src/engines/InstrumentManagerThread.cpp

/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2005 - 2022 Christian Schoenebeck                       *
 *                                                                         *
 *   This library 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 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this library; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include "InstrumentManagerThread.h"

#include "../common/global_private.h"
#include "EngineChannelFactory.h"

// how often periodic jobs for external components shall be executed
// (every 200ms)
#define PERIODIC_JOBS_SEC   0
#define PERIODIC_JOBS_NSEC  (200 * 1000 * 1000)

namespace LinuxSampler {

    InstrumentManagerThread::InstrumentManagerThread() : Thread(true, false, 0, -4) {
        eventHandler.pThread = this;
    }

    InstrumentManagerThread::~InstrumentManagerThread() {
        Thread::StopThread();
    }

    /**
     * @brief Order loading of a new instrument.
     *
     * The request will go into a queue waiting to be processed by the
     * class internal task thread. This method will immediately return and
     * the instrument will be loaded in the background.
     *
     * @param Filename - file name of the instrument
     * @param uiInstrumentIndex - index of the instrument within the file
     * @param pEngineChannel - engine channel on which the instrument should be loaded
     */
    void InstrumentManagerThread::StartNewLoad(String Filename, uint uiInstrumentIndex, EngineChannel* pEngineChannel) {
        dmsg(1,("Scheduling '%s' (Index=%d) to be loaded in background (if not loaded yet).\n",Filename.c_str(),uiInstrumentIndex));

        // the listener only needs to be registered once in the
        // Sampler, but as we don't know if Sampler has been
        // recreated, we simply remove and add every time
        pEngineChannel->GetSampler()->RemoveChannelCountListener(&eventHandler);
        pEngineChannel->GetSampler()->AddChannelCountListener(&eventHandler);
        
        command_t cmd;
        cmd.type           = command_t::DIRECT_LOAD;
        cmd.pEngineChannel = pEngineChannel;
        cmd.instrumentId.Index = uiInstrumentIndex;
        cmd.instrumentId.FileName = Filename;

        {
            LockGuard lock(mutex);
            queue.push_back(cmd);
        }

        StartThread(); // ensure thread is running
        conditionJobsLeft.Set(true); // wake up thread
    }

    /**
     * @brief Order changing the life-time strategy of an instrument.
     *
     * The request will go into a queue waiting to be processed by the
     * class internal task thread. This method will immediately return and
     * in case the instrument has to be loaded due to a mode change to
     * PERSISTENT, it will be loaded in the background.
     *
     * @param pManager - InstrumentManager which manages the instrument
     * @param ID       - unique ID of the instrument
     * @param Mode     - life-time strategy to set for this instrument
     */
    void InstrumentManagerThread::StartSettingMode(InstrumentManager* pManager, const InstrumentManager::instrument_id_t& ID, InstrumentManager::mode_t Mode) {
        command_t cmd;
        cmd.type         = command_t::INSTR_MODE;
        cmd.pManager     = pManager;
        cmd.instrumentId = ID;
        cmd.mode         = Mode;

        {
            LockGuard lock(mutex);
            queue.push_back(cmd);
        }

        StartThread(); // ensure thread is running
        conditionJobsLeft.Set(true); // wake up thread
    }

    // Entry point for the task thread.
    int InstrumentManagerThread::Main() {
        #if DEBUG
        Thread::setNameOfCaller("InstrumentMngr");
        #endif

        while (true) {

            TestCancel();

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

            while (true) {
                command_t cmd;

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

                    cmd = queue.front();
                    queue.pop_front();

                    if (cmd.type == command_t::DIRECT_LOAD) {
                        EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, false);
                    }
                }

                try {
                    switch (cmd.type) {
                        case command_t::DIRECT_LOAD:
                            cmd.pEngineChannel->PrepareLoadInstrument(cmd.instrumentId.FileName.c_str(), cmd.instrumentId.Index);
                            cmd.pEngineChannel->LoadInstrument();
                            EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, true);
                            break;
                        case command_t::INSTR_MODE:
                            cmd.pManager->SetMode(cmd.instrumentId, cmd.mode);
                            break;
                        default:
                            std::cerr << "InstrumentManagerThread: unknown command - BUG!\n" << std::flush;
                    }
                } catch (Exception e) {
                    e.PrintMessage();
                    if (cmd.type == command_t::DIRECT_LOAD) {
                        EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, true);
                    }
                } catch (...) {
                    std::cerr << "InstrumentManagerThread: some exception occured, could not finish task\n" << std::flush;
                    if (cmd.type == command_t::DIRECT_LOAD) {
                        EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, true);
                    }
                }
            }

            // perform periodic, custom jobs on behalf of external components
            {
                LockGuard lock(periodicJobsMutex);
                for (ext_job_t job : periodicJobs) {
                    job.fn();
                }
            }

