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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;
_GC_finalize_on_demand = _malloc(4); setValue(_GC_finalize_on_demand, 0, 'i32')
_GC_java_finalization = _malloc(4); setValue(_GC_java_finalization, 0, 'i32');
_GC_finalizer_notifier = _malloc(4); setValue(_GC_finalizer_notifier, 0, 'i32');
if (ENVIRONMENT_IS_WEB) {
setInterval(function() {
GC.maybeCollect();
}, 1000);
} else {
#if ASSERTIONS
Module.print('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, 'vii')(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(parseInt(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();
},
GC_finalize_on_demand: 0,
GC_java_finalization: 0,
GC_finalizer_notifier: 0,
GC_enable_incremental: function(){},
};
mergeInto(LibraryManager.library, LibraryGC);
}
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