https://github.com/akkartik/mu/blob/master/074wait.cc
1
2
3
4
5
6 :(scenario wait_for_location)
7 def f1 [
8 10:num <- copy 34
9 start-running f2
10 20:location <- copy 10/unsafe
11 wait-for-reset-then-set 20:location
12
13 30:num <- copy 10:num
14 ]
15 def f2 [
16 10:location <- copy 0/unsafe
17 ]
18 +schedule: f1
19 +run: waiting for location 10 to reset
20 +schedule: f2
21 +schedule: waking up routine 1
22 +schedule: f1
23 +mem: storing 1 in location 30
24
25
26
27 :(before "End routine States")
28 WAITING,
29 :(before "End routine Fields")
30
31 int waiting_on_location;
32 :(before "End routine Constructor")
33 waiting_on_location = 0;
34
35 :(before "End Mu Test Teardown")
36 if (Passed && any_routines_waiting())
37 raise << Current_scenario->name << ": deadlock!\n" << end();
38 :(before "End Run Routine")
39 if (any_routines_waiting()) {
40 raise << "deadlock!\n" << end();
41 dump_waiting_routines();
42 }
43 :(before "End Test Teardown")
44 if (Passed && any_routines_with_error())
45 raise << "some routines died with errors\n" << end();
46 :(code)
47 bool any_routines_waiting() {
48 for (int i = 0; i < SIZE(Routines); ++i) {
49 if (Routines.at(i)->state == WAITING)
50 return true;
51 }
52 return false;
53 }
54 void dump_waiting_routines() {
55 for (int i = 0; i < SIZE(Routines); ++i) {
56 if (Routines.at(i)->state == WAITING)
57 cerr << i << ": " << routine_label(Routines.at(i)) << '\n';
58 }
59 }
60
61 :(scenario wait_for_location_can_deadlock)
62 % Hide_errors = true;
63 def main [
64 10:num <- copy 1
65 20:location <- copy 10/unsafe
66 wait-for-reset-then-set 20:location
67 ]
68 +error: deadlock!
69
70
71
72
73
74 :(before "End Primitive Recipe Declarations")
75 WAIT_FOR_RESET_THEN_SET,
76 :(before "End Primitive Recipe Numbers")
77 put(Recipe_ordinal, "wait-for-reset-then-set", WAIT_FOR_RESET_THEN_SET);
78 :(before "End Primitive Recipe Checks")
79 case WAIT_FOR_RESET_THEN_SET: {
80 if (SIZE(inst.ingredients) != 1) {
81 raise << maybe(get(Recipe, r).name) << "'wait-for-reset-then-set' requires exactly one ingredient, but got '" << to_original_string(inst) << "'\n" << end();
82 break;
83 }
84 if (!is_mu_location(inst.ingredients.at(0))) {
85 raise << maybe(get(Recipe, r).name) << "'wait-for-reset-then-set' requires a location ingredient, but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
86 }
87 break;
88 }
89 :(before "End Primitive Recipe Implementations")
90 case WAIT_FOR_RESET_THEN_SET: {
91 int loc = static_cast<int>(ingredients.at(0).at(0));
92 trace(9998, "run") << "wait: *" << loc << " = " << get_or_insert(Memory, loc) << end();
93 if (get_or_insert(Memory, loc) == 0) {
94 trace(9998, "run") << "location " << loc << " is already 0; setting" << end();
95 put(Memory, loc, 1);
96 break;
97 }
98 trace(9998, "run") << "waiting for location " << loc << " to reset" << end();
99 Current_routine->state = WAITING;
100 Current_routine->waiting_on_location = loc;
101 break;
102 }
103
104
105 :(before "End Primitive Recipe Declarations")
106 RESET,
107 :(before "End Primitive Recipe Numbers")
108 put(Recipe_ordinal, "reset", RESET);
109 :(before "End Primitive Recipe Checks")
110 case RESET: {
111 if (SIZE(inst.ingredients) != 1) {
112 raise << maybe(get(Recipe, r).name) << "'reset' requires exactly one ingredient, but got '" << to_original_string(inst) << "'\n" << end();
113 break;
114 }
115 if (!is_mu_location(inst.ingredients.at(0))) {
116 raise << maybe(get(Recipe, r).name) << "'reset' requires a location ingredient, but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
117 }
118 break;
119 }
120 :(before "End Primitive Recipe Implementations")
121 case RESET: {
122 int loc = static_cast<int>(ingredients.at(0).at(0));
123 put(Memory, loc, 0);
124 trace(9998, "run") << "reset: *" << loc << " = " << get_or_insert(Memory, loc) << end();
125 break;
126 }
127
128
129
130 :(before "End Scheduler State Transitions")
131 for (int i = 0; i < SIZE(Routines); ++i) {
