Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(5)

Side by Side Diff: components/scheduler/base/task_queue.h

Issue 2118903002: scheduler: Move the Blink scheduler into Blink (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Another GYP fix Created 4 years, 5 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch
OLDNEW
(Empty)
1 // Copyright 2015 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 #ifndef COMPONENTS_SCHEDULER_BASE_TASK_QUEUE_H_
6 #define COMPONENTS_SCHEDULER_BASE_TASK_QUEUE_H_
7
8 #include "base/macros.h"
9 #include "base/message_loop/message_loop.h"
10 #include "base/single_thread_task_runner.h"
11 #include "base/trace_event/trace_event.h"
12 #include "components/scheduler/scheduler_export.h"
13
14 namespace base {
15 namespace trace_event {
16 class BlameContext;
17 }
18 }
19
20 namespace scheduler {
21 class TimeDomain;
22
23 class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
24 public:
25 TaskQueue() {}
26
27 // Unregisters the task queue after which no tasks posted to it will run and
28 // the TaskQueueManager's reference to it will be released soon.
29 virtual void UnregisterTaskQueue() = 0;
30
31 enum QueuePriority {
32 // Queues with control priority will run before any other queue, and will
33 // explicitly starve other queues. Typically this should only be used for
34 // private queues which perform control operations.
35 CONTROL_PRIORITY,
36 // Queues with high priority will be selected preferentially over normal or
37 // best effort queues. The selector will ensure that high priority queues
38 // cannot completely starve normal priority queues.
39 HIGH_PRIORITY,
40 // Queues with normal priority are the default.
41 NORMAL_PRIORITY,
42 // Queues with best effort priority will only be run if all other queues are
43 // empty. They can be starved by the other queues.
44 BEST_EFFORT_PRIORITY,
45 // Must be the last entry.
46 QUEUE_PRIORITY_COUNT,
47 FIRST_QUEUE_PRIORITY = CONTROL_PRIORITY,
48 };
49
50 // Keep TaskQueue::PumpPolicyToString in sync with this enum.
51 enum class PumpPolicy {
52 // Tasks posted to an incoming queue with an AUTO pump policy will be
53 // automatically scheduled for execution or transferred to the work queue
54 // automatically.
55 AUTO,
56 // Tasks posted to an incoming queue with an AFTER_WAKEUP pump policy
57 // will be scheduled for execution or transferred to the work queue
58 // automatically but only after another queue has executed a task.
59 AFTER_WAKEUP,
60 // Tasks posted to an incoming queue with a MANUAL will not be
61 // automatically scheduled for execution or transferred to the work queue.
62 // Instead, the selector should call PumpQueue() when necessary to bring
63 // in new tasks for execution.
64 MANUAL,
65 // Must be last entry.
66 PUMP_POLICY_COUNT,
67 FIRST_PUMP_POLICY = AUTO,
68 };
69
70 // Keep TaskQueue::WakeupPolicyToString in sync with this enum.
71 enum class WakeupPolicy {
72 // Tasks run on a queue with CAN_WAKE_OTHER_QUEUES wakeup policy can
73 // cause queues with the AFTER_WAKEUP PumpPolicy to be woken up.
74 CAN_WAKE_OTHER_QUEUES,
75 // Tasks run on a queue with DONT_WAKE_OTHER_QUEUES won't cause queues
76 // with the AFTER_WAKEUP PumpPolicy to be woken up.
77 DONT_WAKE_OTHER_QUEUES,
78 // Must be last entry.
79 WAKEUP_POLICY_COUNT,
80 FIRST_WAKEUP_POLICY = CAN_WAKE_OTHER_QUEUES,
81 };
82
83 // Options for constructing a TaskQueue. Once set the |name|,
84 // |should_monitor_quiescence| and |wakeup_policy| are immutable. The
85 // |pump_policy| can be mutated with |SetPumpPolicy()|.
86 struct Spec {
87 // Note |name| must have application lifetime.
88 explicit Spec(const char* name)
89 : name(name),
90 should_monitor_quiescence(false),
91 pump_policy(TaskQueue::PumpPolicy::AUTO),
92 wakeup_policy(TaskQueue::WakeupPolicy::CAN_WAKE_OTHER_QUEUES),
93 time_domain(nullptr),
94 should_notify_observers(true),
95 should_report_when_execution_blocked(false) {}
96
97 Spec SetShouldMonitorQuiescence(bool should_monitor) {
98 should_monitor_quiescence = should_monitor;
99 return *this;
100 }
101
102 Spec SetPumpPolicy(PumpPolicy policy) {
103 pump_policy = policy;
104 return *this;
105 }
106
107 Spec SetWakeupPolicy(WakeupPolicy policy) {
108 wakeup_policy = policy;
109 return *this;
