blob: eeffb56aebc5aa6f43511972291d9c34d690dce2 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CC_BASE_WORKER_POOL_H_
#define CC_BASE_WORKER_POOL_H_
#include <deque>
#include <string>
#include <vector>
#include "base/cancelable_callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/message_loop.h"
#include "cc/base/cc_export.h"
#include "cc/base/scoped_ptr_hash_map.h"
namespace cc {
namespace internal {
class CC_EXPORT WorkerPoolTask
: public base::RefCountedThreadSafe<WorkerPoolTask> {
public:
typedef std::vector<scoped_refptr<WorkerPoolTask> > TaskVector;
virtual void RunOnThread(unsigned thread_index) = 0;
virtual void DispatchCompletionCallback() = 0;
void DidSchedule();
void WillRun();
void DidRun();
void DidComplete();
bool IsReadyToRun() const;
bool HasFinishedRunning() const;
bool HasCompleted() const;
TaskVector& dependencies() { return dependencies_; }
protected:
friend class base::RefCountedThreadSafe<WorkerPoolTask>;
WorkerPoolTask();
explicit WorkerPoolTask(TaskVector* dependencies);
virtual ~WorkerPoolTask();
private:
bool did_schedule_;
bool did_run_;
bool did_complete_;
TaskVector dependencies_;
};
} // namespace internal
} // namespace cc
#if defined(COMPILER_GCC)
namespace BASE_HASH_NAMESPACE {
template <> struct hash<cc::internal::WorkerPoolTask*> {
size_t operator()(cc::internal::WorkerPoolTask* ptr) const {
return hash<size_t>()(reinterpret_cast<size_t>(ptr));
}
};
} // namespace BASE_HASH_NAMESPACE
#endif // COMPILER
namespace cc {
// A worker thread pool that runs tasks provided by task graph and
// guarantees completion of all pending tasks at shutdown.
class CC_EXPORT WorkerPool {
public:
virtual ~WorkerPool();
// Tells the worker pool to shutdown and returns once all pending tasks have
// completed.
virtual void Shutdown();
// Force a check for completed tasks.
virtual void CheckForCompletedTasks();
protected:
class CC_EXPORT GraphNode {
public:
GraphNode(internal::WorkerPoolTask* dependent, unsigned priority);
~GraphNode();
void AddDependent(internal::WorkerPoolTask* dependent);
const internal::WorkerPoolTask::TaskVector& dependents() const {
return dependents_;
}
unsigned priority() const { return priority_; }
private:
internal::WorkerPoolTask::TaskVector dependents_;
unsigned priority_;
DISALLOW_COPY_AND_ASSIGN(GraphNode);
};
typedef ScopedPtrHashMap<internal::WorkerPoolTask*, GraphNode> GraphNodeMap;
typedef GraphNodeMap TaskGraph;
WorkerPool(size_t num_threads, const std::string& thread_name_prefix);
// Schedule running of tasks in |graph|. Any previously scheduled tasks
// that are not already running will be canceled. Canceled tasks don't run
// but completion of them is still processed.
void SetTaskGraph(TaskGraph* graph);
// BuildTaskGraph() takes a task tree as input and constructs a
// unique set of tasks with edges between dependencies pointing in
// the direction of the dependents. Each task is given a unique priority
// which is currently the same as the DFS traversal order.
//
// Input: Output:
//
// root task4 Task | Priority (lower is better)
// / \ / \ -------+---------------------------
// task1 task2 task3 task2 root | 4
// | | | | task1 | 2
// task3 | task1 | task2 | 3
// | | \ / task3 | 1
// task4 task4 root task4 | 0
//
// The output can be used to efficiently maintain a queue of
// "ready to run" tasks.
static unsigned BuildTaskGraphRecursive(
internal::WorkerPoolTask* task,
internal::WorkerPoolTask* dependent,
unsigned priority,
TaskGraph* tasks);
static void BuildTaskGraph(
internal::WorkerPoolTask* root, TaskGraph* tasks);
private:
class Inner;
friend class Inner;
typedef std::deque<scoped_refptr<internal::WorkerPoolTask> > TaskDeque;
void DispatchCompletionCallbacks(TaskDeque* completed_tasks);
bool in_dispatch_completion_callbacks_;
// Hide the gory details of the worker pool in |inner_|.
const scoped_ptr<Inner> inner_;
};
} // namespace cc
#endif // CC_BASE_WORKER_POOL_H_
|
