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comparison: memory/mozalloc/VolatileBufferOSX.cpp
memory/mozalloc/VolatileBufferOSX.cpp
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| -1:000000000000 | 0:ad6161b87256 |
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| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 #include "VolatileBuffer.h" | |
| 6 #include "mozilla/Assertions.h" | |
| 7 #include "mozilla/DebugOnly.h" | |
| 8 #include "mozilla/mozalloc.h" | |
| 9 | |
| 10 #include <mach/mach.h> | |
| 11 #include <sys/mman.h> | |
| 12 #include <unistd.h> | |
| 13 | |
| 14 #define MIN_VOLATILE_ALLOC_SIZE 8192 | |
| 15 | |
| 16 namespace mozilla { | |
| 17 | |
| 18 VolatileBuffer::VolatileBuffer() | |
| 19 : mBuf(nullptr) | |
| 20 , mSize(0) | |
| 21 , mLockCount(0) | |
| 22 , mHeap(false) | |
| 23 { | |
| 24 } | |
| 25 | |
| 26 bool | |
| 27 VolatileBuffer::Init(size_t aSize, size_t aAlignment) | |
| 28 { | |
| 29 MOZ_ASSERT(!mSize && !mBuf, "Init called twice"); | |
| 30 MOZ_ASSERT(!(aAlignment % sizeof(void *)), | |
| 31 "Alignment must be multiple of pointer size"); | |
| 32 | |
| 33 mSize = aSize; | |
| 34 | |
| 35 kern_return_t ret = 0; | |
| 36 if (aSize < MIN_VOLATILE_ALLOC_SIZE) { | |
| 37 goto heap_alloc; | |
| 38 } | |
| 39 | |
| 40 ret = vm_allocate(mach_task_self(), | |
| 41 (vm_address_t*)&mBuf, | |
| 42 mSize, | |
| 43 VM_FLAGS_PURGABLE | VM_FLAGS_ANYWHERE); | |
| 44 if (ret == KERN_SUCCESS) { | |
| 45 return true; | |
| 46 } | |
| 47 | |
| 48 heap_alloc: | |
| 49 (void)moz_posix_memalign(&mBuf, aAlignment, aSize); | |
| 50 mHeap = true; | |
| 51 return !!mBuf; | |
| 52 } | |
| 53 | |
| 54 VolatileBuffer::~VolatileBuffer() | |
| 55 { | |
| 56 if (OnHeap()) { | |
| 57 free(mBuf); | |
| 58 } else { | |
| 59 vm_deallocate(mach_task_self(), (vm_address_t)mBuf, mSize); | |
| 60 } | |
| 61 } | |
| 62 | |
| 63 bool | |
| 64 VolatileBuffer::Lock(void** aBuf) | |
| 65 { | |
| 66 MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer"); | |
| 67 | |
| 68 *aBuf = mBuf; | |
| 69 if (++mLockCount > 1 || OnHeap()) { | |
| 70 return true; | |
| 71 } | |
| 72 | |
| 73 int state = VM_PURGABLE_NONVOLATILE; | |
| 74 kern_return_t ret = | |
| 75 vm_purgable_control(mach_task_self(), | |
| 76 (vm_address_t)mBuf, | |
| 77 VM_PURGABLE_SET_STATE, | |
| 78 &state); | |
| 79 return ret == KERN_SUCCESS && !(state & VM_PURGABLE_EMPTY); | |
| 80 } | |
| 81 | |
| 82 void | |
| 83 VolatileBuffer::Unlock() | |
| 84 { | |
| 85 MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!"); | |
| 86 if (--mLockCount || OnHeap()) { | |
| 87 return; | |
| 88 } | |
| 89 | |
| 90 int state = VM_PURGABLE_VOLATILE | VM_VOLATILE_GROUP_DEFAULT; | |
| 91 DebugOnly<kern_return_t> ret = | |
| 92 vm_purgable_control(mach_task_self(), | |
| 93 (vm_address_t)mBuf, | |
| 94 VM_PURGABLE_SET_STATE, | |
| 95 &state); | |
| 96 MOZ_ASSERT(ret == KERN_SUCCESS, "Failed to set buffer as purgable"); | |
| 97 } | |
| 98 | |
| 99 bool | |
| 100 VolatileBuffer::OnHeap() const | |
| 101 { | |
| 102 return mHeap; | |
| 103 } | |
| 104 | |
| 105 size_t | |
| 106 VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const | |
| 107 { | |
| 108 return OnHeap() ? aMallocSizeOf(mBuf) : 0; | |
| 109 } | |
| 110 | |
| 111 size_t | |
| 112 VolatileBuffer::NonHeapSizeOfExcludingThis() const | |
| 113 { | |
| 114 if (OnHeap()) { | |
| 115 return 0; | |
| 116 } | |
| 117 | |
| 118 unsigned long pagemask = getpagesize() - 1; | |
| 119 return (mSize + pagemask) & ~pagemask; | |
| 120 } | |
| 121 | |
| 122 } // namespace mozilla |
