">413 </span> <span class="Comment"># and don't append this one</span> -<a name="L414"></a><span id="L414" class="LineNr">414 </span> <span class="muControl">loop</span> <span class="Constant">+next-character</span> -<a name="L415"></a><span id="L415" class="LineNr">415 </span> <span class="Delimiter">}</span> -<a name="L416"></a><span id="L416" class="LineNr">416 </span> <span class="Comment"># append anything else</span> -<a name="L417"></a><span id="L417" class="LineNr">417 </span> line <span class="Special"><-</span> append line, c -<a name="L418"></a><span id="L418" class="LineNr">418 </span> line-done?:bool <span class="Special"><-</span> equal c, <span class="Constant">10/newline</span> -<a name="L419"></a><span id="L419" class="LineNr">419 </span> <span class="muControl">break-if</span> line-done? -<a name="L420"></a><span id="L420" class="LineNr">420 </span> <span class="muControl">loop</span> -<a name="L421"></a><span id="L421" class="LineNr">421 </span> <span class="Delimiter">}</span> -<a name="L422"></a><span id="L422" class="LineNr">422 </span> <span class="Comment"># copy line into 'buffered-out'</span> -<a name="L423"></a><span id="L423" class="LineNr">423 </span> i:num <span class="Special"><-</span> copy<span class="Constant"> 0</span> -<a name="L424"></a><span id="L424" class="LineNr">424 </span> line-contents:text <span class="Special"><-</span> get *line, <span class="Constant">data:offset</span> -<a name="L425"></a><span id="L425" class="LineNr">425 </span> max:num <span class="Special"><-</span> get *line, <span class="Constant">length:offset</span> -<a name="L426"></a><span id="L426" class="LineNr">426 </span> <span class="Delimiter">{</span> -<a name="L427"></a><span id="L427" class="LineNr">427 </span> done?:bool <span class="Special"><-</span> greater-or-equal i, max -<a name="L428"></a><span id="L428" class="LineNr">428 </span> <span class="muControl">break-if</span> done? -<a name="L429"></a><span id="L429" class="LineNr">429 </span> c:char <span class="Special"><-</span> index *line-contents, i -<a name="L430"></a><span id="L430" class="LineNr">430 </span> buffered-out <span class="Special"><-</span> write buffered-out, c -<a name="L431"></a><span id="L431" class="LineNr">431 </span> i <span class="Special"><-</span> add i,<span class="Constant"> 1</span> -<a name="L432"></a><span id="L432" class="LineNr">432 </span> <span class="muControl">loop</span> -<a name="L433"></a><span id="L433" class="LineNr">433 </span> <span class="Delimiter">}</span> -<a name="L434"></a><span id="L434" class="LineNr">434 </span> <span class="Delimiter">{</span> -<a name="L435"></a><span id="L435" class="LineNr">435 </span> <span class="muControl">break-unless</span> eof? -<a name="L436"></a><span id="L436" class="LineNr">436 </span> buffered-out <span class="Special"><-</span> close buffered-out -<a name="L437"></a><span id="L437" class="LineNr">437 </span> <span class="muControl">return</span> -<a name="L438"></a><span id="L438" class="LineNr">438 </span> <span class="Delimiter">}</span> -<a name="L439"></a><span id="L439" class="LineNr">439 </span> <span class="muControl">loop</span> -<a name="L440"></a><span id="L440" class="LineNr">440 </span> <span class="Delimiter">}</span> -<a name="L441"></a><span id="L441" class="LineNr">441 </span>] -<a name="L442"></a><span id="L442" class="LineNr">442 </span> -<a name="L443"></a><span id="L443" class="LineNr">443 </span><span class="muScenario">scenario</span> buffer-lines-blocks-until-newline [ -<a name="L444"></a><span id="L444" class="LineNr">444 </span> run [ -<a name="L445"></a><span id="L445" class="LineNr">445 </span> <span class="Constant">local-scope</span> -<a name="L446"></a><span id="L446" class="LineNr">446 </span> source:&:source:char, sink:&:sink:char <span class="Special"><-</span> new-channel <span class="Constant">10/capacity</span> -<a name="L447"></a><span id="L447" class="LineNr">447 </span> _, buffered-stdin:&:sink:char/buffered-stdin <span class="Special"><-</span> new-channel <span class="Constant">10/capacity</span> -<a name="L448"></a><span id="L448" class="LineNr">448 </span> buffered-chan:&:channel:char <span class="Special"><-</span> get *buffered-stdin, <span class="Constant">chan:offset</span> -<a name="L449"></a><span id="L449" class="LineNr">449 </span> empty?:bool <span class="Special"><-</span> channel-empty? buffered-chan -<a name="L450"></a><span id="L450" class="LineNr">450 </span> assert empty?, <span class="Constant">[ </span> -<a name="L451"></a><span id="L451" class="LineNr">451 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after init]</span> -<a name="L452"></a><span id="L452" class="LineNr">452 </span> <span class="Comment"># buffer stdin into buffered-stdin, try to read from buffered-stdin</span> -<a name="L453"></a><span id="L453" class="LineNr">453 </span> buffer-routine:num <span class="Special"><-</span> start-running buffer-lines, source, buffered-stdin -<a name="L454"></a><span id="L454" class="LineNr">454 </span> wait-for-routine-to-block buffer-routine -<a name="L455"></a><span id="L455" class="LineNr">455 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan -<a name="L456"></a><span id="L456" class="LineNr">456 </span> assert empty?:bool, <span class="Constant">[ </span> -<a name="L457"></a><span id="L457" class="LineNr">457 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after buffer-lines bring-up]</span> -<a name="L458"></a><span id="L458" class="LineNr">458 </span> <span class="Comment"># write 'a'</span> -<a name="L459"></a><span id="L459" class="LineNr">459 </span> sink <span class="Special"><-</span> write sink, <span class="Constant">97/a</span> -<a name="L460"></a><span id="L460" class="LineNr">460 </span> restart buffer-routine -<a name="L461"></a><span id="L461" class="LineNr">461 </span> wait-for-routine-to-block buffer-routine -<a name="L462"></a><span id="L462" class="LineNr">462 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan -<a name="L463"></a><span id="L463" class="LineNr">463 </span> assert empty?:bool, <span class="Constant">[ </span> -<a name="L464"></a><span id="L464" class="LineNr">464 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after writing 'a']</span> -<a name="L465"></a><span id="L465" class="LineNr">465 </span> <span class="Comment"># write 'b'</span> -<a name="L466"></a><span id="L466" class="LineNr">466 </span> sink <span class="Special"><-</span> write sink, <span class="Constant">98/b</span> -<a name="L467"></a><span id="L467" class="LineNr">467 </span> restart buffer-routine -<a name="L468"></a><span id="L468" class="LineNr">468 </span> wait-for-routine-to-block buffer-routine -<a name="L469"></a><span id="L469" class="LineNr">469 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan -<a name="L470"></a><span id="L470" class="LineNr">470 </span> assert empty?:bool, <span class="Constant">[ </span> -<a name="L471"></a><span id="L471" class="LineNr">471 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after writing 'b']</span> -<a name="L472"></a><span id="L472" class="LineNr">472 </span> <span class="Comment"># write newline</span> -<a name="L473"></a><span id="L473" class="LineNr">473 </span> sink <span class="Special"><-</span> write sink, <span class="Constant">10/newline</span> -<a name="L474"></a><span