110 }
111
112 Spec SetShouldNotifyObservers(bool run_observers) {
113 should_notify_observers = run_observers;
114 return *this;
115 }
116
117 Spec SetTimeDomain(TimeDomain* domain) {
118 time_domain = domain;
119 return *this;
120 }
121
122 // See TaskQueueManager::Observer::OnTriedToExecuteBlockedTask.
123 Spec SetShouldReportWhenExecutionBlocked(bool should_report) {
124 should_report_when_execution_blocked = should_report;
125 return *this;
126 }
127
128 const char* name;
129 bool should_monitor_quiescence;
130 TaskQueue::PumpPolicy pump_policy;
131 TaskQueue::WakeupPolicy wakeup_policy;
132 TimeDomain* time_domain;
133 bool should_notify_observers;
134 bool should_report_when_execution_blocked;
135 };
136
137 // Enable or disable task execution for this queue. NOTE this must be called
138 // on the thread this TaskQueue was created by.
139 virtual void SetQueueEnabled(bool enabled) = 0;
140
141 // NOTE this must be called on the thread this TaskQueue was created by.
142 virtual bool IsQueueEnabled() const = 0;
143
144 // Returns true if the queue is completely empty.
145 virtual bool IsEmpty() const = 0;
146
147 // Returns true if the queue has work that's ready to execute now, or if it
148 // would have if the queue was pumped. NOTE this must be called on the thread
149 // this TaskQueue was created by.
150 virtual bool HasPendingImmediateWork() const = 0;
151
152 // Returns true if tasks can't run now but could if the queue was pumped.
153 virtual bool NeedsPumping() const = 0;
154
155 // Can be called on any thread.
156 virtual const char* GetName() const = 0;
157
158 // Set the priority of the queue to |priority|. NOTE this must be called on
159 // the thread this TaskQueue was created by.
160 virtual void SetQueuePriority(QueuePriority priority) = 0;
161
162 // Returns the current queue priority.
163 virtual QueuePriority GetQueuePriority() const = 0;
164
165 // Set the pumping policy of the queue to |pump_policy|. NOTE this must be
166 // called on the thread this TaskQueue was created by.
167 virtual void SetPumpPolicy(PumpPolicy pump_policy) = 0;
168
169 // Returns the current PumpPolicy. NOTE this must be called on the thread this
170 // TaskQueue was created by.
171 virtual PumpPolicy GetPumpPolicy() const = 0;
172
173 // Reloads new tasks from the incoming queue into the work queue, regardless
174 // of whether the work queue is empty or not. After this, the function ensures
175 // that the tasks in the work queue, if any, are scheduled for execution.
176 //
177 // This function only needs to be called if automatic pumping is disabled.
178 // By default automatic pumping is enabled for all queues. NOTE this must be
179 // called on the thread this TaskQueue was created by.
180 //
181 // The |may_post_dowork| parameter controls whether or not PumpQueue calls
182 // TaskQueueManager::MaybeScheduleImmediateWork.
183 // TODO(alexclarke): Add a base::RunLoop observer so we can get rid of
184 // |may_post_dowork|.
185 virtual void PumpQueue(bool may_post_dowork) = 0;
186
187 // These functions can only be called on the same thread that the task queue
188 // manager executes its tasks on.
189 virtual void AddTaskObserver(
190 base::MessageLoop::TaskObserver* task_observer) = 0;
191 virtual void RemoveTaskObserver(
192 base::MessageLoop::TaskObserver* task_observer) = 0;
193
194 // Set the blame context which is entered and left while executing tasks from
195 // this task queue. |blame_context| must be null or outlive this task queue.
196 // Must be called on the thread this TaskQueue was created by.
197 virtual void SetBlameContext(
198 base::trace_event::BlameContext* blame_context) = 0;
199
200 // Removes the task queue from the previous TimeDomain and adds it to
201 // |domain|. This is a moderately expensive operation.
202 virtual void SetTimeDomain(TimeDomain* domain) = 0;
203
204 // Returns the queue's current TimeDomain. Can be called from any thread.
205 virtual TimeDomain* GetTimeDomain() const = 0;
206
207 protected:
208 ~TaskQueue() override {}
209
210 DISALLOW_COPY_AND_ASSIGN(TaskQueue);
211 };
212
213 } // namespace scheduler
214
215 #endif // COMPONENTS_SCHEDULER_BASE_TASK_QUEUE_H_
OLDNEW

Powered by Google App Engine
This is Rietveld 408576698