1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
if (GC_SUPPORT) {
var LibraryGC = {
$GC__deps: ['sbrk'],
$GC: {
ALLOCATIONS_TO_GC: 1*1024*1024,
sizes: {}, // if in this map, then a live allocated object. this is iterable
scannables: {},
finalizers: {},
finalizerArgs: {},
totalAllocations: 0, // bytes of all currently active objects
recentAllocations: 0, // bytes allocated since last gc. ignores free()s
init: function() {
assert(!GC.initted);
GC.initted = true;
#if GENERATING_HTML
setInterval(function() {
GC.maybeGC();
}, 1000);
#else
// No HTML intervals, so you need to call GC.maybeCollect() or GC.collect() manually
#endif
},
malloc: function(bytes, clear, scannable) {
if (!bytes) return 0;
var ptr;
if (clear) {
ptr = _calloc(1, bytes);
} else {
ptr = _malloc(bytes);
}
GC.scannables[ptr] = scannable;
GC.sizes[ptr] = bytes;
GC.totalAllocations += bytes;
GC.recentAllocations += bytes;
return ptr;
},
free: function(ptr) { // does not check if anything refers to it, this is a forced free
var finalizer = GC.finalizers[ptr];
if (finalizer) {
Runtime.getFuncWrapper(finalizer)(ptr, GC.finalizerArgs[ptr]);
GC.finalizers[ptr] = 0;
}
_free(ptr);
delete GC.sizes[ptr];
GC.totalAllocations -= GC.sizes[ptr];
},
registerFinalizer: function(ptr, func, arg, oldFunc, oldArg) {
var finalizer = GC.finalizers[ptr];
if (finalizer) {
if (oldFunc) {
{{{ makeSetValue('oldFunc', '0', 'finalizer', 'i32') }}};
}
if (oldArg) {
{{{ makeSetValue('oldArg', '0', 'GC.finalizerArgs[ptr]', 'i32') }}};
}
}
GC.finalizers[ptr] = func;
GC.finalizerArgs[ptr] = arg;
},
maybeCollect: function() {
if (GC.needCollect()) GC.collect();
},
needCollect: function() {
return GC.recentAllocations >= GC.ALLOCATIONS_TO_GC; // TODO: time, etc.
},
collect: function() {
GC.prep();
GC.mark();
GC.sweep();
GC.recentAllocations = 0;
},
scan: function(start, end) { // scans a memory region and adds new reachable objects
for (var i = start; i < end; i += {{{ Runtime.getNativeTypeSize('void*') }}}) {
var ptr = {{{ makeGetValue('i', '0', 'void*') }}};
if (GC.sizes[ptr] && !GC.reachable[ptr]) {
GC.reachable[ptr] = 1;
if (GC.scannables[ptr]) {
GC.reachableList.push(ptr);
}
}
}
},
prep: function() { // Clear reachables and scan for roots
GC.reachable = {}; // 1 if reachable. XXX
GC.reachableList = []; // each reachable is added once to this. XXX
// static data areas
var staticStart = STACK_MAX;
var staticEnd = _sbrk.DYNAMIC_START || STATICTOP; // after DYNAMIC_START, sbrk manages it (but it might not exist yet)
GC.scan(staticStart, staticEnd);
// TODO: scan stack and registers. Currently we assume we run from a timeout or such, so no stack/regs
// stack: STACK_ROOT to STACKTOP
// registers: call scanners
},
mark: function() { // mark all reachable from roots
for (var i = 0; i < GC.reachableList.length; i++) { // note that the list length changes as we push more
var ptr = GC.reachableList[i];
GC.scan(ptr, ptr + GC.sizes[ptr]);
}
},
sweep: function() { // traverse all objects and free all unreachable
var freeList = [];
for (var ptr in GC.sizes) {
if (!GC.reachable[ptr]) {
freeList.push(ptr);
}
}
for (var i = 0; i < freeList.length; i++) {
GC.free(freeList[i]);
}
}
},
GC_INIT__deps: ['$GC'],
GC_INIT: function() {
GC.init();
},
GC_MALLOC__deps: ['$GC'],
GC_MALLOC: function(bytes) {
return GC.malloc(bytes, true, true);
},
GC_MALLOC_ATOMIC__deps: ['$GC'],
GC_MALLOC_ATOMIC: function(bytes) {
return GC.malloc(bytes, false, false);
},
GC_FREE__deps: ['$GC'],
GC_FREE: function(ptr) {
GC.free(ptr);
},
GC_REGISTER_FINALIZER_NO_ORDER__deps: ['$GC'],
GC_REGISTER_FINALIZER_NO_ORDER: function(ptr, func, arg, old_func, old_arg) {
GC.registerFinalizer(ptr, func, arg, old_func, old_arg);
},
GC_MAYBE_COLLECT__deps: ['$GC'],
GC_MAYBE_COLLECT: function() {
GC.maybeCollect();
},
GC_FORCE_COLLECT__deps: ['$GC'],
GC_FORCE_COLLECT: function() {
GC.collect();
}
};
mergeInto(LibraryManager.library, LibraryGC);
}
|
