From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- dom/media/MemoryBlockCache.cpp | 213 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) create mode 100644 dom/media/MemoryBlockCache.cpp (limited to 'dom/media/MemoryBlockCache.cpp') diff --git a/dom/media/MemoryBlockCache.cpp b/dom/media/MemoryBlockCache.cpp new file mode 100644 index 0000000000..2848a3f381 --- /dev/null +++ b/dom/media/MemoryBlockCache.cpp @@ -0,0 +1,213 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim:set ts=2 sw=2 sts=2 et cindent: */ +/* 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 "MemoryBlockCache.h" + +#include "mozilla/Atomics.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/Logging.h" +#include "mozilla/Services.h" +#include "mozilla/StaticPrefs_media.h" +#include "nsWeakReference.h" +#include "prsystem.h" + +namespace mozilla { + +#undef LOG +LazyLogModule gMemoryBlockCacheLog("MemoryBlockCache"); +#define LOG(x, ...) \ + MOZ_LOG(gMemoryBlockCacheLog, LogLevel::Debug, ("%p " x, this, ##__VA_ARGS__)) + +// Combined sizes of all MemoryBlockCache buffers. +// Initialized to 0 by non-local static initialization. +// Increases when a buffer grows (during initialization or unexpected OOB +// writes), decreases when a MemoryBlockCache (with its buffer) is destroyed. +static Atomic gCombinedSizes; + +static int32_t CalculateMaxBlocks(int64_t aContentLength) { + int64_t maxSize = int64_t(StaticPrefs::media_memory_cache_max_size()) * 1024; + MOZ_ASSERT(aContentLength <= maxSize); + MOZ_ASSERT(maxSize % MediaBlockCacheBase::BLOCK_SIZE == 0); + // Note: It doesn't matter if calculations overflow, Init() would later fail. + // We want at least enough blocks to contain the original content length. + const int32_t requiredBlocks = maxSize / MediaBlockCacheBase::BLOCK_SIZE; + // Allow at least 1s of ultra HD (25Mbps). + const int32_t workableBlocks = + 25 * 1024 * 1024 / 8 / MediaBlockCacheBase::BLOCK_SIZE; + return std::max(requiredBlocks, workableBlocks); +} + +MemoryBlockCache::MemoryBlockCache(int64_t aContentLength) + // Buffer whole blocks. + : mInitialContentLength((aContentLength >= 0) ? size_t(aContentLength) : 0), + mMaxBlocks(CalculateMaxBlocks(aContentLength)), + mMutex("MemoryBlockCache"), + mHasGrown(false) { + if (aContentLength <= 0) { + LOG("MemoryBlockCache() MEMORYBLOCKCACHE_ERRORS='InitUnderuse'"); + } +} + +MemoryBlockCache::~MemoryBlockCache() { + MOZ_ASSERT(gCombinedSizes >= mBuffer.Length()); + size_t sizes = static_cast(gCombinedSizes -= mBuffer.Length()); + LOG("~MemoryBlockCache() - destroying buffer of size %zu; combined sizes now " + "%zu", + mBuffer.Length(), sizes); +} + +bool MemoryBlockCache::EnsureBufferCanContain(size_t aContentLength) { + mMutex.AssertCurrentThreadOwns(); + if (aContentLength == 0) { + return true; + } + const size_t initialLength = mBuffer.Length(); + const size_t desiredLength = + ((aContentLength - 1) / BLOCK_SIZE + 1) * BLOCK_SIZE; + if (initialLength >= desiredLength) { + // Already large enough. + return true; + } + // Need larger buffer. If we are allowed more memory, attempt to re-allocate. + const size_t extra = desiredLength - initialLength; + // Only check the very first allocation against the combined MemoryBlockCache + // limit. Further growths will always be allowed, assuming MediaCache won't + // go over GetMaxBlocks() by too much. + if (initialLength == 0) { + // Note: There is a small race between testing `atomic + extra > limit` and + // committing to it with `atomic += extra` below; but this is acceptable, as + // in the worst case it may allow a small number of buffers to go past the + // limit. + // The alternative would have been to reserve the space first with + // `atomic += extra` and then undo it with `atomic -= extra` in case of + // failure; but this would have meant potentially preventing other (small + // but successful) allocations. + static const size_t sysmem = + std::max(PR_GetPhysicalMemorySize(), 32 * 1024 * 1024); + const size_t limit = std::min( + size_t(StaticPrefs::media_memory_caches_combined_limit_kb()) * 