trace_buffer.cc | Explore in Territory

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "src/tracing/service/trace_buffer.h"

#include <limits>

#include "perfetto/base/logging.h"
#include "perfetto/ext/base/utils.h"
#include "perfetto/ext/tracing/core/client_identity.h"
#include "perfetto/ext/tracing/core/shared_memory_abi.h"
#include "perfetto/ext/tracing/core/trace_packet.h"
#include "perfetto/protozero/proto_utils.h"

#define TRACE_BUFFER_VERBOSE_LOGGING() …
#if TRACE_BUFFER_VERBOSE_LOGGING()
#define TRACE_BUFFER_DLOG …
#else
#define TRACE_BUFFER_DLOG(...) …
#endif

namespace perfetto {

namespace {
constexpr uint8_t kFirstPacketContinuesFromPrevChunk = …;
constexpr uint8_t kLastPacketContinuesOnNextChunk = …;
constexpr uint8_t kChunkNeedsPatching = …;
}  // namespace.

const size_t TraceBuffer::InlineChunkHeaderSize = …;

// static
std::unique_ptr<TraceBuffer> TraceBuffer::Create(size_t size_in_bytes,
                                                 OverwritePolicy pol) { … }

TraceBuffer::TraceBuffer(OverwritePolicy pol) : … { … }

TraceBuffer::~TraceBuffer() = default;

bool TraceBuffer::Initialize(size_t size) { … }

// Note: |src| points to a shmem region that is shared with the producer. Assume
// that the producer is malicious and will change the content of |src|
// while we execute here. Don't do any processing on it other than memcpy().
void TraceBuffer::CopyChunkUntrusted(
    ProducerID producer_id_trusted,
    const ClientIdentity& client_identity_trusted,
    WriterID writer_id,
    ChunkID chunk_id,
    uint16_t num_fragments,
    uint8_t chunk_flags,
    bool chunk_complete,
    const uint8_t* src,
    size_t size) { … }

ssize_t TraceBuffer::DeleteNextChunksFor(size_t bytes_to_clear) { … }

void TraceBuffer::AddPaddingRecord(size_t size) { … }

bool TraceBuffer::TryPatchChunkContents(ProducerID producer_id,
                                        WriterID writer_id,
                                        ChunkID chunk_id,
                                        const Patch* patches,
                                        size_t patches_size,
                                        bool other_patches_pending) { … }

void TraceBuffer::BeginRead() { … }

TraceBuffer::SequenceIterator TraceBuffer::GetReadIterForSequence(
    ChunkMap::iterator seq_begin) { … }

void TraceBuffer::SequenceIterator::MoveNext() { … }

bool TraceBuffer::ReadNextTracePacket(
    TracePacket* packet,
    PacketSequenceProperties* sequence_properties,
    bool* previous_packet_on_sequence_dropped) { … }

TraceBuffer::ReadAheadResult TraceBuffer::ReadAhead(TracePacket* packet) { … }

TraceBuffer::ReadPacketResult TraceBuffer::ReadNextPacketInChunk(
    ProducerAndWriterID producer_and_writer_id,
    ChunkMeta* const chunk_meta,
    TracePacket* packet) { … }

void TraceBuffer::DiscardWrite() { … }

std::unique_ptr<TraceBuffer> TraceBuffer::CloneReadOnly() const { … }

TraceBuffer::TraceBuffer(CloneCtor, const TraceBuffer& src)
    : … { … }

}  // namespace perfetto
chromium/third_party/perfetto/src/tracing/service/trace_buffer.cc
