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.
4
5 #include "base/debug/task_annotator.h"
6
7 #include "base/debug/alias.h"
8 #include "base/pending_task.h"
9 #include "base/trace_event/trace_event.h"
10 #include "base/tracked_objects.h"
11
12 namespace base {
13 namespace debug {
14
TaskAnnotator()15 TaskAnnotator::TaskAnnotator() {
16 }
17
~TaskAnnotator()18 TaskAnnotator::~TaskAnnotator() {
19 }
20
DidQueueTask(const char * queue_function,const PendingTask & pending_task)21 void TaskAnnotator::DidQueueTask(const char* queue_function,
22 const PendingTask& pending_task) {
23 TRACE_EVENT_WITH_FLOW0(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"),
24 queue_function,
25 TRACE_ID_MANGLE(GetTaskTraceID(pending_task)),
26 TRACE_EVENT_FLAG_FLOW_OUT);
27 }
28
RunTask(const char * queue_function,const PendingTask & pending_task)29 void TaskAnnotator::RunTask(const char* queue_function,
30 const PendingTask& pending_task) {
31 tracked_objects::TaskStopwatch stopwatch;
32 stopwatch.Start();
33 tracked_objects::Duration queue_duration =
34 stopwatch.StartTime() - pending_task.EffectiveTimePosted();
35
36 TRACE_EVENT_WITH_FLOW1(TRACE_DISABLED_BY_DEFAULT("toplevel.flow"),
37 queue_function,
38 TRACE_ID_MANGLE(GetTaskTraceID(pending_task)),
39 TRACE_EVENT_FLAG_FLOW_IN,
40 "queue_duration",
41 queue_duration.InMilliseconds());
42
43 // Before running the task, store the program counter where it was posted
44 // and deliberately alias it to ensure it is on the stack if the task
45 // crashes. Be careful not to assume that the variable itself will have the
46 // expected value when displayed by the optimizer in an optimized build.
47 // Look at a memory dump of the stack.
48 const void* program_counter = pending_task.posted_from.program_counter();
49 debug::Alias(&program_counter);
50
51 pending_task.task.Run();
52
53 stopwatch.Stop();
54 tracked_objects::ThreadData::TallyRunOnNamedThreadIfTracking(
55 pending_task, stopwatch);
56 }
57
GetTaskTraceID(const PendingTask & task) const58 uint64_t TaskAnnotator::GetTaskTraceID(const PendingTask& task) const {
59 return (static_cast<uint64_t>(task.sequence_num) << 32) |
60 ((static_cast<uint64_t>(reinterpret_cast<intptr_t>(this)) << 32) >>
61 32);
62 }
63
64 } // namespace debug
65 } // namespace base
66