id="L474" class="LineNr">474 </span> restart buffer-routine -<a name="L475"></a><span id="L475" class="LineNr">475 </span> wait-for-routine-to-block buffer-routine -<a name="L476"></a><span id="L476" class="LineNr">476 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan -<a name="L477"></a><span id="L477" class="LineNr">477 </span> data-emitted?:bool <span class="Special"><-</span> not empty? -<a name="L478"></a><span id="L478" class="LineNr">478 </span> assert data-emitted?, <span class="Constant">[ </span> -<a name="L479"></a><span id="L479" class="LineNr">479 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should contain data after writing newline]</span> -<a name="L480"></a><span id="L480" class="LineNr">480 </span> trace<span class="Constant"> 1</span>, <span class="Constant">[test]</span>, <span class="Constant">[reached end]</span> -<a name="L481"></a><span id="L481" class="LineNr">481 </span> ] -<a name="L482"></a><span id="L482" class="LineNr">482 </span> trace-should-contain [ -<a name="L483"></a><span id="L483" class="LineNr">483 </span> test: reached end -<a name="L484"></a><span id="L484" class="LineNr">484 </span> ] -<a name="L485"></a><span id="L485" class="LineNr">485 </span>] -<a name="L486"></a><span id="L486" class="LineNr">486 </span> -<a name="L487"></a><span id="L487" class="LineNr">487 </span><span class="muRecipe">def</span> drain source:&:source:char<span class="muRecipe"> -> </span>result:text, source:&:source:char [ -<a name="L488"></a><span id="L488" class="LineNr">488 </span> <span class="Constant">local-scope</span> -<a name="L489"></a><span id="L489" class="LineNr">489 </span> <span class="Constant">load-ingredients</span> -<a name="L490"></a><span id="L490" class="LineNr">490 </span> buf:&:buffer <span class="Special"><-</span> new-buffer<span class="Constant"> 30</span> -<a name="L491"></a><span id="L491" class="LineNr">491 </span> <span class="Delimiter">{</span> -<a name="L492"></a><span id="L492" class="LineNr">492 </span> c:char, done?:bool <span class="Special"><-</span> read source -<a name="L493"></a><span id="L493" class="LineNr">493 </span> <span class="muControl">break-if</span> done? -<a name="L494"></a><span id="L494" class="LineNr">494 </span> buf <span class="Special"><-</span> append buf, c -<a name="L495"></a><span id="L495" class="LineNr">495 </span> <span class="muControl">loop</span> -<a name="L496"></a><span id="L496" class="LineNr">496 </span> <span class="Delimiter">}</span> -<a name="L497"></a><span id="L497" class="LineNr">497 </span> result <span class="Special"><-</span> buffer-to-array buf -<a name="L498"></a><span id="L498" class="LineNr">498 </span>] +<span id="L1" class="LineNr"> 1 </span><span class="Comment"># Mu synchronizes between routines using channels rather than locks, like</span> +<span id="L2" class="LineNr"> 2 </span><span class="Comment"># Erlang and Go.</span> +<span id="L3" class="LineNr"> 3 </span><span class="Comment">#</span> +<span id="L4" class="LineNr"> 4 </span><span class="Comment"># Key properties of channels:</span> +<span id="L5" class="LineNr"> 5 </span><span class="Comment">#</span> +<span id="L6" class="LineNr"> 6 </span><span class="Comment"># a) Writing to a full channel or reading from an empty one will put the</span> +<span id="L7" class="LineNr"> 7 </span><span class="Comment"># current routine in 'waiting' state until the operation can be completed.</span> +<span id="L8" class="LineNr"> 8 </span><span class="Comment">#</span> +<span id="L9" class="LineNr"> 9 </span><span class="Comment"># b) Writing to a channel implicitly performs a deep copy. This prevents</span> +<span id="L10" class="LineNr"> 10 </span><span class="Comment"># addresses from being shared between routines, and therefore eliminates all</span> +<span id="L11" class="LineNr"> 11 </span><span class="Comment"># possibility of race conditions.</span> +<span id="L12" class="LineNr"> 12 </span><span class="Comment">#</span> +<span id="L13" class="LineNr"> 13 </span><span class="Comment"># There's still a narrow window for race conditions: the ingredients passed in</span> +<span id="L14" class="LineNr"> 14 </span><span class="Comment"># to 'start-running'. Pass only channels into routines and you should be fine.</span> +<span id="L15" class="LineNr"> 15 </span><span class="Comment"># Any other mutable ingredients will require locks.</span> +<span id="L16" class="LineNr"> 16 </span> +<span id="L17" class="LineNr"> 17 </span><span class="muScenario">scenario</span> channel [ +<span id="L18" class="LineNr"> 18 </span> run [ +<span id="L19" class="LineNr"> 19 </span> <span class="Constant">local-scope</span> +<span id="L20" class="LineNr"> 20 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> +<span id="L21" class="LineNr"> 21 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L22" class="LineNr"> 22 </span> 10:num/<span class="Special">raw</span>, 11:bool/<span class="Special">raw</span>, source <span class="Special"><-</span> read source +<span id="L23" class="LineNr"> 23 </span> ] +<span id="L24" class="LineNr"> 24 </span> memory-should-contain [ +<span id="L25" class="LineNr"> 25 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 34</span> +<span id="L26" class="LineNr"> 26 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># read was successful</span> +<span id="L27" class="LineNr"> 27 </span> ] +<span id="L28" class="LineNr"> 28 </span>] +<span id="L29" class="LineNr"> 29 </span> +<span id="L30" class="LineNr"> 30 </span><span class="muData">container</span> channel:_elem [ +<span id="L31" class="LineNr"> 31 </span> lock:bool <span class="Comment"># inefficient but simple: serialize all reads as well as writes</span> +<span id="L32" class="LineNr"> 32 </span> first-full:num <span class="Comment"># for write</span> +<span id="L33" class="LineNr"> 33 </span> first-free:num <span class="Comment"># for read</span> +<span id="L34" class="LineNr"> 34 </span> <span class="Comment"># A circular buffer contains values from index first-full up to (but not</span> +<span id="L35" class="LineNr"> 35 </span> <span class="Comment"># including) index first-empty. The reader always modifies it at first-full,</span> +<span id="L36" class="LineNr"> 36 </span> <span class="Comment"># while the writer always modifies it at first-empty.</span> +<span id="L37" class="LineNr"> 37 </span> data:&:@:_elem +<span id="L38" class="LineNr"> 38 </span>] +<span id="L39" class="LineNr"> 39 </span> +<span id="L40" class="LineNr"> 40 </span><span class="Comment"># Since channels have two ends, and since it's an error to use either end from</span> +<span id="L41" class="LineNr"> 41 </span><span class="Comment"># multiple routines, let's distinguish the ends.