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

            // nothing left to do, sleep until new jobs arrive
            const bool timedOut =
                (AnyPeriodicJobs()) ?
                    // do wait, but with a maximum timeout value
                    conditionJobsLeft.WaitIf(false, PERIODIC_JOBS_SEC, PERIODIC_JOBS_NSEC) :
                    // wait indefinitely
                    conditionJobsLeft.WaitIf(false);
            // reset flag
            if (!timedOut) {
                conditionJobsLeft.Set(false);
                // unlock condition object so it can be turned again by other thread
                conditionJobsLeft.Unlock();
            }
        }
        return 0;
    }

    /**
     * Schedule a job to be executed by instrument manager thread periodically.
     *
     * This method is intended to be used by external components to execute
     * instrument files related tasks periodically. Currently this is hard
     * coded to happen approximately every 200ms, however if the instrument
     * manager thread is currently blocked by executing other tasks (e.g.
     * loading some instrument) then this might also be significantly delayed
     * accordingly.
     *
     * The scheduled task will continue to be executed indefinitely until
     * @c RemovePeriodicJob() is called.
     *
     * Currently this method is only used by the SFZ engine for its auto
     * reload feature (i.e. on modifications of .sfz files by external apps).
     *
     * @param name - arbitrary but unique ID for the task
     * @param fn - actual callback for the task to be executed
     */
    void InstrumentManagerThread::AddPeriodicJob(String name, std::function<void()> fn) {
        LockGuard lock(periodicJobsMutex);
        RemovePeriodicJobWithoutLock(name);
        periodicJobs.push_back({
            .name = name,
            .fn = fn
        });
    }

    /**
     * Unschedule a periodic task previously scheduled by @c AddPeriodicJob().
     *
     * @param name - unique ID of the previously scheduled periodic task
     */
    void InstrumentManagerThread::RemovePeriodicJob(String name) {
        LockGuard lock(periodicJobsMutex);
        RemovePeriodicJobWithoutLock(name);
    }

    void InstrumentManagerThread::RemovePeriodicJobWithoutLock(String name) {
        for (size_t i = 0; i < periodicJobs.size(); ++i) {
            if (periodicJobs[i].name == name) {
                periodicJobs.erase( periodicJobs.begin() + i );
                return;
            }
        }
    }

    bool InstrumentManagerThread::AnyPeriodicJobs() {
        // would probably be OK without a lock, but strictly it would be undefined behaviour
        LockGuard lock(periodicJobsMutex);
        return !periodicJobs.empty();
    }

    void InstrumentManagerThread::EventHandler::ChannelToBeRemoved(SamplerChannel* pChannel) {
        /*
           Removing from the queue an eventual scheduled loading of an instrument
           to a sampler channel which is going to be removed.
        */
        LockGuard lock(pThread->mutex);
        std::list<command_t>::iterator it;
        for (it = pThread->queue.begin(); it != pThread->queue.end();){
            if ((*it).type != command_t::DIRECT_LOAD) { ++it; continue; }
            if ((*it).pEngineChannel == pChannel->GetEngineChannel()) {
                it = pThread->queue.erase(it);
                // we don't break here because the same engine channel could
                // occur more than once in the queue, so don't make optimizations
            } else {
                ++it;
            }
        } 
    }

#if defined(__APPLE__) && !defined(__x86_64__)
    int InstrumentManagerThread::StopThread() {
        // This is a fix for Mac OS X 32 bit, where SignalStopThread
        // doesn't wake up a thread waiting for a condition variable.
        SignalStopThread(); // send stop signal, but don't wait
        conditionJobsLeft.Set(true); // wake thread
        return Thread::StopThread(); // then wait for it to cancel
    }
#endif

#ifdef WIN32
    int InstrumentManagerThread::StopThread() {
        int res = Thread::StopThread();
        conditionJobsLeft.Reset();
        return res;
    }
#endif

