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comparison: memory/mozalloc/VolatileBufferAshmem.cpp
memory/mozalloc/VolatileBufferAshmem.cpp
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| -1:000000000000 | 0:a7627815c0a7 |
|---|---|
| 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/NullPtr.h" | |
| 8 #include "mozilla/mozalloc.h" | |
| 9 | |
| 10 #include <fcntl.h> | |
| 11 #include <linux/ashmem.h> | |
| 12 #include <sys/mman.h> | |
| 13 #include <sys/stat.h> | |
| 14 #include <sys/types.h> | |
| 15 #include <unistd.h> | |
| 16 | |
| 17 #ifdef MOZ_MEMORY | |
| 18 #ifdef MOZ_WIDGET_ANDROID | |
| 19 extern "C" int __wrap_posix_memalign(void** memptr, size_t alignment, size_t size); | |
| 20 #else | |
| 21 extern "C" int posix_memalign(void** memptr, size_t alignment, size_t size); | |
| 22 #endif | |
| 23 #endif | |
| 24 | |
| 25 #define MIN_VOLATILE_ALLOC_SIZE 8192 | |
| 26 | |
| 27 namespace mozilla { | |
| 28 | |
| 29 VolatileBuffer::VolatileBuffer() | |
| 30 : mBuf(nullptr) | |
| 31 , mSize(0) | |
| 32 , mLockCount(0) | |
| 33 , mFd(-1) | |
| 34 { | |
| 35 } | |
| 36 | |
| 37 bool | |
| 38 VolatileBuffer::Init(size_t aSize, size_t aAlignment) | |
| 39 { | |
| 40 MOZ_ASSERT(!mSize && !mBuf, "Init called twice"); | |
| 41 MOZ_ASSERT(!(aAlignment % sizeof(void *)), | |
| 42 "Alignment must be multiple of pointer size"); | |
| 43 | |
| 44 mSize = aSize; | |
| 45 if (aSize < MIN_VOLATILE_ALLOC_SIZE) { | |
| 46 goto heap_alloc; | |
| 47 } | |
| 48 | |
| 49 mFd = open("/" ASHMEM_NAME_DEF, O_RDWR); | |
| 50 if (mFd < 0) { | |
| 51 goto heap_alloc; | |
| 52 } | |
| 53 | |
| 54 if (ioctl(mFd, ASHMEM_SET_SIZE, mSize) < 0) { | |
| 55 close(mFd); | |
| 56 mFd = -1; | |
| 57 goto heap_alloc; | |
| 58 } | |
| 59 | |
| 60 mBuf = mmap(nullptr, mSize, PROT_READ | PROT_WRITE, MAP_SHARED, mFd, 0); | |
| 61 if (mBuf != MAP_FAILED) { | |
| 62 return true; | |
| 63 } | |
| 64 | |
| 65 heap_alloc: | |
| 66 #ifdef MOZ_MEMORY | |
| 67 #ifdef MOZ_WIDGET_ANDROID | |
| 68 __wrap_posix_memalign(&mBuf, aAlignment, aSize); | |
| 69 #else | |
| 70 posix_memalign(&mBuf, aAlignment, aSize); | |
| 71 #endif | |
| 72 #else | |
| 73 mBuf = memalign(aAlignment, aSize); | |
| 74 #endif | |
| 75 return !!mBuf; | |
| 76 } | |
| 77 | |
| 78 VolatileBuffer::~VolatileBuffer() | |
| 79 { | |
| 80 if (OnHeap()) { | |
| 81 free(mBuf); | |
| 82 } else { | |
| 83 munmap(mBuf, mSize); | |
| 84 close(mFd); | |
| 85 } | |
| 86 } | |
| 87 | |
| 88 bool | |
| 89 VolatileBuffer::Lock(void** aBuf) | |
| 90 { | |
| 91 MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer"); | |
| 92 | |
| 93 *aBuf = mBuf; | |
| 94 if (++mLockCount > 1 || OnHeap()) { | |
| 95 return true; | |
| 96 } | |
| 97 | |
| 98 // Zero offset and zero length means we want to pin/unpin the entire thing. | |
| 99 struct ashmem_pin pin = { 0, 0 }; | |
| 100 return ioctl(mFd, ASHMEM_PIN, &pin) == ASHMEM_NOT_PURGED; | |
| 101 } | |
| 102 | |
| 103 void | |
| 104 VolatileBuffer::Unlock() | |
| 105 { | |
| 106 MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!"); | |
| 107 if (--mLockCount || OnHeap()) { | |
| 108 return; | |
| 109 } | |
| 110 | |
| 111 struct ashmem_pin pin = { 0, 0 }; | |
| 112 ioctl(mFd, ASHMEM_UNPIN, &pin); | |
| 113 } | |
| 114 | |
| 115 bool | |
| 116 VolatileBuffer::OnHeap() const | |
| 117 { | |
| 118 return mFd < 0; | |
| 119 } | |
| 120 | |
| 121 size_t | |
| 122 VolatileBuffer::HeapSizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const | |
| 123 { | |
| 124 return OnHeap() ? aMallocSizeOf(mBuf) : 0; | |
| 125 } | |
| 126 | |
| 127 size_t | |
| 128 VolatileBuffer::NonHeapSizeOfExcludingThis() const | |
| 129 { | |
| 130 if (OnHeap()) { | |
| 131 return 0; | |
| 132 } | |
| 133 | |
| 134 return (mSize + (PAGE_SIZE - 1)) & PAGE_MASK; | |
| 135 } | |
| 136 | |
| 137 } // namespace mozilla |
