bool EnableLowFragmentationHeap() {
HMODULE kernel32 = GetModuleHandle(L"kernel32.dll");
HeapSetFn heap_set = reinterpret_cast<HeapSetFn>(GetProcAddress(
kernel32,
"HeapSetInformation"));
// On Windows 2000, the function is not exported. This is not a reason to
// fail.
if (!heap_set)
return true;
unsigned number_heaps = GetProcessHeaps(0, NULL);
if (!number_heaps)
return false;
// Gives us some extra space in the array in case a thread is creating heaps
// at the same time we're querying them.
static const int MARGIN = 8;
scoped_ptr<HANDLE[]> heaps(new HANDLE[number_heaps + MARGIN]);
number_heaps = GetProcessHeaps(number_heaps + MARGIN, heaps.get());
if (!number_heaps)
return false;
for (unsigned i = 0; i < number_heaps; ++i) {
ULONG lfh_flag = 2;
// Don't bother with the result code. It may fails on heaps that have the
// HEAP_NO_SERIALIZE flag. This is expected and not a problem at all.
heap_set(heaps[i],
HeapCompatibilityInformation,
&lfh_flag,
sizeof(lfh_flag));
}
return true;
}
void register_extra_heap(Heap &heap) {
heaps().push_back(&heap);
}
Heap *get_heap(unsigned i) {
return heaps()[i];
}
unsigned heap_count() {
return heaps().size();
}
