1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/memory/mozalloc/VolatileBufferOSX.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,122 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include "VolatileBuffer.h"
1.9 +#include "mozilla/Assertions.h"
1.10 +#include "mozilla/DebugOnly.h"
1.11 +#include "mozilla/mozalloc.h"
1.12 +
1.13 +#include <mach/mach.h>
1.14 +#include <sys/mman.h>
1.15 +#include <unistd.h>
1.16 +
1.17 +#define MIN_VOLATILE_ALLOC_SIZE 8192
1.18 +
1.19 +namespace mozilla {
1.20 +
1.21 +VolatileBuffer::VolatileBuffer()
1.22 + : mBuf(nullptr)
1.23 + , mSize(0)
1.24 + , mLockCount(0)
1.25 + , mHeap(false)
1.26 +{
1.27 +}
1.28 +
1.29 +bool
1.30 +VolatileBuffer::Init(size_t aSize, size_t aAlignment)
1.31 +{
1.32 + MOZ_ASSERT(!mSize && !mBuf, "Init called twice");
1.33 + MOZ_ASSERT(!(aAlignment % sizeof(void *)),
1.34 + "Alignment must be multiple of pointer size");
1.35 +
1.36 + mSize = aSize;
1.37 +
1.38 + kern_return_t ret = 0;
1.39 + if (aSize < MIN_VOLATILE_ALLOC_SIZE) {
1.40 + goto heap_alloc;
1.41 + }
1.42 +
1.43 + ret = vm_allocate(mach_task_self(),
1.44 + (vm_address_t*)&mBuf,
1.45 + mSize,
1.46 + VM_FLAGS_PURGABLE | VM_FLAGS_ANYWHERE);
1.47 + if (ret == KERN_SUCCESS) {
1.48 + return true;
1.49 + }
1.50 +
1.51 +heap_alloc:
1.52 + (void)moz_posix_memalign(&mBuf, aAlignment, aSize);
1.53 + mHeap = true;
1.54 + return !!mBuf;
1.55 +}
1.56 +
1.57 +VolatileBuffer::~VolatileBuffer()
1.58 +{
1.59 + if (OnHeap()) {
1.60 + free(mBuf);
1.61 + } else {
1.62 + vm_deallocate(mach_task_self(), (vm_address_t)mBuf, mSize);
1.63 + }
1.64 +}
1.65 +
1.66 +bool
1.67 +VolatileBuffer::Lock(void** aBuf)
1.68 +{
1.69 + MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer");
1.70 +
1.71 + *aBuf = mBuf;
1.72 + if (++mLockCount > 1 || OnHeap()) {
1.73 + return true;
1.74 + }
1.75 +
1.76 + int state = VM_PURGABLE_NONVOLATILE;
1.77 + kern_return_t ret =
1.78 + vm_purgable_control(mach_task_self(),
1.79 + (vm_address_t)mBuf,
1.80 + VM_PURGABLE_SET_STATE,
1.81 + &state);
1.82 + return ret == KERN_SUCCESS && !(state & VM_PURGABLE_EMPTY);
1.83 +}
1.84 +
1.85 +void
1.86 +VolatileBuffer::Unlock()
1.87 +{
1.88 + MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!");
1.89 + if (--mLockCount || OnHeap()) {
1.90 + return;
1.91 + }
1.92 +
1.93 + int state = VM_PURGABLE_VOLATILE | VM_VOLATILE_GROUP_DEFAULT;
1.94 + DebugOnly<kern_return_t> ret =
1.95 + vm_purgable_control(mach_task_self(),
1.96 + (vm_address_t)mBuf,
1.97 + VM_PURGABLE_SET_STATE,
1.98 + &state);
1.99 + MOZ_ASSERT(ret == KERN_SUCCESS, "Failed to set buffer as purgable");
1.100 +}
1.101 +
1.102 +bool
1.103 +VolatileBuffer::OnHeap() const
1.104 +{
1.105 + return mHeap;
1.106 +}
1.107 +
1.108 +size_t
1.109 +VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
1.110 +{
1.111 + return OnHeap() ? aMallocSizeOf(mBuf) : 0;
1.112 +}
1.113 +
1.114 +size_t
1.115 +VolatileBuffer::NonHeapSizeOfExcludingThis() const
1.116 +{
1.117 + if (OnHeap()) {
1.118 + return 0;
1.119 + }
1.120 +
1.121 + unsigned long pagemask = getpagesize() - 1;
1.122 + return (mSize + pagemask) & ~pagemask;
1.123 +}
1.124 +
1.125 +} // namespace mozilla