132 if (Routines.at(i)->state != WAITING) continue;
133 int loc = Routines.at(i)->waiting_on_location;
134 if (loc && get_or_insert(Memory, loc) == 0) {
135 trace("schedule") << "waking up routine " << Routines.at(i)->id << end();
136 put(Memory, loc, 1);
137 Routines.at(i)->state = RUNNING;
138 Routines.at(i)->waiting_on_location = 0;
139 }
140 }
141
142
143
144
145
146 :(scenario get_location)
147 def main [
148 12:num <- copy 34
149 13:num <- copy 35
150 15:location <- get-location 12:point, 1:offset
151 ]
152 +mem: storing 13 in location 15
153
154 :(before "End Primitive Recipe Declarations")
155 GET_LOCATION,
156 :(before "End Primitive Recipe Numbers")
157 put(Recipe_ordinal, "get-location", GET_LOCATION);
158 :(before "End Primitive Recipe Checks")
159 case GET_LOCATION: {
160 if (SIZE(inst.ingredients) != 2) {
161 raise << maybe(get(Recipe, r).name) << "'get-location' expects exactly 2 ingredients in '" << to_original_string(inst) << "'\n" << end();
162 break;
163 }
164 reagent base = inst.ingredients.at(0);
165 if (!canonize_type(base)) break;
166 if (!base.type) {
167 raise << maybe(get(Recipe, r).name) << "first ingredient of 'get-location' should be a container, but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
168 break;
169 }
170 const type_tree* base_root_type = base.type->atom ? base.type : base.type->left;
171 if (!base_root_type->atom || base_root_type->value == 0 || !contains_key(Type, base_root_type->value) || get(Type, base_root_type->value).kind != CONTAINER) {
172 raise << maybe(get(Recipe, r).name) << "first ingredient of 'get-location' should be a container, but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
173 break;
174 }
175 type_ordinal base_type = base.type->value;
176 const reagent& offset = inst.ingredients.at(1);
177 if (!is_literal(offset) || !is_mu_scalar(offset)) {
178 raise &lclass="p"><span id="L11" class="LineNr"> 11 </span><span class="subxComment"># To reduce the odds of such "use after free" errors, SubX programs tend to not</span>
<span id="L12" class="LineNr"> 12 </span><span class="subxComment"># reclaim and reuse dynamically allocated memory. (Running out of memory is far</span>
<span id="L13" class="LineNr"> 13 </span><span class="subxComment"># easier to debug.) Long-running programs that want to reuse memory are mostly</span>
<span id="L14" class="LineNr"> 14 </span><span class="subxComment"># on their own to be careful. However, they do get one bit of help: they can</span>
<span id="L15" class="LineNr"> 15 </span><span class="subxComment"># carve out chunks of memory and then allocate from them manually using this</span>
<span id="L16" class="LineNr"> 16 </span><span class="subxComment"># very same 'allocate' helper. They just need a new allocation descriptor for</span>
<span id="L17" class="LineNr"> 17 </span><span class="subxComment"># their book-keeping.</span>
<span id="L18" class="LineNr"> 18 </span>
<span id="L19" class="LineNr"> 19 </span>== data
<span id="L20" class="LineNr"> 20 </span>
<span id="L21" class="LineNr"> 21 </span><span class="subxComment"># The 'global' allocation descriptor. Pass this into 'allocate' to claim a</span>
<span id="L22" class="LineNr"> 22 </span><span class="subxComment"># hitherto unused bit of memory.</span>
<span id="L23" class="LineNr"> 23 </span><span class="SpecialChar">Heap</span>:
<span id="L24" class="LineNr"> 24 </span> <span class="SpecialChar">Start-of-heap</span>/imm32 <span class="subxComment"># curr</span>
<span id="L25" class="LineNr"> 25 </span> 0x0b000000/imm32 <span class="subxComment"># limit; keep sync'd with DATA_SEGMENT + SEGMENT_ALIGNMENT</span>
<span id="L26" class="LineNr"> 26 </span>
<span id="L27" class="LineNr"> 27 </span>== code
<span id="L28" class="LineNr"> 28 </span><span class="subxComment"># instruction effective address register displacement immediate</span>
<span id="L29" class="LineNr"> 29 </span><span class="subxS1Comment"># . op subop mod rm32 base index scale r32</span>
