src/common/Thread.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2007 Christian Schoenebeck                       *
 *                                                                         *
 *   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., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include "Thread.h"

namespace LinuxSampler {

Thread::Thread(bool LockMemory, bool RealTime, int PriorityMax, int PriorityDelta) {
    this->bLockedMemory     = LockMemory;
    this->isRealTime        = RealTime;
    this->Running           = false;
    this->PriorityDelta     = PriorityDelta;
    this->PriorityMax       = PriorityMax;
    __thread_destructor_key = 0;
    pthread_mutex_init(&__thread_state_mutex, NULL);
    pthread_cond_init(&__thread_start_condition, NULL);
    pthread_cond_init(&__thread_exit_condition, NULL);
}

Thread::~Thread() {
    StopThread();
    pthread_cond_destroy(&__thread_start_condition);
    pthread_cond_destroy(&__thread_exit_condition);
    pthread_mutex_destroy(&__thread_state_mutex);
}

/**
 *  Starts the thread. This method will wait until the thread actually
 *  started it's execution before it will return. The abstract method
 *  Main() is the entry point for the new thread. You have to implement the
 *  Main() method in your subclass.
 */
int Thread::StartThread() {
    pthread_mutex_lock(&__thread_state_mutex);
    if (!Running) {
        SignalStartThread();
        pthread_cond_wait(&__thread_start_condition, &__thread_state_mutex);
    }
    pthread_mutex_unlock(&__thread_state_mutex);
    return 0;
}

/**
 *  Starts the thread. This method will signal to start the thread and
 *  return immediately. Note that the thread might not yet run when this
 *  method returns! The abstract method Main() is the entry point for the
 *  new thread. You have to implement the Main() method in your subclass.
 *
 *  @see StartThread()
 */
int Thread::SignalStartThread() {
    // Create and run the thread
    int res = pthread_create(&this->__thread_id, NULL, __pthread_launcher, this);
    switch (res) {
        case 0: // Success
            break;
        case EAGAIN:
            std::cerr << "Thread creation failed: System doesn't allow to create another thread."
                      << std::endl << std::flush;
            this->Running = false;
            break;
        case EPERM:
            std::cerr << "Thread creation failed: You're lacking permisssions to set required scheduling policy and parameters."
                      << std::endl << std::flush;
            this->Running = false;
            break;
        default:
            std::cerr << "Thread creation failed: Unknown cause."
                      << std::endl << std::flush;
            this->Running = false;
            break;
    }
    return res;
}

/**
 *  Stops the thread. This method will wait until the thread actually stopped
 *  it's execution before it will return.
 */
int Thread::StopThread() {
    pthread_mutex_lock(&__thread_state_mutex);
    if (Running) {
        SignalStopThread();
        pthread_cond_wait(&__thread_exit_condition, &__thread_state_mutex);
        pthread_detach(__thread_id);
    }
    pthread_mutex_unlock(&__thread_state_mutex);
    return 0;
}

/**
 *  Stops the thread. This method will signal to stop the thread and return
 *  immediately. Note that the thread might still run when this method
 *  returns!
 *
 *  @see StopThread()
 */
int Thread::SignalStopThread() {
    pthread_cancel(__thread_id);
    return 0;
}

/**
 * Returns @c true in case the thread is currently running.
 */
bool Thread::IsRunning() {
    return Running;
}

/**
 *  Sets the process SCHED_FIFO policy,  if max=1 then set at max priority,
 *  else use min priority. delta is added to the priority so that we can
 *  for example set 3 SCHED_FIFO tasks to different priorities by specifying
 *  delta  0 , -1 , -2  ( 0 = highest priority because -1 is subtracted to the
 *  current priority).
 */
int Thread::SetSchedulingPriority() {
#if !defined(__APPLE__)
    struct sched_param schp;

    if (!isRealTime) return 0;

    /*
     * set the process to realtime privs
     */
    memset(&schp, 0, sizeof(schp));
    if (this->PriorityMax == 1) {
        schp.sched_priority = sched_get_priority_max(SCHED_FIFO) + this->PriorityDelta;
    }
    if (this->PriorityMax == -1) {
        schp.sched_priority = sched_get_priority_min(SCHED_FIFO) + this->PriorityDelta;
    }

    if (sched_setscheduler(0, SCHED_FIFO, &schp) != 0) {
        perror("Thread: WARNING, can't assign realtime scheduling to thread!");
        return -1;
    }
#endif
    return 0;
}