1024, + sysmem * StaticPrefs::media_memory_caches_combined_limit_pc_sysmem() / + 100); + const size_t currentSizes = static_cast(gCombinedSizes); + if (currentSizes + extra > limit) { + LOG("EnsureBufferCanContain(%zu) - buffer size %zu, wanted + %zu = %zu;" + " combined sizes %zu + %zu > limit %zu", + aContentLength, initialLength, extra, desiredLength, currentSizes, + extra, limit); + return false; + } + } + if (!mBuffer.SetLength(desiredLength, mozilla::fallible)) { + LOG("EnsureBufferCanContain(%zu) - buffer size %zu, wanted + %zu = %zu, " + "allocation failed", + aContentLength, initialLength, extra, desiredLength); + return false; + } + MOZ_ASSERT(mBuffer.Length() == desiredLength); + const size_t capacity = mBuffer.Capacity(); + const size_t extraCapacity = capacity - desiredLength; + if (extraCapacity != 0) { + // Our buffer was given a larger capacity than the requested length, we may + // as well claim that extra capacity, both for our accounting, and to + // possibly bypass some future growths that would fit in this new capacity. + mBuffer.SetLength(capacity); + } + const size_t newSizes = gCombinedSizes += (extra + extraCapacity); + LOG("EnsureBufferCanContain(%zu) - buffer size %zu + requested %zu + bonus " + "%zu = %zu; combined sizes %zu", + aContentLength, initialLength, extra, extraCapacity, capacity, newSizes); + mHasGrown = true; + return true; +} + +nsresult MemoryBlockCache::Init() { + LOG("Init()"); + MutexAutoLock lock(mMutex); + MOZ_ASSERT(mBuffer.IsEmpty()); + // Attempt to pre-allocate buffer for expected content length. + if (!EnsureBufferCanContain(mInitialContentLength)) { + LOG("Init() MEMORYBLOCKCACHE_ERRORS='InitAllocation'"); + return NS_ERROR_FAILURE; + } + return NS_OK; +} + +void MemoryBlockCache::Flush() { + LOG("Flush()"); + MutexAutoLock lock(mMutex); + MOZ_ASSERT(mBuffer.Length() >= mInitialContentLength); + memset(mBuffer.Elements(), 0, mBuffer.Length()); + mHasGrown = false; +} + +nsresult MemoryBlockCache::WriteBlock(uint32_t aBlockIndex, + Span aData1, + Span aData2) { + MutexAutoLock lock(mMutex); + + size_t offset = BlockIndexToOffset(aBlockIndex); + if (offset + aData1.Length() + aData2.Length() > mBuffer.Length() && + !mHasGrown) { + LOG("WriteBlock() MEMORYBLOCKCACHE_ERRORS='WriteBlockOverflow'"); + } + if (!EnsureBufferCanContain(offset + aData1.Length() + aData2.Length())) { + LOG("WriteBlock() MEMORYBLOCKCACHE_ERRORS='WriteBlockCannotGrow'"); + return NS_ERROR_FAILURE; + } + + memcpy(mBuffer.Elements() + offset, aData1.Elements(), aData1.Length()); + if (aData2.Length() > 0) { + memcpy(mBuffer.Elements() + offset + aData1.Length(), aData2.Elements(), + aData2.Length()); + } + + return NS_OK; +} + +nsresult MemoryBlockCache::Read(int64_t aOffset, uint8_t* aData, + int32_t aLength, int32_t* aBytes) { + MutexAutoLock lock(mMutex); + + MOZ_ASSERT(aOffset >= 0); + if (aOffset + aLength > int64_t(mBuffer.Length())) { + LOG("Read() MEMORYBLOCKCACHE_ERRORS='ReadOverrun'"); + return NS_ERROR_FAILURE; + } + + memcpy(aData, mBuffer.Elements() + aOffset, aLength); + *aBytes = aLength; + + return NS_OK; +} + +nsresult MemoryBlockCache::MoveBlock(int32_t aSourceBlockIndex, + int32_t aDestBlockIndex) { + MutexAutoLock lock(mMutex); + + size_t sourceOffset = BlockIndexToOffset(aSourceBlockIndex); + size_t destOffset = BlockIndexToOffset(aDestBlockIndex); + if (sourceOffset + BLOCK_SIZE > mBuffer.Length()) { + LOG("MoveBlock() MEMORYBLOCKCACHE_ERRORS='MoveBlockSourceOverrun'"); + return NS_ERROR_FAILURE; + } + if (destOffset + BLOCK_SIZE > mBuffer.Length() && !mHasGrown) { + LOG("MoveBlock() MEMORYBLOCKCACHE_ERRORS='MoveBlockDestOverflow'"); + } + if (!EnsureBufferCanContain(destOffset + BLOCK_SIZE)) { + LOG("MoveBlock() MEMORYBLOCKCACHE_ERRORS='MoveBlockCannotGrow'"); + return NS_ERROR_FAILURE; + } + + memcpy(mBuffer.Elements() + destOffset, mBuffer.Elements() + sourceOffset, + BLOCK_SIZE); + + return NS_OK; +} + +} // End namespace mozilla. + +// avoid redefined macro in unified build +#undef LOG -- cgit v1.2.3