static void *
osTryReserveHeapMemory (W_ len, void *hint)
{
void *base, *top;
void *start, *end;
/* We try to allocate len + MBLOCK_SIZE,
because we need memory which is MBLOCK_SIZE aligned,
and then we discard what we don't need */
base = my_mmap(hint, len + MBLOCK_SIZE, MEM_RESERVE);
top = (void*)((W_)base + len + MBLOCK_SIZE);
if (((W_)base & MBLOCK_MASK) != 0) {
start = MBLOCK_ROUND_UP(base);
end = MBLOCK_ROUND_DOWN(top);
ASSERT(((W_)end - (W_)start) == len);
if (munmap(base, (W_)start-(W_)base) < 0) {
sysErrorBelch("unable to release slop before heap");
}
if (munmap(end, (W_)top-(W_)end) < 0) {
sysErrorBelch("unable to release slop after heap");
}
} else {
start = base;
}
return start;
}
void *osReserveHeapMemory (void *startAddress, W_ *len)
{
void *start;
heap_base = VirtualAlloc(startAddress, *len + MBLOCK_SIZE,
MEM_RESERVE, PAGE_READWRITE);
if (heap_base == NULL) {
if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY) {
errorBelch("out of memory");
} else {
sysErrorBelch(
"osReserveHeapMemory: VirtualAlloc MEM_RESERVE %llu bytes \
at address %p bytes failed",
len + MBLOCK_SIZE, startAddress);
}
stg_exit(EXIT_FAILURE);
}
// VirtualFree MEM_RELEASE must always match a
// previous MEM_RESERVE call, in address and size
// so we necessarily leak some address space here,
// before and after the aligned area
// It is not a huge problem because we never commit
// that memory
start = MBLOCK_ROUND_UP(heap_base);
return start;
}