</span> +<span id="L42" class="LineNr"> 42 </span> +<span id="L43" class="LineNr"> 43 </span><span class="muData">container</span> source:_elem [ +<span id="L44" class="LineNr"> 44 </span> chan:&:channel:_elem +<span id="L45" class="LineNr"> 45 </span>] +<span id="L46" class="LineNr"> 46 </span> +<span id="L47" class="LineNr"> 47 </span><span class="muData">container</span> sink:_elem [ +<span id="L48" class="LineNr"> 48 </span> chan:&:channel:_elem +<span id="L49" class="LineNr"> 49 </span>] +<span id="L50" class="LineNr"> 50 </span> +<span id="L51" class="LineNr"> 51 </span><span class="muRecipe">def</span> new-channel capacity:num<span class="muRecipe"> -> </span>in:&:source:_elem, out:&:sink:_elem [ +<span id="L52" class="LineNr"> 52 </span> <span class="Constant">local-scope</span> +<span id="L53" class="LineNr"> 53 </span> <span class="Constant">load-ingredients</span> +<span id="L54" class="LineNr"> 54 </span> result:&:channel:_elem <span class="Special"><-</span> new <span class="Delimiter">{</span>(channel _elem): type<span class="Delimiter">}</span> +<span id="L55" class="LineNr"> 55 </span> *result <span class="Special"><-</span> put *result, <span class="Constant">first-full:offset</span>,<span class="Constant"> 0</span> +<span id="L56" class="LineNr"> 56 </span> *result <span class="Special"><-</span> put *result, <span class="Constant">first-free:offset</span>,<span class="Constant"> 0</span> +<span id="L57" class="LineNr"> 57 </span> capacity <span class="Special"><-</span> add capacity,<span class="Constant"> 1</span> <span class="Comment"># unused slot for 'full?' below</span> +<span id="L58" class="LineNr"> 58 </span> data:&:@:_elem <span class="Special"><-</span> new <span class="Constant">_elem:type</span>, capacity +<span id="L59" class="LineNr"> 59 </span> *result <span class="Special"><-</span> put *result, <span class="Constant">data:offset</span>, data +<span id="L60" class="LineNr"> 60 </span> in <span class="Special"><-</span> new <span class="Delimiter">{</span>(source _elem): type<span class="Delimiter">}</span> +<span id="L61" class="LineNr"> 61 </span> *in <span class="Special"><-</span> put *in, <span class="Constant">chan:offset</span>, result +<span id="L62" class="LineNr"> 62 </span> out <span class="Special"><-</span> new <span class="Delimiter">{</span>(sink _elem): type<span class="Delimiter">}</span> +<span id="L63" class="LineNr"> 63 </span> *out <span class="Special"><-</span> put *out, <span class="Constant">chan:offset</span>, result +<span id="L64" class="LineNr"> 64 </span>] +<span id="L65" class="LineNr"> 65 </span> +<span id="L66" class="LineNr"> 66 </span><span class="muRecipe">def</span> write out:&:sink:_elem, val:_elem<span class="muRecipe"> -> </span>out:&:sink:_elem [ +<span id="L67" class="LineNr"> 67 </span> <span class="Constant">local-scope</span> +<span id="L68" class="LineNr"> 68 </span> <span class="Constant">load-ingredients</span> +<span id="L69" class="LineNr"> 69 </span> assert out, <span class="Constant">[write to null channel]</span> +<span id="L70" class="LineNr"> 70 </span> chan:&:channel:_elem <span class="Special"><-</span> get *out, <span class="Constant">chan:offset</span> +<span id="L71" class="LineNr"> 71 </span><span class="Constant"> <channel-write-initial></span> +<span id="L72" class="LineNr"> 72 </span> <span class="Comment"># block until lock is acquired AND queue has room</span> +<span id="L73" class="LineNr"> 73 </span> lock:location <span class="Special"><-</span> get-location *chan, <span class="Constant">lock:offset</span> +<span id="L74" class="LineNr"> 74 </span><span class="CommentedCode">#? $print [write], 10/newline</span> +<span id="L75" class="LineNr"> 75 </span> <span class="Delimiter">{</span> +<span id="L76" class="LineNr"> 76 </span><span class="CommentedCode">#? $print [trying to acquire lock for writing], 10/newline</span> +<span id="L77" class="LineNr"> 77 </span> wait-for-reset-then-set lock +<span id="L78" class="LineNr"> 78 </span><span class="CommentedCode">#? $print [lock acquired for writing], 10/newline</span> +<span id="L79" class="LineNr"> 79 </span> full?:bool <span class="Special"><-</span> channel-full? chan +<span id="L80" class="LineNr"> 80 </span> <span class="muControl">break-unless</span> full? +<span id="L81" class="LineNr"> 81 </span><span class="CommentedCode">#? $print [but channel is full; relinquishing lock], 10/newline</span> +<span id="L82" class="LineNr"> 82 </span> <span class="Comment"># channel is full; relinquish lock and give a reader the opportunity to</span> +<span id="L83" class="LineNr"> 83 </span> <span class="Comment"># create room on it</span> +<span id="L84" class="LineNr"> 84 </span> reset lock +<span id="L85" class="LineNr"> 85 </span> current-routine-is-blocked +<span id="L86" class="LineNr"> 86 </span> switch <span class="Comment"># avoid spinlocking</span> +<span id="L87" class="LineNr"> 87 </span> <span class="muControl">loop</span> +<span id="L88" class="LineNr"> 88 </span> <span class="Delimiter">}</span> +<span id="L89" class="LineNr"> 89 </span> current-routine-is-unblocked +<span id="L90" class="LineNr"> 90 </span><span class="CommentedCode">#? $print [performing write], 10/newline</span> +<span id="L91" class="LineNr"> 91 </span> <span class="Comment"># store a deep copy of val</span> +<span id="L92" class="LineNr"> 92 </span> circular-buffer:&:@:_elem <span class="Special"><-</span> get *chan, <span class="Constant">data:offset</span> +<span id="L93" class="LineNr"> 93 </span> free:num <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L94" class="LineNr"> 94 </span> val-copy:_elem <span class="Special"><-</span> deep-copy val <span class="Comment"># on this instruction rests all Mu's concurrency-safety</span> +<span id="L95" class="LineNr"> 95 </span> *circular-buffer <span class="Special"><-</span> put-index *circular-buffer, free, val-copy +<span id="L96" class="LineNr"> 96 </span> <span class="Comment"># mark its slot as filled</span> +<span id="L97" class="LineNr"> 97 </span> free <span class="Special"><-</span> add free,<span class="Constant"> 1</span> +<span id="L98" class="LineNr"> 98 </span> <span class="Delimiter">{</span> +<span id="L99" class="LineNr"> 99 </span> <span class="Comment"># wrap free around to 0 if necessary</span> +<span id="L100" class="LineNr">100 </span> len:num <span class="Special"><-</span> length *circular-buffer +<span id="L101" class="LineNr">101 </span> at-end?:bool <span class="Special"><-</span> greater-or-equal free, len +<span id="L102" class="LineNr">102 </span> <span class="muControl">break-unless</span> at-end? +<span id="L103" class="LineNr">103 </span> free <span class="Special"><-</span> copy<span class="Constant"> 0</span> +<span id="L104" class="LineNr">104 </span> <span class="Delimiter">}</span> +<span id="L105" class="LineNr">105 </span> <span class="Comment"># write back</span> +<span id="L106" class="LineNr">106 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">first-free:offset</span>, free +<span id="L107" class="LineNr">107 </span><span class="CommentedCode">#? $print [relinquishing lock after writing], 10/newline</span> +<span id="L108" class="LineNr">108 </span> reset lock +<span id="L109" class="LineNr">109 </span>] +<span id="L110" class="LineNr">110 </span> +<span id="L111" class="LineNr">111 </span><span class="muRecipe">def</span> read in:&:source:_elem<span class="muRecipe"> -> </span>result:_elem, eof?:bool, in:&:source:_elem [ +<span id="L112" class="LineNr">112 </span> <span class="Constant">local-scope</span> +<span id="L113" class="LineNr">113 </span> <span class="Constant">load-ingredients</span> +<span id="L114" class="LineNr">114 </span> assert in, <span class="Constant">[read on null channel]</span> +<span id="L115" class="LineNr">115 </span> eof? <span class="Special"><-</span> copy <span class="Constant">0/false</span> <span