void* OSAllocator::reserveUncommitted(size_t bytes, Usage usage, bool writable, bool executable, bool includesGuardPages)
{
#if OS(QNX)
// Reserve memory with PROT_NONE and MAP_LAZY so it isn't committed now.
void* result = mmap(0, bytes, PROT_NONE, MAP_LAZY | MAP_PRIVATE | MAP_ANON, -1, 0);
if (result == MAP_FAILED)
CRASH();
#elif OS(LINUX)
UNUSED_PARAM(usage);
UNUSED_PARAM(writable);
UNUSED_PARAM(executable);
UNUSED_PARAM(includesGuardPages);
void* result = mmap(0, bytes, PROT_NONE, MAP_NORESERVE | MAP_PRIVATE | MAP_ANON, -1, 0);
if (result == MAP_FAILED)
CRASH();
madvise(result, bytes, MADV_DONTNEED);
#else
void* result = reserveAndCommit(bytes, usage, writable, executable, includesGuardPages);
#if HAVE(MADV_FREE_REUSE)
// To support the "reserve then commit" model, we have to initially decommit.
while (madvise(result, bytes, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN) { }
#endif
#endif // OS(QNX)
return result;
}
void* OSAllocator::reserveUncommitted(size_t bytes, Usage usage, bool writable, bool executable)
{
void* result = reserveAndCommit(bytes, usage, writable, executable);
#if HAVE_MADV_FREE_REUSE
// To support the "reserve then commit" model, we have to initially decommit.
while (madvise(result, bytes, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN) { }
#endif
return result;
}
void* OSAllocator::reserveUncommitted(size_t bytes, Usage usage, bool writable, bool executable, bool includesGuardPages)
{
EA::WebKit::Allocator* pAllocator = EA::WebKit::GetAllocator();
if(pAllocator->SupportsOSMemoryManagement())
{
return pAllocator->ReserveUncommitted(bytes,writable,executable);
}
else
{
// We don't make a distinction.
return reserveAndCommit(bytes, usage, writable, executable, includesGuardPages);
}
}