/**
 * Locks the memory so it will not be swapped out by the operating system.
 */
int Thread::LockMemory() {
#if !defined(__APPLE__)
    if (!bLockedMemory) return 0;
    if (mlockall(MCL_CURRENT | MCL_FUTURE) < 0) {
        perror("Thread: WARNING, can't mlockall() memory!");
        return -1;
    }
#endif
    return 0;
}

/**
 *  Registers thread destructor callback function which will be executed when
 *  the thread stops it's execution and sets the 'Running' flag to true. This
 *  method will be called by the __pthread_launcher callback function, DO NOT
 *  CALL THIS METHOD YOURSELF!
 */
void Thread::EnableDestructor() {
    pthread_mutex_lock(&__thread_state_mutex);
    pthread_key_create(&__thread_destructor_key, __pthread_destructor);
    pthread_setspecific(__thread_destructor_key, this);
    Running = true;
    pthread_mutex_unlock(&__thread_state_mutex);
    pthread_cond_broadcast(&__thread_start_condition);
}

/**
 *  Will be called by the kernel when the thread stops it's execution.
 */
int Thread::Destructor() {
    pthread_key_delete(__thread_destructor_key);
    pthread_mutex_lock(&__thread_state_mutex);
    Running = false;
    pthread_mutex_unlock(&__thread_state_mutex);
    pthread_cond_broadcast(&__thread_exit_condition);
    return 0;
}

/// Callback function for the POSIX thread API
void* __pthread_launcher(void* thread) {
    pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL); // let the thread be killable under any circumstances
    Thread* t;
    t = (Thread*) thread;
    t->SetSchedulingPriority();
    t->LockMemory();
    t->EnableDestructor();
    t->Main();
    return NULL;
}

/// Callback function for the POSIX thread API
void __pthread_destructor(void* thread) {
    Thread* t;
    t = (Thread*) thread;
    t->Destructor();
}

