1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "base/debug/task_annotator.h"
7 #include "base/debug/alias.h"
8 #include "base/debug/trace_event.h"
9 #include "base/pending_task.h"
10 #include "base/tracked_objects.h"
15 TaskAnnotator::TaskAnnotator() {
18 TaskAnnotator::~TaskAnnotator() {
21 void TaskAnnotator::DidQueueTask(const char* queue_function,
22 const PendingTask& pending_task) {
23 TRACE_EVENT_FLOW_BEGIN0(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"),
25 TRACE_ID_MANGLE(GetTaskTraceID(pending_task)));
28 void TaskAnnotator::RunTask(const char* queue_function,
29 const char* run_function,
30 const PendingTask& pending_task) {
31 tracked_objects::ThreadData::PrepareForStartOfRun(pending_task.birth_tally);
32 tracked_objects::TaskStopwatch stopwatch;
33 tracked_objects::Duration queue_duration =
34 stopwatch.StartTime() - pending_task.EffectiveTimePosted();
36 TRACE_EVENT_FLOW_END1(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"),
38 TRACE_ID_MANGLE(GetTaskTraceID(pending_task)),
40 queue_duration.InMilliseconds());
42 // When tracing memory for posted tasks it's more valuable to attribute the
43 // memory allocations to the source function than generically to the task
45 TRACE_EVENT_WITH_MEMORY_TAG2(
48 pending_task.posted_from.function_name(), // Name for memory tracking.
50 pending_task.posted_from.file_name(),
52 pending_task.posted_from.function_name());
54 // Before running the task, store the program counter where it was posted
55 // and deliberately alias it to ensure it is on the stack if the task
56 // crashes. Be careful not to assume that the variable itself will have the
57 // expected value when displayed by the optimizer in an optimized build.
58 // Look at a memory dump of the stack.
59 const void* program_counter = pending_task.posted_from.program_counter();
60 debug::Alias(&program_counter);
62 pending_task.task.Run();
65 tracked_objects::ThreadData::TallyRunOnNamedThreadIfTracking(
66 pending_task, stopwatch);
69 uint64 TaskAnnotator::GetTaskTraceID(const PendingTask& task) const {
70 return (static_cast<uint64>(task.sequence_num) << 32) |
71 ((static_cast<uint64>(reinterpret_cast<intptr_t>(this)) << 32) >> 32);