bool
VolatileBuffer::Lock(void** aBuf)
{
MutexAutoLock lock(mMutex);
MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer");
*aBuf = mBuf;
if (++mLockCount > 1 || OnHeap()) {
return true;
}
// MEM_RESET_UNDO's behavior is undefined when called on memory that
// hasn't been MEM_RESET.
if (mFirstLock) {
mFirstLock = false;
return true;
}
void* addr = VirtualAllocEx(GetCurrentProcess(),
mBuf,
mSize,
MEM_RESET_UNDO,
PAGE_READWRITE);
return !!addr;
}
VolatileBuffer::~VolatileBuffer()
{
if (OnHeap()) {
free(mBuf);
} else {
vm_deallocate(mach_task_self(), (vm_address_t)mBuf, mSize);
}
}
size_t
VolatileBuffer::NonHeapSizeOfExcludingThis() const
{
if (OnHeap()) {
return 0;
}
return (mSize + 4095) & ~4095;
}
VolatileBuffer::~VolatileBuffer()
{
MOZ_ASSERT(mLockCount == 0, "Being destroyed with non-zero lock count?");
if (OnHeap()) {
free(mBuf);
} else {
vm_deallocate(mach_task_self(), (vm_address_t)mBuf, mSize);
}
}
size_t
VolatileBuffer::NonHeapSizeOfExcludingThis() const
{
if (OnHeap()) {
return 0;
}
unsigned long pagemask = getpagesize() - 1;
return (mSize + pagemask) & ~pagemask;
}
VolatileBuffer::~VolatileBuffer()
{
if (OnHeap()) {
#ifdef MOZ_MEMORY
free(mBuf);
#else
_aligned_free(mBuf);
#endif
} else {
VirtualFreeEx(GetCurrentProcess(), mBuf, 0, MEM_RELEASE);
}
}
size_t
VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
if (OnHeap()) {
#ifdef MOZ_MEMORY
return aMallocSizeOf(mBuf);
#else
return mSize;
#endif
}
return 0;
}
VolatileBuffer::~VolatileBuffer()
{
MOZ_ASSERT(mLockCount == 0, "Being destroyed with non-zero lock count?");
if (OnHeap()) {
#ifdef MOZ_MEMORY
free(mBuf);
#else
_aligned_free(mBuf);
#endif
} else {
VirtualFreeEx(GetCurrentProcess(), mBuf, 0, MEM_RELEASE);
}
}
void
VolatileBuffer::Unlock()
{
MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!");
if (--mLockCount || OnHeap()) {
return;
}
void* addr = VirtualAllocEx(GetCurrentProcess(),
mBuf,
mSize,
MEM_RESET,
PAGE_READWRITE);
MOZ_ASSERT(addr, "Failed to MEM_RESET");
}
void
VolatileBuffer::Unlock()
{
MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!");
if (--mLockCount || OnHeap()) {
return;
}
int state = VM_PURGABLE_VOLATILE | VM_VOLATILE_GROUP_DEFAULT;
DebugOnly<kern_return_t> ret =
vm_purgable_control(mach_task_self(),
(vm_address_t)mBuf,
VM_PURGABLE_SET_STATE,
&state);
MOZ_ASSERT(ret == KERN_SUCCESS, "Failed to set buffer as purgable");
}
bool
VolatileBuffer::Lock(void** aBuf)
{
MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer");
*aBuf = mBuf;
if (++mLockCount > 1 || OnHeap()) {
return true;
}
int state = VM_PURGABLE_NONVOLATILE;
kern_return_t ret =
vm_purgable_control(mach_task_self(),
(vm_address_t)mBuf,
VM_PURGABLE_SET_STATE,
&state);
return ret == KERN_SUCCESS && !(state & VM_PURGABLE_EMPTY);
}
size_t
VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
return OnHeap() ? aMallocSizeOf(mBuf) : 0;
}
