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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /memory/volatile/VolatileBufferAshmem.cpp | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream/115.8.0esr.tar.xz firefox-esr-upstream/115.8.0esr.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'memory/volatile/VolatileBufferAshmem.cpp')
-rw-r--r-- | memory/volatile/VolatileBufferAshmem.cpp | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/memory/volatile/VolatileBufferAshmem.cpp b/memory/volatile/VolatileBufferAshmem.cpp new file mode 100644 index 0000000000..99a0d1307f --- /dev/null +++ b/memory/volatile/VolatileBufferAshmem.cpp @@ -0,0 +1,120 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "VolatileBuffer.h" +#include "mozilla/Assertions.h" +#include "mozilla/mozalloc.h" + +#include <fcntl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include "mozilla/Ashmem.h" + +#ifdef MOZ_MEMORY +extern "C" int posix_memalign(void** memptr, size_t alignment, size_t size); +#endif + +#define MIN_VOLATILE_ALLOC_SIZE 8192 + +namespace mozilla { + +VolatileBuffer::VolatileBuffer() + : mMutex("VolatileBuffer"), + mBuf(nullptr), + mSize(0), + mLockCount(0), + mFd(-1) {} + +bool VolatileBuffer::Init(size_t aSize, size_t aAlignment) { + MOZ_ASSERT(!mSize && !mBuf, "Init called twice"); + MOZ_ASSERT(!(aAlignment % sizeof(void*)), + "Alignment must be multiple of pointer size"); + + mSize = aSize; + if (aSize < MIN_VOLATILE_ALLOC_SIZE) { + goto heap_alloc; + } + + mFd = mozilla::android::ashmem_create(nullptr, mSize); + if (mFd < 0) { + goto heap_alloc; + } + + mBuf = mmap(nullptr, mSize, PROT_READ | PROT_WRITE, MAP_SHARED, mFd, 0); + if (mBuf != MAP_FAILED) { + return true; + } + +heap_alloc: + mBuf = nullptr; + if (mFd >= 0) { + close(mFd); + mFd = -1; + } + +#ifdef MOZ_MEMORY + posix_memalign(&mBuf, aAlignment, aSize); +#else + mBuf = memalign(aAlignment, aSize); +#endif + return !!mBuf; +} + +VolatileBuffer::~VolatileBuffer() { + MOZ_ASSERT(mLockCount == 0, "Being destroyed with non-zero lock count?"); + + if (OnHeap()) { + free(mBuf); + } else { + munmap(mBuf, mSize); + close(mFd); + } +} + +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; + } + + // Zero offset and zero length means we want to pin/unpin the entire thing. + struct ashmem_pin pin = {0, 0}; + return ioctl(mFd, ASHMEM_PIN, &pin) == ASHMEM_NOT_PURGED; +} + +void VolatileBuffer::Unlock() { + MutexAutoLock lock(mMutex); + + MOZ_ASSERT(mLockCount > 0, "VolatileBuffer unlocked too many times!"); + if (--mLockCount || OnHeap()) { + return; + } + + struct ashmem_pin pin = {0, 0}; + ioctl(mFd, ASHMEM_UNPIN, &pin); +} + +bool VolatileBuffer::OnHeap() const { return mFd < 0; } + +size_t VolatileBuffer::HeapSizeOfExcludingThis( + MallocSizeOf aMallocSizeOf) const { + return OnHeap() ? aMallocSizeOf(mBuf) : 0; +} + +size_t VolatileBuffer::NonHeapSizeOfExcludingThis() const { + if (OnHeap()) { + return 0; + } + + return (mSize + (PAGE_SIZE - 1)) & PAGE_MASK; +} + +} // namespace mozilla |