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
|
/********************************************************************************
* *
* T a s k G r o u p C l a s s *
* *
*********************************************************************************
* Copyright (C) 2012,2022 by Jeroen van der Zijp. All Rights Reserved. *
*********************************************************************************
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/> *
********************************************************************************/
#ifndef FXTASKGROUP_H
#define FXTASKGROUP_H
namespace FX {
class FXThreadPool;
/**
* An FXTaskGroup manages a number of tasks, executing on the associated FXThreadPool.
* In a typical use, an FXTaskGroup is constructed on the stack of the calling function.
* If an explicit FXThreadPool is passed to the constructor of the FXTaskGroup, this is
* the FXThreadPool that will be used to execute the tasks. Otherwise, an instance of
* FXThreadPool will be located through a thread-local variable from the calling thread.
* This thread-local variable will be set if the calling thread is a worker thread from
* the FXThreadPool, or is the thread that called start() on the FXThreadPool.
* Tasks managed by the FXTaskGroup may be started at any time during the FXTaskGroup's
* lifetime. However, the FXTaskGroup can not be destroyed until the last task in the
* group has finished execution: the FXTaskGroup's destructor will wait until all tasks
* (if any) have finished executing.
* The calling thread can enter the task-processing loop in the FXThreadPool; it returns
* when either the tasks from this FXTaskGroup have been completed (count reaching zero),
* or when the task-queue is empty (in this case another thread may still be working on
* a task from the FXTaskGroup). Thus, the calling thread should block on the completion
* semaphore to ensure all tasks are completed.
*/
class FXAPI FXTaskGroup {
private:
class Task : public FXRunnable {
private:
FXTaskGroup *taskgroup; // Backlink to taskgroup
FXRunnable *runnable; // Wrapped runnable
private:
Task(const Task&);
Task &operator=(const Task&);
public:
Task(FXTaskGroup* g,FXRunnable *r);
virtual FXint run();
virtual ~Task();
};
private:
FXThreadPool *threadpool; // Thread pool used by task group
FXCompletion completion; // Completion counter
private:
FXTaskGroup(const FXTaskGroup&);
FXTaskGroup &operator=(const FXTaskGroup&);
public:
/**
* Create new task group, using the calling thread's associated
* thread pool.
*/
FXTaskGroup();
/**
* Create new task group, using the given thread pool.
*/
FXTaskGroup(FXThreadPool* p);
/**
* Return threadpool.
*/
FXThreadPool* getThreadPool() const { return threadpool; }
/**
* Return number of tasks.
*/
FXuint getRunningTasks() const { return completion.count(); }
/**
* Start a task in this task group.
*/
FXbool execute(FXRunnable* task);
/**
* Start task in this task group, and then enter the task-processing
* loop, returning when all tasks have been completed.
* Return false if unable to start the task.
*/
FXbool executeAndWait(FXRunnable* task);
/**
* Wait until all tasks of this group have finished executing, then return.
* The completion semaphore is reset after being signaled by the last completed
* task.
*/
FXbool wait();
/**
* Wait for the semaphore to be signaled, then destroy the task group.
*/
virtual ~FXTaskGroup();
};
}
#endif
|