class="Comment"># default result</span> +<span id="L116" class="LineNr">116 </span> chan:&:channel:_elem <span class="Special"><-</span> get *in, <span class="Constant">chan:offset</span> +<span id="L117" class="LineNr">117 </span> <span class="Comment"># block until lock is acquired AND queue has data</span> +<span id="L118" class="LineNr">118 </span> lock:location <span class="Special"><-</span> get-location *chan, <span class="Constant">lock:offset</span> +<span id="L119" class="LineNr">119 </span><span class="CommentedCode">#? $print [read], 10/newline</span> +<span id="L120" class="LineNr">120 </span> <span class="Delimiter">{</span> +<span id="L121" class="LineNr">121 </span><span class="CommentedCode">#? $print [trying to acquire lock for reading], 10/newline</span> +<span id="L122" class="LineNr">122 </span> wait-for-reset-then-set lock +<span id="L123" class="LineNr">123 </span><span class="CommentedCode">#? $print [lock acquired for reading], 10/newline</span> +<span id="L124" class="LineNr">124 </span> empty?:bool <span class="Special"><-</span> channel-empty? chan +<span id="L125" class="LineNr">125 </span> <span class="muControl">break-unless</span> empty? +<span id="L126" class="LineNr">126 </span><span class="CommentedCode">#? $print [but channel is empty; relinquishing lock], 10/newline</span> +<span id="L127" class="LineNr">127 </span> <span class="Comment"># channel is empty; relinquish lock and give a writer the opportunity to</span> +<span id="L128" class="LineNr">128 </span> <span class="Comment"># add to it</span> +<span id="L129" class="LineNr">129 </span> reset lock +<span id="L130" class="LineNr">130 </span> current-routine-is-blocked +<span id="L131" class="LineNr">131 </span><span class="Constant"> <channel-read-empty></span> +<span id="L132" class="LineNr">132 </span> switch <span class="Comment"># avoid spinlocking</span> +<span id="L133" class="LineNr">133 </span> <span class="muControl">loop</span> +<span id="L134" class="LineNr">134 </span> <span class="Delimiter">}</span> +<span id="L135" class="LineNr">135 </span> current-routine-is-unblocked +<span id="L136" class="LineNr">136 </span> <span class="Comment"># pull result off</span> +<span id="L137" class="LineNr">137 </span> full:num <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L138" class="LineNr">138 </span> circular-buffer:&:@:_elem <span class="Special"><-</span> get *chan, <span class="Constant">data:offset</span> +<span id="L139" class="LineNr">139 </span> result <span class="Special"><-</span> index *circular-buffer, full +<span id="L140" class="LineNr">140 </span> <span class="Comment"># clear the slot</span> +<span id="L141" class="LineNr">141 </span> empty:&:_elem <span class="Special"><-</span> new <span class="Constant">_elem:type</span> +<span id="L142" class="LineNr">142 </span> *circular-buffer <span class="Special"><-</span> put-index *circular-buffer, full, *empty +<span id="L143" class="LineNr">143 </span> <span class="Comment"># mark its slot as empty</span> +<span id="L144" class="LineNr">144 </span> full <span class="Special"><-</span> add full,<span class="Constant"> 1</span> +<span id="L145" class="LineNr">145 </span> <span class="Delimiter">{</span> +<span id="L146" class="LineNr">146 </span> <span class="Comment"># wrap full around to 0 if necessary</span> +<span id="L147" class="LineNr">147 </span> len:num <span class="Special"><-</span> length *circular-buffer +<span id="L148" class="LineNr">148 </span> at-end?:bool <span class="Special"><-</span> greater-or-equal full, len +<span id="L149" class="LineNr">149 </span> <span class="muControl">break-unless</span> at-end? +<span id="L150" class="LineNr">150 </span> full <span class="Special"><-</span> copy<span class="Constant"> 0</span> +<span id="L151" class="LineNr">151 </span> <span class="Delimiter">}</span> +<span id="L152" class="LineNr">152 </span> <span class="Comment"># write back</span> +<span id="L153" class="LineNr">153 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">first-full:offset</span>, full +<span id="L154" class="LineNr">154 </span><span class="CommentedCode">#? $print [relinquishing lock after reading], 10/newline</span> +<span id="L155" class="LineNr">155 </span> reset lock +<span id="L156" class="LineNr">156 </span>] +<span id="L157" class="LineNr">157 </span> +<span id="L158" class="LineNr">158 </span><span class="Comment"># todo: create a notion of iterator and iterable so we can read/write whole</span> +<span id="L159" class="LineNr">159 </span><span class="Comment"># aggregates (arrays, lists, ..) of _elems at once.</span> +<span id="L160" class="LineNr">160 </span> +<span id="L161" class="LineNr">161 </span><span class="muRecipe">def</span> clear in:&:source:_elem<span class="muRecipe"> -> </span>in:&:source:_elem [ +<span id="L162" class="LineNr">162 </span> <span class="Constant">local-scope</span> +<span id="L163" class="LineNr">163 </span> <span class="Constant">load-ingredients</span> +<span id="L164" class="LineNr">164 </span> chan:&:channel:_elem <span class="Special"><-</span> get *in, <span class="Constant">chan:offset</span> +<span id="L165" class="LineNr">165 </span> <span class="Delimiter">{</span> +<span id="L166" class="LineNr">166 </span> empty?:bool <span class="Special"><-</span> channel-empty? chan +<span id="L167" class="LineNr">167 </span> <span class="muControl">break-if</span> empty? +<span id="L168" class="LineNr">168 </span> _, _, in <span class="Special"><-</span> read in +<span id="L169" class="LineNr">169 </span> <span class="Delimiter">}</span> +<span id="L170" class="LineNr">170 </span>] +<span id="L171" class="LineNr">171 </span> +<span id="L172" class="LineNr">172 </span><span class="muScenario">scenario</span> channel-initialization [ +<span id="L173" class="LineNr">173 </span> run [ +<span id="L174" class="LineNr">174 </span> <span class="Constant">local-scope</span> +<span id="L175" class="LineNr">175 </span> source:&:source:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> +<span id="L176" class="LineNr">176 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L177" class="LineNr">177 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L178" class="LineNr">178 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L179" class="LineNr">179 </span> ] +<span id="L180" class="LineNr">180 </span> memory-should-contain [ +<span id="L181" class="LineNr">181 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-full</span> +<span id="L182" class="LineNr">182 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-free</span> +<span id="L183" class="LineNr">183 </span> ] +<span id="L184" class="LineNr">184 </span>] +<span id="L185" class="LineNr">185 </span> +<span id="L186" class="LineNr">186 </span><span class="muScenario">scenario</span> channel-write-increments-free [ +<span id="L187" class="LineNr">187 </span> <span class="Constant">local-scope</span> +<span id="L188" class="LineNr">188 </span> _, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> +<span id="L189" class="LineNr">189 </span> run [ +<span id="L190" class="LineNr">190 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L191" class="LineNr">191 </span> chan:&:channel:num <span class="Special"><-</span> get *sink, <span class="Constant">chan:offset</span> +<span id="L192" class="LineNr">192 