src/common/WorkerThread.cpp

/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2007 - 2020 Christian Schoenebeck                       *
 *   Copyright (C) 2007 - 2013 Grigor Iliev                                *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the Free Software           *
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,                *
 *   MA  02110-1301  USA                                                   *
 ***************************************************************************/

#include "WorkerThread.h"

#include "Exception.h"

namespace LinuxSampler {

    WorkerThread::WorkerThread() : Thread(true, false, 0, -4) { }

    void WorkerThread::Execute(Runnable* pJob) {
        {
            LockGuard lock(mutex);
            queue.push_back(pJob);
        }
        StartThread(); // ensure thread is running
        conditionJobsLeft.Set(true); // wake up thread
    }

    // Entry point for the worker thread.
    int WorkerThread::Main() {

        #if DEBUG
        Thread::setNameOfCaller("LSWorker");
        #endif

        while (true) {

            TestCancel();

            // prevent worker thread from being cancelled
            // (e.g. to prevent deadlocks while holding mutex lock(s))
            pushCancelable(false);

            while (true) {
                Runnable* pJob;

                // grab a new job from the queue
                {
                    LockGuard lock(mutex);
                    if (queue.empty()) break;

                    pJob = queue.front();
                    queue.pop_front();
                }

                try {
                    pJob->Run();
                } catch (Exception e) {
                    e.PrintMessage();
                } catch (...) {
                    std::cerr << "WorkerThread: an exception occured, could not finish the job";
                    std::cerr << std::endl << std::flush;
                }

                delete pJob;
            }

            // now allow worker thread being cancelled again
            // (since all mutexes are now unlocked)
            popCancelable();

            // nothing left to do, sleep until new jobs arrive
            conditionJobsLeft.WaitIf(false);
            // reset flag
            conditionJobsLeft.Set(false);
            // unlock condition object so it can be turned again by other thread
            conditionJobsLeft.Unlock();
        }
        return 0;
    }

} // namespace LinuxSampler
1	/***************************************************************************
2	* *
3	* Copyright (C) 2007 - 2020 Christian Schoenebeck *
4	* Copyright (C) 2007 - 2013 Grigor Iliev *
5	* *
6	* This program is free software; you can redistribute it and/or modify *
7	* it under the terms of the GNU General Public License as published by *
8	* the Free Software Foundation; either version 2 of the License, or *
9	* (at your option) any later version. *
10	* *
11	* This program is distributed in the hope that it will be useful, *
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
14	* GNU General Public License for more details. *
15	* *
16	* You should have received a copy of the GNU General Public License *
17	* along with this program; if not, write to the Free Software *
18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, *
19	* MA 02110-1301 USA *
20	***************************************************************************/
21
22	#include "WorkerThread.h"
23
24	#include "Exception.h"
25
26	namespace LinuxSampler {
27
28	WorkerThread::WorkerThread() : Thread(true, false, 0, -4) { }
29
30	void WorkerThread::Execute(Runnable* pJob) {
31	{
32	LockGuard lock(mutex);
33	queue.push_back(pJob);
34	}
35	StartThread(); // ensure thread is running
36	conditionJobsLeft.Set(true); // wake up thread
37	}
38
39	// Entry point for the worker thread.
40	int WorkerThread::Main() {
41
42	#if DEBUG
43	Thread::setNameOfCaller("LSWorker");
44	#endif
45
46	while (true) {
47
48	TestCancel();
49
50	// prevent worker thread from being cancelled
51	// (e.g. to prevent deadlocks while holding mutex lock(s))
52	pushCancelable(false);
53
54	while (true) {
55	Runnable* pJob;
56
57	// grab a new job from the queue
58	{
59	LockGuard lock(mutex);
60	if (queue.empty()) break;
61
62	pJob = queue.front();
63	queue.pop_front();
64	}
65
66	try {
67	pJob->Run();
68	} catch (Exception e) {
69	e.PrintMessage();
70	} catch (...) {
71	std::cerr << "WorkerThread: an exception occured, could not finish the job";
72	std::cerr << std::endl << std::flush;
73	}
74
75	delete pJob;
76	}
77
78	// now allow worker thread being cancelled again
79	// (since all mutexes are now unlocked)
80	popCancelable();
81
82	// nothing left to do, sleep until new jobs arrive
83	conditionJobsLeft.WaitIf(false);
84	// reset flag
85	conditionJobsLeft.Set(false);
86	// unlock condition object so it can be turned again by other thread
87	conditionJobsLeft.Unlock();
88	}
89	return 0;
90	}
91
92	} // namespace LinuxSampler