} // namespace LinuxSampler
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 - 2007 Christian Schoenebeck *
7	* *
8	* This program is free software; you can redistribute it and/or modify *
9	* it under the terms of the GNU General Public License as published by *
10	* the Free Software Foundation; either version 2 of the License, or *
11	* (at your option) any later version. *
12	* *
13	* This program is distributed in the hope that it will be useful, *
14	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16	* GNU General Public License for more details. *
17	* *
18	* You should have received a copy of the GNU General Public License *
19	* along with this program; if not, write to the Free Software *
20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21	* MA 02111-1307 USA *
22	***************************************************************************/
23
24	#include "Thread.h"
25
26	namespace LinuxSampler {
27
28	Thread::Thread(bool LockMemory, bool RealTime, int PriorityMax, int PriorityDelta) {
29	this->bLockedMemory = LockMemory;
30	this->isRealTime = RealTime;
31	this->Running = false;
32	this->PriorityDelta = PriorityDelta;
33	this->PriorityMax = PriorityMax;
34	__thread_destructor_key = 0;
35	pthread_mutex_init(&__thread_state_mutex, NULL);
36	pthread_cond_init(&__thread_start_condition, NULL);
37	pthread_cond_init(&__thread_exit_condition, NULL);
38	}
39
40	Thread::~Thread() {
41	StopThread();
42	pthread_cond_destroy(&__thread_start_condition);
43	pthread_cond_destroy(&__thread_exit_condition);
44	pthread_mutex_destroy(&__thread_state_mutex);
45	}
46
47	/**
48	* Starts the thread. This method will wait until the thread actually
49	* started it's execution before it will return. The abstract method
50	* Main() is the entry point for the new thread. You have to implement the
51	* Main() method in your subclass.
52	*/
53	int Thread::StartThread() {
54	pthread_mutex_lock(&__thread_state_mutex);
55	if (!Running) {
56	SignalStartThread();
57	pthread_cond_wait(&__thread_start_condition, &__thread_state_mutex);
58	}
59	pthread_mutex_unlock(&__thread_state_mutex);
60	return 0;
61	}
62
63	/**
64	* Starts the thread. This method will signal to start the thread and
65	* return immediately. Note that the thread might not yet run when this
66	* method returns! The abstract method Main() is the entry point for the
67	* new thread. You have to implement the Main() method in your subclass.
68	*
69	* @see StartThread()
70	*/
71	int Thread::SignalStartThread() {
72	// Create and run the thread
73	int res = pthread_create(&this->__thread_id, NULL, __pthread_launcher, this);
74	switch (res) {
75	case 0: // Success
76	break;
77	case EAGAIN:
78	std::cerr << "Thread creation failed: System doesn't allow to create another thread."
79	<< std::endl << std::flush;
80	this->Running = false;
81	break;
82	case EPERM:
83	std::cerr << "Thread creation failed: You're lacking permisssions to set required scheduling policy and parameters."
84	<< std::endl << std::flush;
85	this->Running = false;
86	break;
87	default:
88	std::cerr << "Thread creation failed: Unknown cause."
89	<< std::endl << std::flush;
90	this->Running = false;
91	break;
92	}
93	return res;
94	}
95
96	/**
97	* Stops the thread. This method will wait until the thread actually stopped
98	* it's execution before it will return.
99	*/
100	int Thread::StopThread() {
101	pthread_mutex_lock(&__thread_state_mutex);
102	if (Running) {
103	SignalStopThread();
104	pthread_cond_wait(&__thread_exit_condition, &__thread_state_mutex);
105	pthread_detach(__thread_id);
106	}
107	pthread_mutex_unlock(&__thread_state_mutex);
108	return 0;
109	}
110
111	/**
112	* Stops the thread. This method will signal to stop the thread and return
113	* immediately. Note that the thread might still run when this method
114	* returns!
115	*
116	* @see StopThread()
117	*/
118	int Thread::SignalStopThread() {
119	pthread_cancel(__thread_id);
120	return 0;
121	}
122
123	/**
124	* Returns @c true in case the thread is currently running.
125	*/
126	bool Thread::IsRunning() {
127	return Running;
128	}
129
130	/**
131	* Sets the process SCHED_FIFO policy, if max=1 then set at max priority,
132	* else use min priority. delta is added to the priority so that we can
133	* for example set 3 SCHED_FIFO tasks to different priorities by specifying
134	* delta 0 , -1 , -2 ( 0 = highest priority because -1 is subtracted to the
135	* current priority).
136	*/
137	int Thread::SetSchedulingPriority() {
138	#if !defined(__APPLE__)
139	struct sched_param schp;
140
141	if (!isRealTime) return 0;
142
143	/*
144	* set the process to realtime privs
145	*/
146	memset(&schp, 0, sizeof(schp));
147	if (this->PriorityMax == 1) {
148	schp.sched_priority = sched_get_priority_max(SCHED_FIFO) + this->PriorityDelta;
149	}
150	if (this->PriorityMax == -1) {
151	schp.sched_priority = sched_get_priority_min(SCHED_FIFO) + this->PriorityDelta;
152	}
153
154	if (sched_setscheduler(0, SCHED_FIFO, &schp) != 0) {
155	perror("Thread: WARNING, can't assign realtime scheduling to thread!");
156	return -1;
157	}
158	#endif
159	return 0;
160	}
161
162	/**
163	* Locks the memory so it will not be swapped out by the operating system.
164	*/
165	int Thread::LockMemory() {
166	#if !defined(__APPLE__)
167	if (!bLockedMemory) return 0;
168	if (mlockall(MCL_CURRENT \| MCL_FUTURE) < 0) {
169	perror("Thread: WARNING, can't mlockall() memory!");
170	return -1;
171	}
172	#endif
173	return 0;
174	}
175
176	/**
177	* Registers thread destructor callback function which will be executed when
178	* the thread stops it's execution and sets the 'Running' flag to true. This
179	* method will be called by the __pthread_launcher callback function, DO NOT
180	* CALL THIS METHOD YOURSELF!
181	*/
182	void Thread::EnableDestructor() {
183	pthread_mutex_lock(&__thread_state_mutex);
184	pthread_key_create(&__thread_destructor_key, __pthread_destructor);
185	pthread_setspecific(__thread_destructor_key, this);
186	Running = true;
187	pthread_mutex_unlock(&__thread_state_mutex);
188	pthread_cond_broadcast(&__thread_start_condition);
189	}
190
191	/**
192	* Will be called by the kernel when the thread stops it's execution.
193	*/
194	int Thread::Destructor() {
195	pthread_key_delete(__thread_destructor_key);
196	pthread_mutex_lock(&__thread_state_mutex);
197	Running = false;
198	pthread_mutex_unlock(&__thread_state_mutex);
199	pthread_cond_broadcast(&__thread_exit_condition);
200	return 0;
201	}
202
203	/// Callback function for the POSIX thread API
204	void* __pthread_launcher(void* thread) {
205	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL); // let the thread be killable under any circumstances
206	Thread* t;
207	t = (Thread*) thread;
208	t->SetSchedulingPriority();
209	t->LockMemory();
210	t->EnableDestructor();
211	t->Main();
212	return NULL;
213	}
214
215	/// Callback function for the POSIX thread API
216	void __pthread_destructor(void* thread) {
217	Thread* t;
218	t = (Thread*) thread;
219	t->Destructor();
220	}
221
222	} // namespace LinuxSampler