From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- .../public/ProfileBufferChunkManagerSingle.h | 172 +++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h (limited to 'mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h') diff --git a/mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h b/mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h new file mode 100644 index 0000000000..c91b38cbdb --- /dev/null +++ b/mozglue/baseprofiler/public/ProfileBufferChunkManagerSingle.h @@ -0,0 +1,172 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/. */ + +#ifndef ProfileBufferChunkManagerSingle_h +#define ProfileBufferChunkManagerSingle_h + +#include "mozilla/ProfileBufferChunkManager.h" + +#ifdef DEBUG +# include "mozilla/Atomics.h" +#endif // DEBUG + +namespace mozilla { + +// Manages only one Chunk. +// The first call to `Get`/`RequestChunk()` will retrieve the one chunk, and all +// subsequent calls will return nullptr. That chunk may still be released, but +// it will never be destroyed or recycled. +// Unlike others, this manager may be `Reset()`, to allow another round of +// small-data gathering. +// The main use is with short-lived ProfileChunkedBuffers that collect little +// data that can fit in one chunk, e.g., capturing one stack. +// It is not thread-safe. +class ProfileBufferChunkManagerSingle final : public ProfileBufferChunkManager { + public: + using Length = ProfileBufferChunk::Length; + + // Use a preallocated chunk. (Accepting null to gracefully handle OOM.) + explicit ProfileBufferChunkManagerSingle(UniquePtr aChunk) + : mInitialChunk(std::move(aChunk)), + mBufferBytes(mInitialChunk ? mInitialChunk->BufferBytes() : 0) { + MOZ_ASSERT(!mInitialChunk || !mInitialChunk->GetNext(), + "Expected at most one chunk"); + } + + // ChunkMinBufferBytes: Minimum number of user-available bytes in the Chunk. + // Note that Chunks use a bit more memory for their header. + explicit ProfileBufferChunkManagerSingle(Length aChunkMinBufferBytes) + : mInitialChunk(ProfileBufferChunk::Create(aChunkMinBufferBytes)), + mBufferBytes(mInitialChunk ? mInitialChunk->BufferBytes() : 0) {} + +#ifdef DEBUG + ~ProfileBufferChunkManagerSingle() { MOZ_ASSERT(mVirtuallyLocked == false); } +#endif // DEBUG + + // Reset this manager, using the provided chunk (probably coming from the + // ProfileChunkedBuffer that just used it); if null, fallback on current or + // released chunk. + void Reset(UniquePtr aPossibleChunk) { + if (aPossibleChunk) { + mInitialChunk = std::move(aPossibleChunk); + mReleasedChunk = nullptr; + } else if (!mInitialChunk) { + MOZ_ASSERT(!!mReleasedChunk, "Can't reset properly!"); + mInitialChunk = std::move(mReleasedChunk); + } + + if (mInitialChunk) { + mInitialChunk->MarkRecycled(); + mBufferBytes = mInitialChunk->BufferBytes(); + } else { + mBufferBytes = 0; + } + } + + [[nodiscard]] size_t MaxTotalSize() const final { return mBufferBytes; } + + // One of `GetChunk` and `RequestChunk` will only work the very first time (if + // there's even a chunk). + [[nodiscard]] UniquePtr GetChunk() final { + MOZ_ASSERT(mUser, "Not registered yet"); + return std::move(mInitialChunk); + } + + void RequestChunk(std::function)>&& + aChunkReceiver) final { + MOZ_ASSERT(mUser, "Not registered yet"); + // Simple retrieval. + std::move(aChunkReceiver)(GetChunk()); + } + + void FulfillChunkRequests() final { + // Nothing to do here. + } + + void ReleaseChunk(UniquePtr aChunk) final { + MOZ_ASSERT(mUser, "Not registered yet"); + if (!aChunk) { + return; + } + MOZ_ASSERT(!mReleasedChunk, "Unexpected 2nd released chunk"); + MOZ_ASSERT(!aChunk->GetNext(), "Only expected one released chunk"); + mReleasedChunk = std::move(aChunk); + } + + void SetChunkDestroyedCallback( + std::function&& aChunkDestroyedCallback) + final { + MOZ_ASSERT(mUser, "Not registered yet"); + // The chunk-destroyed callback will never actually be called, but we keep + // the callback here in case the caller expects it to live as long as this + // manager. + mChunkDestroyedCallback = std::move(aChunkDestroyedCallback); + } + + [[nodiscard]] UniquePtr GetExtantReleasedChunks() final { + MOZ_ASSERT(mUser, "Not registered yet"); + return std::move(mReleasedChunk); + } + + void ForgetUnreleasedChunks() final { + MOZ_ASSERT(mUser, "Not registered yet"); + } + + [[nodiscard]] size_t SizeOfExcludingThis( + MallocSizeOf aMallocSizeOf) const final { + MOZ_ASSERT(mUser, "Not registered yet"); + size_t size = 0; + if (mInitialChunk) { + size += mInitialChunk->SizeOfIncludingThis(aMallocSizeOf); + } + if (mReleasedChunk) { + size += mReleasedChunk->SizeOfIncludingThis(aMallocSizeOf); + } + // Note: Missing size of std::function external resources (if any). + return size; + } + + [[nodiscard]] size_t SizeOfIncludingThis( + MallocSizeOf aMallocSizeOf) const final { + MOZ_ASSERT(mUser, "Not registered yet"); + return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf); + } + + protected: + // This manager is not thread-safe, so there's not actual locking needed. + const ProfileBufferChunk* PeekExtantReleasedChunksAndLock() final { + MOZ_ASSERT(mVirtuallyLocked.compareExchange(false, true)); + MOZ_ASSERT(mUser, "Not registered yet"); + return mReleasedChunk.get(); + } + void UnlockAfterPeekExtantReleasedChunks() final { + MOZ_ASSERT(mVirtuallyLocked.compareExchange(true, false)); + } + + private: + // Initial chunk created with this manager, given away at first Get/Request. + UniquePtr mInitialChunk; + + // Storage for the released chunk (which should probably not happen, as it + // means the chunk is full). + UniquePtr mReleasedChunk; + + // Size of the one chunk we're managing. Stored here, because the chunk may + // be moved out and inaccessible from here. + Length mBufferBytes; + + // The chunk-destroyed callback will never actually be called, but we keep it + // here in case the caller expects it to live as long as this manager. + std::function mChunkDestroyedCallback; + +#ifdef DEBUG + mutable Atomic mVirtuallyLocked{false}; +#endif // DEBUG +}; + +} // namespace mozilla + +#endif // ProfileBufferChunkManagerSingle_h -- cgit v1.2.3