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L193" class="LineNr">193 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L194" class="LineNr">194 </span> ] +<span id="L195" class="LineNr">195 </span> memory-should-contain [ +<span id="L196" class="LineNr">196 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-full</span> +<span id="L197" class="LineNr">197 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-free</span> +<span id="L198" class="LineNr">198 </span> ] +<span id="L199" class="LineNr">199 </span>] +<span id="L200" class="LineNr">200 </span> +<span id="L201" class="LineNr">201 </span><span class="muScenario">scenario</span> channel-read-increments-full [ +<span id="L202" class="LineNr">202 </span> <span class="Constant">local-scope</span> +<span id="L203" class="LineNr">203 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> +<span id="L204" class="LineNr">204 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L205" class="LineNr">205 </span> run [ +<span id="L206" class="LineNr">206 </span> _, _, source <span class="Special"><-</span> read source +<span id="L207" class="LineNr">207 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L208" class="LineNr">208 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L209" class="LineNr">209 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L210" class="LineNr">210 </span> ] +<span id="L211" class="LineNr">211 </span> memory-should-contain [ +<span id="L212" class="LineNr">212 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-full</span> +<span id="L213" class="LineNr">213 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-free</span> +<span id="L214" class="LineNr">214 </span> ] +<span id="L215" class="LineNr">215 </span>] +<span id="L216" class="LineNr">216 </span> +<span id="L217" class="LineNr">217 </span><span class="muScenario">scenario</span> channel-wrap [ +<span id="L218" class="LineNr">218 </span> <span class="Constant">local-scope</span> +<span id="L219" class="LineNr">219 </span> <span class="Comment"># channel with just 1 slot</span> +<span id="L220" class="LineNr">220 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">1/capacity</span> +<span id="L221" class="LineNr">221 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L222" class="LineNr">222 </span> <span class="Comment"># write and read a value</span> +<span id="L223" class="LineNr">223 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L224" class="LineNr">224 </span> _, _, source <span class="Special"><-</span> read source +<span id="L225" class="LineNr">225 </span> run [ +<span id="L226" class="LineNr">226 </span> <span class="Comment"># first-free will now be 1</span> +<span id="L227" class="LineNr">227 </span> 10:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L228" class="LineNr">228 </span> 11:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L229" class="LineNr">229 </span> <span class="Comment"># write second value, verify that first-free wraps</span> +<span id="L230" class="LineNr">230 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L231" class="LineNr">231 </span> 20:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L232" class="LineNr">232 </span> <span class="Comment"># read second value, verify that first-full wraps</span> +<span id="L233" class="LineNr">233 </span> _, _, source <span class="Special"><-</span> read source +<span id="L234" class="LineNr">234 </span> 30:num/<span class="Special">raw</span> <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L235" class="LineNr">235 </span> ] +<span id="L236" class="LineNr">236 </span> memory-should-contain [ +<span id="L237" class="LineNr">237 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-free after first write</span> +<span id="L238" class="LineNr">238 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># first-full after first read</span> +<span id="L239" class="LineNr">239 </span> <span class="Constant"> 20</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-free after second write, wrapped</span> +<span id="L240" class="LineNr">240 </span> <span class="Constant"> 30</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># first-full after second read, wrapped</span> +<span id="L241" class="LineNr">241 </span> ] +<span id="L242" class="LineNr">242 </span>] +<span id="L243" class="LineNr">243 </span> +<span id="L244" class="LineNr">244 </span><span class="muScenario">scenario</span> channel-new-empty-not-full [ +<span id="L245" class="LineNr">245 </span> run [ +<span id="L246" class="LineNr">246 </span> <span class="Constant">local-scope</span> +<span id="L247" class="LineNr">247 </span> source:&:source:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> +<span id="L248" class="LineNr">248 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L249" class="LineNr">249 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan +<span id="L250" class="LineNr">250 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan +<span id="L251" class="LineNr">251 </span> ] +<span id="L252" class="LineNr">252 </span> memory-should-contain [ +<span id="L253" class="LineNr">253 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># empty?</span> +<span id="L254" class="LineNr">254 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># full?</span> +<span id="L255" class="LineNr">255 </span> ] +<span id="L256" class="LineNr">256 </span>] +<span id="L257" class="LineNr">257 </span> +<span id="L258" class="LineNr">258 </span><span class="muScenario">scenario</span> channel-write-not-empty [ +<span id="L259" class="LineNr">259 </span> <span class="Constant">local-scope</span> +<span id="L260" class="LineNr">260 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">3/capacity</span> +<span id="L261" class="LineNr">261 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L262" class="LineNr">262 </span> run [ +<span id="L263" class="LineNr">263 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L264" class="LineNr">264 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan +<span id="L265" class="LineNr">265 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan +<span id="L266" class="LineNr">266 </span> ] +<span id="L267" class="LineNr">267 </span> memory-should-contain [ +<span id="L268" class="LineNr">268 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># empty?</span> +<span id="L269" class="LineNr">269 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># full?</span> +<span id="L270" class="LineNr">270 </span> ] +<span id="L271" class="LineNr">271 </span>] +<span id="L272" class="LineNr">272 </span> +<span id="L273" class="LineNr">273 </span><span class="muScenario">scenario</span> channel-write-full [ +<span id="L274" class="LineNr">274 </span> <span class="Constant">local-scope</span> +<span id="L275" class="LineNr">275 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">1/capacity</span> +<span id="L276" class="LineNr">276 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L277" class="LineNr">277 </span> run [ +<span id="L278" class="LineNr">278 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L279" class="LineNr">279 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan +<span id="L280" class="LineNr">280 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan +<span id="L281" class="LineNr">281 </span> ] +<span id="L282" class="LineNr">282 </span> memory-should-contain [ +<span id="L283" class="LineNr">283 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># empty?