mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

	Commit message (Expand)	Author	Age	Files	Lines
*	7444	Kartik Agaram	2020-12-28	1	-1/+1
*	7173	Kartik Agaram	2020-11-03	1	-1/+1
*	7138 - type-check array 'length' instruction	Kartik Agaram	2020-10-29	1	-1/+1
*	6719 - error-checking for 'index' instructions	Kartik Agaram	2020-08-21	1	-1/+1
*	6528	Kartik Agaram	2020-06-15	1	-1/+1
*	6526	Kartik Agaram	2020-06-15	1	-1/+1
*	6382 - re-enable mu.subx in CI	Kartik Agaram	2020-05-22	1	-1/+1
*	increase some buffer sizes	Kartik Agaram	2020-05-22	1	-2/+2
*	6094 - new 'compute-offset' instruction	Kartik Agaram	2020-03-07	1	-1/+1
*	6064	Kartik Agaram	2020-02-27	1	-2/+2
*	5999	Kartik Agaram	2020-02-09	1	-1/+1
*	5933	Kartik Agaram	2020-01-27	1	-2/+2
*	5765	Kartik Agaram	2019-11-26	1	-0/+4
*	5675 - move helpers from subx-common into layers	Kartik Agaram	2019-09-19	1	-0/+15

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - 036abandon.cc</title> <meta name="Generator" content="Vim/8.0"> <meta name="plugin-version" content="vim7.4_v2"> <meta name="syntax" content="cpp"> <meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy="> <meta name="colorscheme" content="minimal-light"> <style type="text/css">  </style> <script type='text/javascript'>  </script> </head> <body onload='JumpToLine();'> <a href='https://github.com/akkartik/mu/blob/master/036abandon.cc'>https://github.com/akkartik/mu/blob/master/036abandon.cc</a> <pre id='vimCodeElement'> 1 //: Reclaiming memory when it's no longer used. 2 3 :(scenario new_reclaim) 4 def <a href='000organization.cc.html#L113'>main</a> [ 5 10:&:num <- new number:type 6 20:num <- deaddress 10:&:num 7 <a href='036abandon.cc.html#L63'>abandon</a> 10:&:num 8 30:&:num <- new number:type # must be same size as abandoned memory to reuse 9 40:num <- deaddress 30:&:num 10 50:bool <- equal 20:num, 40:num 11 ] 12 # both allocations should have returned the same address 13 +mem: storing 1 in location 50 14 15 //: When abandoning addresses we'll save them to a 'free list', segregated by size. 16 17 //: Before, suppose variable V contains address A which points to payload P: 18 //: location V contains an alloc-id N 19 //: location V+1 contains A 20 //: location A contains alloc-id N 21 //: location A+1 onwards contains P 22 //: Additionally, suppose the head of the free list is initially F. 23 //: After abandoning: 24 //: location V contains invalid alloc-id -1 25 //: location V+1 contains 0 26 //: location A contains invalid alloc-id N 27 //: location A+1 contains the previous head of free-list F 28 29 :(before "End routine Fields") 30 map<int, int> free_list; 31 32 :(before "End Primitive Recipe Declarations") 33 ABANDON, 34 :(before "End Primitive Recipe Numbers") 35 <a href='001help.cc.html#L221'>put</a>(Recipe_ordinal, "abandon", ABANDON); 36 :(before "End Primitive Recipe Checks") 37 case ABANDON: { 38 if (!inst.products.empty()) { 39 <a href='003trace.cc.html#L196'>raise</a> << <a href='013update_operation.cc.html#L25'>maybe</a>(get(Recipe, r).name) << "'abandon' shouldn't write to any products in '" << to_original_string(inst) << "'\n" << end(); 40 break; 41 } 42 for (int i = 0; i < <a href='001help.cc.html#L141'>SIZE</a>(inst.ingredients); ++i) { 43 if (!is_mu_address(inst.ingredients.at(i))) 44 <a href='003trace.cc.html#L196'>raise</a> << <a href='013update_operation.cc.html#L25'>maybe</a>(get(Recipe, r).name) << "ingredients of 'abandon' should be addresses, but ingredient " <" is '" << to_string(inst.ingredients.at(i)) << '\n' << end(); 45 break; 46 } 47 break; 48 } 49 :(before "End Primitive Recipe Implementations") 50 case ABANDON: { 51 for (int i = 0; i < <a href='001help.cc.html#L141'>SIZE</a>(<a href='026call.cc.html#L89'>current_instruction</a>().ingredients); ++i) { 52 reagent/*copy*/ ingredient = <a href='026call.cc.html#L89'>current_instruction</a>().ingredients.at(i); 53 <a href='035lookup.cc.html#L66'>canonize</a>(ingredient); 54 <a href='036abandon.cc.html#L63'>abandon</a>(<a href='001help.cc.html#L229'>get_or_insert</a>(Memory, ingredient.value+/*skip alloc id*/1), <a href='036abandon.cc.html#L75'>payload_size</a>(ingredient)); 55 //? cerr << "clear after abandon: " << ingredient.value << '\n'; 56 <a href='001help.cc.html#L221'>put</a>(Memory, /*alloc id*/ingredient.value, /*invalid*/-1); 