} // namespace LinuxSampler
1	/***************************************************************************
2	* *
3	* Copyright (C) 2005 - 2022 Christian Schoenebeck *
4	* *
5	* This library is free software; you can redistribute it and/or modify *
6	* it under the terms of the GNU General Public License as published by *
7	* the Free Software Foundation; either version 2 of the License, or *
8	* (at your option) any later version. *
9	* *
10	* This library is distributed in the hope that it will be useful, *
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13	* GNU General Public License for more details. *
14	* *
15	* You should have received a copy of the GNU General Public License *
16	* along with this library; if not, write to the Free Software *
17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
18	* MA 02111-1307 USA *
19	***************************************************************************/
20
21	#include "InstrumentManagerThread.h"
22
23	#include "../common/global_private.h"
24	#include "EngineChannelFactory.h"
25
26	// how often periodic jobs for external components shall be executed
27	// (every 200ms)
28	#define PERIODIC_JOBS_SEC 0
29	#define PERIODIC_JOBS_NSEC (200 * 1000 * 1000)
30
31	namespace LinuxSampler {
32
33	InstrumentManagerThread::InstrumentManagerThread() : Thread(true, false, 0, -4) {
34	eventHandler.pThread = this;
35	}
36
37	InstrumentManagerThread::~InstrumentManagerThread() {
38	Thread::StopThread();
39	}
40
41	/**
42	* @brief Order loading of a new instrument.
43	*
44	* The request will go into a queue waiting to be processed by the
45	* class internal task thread. This method will immediately return and
46	* the instrument will be loaded in the background.
47	*
48	* @param Filename - file name of the instrument
49	* @param uiInstrumentIndex - index of the instrument within the file
50	* @param pEngineChannel - engine channel on which the instrument should be loaded
51	*/
52	void InstrumentManagerThread::StartNewLoad(String Filename, uint uiInstrumentIndex, EngineChannel* pEngineChannel) {
53	dmsg(1,("Scheduling '%s' (Index=%d) to be loaded in background (if not loaded yet).\n",Filename.c_str(),uiInstrumentIndex));
54
55	// the listener only needs to be registered once in the
56	// Sampler, but as we don't know if Sampler has been
57	// recreated, we simply remove and add every time
58	pEngineChannel->GetSampler()->RemoveChannelCountListener(&eventHandler);
59	pEngineChannel->GetSampler()->AddChannelCountListener(&eventHandler);
60
61	command_t cmd;
62	cmd.type = command_t::DIRECT_LOAD;
63	cmd.pEngineChannel = pEngineChannel;
64	cmd.instrumentId.Index = uiInstrumentIndex;
65	cmd.instrumentId.FileName = Filename;
66
67	{
68	LockGuard lock(mutex);
69	queue.push_back(cmd);
70	}
71
72	StartThread(); // ensure thread is running
73	conditionJobsLeft.Set(true); // wake up thread
74	}
75
76	/**
77	* @brief Order changing the life-time strategy of an instrument.
78	*
79	* The request will go into a queue waiting to be processed by the
80	* class internal task thread. This method will immediately return and
81	* in case the instrument has to be loaded due to a mode change to
82	* PERSISTENT, it will be loaded in the background.
83	*
84	* @param pManager - InstrumentManager which manages the instrument
85	* @param ID - unique ID of the instrument
86	* @param Mode - life-time strategy to set for this instrument
87	*/
88	void InstrumentManagerThread::StartSettingMode(InstrumentManager* pManager, const InstrumentManager::instrument_id_t& ID, InstrumentManager::mode_t Mode) {
89	command_t cmd;
90	cmd.type = command_t::INSTR_MODE;
91	cmd.pManager = pManager;
92	cmd.instrumentId = ID;
93	cmd.mode = Mode;
94
95	{
96	LockGuard lock(mutex);
97	queue.push_back(cmd);
98	}
99
100	StartThread(); // ensure thread is running
101	conditionJobsLeft.Set(true); // wake up thread
102	}
103
104	// Entry point for the task thread.
105	int InstrumentManagerThread::Main() {
106	#if DEBUG
107	Thread::setNameOfCaller("InstrumentMngr");
108	#endif
109
110	while (true) {
111
112	TestCancel();
113
114	// prevent thread from being cancelled
115	// (e.g. to prevent deadlocks while holding mutex lock(s))
116	pushCancelable(false);
117
118	while (true) {
119	command_t cmd;
120
121	// grab a new command from the queue
122	{
123	LockGuard lock(mutex);
124	if (queue.empty()) break;
125
126	cmd = queue.front();
127	queue.pop_front();
128
129	if (cmd.type == command_t::DIRECT_LOAD) {
130	EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, false);
131	}
132	}
133
134	try {
135	switch (cmd.type) {
136	case command_t::DIRECT_LOAD:
137	cmd.pEngineChannel->PrepareLoadInstrument(cmd.instrumentId.FileName.c_str(), cmd.instrumentId.Index);
138	cmd.pEngineChannel->LoadInstrument();