</span> +<span id="L284" class="LineNr">284 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># full?</span> +<span id="L285" class="LineNr">285 </span> ] +<span id="L286" class="LineNr">286 </span>] +<span id="L287" class="LineNr">287 </span> +<span id="L288" class="LineNr">288 </span><span class="muScenario">scenario</span> channel-read-not-full [ +<span id="L289" class="LineNr">289 </span> <span class="Constant">local-scope</span> +<span id="L290" class="LineNr">290 </span> source:&:source:num, sink:&:sink:num <span class="Special"><-</span> new-channel <span class="Constant">1/capacity</span> +<span id="L291" class="LineNr">291 </span> chan:&:channel:num <span class="Special"><-</span> get *source, <span class="Constant">chan:offset</span> +<span id="L292" class="LineNr">292 </span> sink <span class="Special"><-</span> write sink,<span class="Constant"> 34</span> +<span id="L293" class="LineNr">293 </span> run [ +<span id="L294" class="LineNr">294 </span> _, _, source <span class="Special"><-</span> read source +<span id="L295" class="LineNr">295 </span> 10:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-empty? chan +<span id="L296" class="LineNr">296 </span> 11:bool/<span class="Special">raw</span> <span class="Special"><-</span> channel-full? chan +<span id="L297" class="LineNr">297 </span> ] +<span id="L298" class="LineNr">298 </span> memory-should-contain [ +<span id="L299" class="LineNr">299 </span> <span class="Constant"> 10</span> <span class="Special"><-</span><span class="Constant"> 1</span> <span class="Comment"># empty?</span> +<span id="L300" class="LineNr">300 </span> <span class="Constant"> 11</span> <span class="Special"><-</span><span class="Constant"> 0</span> <span class="Comment"># full?</span> +<span id="L301" class="LineNr">301 </span> ] +<span id="L302" class="LineNr">302 </span>] +<span id="L303" class="LineNr">303 </span> +<span id="L304" class="LineNr">304 </span><span class="SalientComment">## cancelling channels</span> +<span id="L305" class="LineNr">305 </span> +<span id="L306" class="LineNr">306 </span><span class="Comment"># every channel comes with a boolean signifying if it's been closed</span> +<span id="L307" class="LineNr">307 </span><span class="Comment"># initially this boolean is false</span> +<span id="L308" class="LineNr">308 </span><span class="muData">container</span> channel:_elem [ +<span id="L309" class="LineNr">309 </span> closed?:bool +<span id="L310" class="LineNr">310 </span>] +<span id="L311" class="LineNr">311 </span> +<span id="L312" class="LineNr">312 </span><span class="Comment"># a channel can be closed from either the source or the sink</span> +<span id="L313" class="LineNr">313 </span><span class="Comment"># both routines can modify the 'closed?' bit, but they can only ever set it, so this is a benign race</span> +<span id="L314" class="LineNr">314 </span><span class="muRecipe">def</span> close x:&:source:_elem<span class="muRecipe"> -> </span>x:&:source:_elem [ +<span id="L315" class="LineNr">315 </span> <span class="Constant">local-scope</span> +<span id="L316" class="LineNr">316 </span> <span class="Constant">load-ingredients</span> +<span id="L317" class="LineNr">317 </span> chan:&:channel:_elem <span class="Special"><-</span> get *x, <span class="Constant">chan:offset</span> +<span id="L318" class="LineNr">318 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">closed?:offset</span>, <span class="Constant">1/true</span> +<span id="L319" class="LineNr">319 </span>] +<span id="L320" class="LineNr">320 </span><span class="muRecipe">def</span> close x:&:sink:_elem<span class="muRecipe"> -> </span>x:&:sink:_elem [ +<span id="L321" class="LineNr">321 </span> <span class="Constant">local-scope</span> +<span id="L322" class="LineNr">322 </span> <span class="Constant">load-ingredients</span> +<span id="L323" class="LineNr">323 </span> chan:&:channel:_elem <span class="Special"><-</span> get *x, <span class="Constant">chan:offset</span> +<span id="L324" class="LineNr">324 </span> *chan <span class="Special"><-</span> put *chan, <span class="Constant">closed?:offset</span>, <span class="Constant">1/true</span> +<span id="L325" class="LineNr">325 </span>] +<span id="L326" class="LineNr">326 </span> +<span id="L327" class="LineNr">327 </span><span class="Comment"># once a channel is closed from one side, no further operations are expected from that side</span> +<span id="L328" class="LineNr">328 </span><span class="Comment"># if a channel is closed for reading,</span> +<span id="L329" class="LineNr">329 </span><span class="Comment"># no further writes will be let through</span> +<span id="L330" class="LineNr">330 </span><span class="Comment"># if a channel is closed for writing,</span> +<span id="L331" class="LineNr">331 </span><span class="Comment"># future reads continue until the channel empties,</span> +<span id="L332" class="LineNr">332 </span><span class="Comment"># then the channel is also closed for reading</span> +<span id="L333" class="LineNr">333 </span><span class="muRecipe">after</span> <span class="Constant"><channel-write-initial></span> [ +<span id="L334" class="LineNr">334 </span> closed?:bool <span class="Special"><-</span> get *chan, <span class="Constant">closed?:offset</span> +<span id="L335" class="LineNr">335 </span> <span class="muControl">return-if</span> closed? +<span id="L336" class="LineNr">336 </span>] +<span id="L337" class="LineNr">337 </span><span class="muRecipe">after</span> <span class="Constant"><channel-read-empty></span> [ +<span id="L338" class="LineNr">338 </span> closed?:bool <span class="Special"><-</span> get *chan, <span class="Constant">closed?:offset</span> +<span id="L339" class="LineNr">339 </span> <span class="Delimiter">{</span> +<span id="L340" class="LineNr">340 </span> <span class="muControl">break-unless</span> closed? +<span id="L341" class="LineNr">341 </span> empty-result:&:_elem <span class="Special"><-</span> new <span class="Constant">_elem:type</span> +<span id="L342" class="LineNr">342 </span> current-routine-is-unblocked +<span id="L343" class="LineNr">343 </span> <span class="muControl">return</span> *empty-result, <span class="Constant">1/true</span> +<span id="L344" class="LineNr">344 </span> <span class="Delimiter">}</span> +<span id="L345" class="LineNr">345 </span>] +<span id="L346" class="LineNr">346 </span> +<span id="L347" class="LineNr">347 </span><span class="SalientComment">## helpers</span> +<span id="L348" class="LineNr">348 </span> +<span id="L349" class="LineNr">349 </span><span class="Comment"># An empty channel has first-empty and first-full both at the same value.</span> +<span id="L350" class="LineNr">350 </span><span class="muRecipe">def</span> channel-empty? chan:&:channel:_elem<span class="muRecipe"> -> </span>result:bool [ +<span id="L351" class="LineNr">351 </span> <span class="Constant">local-scope</span> +<span id="L352" class="LineNr">352 </span> <span class="Constant">load-ingredients</span> +<span id="L353" class="LineNr">353 </span> <span class="Comment"># return chan.first-full == chan.first-free</span> +<span id="L354" class="LineNr">354 </span> full:num <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L355" class="LineNr">355 </span> free:num <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L356" class="LineNr">356 </span> result <span class="Special"><-</span> equal full, free +<span id="L357" class="LineNr">357 </span>] +<span id="L358" class="LineNr">358 </span> +<span id="L359" class="LineNr">359 </span><span class="Comment"># A full channel has first-empty just before first-full, wasting one slot.