Add sync marker traces to allow fast parsing
Periodically writes a fixed 128 bits sync marker to traces,
every 10s, together with the clock snapshots. This is to
allow concurrent offline processing of traces, by being able to
quickly seek the markers and partitioning the trace.
Test: perfetto_unittests --gtest_filter=*ResynchronizeTraceStreamUsingSyncMarker
Change-Id: If598da06c165210e28416c33aeb5cd00bc84b065
diff --git a/src/tracing/core/tracing_service_impl.h b/src/tracing/core/tracing_service_impl.h
index a4dd848..62961b3 100644
--- a/src/tracing/core/tracing_service_impl.h
+++ b/src/tracing/core/tracing_service_impl.h
@@ -56,6 +56,9 @@
static constexpr size_t kDefaultShmSize = 256 * 1024ul;
static constexpr size_t kMaxShmSize = 32 * 1024 * 1024ul;
static constexpr uint32_t kDataSourceStopTimeoutMs = 5000;
+ static constexpr uint8_t kSyncMarker[] = {0x82, 0x47, 0x7a, 0x76, 0xb2, 0x8d,
+ 0x42, 0xba, 0x81, 0xdc, 0x33, 0x32,
+ 0x6d, 0x57, 0xa0, 0x79};
// The implementation behind the service endpoint exposed to each producer.
class ProducerEndpointImpl : public TracingService::ProducerEndpoint {
@@ -252,11 +255,9 @@
// many entries as |config.buffers_size()|.
std::vector<BufferID> buffers_index;
- // When the last clock snapshot was emitted into the output stream.
- base::TimeMillis last_clock_snapshot = {};
-
- // When the last TraceStats snapshot was emitted into the output stream.
- base::TimeMillis last_stats_snapshot = {};
+ // When the last snapshots (clock, stats, sync marker) were emitted into
+ // the output stream.
+ base::TimeMillis last_snapshot_time = {};
// Whether we mirrored the trace config back to the trace output yet.
bool did_emit_config = false;
@@ -292,9 +293,10 @@
// shared memory and trace buffers.
void UpdateMemoryGuardrail();
- void MaybeSnapshotClocks(TracingSession*, std::vector<TracePacket>*);
+ void SnapshotSyncMarker(std::vector<TracePacket>*);
+ void SnapshotClocks(std::vector<TracePacket>*);
+ void SnapshotStats(TracingSession*, std::vector<TracePacket>*);
void MaybeEmitTraceConfig(TracingSession*, std::vector<TracePacket>*);
- void MaybeSnapshotStats(TracingSession*, std::vector<TracePacket>*);
void OnFlushTimeout(TracingSessionID, FlushRequestID);
void OnDisableTracingTimeout(TracingSessionID);
void DisableTracingNotifyConsumerAndFlushFile(TracingSession*);
@@ -319,6 +321,10 @@
std::map<BufferID, std::unique_ptr<TraceBuffer>> buffers_;
bool lockdown_mode_ = false;
+ uint32_t min_write_period_ms_ = 100; // Overridable for testing.
+
+ uint8_t sync_marker_packet_[32]; // Lazily initialized.
+ size_t sync_marker_packet_size_ = 0;
PERFETTO_THREAD_CHECKER(thread_checker_)