1 // Copyright 2012 The Chromium Authors
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/task/sequenced_task_runner.h"
6
7 #include <utility>
8
9 #include "base/functional/bind.h"
10 #include "base/task/default_delayed_task_handle_delegate.h"
11 #include "base/time/time.h"
12 #include "third_party/abseil-cpp/absl/base/attributes.h"
13
14 namespace base {
15
16 namespace {
17
18 ABSL_CONST_INIT thread_local SequencedTaskRunner::CurrentDefaultHandle*
19 current_default_handle = nullptr;
20
21 } // namespace
22
PostNonNestableTask(const Location & from_here,OnceClosure task)23 bool SequencedTaskRunner::PostNonNestableTask(const Location& from_here,
24 OnceClosure task) {
25 return PostNonNestableDelayedTask(from_here, std::move(task),
26 base::TimeDelta());
27 }
28
PostCancelableDelayedTask(subtle::PostDelayedTaskPassKey,const Location & from_here,OnceClosure task,TimeDelta delay)29 DelayedTaskHandle SequencedTaskRunner::PostCancelableDelayedTask(
30 subtle::PostDelayedTaskPassKey,
31 const Location& from_here,
32 OnceClosure task,
33 TimeDelta delay) {
34 auto delayed_task_handle_delegate =
35 std::make_unique<DefaultDelayedTaskHandleDelegate>();
36
37 task = delayed_task_handle_delegate->BindCallback(std::move(task));
38
39 DelayedTaskHandle delayed_task_handle(
40 std::move(delayed_task_handle_delegate));
41
42 PostDelayedTask(from_here, std::move(task), delay);
43
44 return delayed_task_handle;
45 }
46
PostCancelableDelayedTaskAt(subtle::PostDelayedTaskPassKey pass_key,const Location & from_here,OnceClosure task,TimeTicks delayed_run_time,subtle::DelayPolicy deadline_policy)47 DelayedTaskHandle SequencedTaskRunner::PostCancelableDelayedTaskAt(
48 subtle::PostDelayedTaskPassKey pass_key,
49 const Location& from_here,
50 OnceClosure task,
51 TimeTicks delayed_run_time,
52 subtle::DelayPolicy deadline_policy) {
53 auto delayed_task_handle_delegate =
54 std::make_unique<DefaultDelayedTaskHandleDelegate>();
55
56 task = delayed_task_handle_delegate->BindCallback(std::move(task));
57
58 DelayedTaskHandle delayed_task_handle(
59 std::move(delayed_task_handle_delegate));
60
61 if (!PostDelayedTaskAt(pass_key, from_here, std::move(task), delayed_run_time,
62 deadline_policy)) {
63 DCHECK(!delayed_task_handle.IsValid());
64 }
65 return delayed_task_handle;
66 }
67
PostDelayedTaskAt(subtle::PostDelayedTaskPassKey,const Location & from_here,OnceClosure task,TimeTicks delayed_run_time,subtle::DelayPolicy deadline_policy)68 bool SequencedTaskRunner::PostDelayedTaskAt(
69 subtle::PostDelayedTaskPassKey,
70 const Location& from_here,
71 OnceClosure task,
72 TimeTicks delayed_run_time,
73 subtle::DelayPolicy deadline_policy) {
74 return PostDelayedTask(from_here, std::move(task),
75 delayed_run_time.is_null()
76 ? base::TimeDelta()
77 : delayed_run_time - TimeTicks::Now());
78 }
79
RunOrPostTask(subtle::RunOrPostTaskPassKey,const Location & from_here,OnceClosure task)80 bool SequencedTaskRunner::RunOrPostTask(subtle::RunOrPostTaskPassKey,
81 const Location& from_here,
82 OnceClosure task) {
83 return PostTask(from_here, std::move(task));
84 }
85
86 // static
87 const scoped_refptr<SequencedTaskRunner>&
GetCurrentDefault()88 SequencedTaskRunner::GetCurrentDefault() {
89 CHECK(HasCurrentDefault())
90 << "Error: This caller requires a sequenced context (i.e. the current "
91 "task needs to run from a SequencedTaskRunner). If you're in a test "
92 "refer to //docs/threading_and_tasks_testing.md.";
93 return current_default_handle->task_runner_;
94 }
95
96 // static
HasCurrentDefault()97 bool SequencedTaskRunner::HasCurrentDefault() {
98 return !!current_default_handle && !!current_default_handle->task_runner_;
99 }
100
CurrentDefaultHandle(scoped_refptr<SequencedTaskRunner> task_runner)101 SequencedTaskRunner::CurrentDefaultHandle::CurrentDefaultHandle(
102 scoped_refptr<SequencedTaskRunner> task_runner)
103 : CurrentDefaultHandle(std::move(task_runner), MayAlreadyExist{}) {
104 CHECK(!previous_handle_ || !previous_handle_->task_runner_);
105 }
106
~CurrentDefaultHandle()107 SequencedTaskRunner::CurrentDefaultHandle::~CurrentDefaultHandle() {
108 DCHECK_EQ(current_default_handle, this);
109 current_default_handle = previous_handle_;
110 }
111
CurrentDefaultHandle(scoped_refptr<SequencedTaskRunner> task_runner,MayAlreadyExist)112 SequencedTaskRunner::CurrentDefaultHandle::CurrentDefaultHandle(
113 scoped_refptr<SequencedTaskRunner> task_runner,
114 MayAlreadyExist)
115 : task_runner_(std::move(task_runner)),
116 previous_handle_(current_default_handle) {
117 // Support overriding the current default with a null task runner or a task
118 // runner that runs its tasks in the current sequence.
119 DCHECK(!task_runner_ || task_runner_->RunsTasksInCurrentSequence());
120 current_default_handle = this;
121 }
122
DeleteOrReleaseSoonInternal(const Location & from_here,void (* deleter)(const void *),const void * object)123 bool SequencedTaskRunner::DeleteOrReleaseSoonInternal(
124 const Location& from_here,
125 void (*deleter)(const void*),
126 const void* object) {
127 return PostNonNestableTask(from_here, BindOnce(deleter, object));
128 }
129
OnTaskRunnerDeleter(scoped_refptr<SequencedTaskRunner> task_runner)130 OnTaskRunnerDeleter::OnTaskRunnerDeleter(
131 scoped_refptr<SequencedTaskRunner> task_runner)
132 : task_runner_(std::move(task_runner)) {
133 }
134
135 OnTaskRunnerDeleter::~OnTaskRunnerDeleter() = default;
136
137 OnTaskRunnerDeleter::OnTaskRunnerDeleter(OnTaskRunnerDeleter&&) = default;
138
139 OnTaskRunnerDeleter& OnTaskRunnerDeleter::operator=(
140 OnTaskRunnerDeleter&&) = default;
141
142 } // namespace base
143