<span id="L30" class="LineNr"> 30 </span><span class="subxS1Comment"># . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes</span>
<span id="L31" class="LineNr"> 31 </span>
<span id="L32" class="LineNr"> 32 </span><span class="subxComment"># Claim the next 'n' bytes of memory starting at ad->curr and update ad->curr.</span>
<span id="L33" class="LineNr"> 33 </span><span class="subxComment"># If there isn't enough memory before ad->limit, return 0 and leave 'ad' unmodified.</span>
<span id="L34" class="LineNr"> 34 </span><span class="subxFunction">allocate</span>: <span class="subxComment"># ad : (address allocation-descriptor), n : int -> address-or-null/EAX</span>
<span id="L35" class="LineNr"> 35 </span> <span class="subxS1Comment"># . prolog</span>
<span id="L36" class="LineNr"> 36 </span> 55/push-EBP
<span id="L37" class="LineNr"> 37 </span> 89/copy 3/mod/direct 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ESP to EBP</span>
<span id="L38" class="LineNr"> 38 </span> <span class="subxS1Comment"># . save registers</span>
<span id="L39" class="LineNr"> 39 </span> 51/push-ECX
<span id="L40" class="LineNr"> 40 </span> 52/push-EDX
<span id="L41" class="LineNr"> 41 </span> <span class="subxComment"># ECX = ad</span>
<span id="L42" class="LineNr"> 42 </span> 8b/copy 1/mod/*+disp8 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 1/r32/ECX 8/disp8 <span class="Normal"> . </span> <span class="subxComment"># copy *(EBP+8) to ECX</span>
<span id="L43" class="LineNr"> 43 </span> <span class="subxComment"># save ad->curr</span>
<span id="L44" class="LineNr"> 44 </span> 8b/copy 0/mod/indirect 1/rm32/ECX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/EAX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy *ECX to EAX</span>
<span id="L45" class="LineNr"> 45 </span> <span class="subxComment"># check if there's enough space</span>
<span id="L46" class="LineNr"> 46 </span> <span class="subxS1Comment"># . EDX = ad->curr + n</span>
<span id="L47" class="LineNr"> 47 </span> 89/copy 3/mod/direct 2/rm32/EDX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0/r32/EAX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy EAX to EDX</span>
<span id="L48" class="LineNr"> 48 </span> 03/add 1/mod/*+disp8 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/EDX 0xc/disp8 <span class="Normal"> . </span> <span class="subxComment"># add *(EBP+12) to EDX</span>
<span id="L49" class="LineNr"> 49 </span> 3b/compare 1/mod/*+disp8 1/rm32/ECX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/EDX 4/disp8 <span class="Normal"> . </span> <span class="subxComment"># compare EDX with *(ECX+4)</span>
<span id="L50" class="LineNr"> 50 </span> 7c/jump-if-lesser $allocate:commit/disp8
<span id="L51" class="LineNr"> 51 </span> <span class="subxComment"># return null if not</span>
<span id="L52" class="LineNr"> 52 </span> b8/copy-to-EAX 0/imm32
<span id="L53" class="LineNr"> 53 </span> eb/jump $allocate:end/disp8
<span id="L54" class="LineNr"> 54 </span><span class="Constant">$allocate:commit</span>:
<span id="L55" class="LineNr"> 55 </span> <span class="subxComment"># update ad->curr</span>
<span id="L56" class="LineNr"> 56 </span> 89/copy 0/mod/indirect 1/rm32/ECX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 2/r32/EDX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy EDX to *ECX</span>
<span id="L57" class="LineNr"> 57 </span><span class="Constant">$allocate:end</span>:
<span id="L58" class="LineNr"> 58 </span> <span class="subxS1Comment"># . restore registers</span>
<span id="L59" class="LineNr"> 59 </span> 5a/pop-to-EDX
<span id="L60" class="LineNr"> 60 </span> 59/pop-to-ECX
<span id="L61" class="LineNr"> 61 </span> <span class="subxS1Comment"># . epilog</span>
<span id="L62" class="LineNr"> 62 </span> 89/copy 3/mod/direct 4/rm32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 5/r32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy EBP to ESP</span>