</span> +<span id="L360" class="LineNr">360 </span><span class="Comment"># (Other alternatives: <a href="https://en.wikipedia.org/wiki/Circular_buffer#Full_.2F_Empty_Buffer_Distinction)">https://en.wikipedia.org/wiki/Circular_buffer#Full_.2F_Empty_Buffer_Distinction)</a></span> +<span id="L361" class="LineNr">361 </span><span class="muRecipe">def</span> channel-full? chan:&:channel:_elem<span class="muRecipe"> -> </span>result:bool [ +<span id="L362" class="LineNr">362 </span> <span class="Constant">local-scope</span> +<span id="L363" class="LineNr">363 </span> <span class="Constant">load-ingredients</span> +<span id="L364" class="LineNr">364 </span> <span class="Comment"># tmp = chan.first-free + 1</span> +<span id="L365" class="LineNr">365 </span> tmp:num <span class="Special"><-</span> get *chan, <span class="Constant">first-free:offset</span> +<span id="L366" class="LineNr">366 </span> tmp <span class="Special"><-</span> add tmp,<span class="Constant"> 1</span> +<span id="L367" class="LineNr">367 </span> <span class="Delimiter">{</span> +<span id="L368" class="LineNr">368 </span> <span class="Comment"># if tmp == chan.capacity, tmp = 0</span> +<span id="L369" class="LineNr">369 </span> len:num <span class="Special"><-</span> capacity chan +<span id="L370" class="LineNr">370 </span> at-end?:bool <span class="Special"><-</span> greater-or-equal tmp, len +<span id="L371" class="LineNr">371 </span> <span class="muControl">break-unless</span> at-end? +<span id="L372" class="LineNr">372 </span> tmp <span class="Special"><-</span> copy<span class="Constant"> 0</span> +<span id="L373" class="LineNr">373 </span> <span class="Delimiter">}</span> +<span id="L374" class="LineNr">374 </span> <span class="Comment"># return chan.first-full == tmp</span> +<span id="L375" class="LineNr">375 </span> full:num <span class="Special"><-</span> get *chan, <span class="Constant">first-full:offset</span> +<span id="L376" class="LineNr">376 </span> result <span class="Special"><-</span> equal full, tmp +<span id="L377" class="LineNr">377 </span>] +<span id="L378" class="LineNr">378 </span> +<span id="L379" class="LineNr">379 </span><span class="muRecipe">def</span> capacity chan:&:channel:_elem<span class="muRecipe"> -> </span>result:num [ +<span id="L380" class="LineNr">380 </span> <span class="Constant">local-scope</span> +<span id="L381" class="LineNr">381 </span> <span class="Constant">load-ingredients</span> +<span id="L382" class="LineNr">382 </span> q:&:@:_elem <span class="Special"><-</span> get *chan, <span class="Constant">data:offset</span> +<span id="L383" class="LineNr">383 </span> result <span class="Special"><-</span> length *q +<span id="L384" class="LineNr">384 </span>] +<span id="L385" class="LineNr">385 </span> +<span id="L386" class="LineNr">386 </span><span class="SalientComment">## helpers for channels of characters in particular</span> +<span id="L387" class="LineNr">387 </span> +<span id="L388" class="LineNr">388 </span><span class="muRecipe">def</span> buffer-lines in:&:source:char, buffered-out:&:sink:char<span class="muRecipe"> -> </span>buffered-out:&:sink:char, in:&:source:char [ +<span id="L389" class="LineNr">389 </span> <span class="Constant">local-scope</span> +<span id="L390" class="LineNr">390 </span> <span class="Constant">load-ingredients</span> +<span id="L391" class="LineNr">391 </span> <span class="Comment"># repeat forever</span> +<span id="L392" class="LineNr">392 </span> eof?:bool <span class="Special"><-</span> copy <span class="Constant">0/false</span> +<span id="L393" class="LineNr">393 </span> <span class="Delimiter">{</span> +<span id="L394" class="LineNr">394 </span> line:&:buffer <span class="Special"><-</span> new-buffer<span class="Constant"> 30</span> +<span id="L395" class="LineNr">395 </span> <span class="Comment"># read characters from 'in' until newline, copy into line</span> +<span id="L396" class="LineNr">396 </span> <span class="Delimiter">{</span> +<span id="L397" class="LineNr">397 </span><span class="Constant"> +next-character</span> +<span id="L398" class="LineNr">398 </span> c:char, eof?:bool, in <span class="Special"><-</span> read in +<span id="L399" class="LineNr">399 </span> <span class="muControl">break-if</span> eof? +<span id="L400" class="LineNr">400 </span> <span class="Comment"># drop a character on backspace</span> +<span id="L401" class="LineNr">401 </span> <span class="Delimiter">{</span> +<span id="L402" class="LineNr">402 </span> <span class="Comment"># special-case: if it's a backspace</span> +<span id="L403" class="LineNr">403 </span> backspace?:bool <span class="Special"><-</span> equal c,<span class="Constant"> 8</span> +<span id="L404" class="LineNr">404 </span> <span class="muControl">break-unless</span> backspace? +<span id="L405" class="LineNr">405 </span> <span class="Comment"># drop previous character</span> +<span id="L406" class="LineNr">406 </span> <span class="Delimiter">{</span> +<span id="L407" class="LineNr">407 </span> buffer-length:num <span class="Special"><-</span> get *line, <span class="Constant">length:offset</span> +<span id="L408" class="LineNr">408 </span> buffer-empty?:bool <span class="Special"><-</span> equal buffer-length,<span class="Constant"> 0</span> +<span id="L409" class="LineNr">409 </span> <span class="muControl">break-if</span> buffer-empty? +<span id="L410" class="LineNr">410 </span> buffer-length <span class="Special"><-</span> subtract buffer-length,<span class="Constant"> 1</span> +<span id="L411" class="LineNr">411 </span> *line <span class="Special"><-</span> put *line, <span class="Constant">length:offset</span>, buffer-length +<span id="L412" class="LineNr">412 </span> <span class="Delimiter">}</span> +<span id="L413" class="LineNr">413 </span> <span class="Comment"># and don't append this one</span> +<span id="L414" class="LineNr">414 </span> <span class="muControl">loop</span> <span class="Constant">+next-character</span> +<span id="L415" class="LineNr">415 </span> <span class="Delimiter">}</span> +<span id="L416" class="LineNr">416 </span> <span class="Comment"># append anything else</span> +<span id="L417" class="LineNr">417 </span> line <span class="Special"><-</span> append line, c +<span id="L418" class="LineNr">418 </span> line-done?:bool <span class="Special"><-</span> equal c, <span class="Constant">10/newline</span> +<span id="L419" class="LineNr">419 </span> <span class="muControl">break-if</span> line-done? +<span id="L420" class="LineNr">420 </span> <span class="muControl">loop</span> +<span id="L421" class="LineNr">421 </span> <span class="Delimiter">}</span> +<span id="L422" class="LineNr">422 </span> <span class="Comment"># copy line into 'buffered-out'</span> +<span id="L423" class="LineNr">423 </span> i:num <span class="Special"><-</span> copy<span class="Constant"> 0</span> +<span id="L424" class="LineNr">424 </span> line-contents:text <span class="Special"><-</span> get *line, <span class="Constant">data:offset</span> +<span id="L425" class="LineNr">425 </span> max:num <span class="Special"><-</span> get *line, <span class="Constant">length:offset</span> +<span id="L426" class="LineNr">426 </span> <span class="Delimiter">{</span> +<span id="L427" class="LineNr">427 </span> done?:bool <span class="Special"><-</span> greater-or-equal i, max +<span id="L428" class="LineNr">428 </span> <span class="muControl">break-if</span> done? +<span id="L429" class="LineNr">429 </span> c:char <span class="Special"><-</span> index *line-contents, i +<span id="L430" class="LineNr">430 </span> buffered-out <span class="Special"><-</span> write buffered-out, c +<span id="L431" class="LineNr">431 </span> i <span class="Special"><-</span> add i,<span class="Constant"> 1</span> +<span id="L432" class="LineNr">432 </span> <span class="muControl">loop</span> +<span id="L433" class="LineNr">433 </span> <span class="Delimiter">}</span> +<span id="L434" class="LineNr">434 </span> <span class="Delimiter">{</span> +<span id="L435" class="LineNr">435 </span> <span class="muControl">break-unless</span> eof? +<span id="L436" class="LineNr">436 </span> buffered-out <span class="Special"><-</span> close buffered-out +<span id="L437" class="LineNr">437 </span> <span class="muControl">return</span> +<span id="L438" class="LineNr">438 </span> <span class="Delimiter">}</span> +<span id="L439" class="LineNr">439 </span> <span class="muControl">loop</span> +<span id="L440" class="LineNr">440 </span> <span class="Delimiter">}</span> +<span id="L441" class="LineNr">441 </span>] +<span id="L442" class="LineNr">442 </span> +<span id="L443" class="LineNr">443 </span><span class="muScenario">scenario</span> buffer-lines-blocks-until-newline [ +<span id="L444" class="LineNr">444 </span> run [ +<span id="L445" class="LineNr">445 </span> <span class="Constant">local-scope</span> +<span id="L446" class="LineNr">446 </span> source:&:source:char, sink:&:sink:char <span class="Special"><-</span> new-channel <span class="Constant">10/capacity</span> +<span id="L447" class="LineNr">447 </span> _, buffered-stdin:&:sink:char/buffered-stdin <span class="Special"><-</span> new-channel <span class="Constant">10/capacity</span> +<span id="L448" class="LineNr">448 </span> buffered-chan:&:channel:char <span class="Special"><-</span> get *buffered-stdin, <span class="Constant">chan:offset</span> +<span id="L449" class="LineNr">449 </span> empty?:bool <span class="Special"><-</span> channel-empty? buffered-chan +<span id="L450" class="LineNr">450 </span> assert empty?, <span class="Constant">[ </span> +<span id="L451" class="LineNr">451 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after init]</span> +<span id="L452" class="LineNr">452 </span> <span class="Comment"># buffer stdin into buffered-stdin, try to read from buffered-stdin</span> +<span id="L453" class="LineNr">453 </span> buffer-routine:num <span class="Special"><-</span> start-running buffer-lines, source, buffered-stdin +<span id="L454" class="LineNr">454 </span> wait-for-routine-to-block buffer-routine +<span id="L455" class="LineNr">455 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan +<span id="L456" class="LineNr">456 </span> assert empty?:bool, <span class="Constant">[ </span> +<span id="L457" class="LineNr">457 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after buffer-lines bring-up]</span> +<span id="L458" class="LineNr">458 </span> <span class="Comment"># write 'a'</span> +<span id="L459" class="LineNr">459 </span> sink <span class="Special"><-</span> write sink, <span class="Constant">97/a</span> +<span id="L460" class="LineNr">460 </span> restart buffer-routine +<span id="L461" class="LineNr">461 </span> wait-for-routine-to-block buffer-routine +<span id="L462" class="LineNr">462 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan +<span id="L463" class="LineNr">463 </span> assert empty?:bool, <span class="Constant">[ </span> +<span id="L464" class="LineNr">464 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after writing 'a']</span> +<span id="L465" class="LineNr">465 </span> <span class="Comment"># write 'b'</span> +<span id="L466" class="LineNr">466 </span> sink <span class="Special"><-</span> write sink, <span class="Constant">98/b</span> +<span id="L467" class="LineNr">467 </span> restart buffer-routine +<span id="L468" class="LineNr">468 </span> wait-for-routine-to-block buffer-routine +<span id="L469" class="LineNr">469 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan +<span id="L470" class="LineNr">470 </span> assert empty?:bool, <span class="Constant">[ </span> +<span id="L471" class="LineNr">471 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should be empty after writing 'b']</span> +<span id="L472" class="LineNr">472 </span> <span class="Comment"># write newline</span> +<span id="L473" class="LineNr">473 </span> sink <span class="Special"><-</span> write sink, <span class="Constant">10/newline</span> +<span id="L474" class="LineNr">474 </span> restart buffer-routine +<span id="L475" class="LineNr">475 </span> wait-for-routine-to-block buffer-routine +<span id="L476" class="LineNr">476 </span> empty? <span class="Special"><-</span> channel-empty? buffered-chan +<span id="L477" class="LineNr">477 </span> data-emitted?:bool <span class="Special"><-</span> not empty? +<span id="L478" class="LineNr">478 </span> assert data-emitted?, <span class="Constant">[ </span> +<span id="L479" class="LineNr">479 </span><span class="Constant">F buffer-lines-blocks-until-newline: channel should contain data after writing newline]</span> +<span id="L480" class="LineNr">480 </span> trace<span class="Constant"> 1</span>, <span class="Constant">[test]</span>, <span class="Constant">[reached end]</span> +<span id="L481" class="LineNr">481 </span> ] +<span id="L482" class="LineNr">482 </span> trace-should-contain [ +<span id="L483" class="LineNr">483 </span> test: reached end +<span id="L484" class="LineNr">484 </span> ] +<span id="L485" class="LineNr">485 </span>] +<span id="L486" class="LineNr">486 </span> +<span id="L487" class="LineNr">487 </span><span class="muRecipe">def</span> drain source:&:source:char<span class="muRecipe"> -> </span>result:text, source:&:source:char [ +<span id="L488" class="LineNr">488 </span> <span class="Constant">local-scope</span> +<span id="L489" class="LineNr">489 </span> <span class="Constant">load-ingredients</span> +<span id="L490" class="LineNr">490 </span> buf:&:buffer <span class="Special"><-</span> new-buffer<span class="Constant"> 30</span> +<span id="L491" class="LineNr">491 </span> <span class="Delimiter">{</span> +<span id="L492" class="LineNr">492 </span> c:char, done?:bool <span class="Special"><-</span> read source +<span id="L493" class="LineNr">493 </span> <span class="muControl">break-if</span> done? +<span id="L494" class="LineNr">494 </span> buf <span class="Special"><-</span> append buf, c +<span id="L495" class="LineNr">495 </span> <span class="muControl">loop</span> +<span id="L496" class="LineNr">496 </span> <span class="Delimiter">}</span> +<span id="L497" class="LineNr">497 </span> result <span class="Special"><-</span> buffer-to-array buf +<span id="L498" class="LineNr">498 </span>] </pre> </body> </html> |