57 <a href='001help.cc.html#L221'>put</a>(Memory, /*<a href='043space.cc.html#L101'>address</a>*/ingredient.value+1, 0); 58 } 59 break; 60 } 61 62 :(code) 63 void <a href='036abandon.cc.html#L63'>abandon</a>(int <a href='043space.cc.html#L101'>address</a>, int <a href='036abandon.cc.html#L75'>payload_size</a>) { 64 <a href='001help.cc.html#L221'>put</a>(Memory, <a href='043space.cc.html#L101'>address</a>, /*invalid alloc-id*/-1); 65 //? cerr << "abandon: " << address << '\n'; 66 // clear rest of payload 67 for (int curr = address+1; curr < address+payload_size; ++curr) 68 <a href='001help.cc.html#L221'>put</a>(Memory, curr, 0); 69 // append existing free list to address 70 <a href='003trace.cc.html#L189'>trace</a>("abandon") << "saving " << <a href='043space.cc.html#L101'>address</a> << " in free-list of size " << <a href='036abandon.cc.html#L75'>payload_size</a> << <a href='003trace.cc.html#L225'>end</a>(); 71 <a href='001help.cc.html#L221'>put</a>(Memory, address+/*skip invalid alloc-id*/1, <a href='001help.cc.html#L229'>get_or_insert</a>(Current_routine->free_list, <a href='036abandon.cc.html#L75'>payload_size</a>)); 72 <a href='001help.cc.html#L221'>put</a>(Current_routine->free_list, <a href='036abandon.cc.html#L75'>payload_size</a>, <a href='043space.cc.html#L101'>address</a>); 73 } 74 75 int <a href='036abandon.cc.html#L75'>payload_size</a>(reagent/*copy*/ x) { 76 x.properties.push_back(pair<string, string_tree*>("lookup", NULL)); 77 <a href='035lookup.cc.html#L88'>lookup_memory_core</a>(x, /*check_for_null*/false); 78 return size_of(x)+/*alloc id*/1; 79 } 80 81 :(after "Allocate Special-cases") 82 if (<a href='001help.cc.html#L229'>get_or_insert</a>(Current_routine->free_list, size)) { 83 <a href='003trace.cc.html#L189'>trace</a>("abandon") << "picking up space from free-list of size " << size << <a href='003trace.cc.html#L225'>end</a>(); 84 int result = <a href='001help.cc.html#L229'>get_or_insert</a>(Current_routine->free_list, size); 85 <a href='003trace.cc.html#L189'>trace</a>("mem") << "new alloc from free list: " << result << <a href='003trace.cc.html#L225'>end</a>(); 86 <a href='001help.cc.html#L221'>put</a>(Current_routine->free_list, size, <a href='001help.cc.html#L229'>get_or_insert</a>(Memory, result+/*skip alloc id*/1)); 87 // clear 'deleted' tag 88 <a href='001help.cc.html#L221'>put</a>(Memory, result, 0); 89 // clear next pointer 90 <a href='001help.cc.html#L221'>put</a>(Memory, result+/*skip alloc id*/1, 0); 91 for (int curr = result; curr < result+size; ++curr) { 92 if (<a href='001help.cc.html#L229'>get_or_insert</a>(Memory, curr) != 0) { 93 <a href='003trace.cc.html#L196'>raise</a> << <a href='013update_operation.cc.html#L25'>maybe</a>(<a href='026call.cc.html#L87'>current_recipe_name</a>()) << "memory in free list was not zeroed out: " << curr << '/' << result << "; somebody wrote to us after free!!!\n" << <a href='003trace.cc.html#L225'>end</a>(); 94 break; // always fatal 95 } 96 } 97 return result; 98 } 99 100 :(scenario new_differing_size_no_reclaim) 101 def <a href='000organization.cc.html#L113'>main</a> [ 102 1:&:num <- new number:type 103 2:num <- deaddress 1:&:num 104 <a href='036abandon.cc.html#L63'>abandon</a> 1:&:num 105 3:&:@:num <- new number:type, 2 # different size 106 4:num <- deaddress 3:&:@:num 107 5:bool <- equal 2:num, 4:num 108 ] 109 # no reuse 110 +mem: storing 0 in location 5 111 112 :(scenario new_reclaim_array) 113 def <a href='000organization.cc.html#L113'>main</a> [ 114 10:&:@:num <- new number:type, 2 115 20:num <- deaddress 10:&:@:num 116 <a href='036abandon.cc.html#L63'>abandon</a> 10:&:@:num 117 30:&:@:num <- new number:type, 2 # same size 118 40:num <- deaddress 30:&:@:num 119 50:bool <- equal 20:num, 40:num 120 ] 121 # both calls to new returned identical addresses 122 +mem: storing 1 in location 50 123 124 :(scenario lookup_of_abandoned_address_raises_error) 125 % Hide_errors = true; 126 def <a href='000organization.cc.html#L113'>main</a> [ 127 1:&:num <- new num:type 128 3:&:num <- copy 1:&:num 129 <a href='036abandon.cc.html#L63'>abandon</a> 1:&:num 130 5:num/raw <- copy *3:&:num 131 ] 132 +error: <a href='000organization.cc.html#L113'>main</a>: <a href='043space.cc.html#L101'>address</a> is already abandoned in '5:num/raw <- copy *3:&:num' </pre> </body> </html>