<span id="L63" class="LineNr"> 63 </span> 5d/pop-to-EBP
<span id="L64" class="LineNr"> 64 </span> c3/return
<span id="L65" class="LineNr"> 65 </span>
<span id="L66" class="LineNr"> 66 </span><span class="subxTest">test-allocate-success</span>:
<span id="L67" class="LineNr"> 67 </span> <span class="subxS1Comment"># . prolog</span>
<span id="L68" class="LineNr"> 68 </span> 55/push-EBP
<span id="L69" class="LineNr"> 69 </span> 89/copy 3/mod/direct 5/rm32/EBP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ESP to EBP</span>
<span id="L70" class="LineNr"> 70 </span> <span class="subxComment"># var ad/ECX : (address allocation-descriptor) = {11, 15}</span>
<span id="L71" class="LineNr"> 71 </span> 68/push 0xf/imm32/limit
<span id="L72" class="LineNr"> 72 </span> 68/push 0xb/imm32/curr
<span id="L73" class="LineNr"> 73 </span> 89/copy 3/mod/direct 1/rm32/ECX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 4/r32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># copy ESP to ECX</span>
<span id="L74" class="LineNr"> 74 </span> <span class="subxComment"># EAX = allocate(ad, 3)</span>
<span id="L75" class="LineNr"> 75 </span> <span class="subxS2Comment"># . . push args</span>
<span id="L76" class="LineNr"> 76 </span> 68/push 3/imm32
<span id="L77" class="LineNr"> 77 </span> 51/push-ECX
<span id="L78" class="LineNr"> 78 </span> <span class="subxS2Comment"># . . call</span>
<span id="L79" class="LineNr"> 79 </span> e8/call <a href='069allocate.subx.html#L34'>allocate</a>/disp32
<span id="L80" class="LineNr"> 80 </span> <span class="subxS2Comment"># . . discard args</span>
<span id="L81" class="LineNr"> 81 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 8/imm32 <span class="subxComment"># add to ESP</span>
<span id="L82" class="LineNr"> 82 </span> <span class="subxComment"># check-ints-equal(EAX, 11, msg)</span>
<span id="L83" class="LineNr"> 83 </span> <span class="subxS2Comment"># . . push args</span>
<span id="L84" class="LineNr"> 84 </span> 68/push <span class="Constant">"F - <a href='069allocate.subx.html#L66'>test-allocate-success</a>: returns current pointer of allocation descriptor"</span>/imm32
<span id="L85" class="LineNr"> 85 </span> 68/push 0xb/imm32
<span id="L86" class="LineNr"> 86 </span> 50/push-EAX
<span id="L87" class="LineNr"> 87 </span> <span class="subxS2Comment"># . . call</span>
<span id="L88" class="LineNr"> 88 </span> e8/call <a href='051test.subx.html#L24'>check-ints-equal</a>/disp32
<span id="L89" class="LineNr"> 89 </span> <span class="subxS2Comment"># . . discard args</span>
<span id="L90" class="LineNr"> 90 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0xc/imm32 <span class="subxComment"># add to ESP</span>
<span id="L91" class="LineNr"> 91 </span> <span class="subxComment"># check-ints-equal(ad->curr, 14, msg)</span>
<span id="L92" class="LineNr"> 92 </span> <span class="subxS2Comment"># . . push args</span>
<span id="L93" class="LineNr"> 93 </span> 68/push <span class="Constant">"F - <a href='069allocate.subx.html#L66'>test-allocate-success</a>: updates allocation descriptor"</span>/imm32
<span id="L94" class="LineNr"> 94 </span> 68/push 0xe/imm32
<span id="L95" class="LineNr"> 95 </span> ff 6/subop/push 0/mod/indirect 1/rm32/ECX <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="subxComment"># push *ECX</span>
<span id="L96" class="LineNr"> 96 </span> <span class="subxS2Comment"># . . call</span>
<span id="L97" class="LineNr"> 97 </span> e8/call <a href='051test.subx.html#L24'>check-ints-equal</a>/disp32
<span id="L98" class="LineNr"> 98 </span> <span class="subxS2Comment"># . . discard args</span>
<span id="L99" class="LineNr"> 99 </span> 81 0/subop/add 3/mod/direct 4/rm32/ESP <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> <span class="Normal"> . </span> 0xc/imm32 <span class="subxComment"># add to ESP</span>
<span id="L100" class="LineNr">100 </span> <span class