139	EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, true);
140	break;
141	case command_t::INSTR_MODE:
142	cmd.pManager->SetMode(cmd.instrumentId, cmd.mode);
143	break;
144	default:
145	std::cerr << "InstrumentManagerThread: unknown command - BUG!\n" << std::flush;
146	}
147	} catch (Exception e) {
148	e.PrintMessage();
149	if (cmd.type == command_t::DIRECT_LOAD) {
150	EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, true);
151	}
152	} catch (...) {
153	std::cerr << "InstrumentManagerThread: some exception occured, could not finish task\n" << std::flush;
154	if (cmd.type == command_t::DIRECT_LOAD) {
155	EngineChannelFactory::SetDeleteEnabled(cmd.pEngineChannel, true);
156	}
157	}
158	}
159
160	// perform periodic, custom jobs on behalf of external components
161	{
162	LockGuard lock(periodicJobsMutex);
163	for (ext_job_t job : periodicJobs) {
164	job.fn();
165	}
166	}
167
168	// now allow thread being cancelled again
169	// (since all mutexes are now unlocked)
170	popCancelable();
171
172	// nothing left to do, sleep until new jobs arrive
173	const bool timedOut =
174	(AnyPeriodicJobs()) ?
175	// do wait, but with a maximum timeout value
176	conditionJobsLeft.WaitIf(false, PERIODIC_JOBS_SEC, PERIODIC_JOBS_NSEC) :
177	// wait indefinitely
178	conditionJobsLeft.WaitIf(false);
179	// reset flag
180	if (!timedOut) {
181	conditionJobsLeft.Set(false);
182	// unlock condition object so it can be turned again by other thread
183	conditionJobsLeft.Unlock();
184	}
185	}
186	return 0;
187	}
188
189	/**
190	* Schedule a job to be executed by instrument manager thread periodically.
191	*
192	* This method is intended to be used by external components to execute
193	* instrument files related tasks periodically. Currently this is hard
194	* coded to happen approximately every 200ms, however if the instrument
195	* manager thread is currently blocked by executing other tasks (e.g.
196	* loading some instrument) then this might also be significantly delayed
197	* accordingly.
198	*
199	* The scheduled task will continue to be executed indefinitely until
200	* @c RemovePeriodicJob() is called.
201	*
202	* Currently this method is only used by the SFZ engine for its auto
203	* reload feature (i.e. on modifications of .sfz files by external apps).
204	*
205	* @param name - arbitrary but unique ID for the task
206	* @param fn - actual callback for the task to be executed
207	*/
208	void InstrumentManagerThread::AddPeriodicJob(String name, std::function<void()> fn) {
209	LockGuard lock(periodicJobsMutex);
210	RemovePeriodicJobWithoutLock(name);
211	periodicJobs.push_back({
212	.name = name,
213	.fn = fn
214	});
215	}
216
217	/**
218	* Unschedule a periodic task previously scheduled by @c AddPeriodicJob().
219	*
220	* @param name - unique ID of the previously scheduled periodic task
221	*/
222	void InstrumentManagerThread::RemovePeriodicJob(String name) {
223	LockGuard lock(periodicJobsMutex);
224	RemovePeriodicJobWithoutLock(name);
225	}
226
227	void InstrumentManagerThread::RemovePeriodicJobWithoutLock(String name) {
228	for (size_t i = 0; i < periodicJobs.size(); ++i) {
229	if (periodicJobs[i].name == name) {
230	periodicJobs.erase( periodicJobs.begin() + i );
231	return;
232	}
233	}
234	}
235
236	bool InstrumentManagerThread::AnyPeriodicJobs() {
237	// would probably be OK without a lock, but strictly it would be undefined behaviour
238	LockGuard lock(periodicJobsMutex);
239	return !periodicJobs.empty();
240	}
241
242	void InstrumentManagerThread::EventHandler::ChannelToBeRemoved(SamplerChannel* pChannel) {
243	/*
244	Removing from the queue an eventual scheduled loading of an instrument
245	to a sampler channel which is going to be removed.
246	*/
247	LockGuard lock(pThread->mutex);
248	std::list<command_t>::iterator it;
249	for (it = pThread->queue.begin(); it != pThread->queue.end();){
250	if ((*it).type != command_t::DIRECT_LOAD) { ++it; continue; }
251	if ((*it).pEngineChannel == pChannel->GetEngineChannel()) {
252	it = pThread->queue.erase(it);
253	// we don't break here because the same engine channel could
254	// occur more than once in the queue, so don't make optimizations
255	} else {
256	++it;
257	}
258	}
259	}
260
261	#if defined(__APPLE__) && !defined(__x86_64__)
262	int InstrumentManagerThread::StopThread() {
263	// This is a fix for Mac OS X 32 bit, where SignalStopThread
264	// doesn't wake up a thread waiting for a condition variable.
265	SignalStopThread(); // send stop signal, but don't wait
266	conditionJobsLeft.Set(true); // wake thread
267	return Thread::StopThread(); // then wait for it to cancel
268	}
269	#endif
270
271	#ifdef WIN32
272	int InstrumentManagerThread::StopThread() {
273	int res = Thread::StopThread();
274	conditionJobsLeft.Reset();
275	return res;
276	}
277	#endif
278
279	} // namespace LinuxSampler