src/common/Thread.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and 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"

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;
}

/**
 *  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);
}

/// 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();
}

/// Callback function for the POSIX thread API
void __pthread_destructor(void* thread) {
    Thread* t;
    t = (Thread*) thread;
    t->Destructor();
}
1	schoenebeck	53	/***************************************************************************
2			* *
3			* LinuxSampler - modular, streaming capable sampler *
4			* *
5	schoenebeck	56	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	schoenebeck	53	* *
7			* This program is free software; you can redistribute it and/or modify *
8			* it under the terms of the GNU General Public License as published by *
9			* the Free Software Foundation; either version 2 of the License, or *
10			* (at your option) any later version. *
11			* *
12			* This program is distributed in the hope that it will be useful, *
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of *
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15			* GNU General Public License for more details. *
16			* *
17			* You should have received a copy of the GNU General Public License *
18			* along with this program; if not, write to the Free Software *
19			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20			* MA 02111-1307 USA *
21			***************************************************************************/
22
23			#include "Thread.h"
24
25	schoenebeck	392	Thread::Thread(bool LockMemory, bool RealTime, int PriorityMax, int PriorityDelta) {
26			this->bLockedMemory = LockMemory;
27	schoenebeck	53	this->isRealTime = RealTime;
28			this->Running = false;
29			this->PriorityDelta = PriorityDelta;
30			this->PriorityMax = PriorityMax;
31			__thread_destructor_key = 0;
32			pthread_mutex_init(&__thread_state_mutex, NULL);
33	schoenebeck	57	pthread_cond_init(&__thread_start_condition, NULL);
34	schoenebeck	53	pthread_cond_init(&__thread_exit_condition, NULL);
35			}
36
37			Thread::~Thread() {
38	schoenebeck	57	StopThread();
39			pthread_cond_destroy(&__thread_start_condition);
40	schoenebeck	53	pthread_cond_destroy(&__thread_exit_condition);
41			pthread_mutex_destroy(&__thread_state_mutex);
42			}
43
44			/**
45	schoenebeck	57	* Starts the thread. This method will wait until the thread actually
46			* started it's execution before it will return. The abstract method
47			* Main() is the entry point for the new thread. You have to implement the
48			* Main() method in your subclass.
49	schoenebeck	53	*/
50			int Thread::StartThread() {
51	schoenebeck	57	pthread_mutex_lock(&__thread_state_mutex);
52			if (!Running) {
53			SignalStartThread();
54			pthread_cond_wait(&__thread_start_condition, &__thread_state_mutex);
55			}
56			pthread_mutex_unlock(&__thread_state_mutex);
57			return 0;
58			}
59
60			/**
61			* Starts the thread. This method will signal to start the thread and
62			* return immediately. Note that the thread might not yet run when this
63			* method returns! The abstract method Main() is the entry point for the
64			* new thread. You have to implement the Main() method in your subclass.
65			*
66			* @see StartThread()
67			*/
68			int Thread::SignalStartThread() {
69	schoenebeck	53	// Create and run the thread
70			int res = pthread_create(&this->__thread_id, NULL, __pthread_launcher, this);
71			switch (res) {
72			case 0: // Success
73			break;
74			case EAGAIN:
75			std::cerr << "Thread creation failed: System doesn't allow to create another thread."
76			<< std::endl << std::flush;
77			this->Running = false;
78			break;
79			case EPERM:
80			std::cerr << "Thread creation failed: You're lacking permisssions to set required scheduling policy and parameters."
81			<< std::endl << std::flush;
82			this->Running = false;
83			break;
84			default:
85			std::cerr << "Thread creation failed: Unknown cause."
86			<< std::endl << std::flush;
87			this->Running = false;
88			break;
89			}
90			return res;
91			}
92
93			/**
94			* Stops the thread. This method will wait until the thread actually stopped
95			* it's execution before it will return.
96			*/
97			int Thread::StopThread() {
98			pthread_mutex_lock(&__thread_state_mutex);
99			if (Running) {
100			SignalStopThread();
101			pthread_cond_wait(&__thread_exit_condition, &__thread_state_mutex);
102	schoenebeck	351	pthread_detach(__thread_id);
103	schoenebeck	53	}
104			pthread_mutex_unlock(&__thread_state_mutex);
105			return 0;
106			}
107
108			/**
109			* Stops the thread. This method will signal to stop the thread and return
110			* immediately. Note that the thread might still run when this method
111			* returns!
112	schoenebeck	57	*
113			* @see StopThread()
114	schoenebeck	53	*/
115			int Thread::SignalStopThread() {
116			pthread_cancel(__thread_id);
117			return 0;
118			}
119
120			/**
121			* Sets the process SCHED_FIFO policy, if max=1 then set at max priority,
122			* else use min priority. delta is added to the priority so that we can
123			* for example set 3 SCHED_FIFO tasks to different priorities by specifying
124			* delta 0 , -1 , -2 ( 0 = highest priority because -1 is subtracted to the
125			* current priority).
126			*/
127			int Thread::SetSchedulingPriority() {
128	schoenebeck	361	#if !defined(__APPLE__)
129	schoenebeck	53	struct sched_param schp;
130
131	schoenebeck	57	if (!isRealTime) return 0;
132
133	schoenebeck	53	/*
134			* set the process to realtime privs
135			*/
136			memset(&schp, 0, sizeof(schp));
137			if (this->PriorityMax == 1) {
138			schp.sched_priority = sched_get_priority_max(SCHED_FIFO) + this->PriorityDelta;
139			}
140			if (this->PriorityMax == -1) {
141			schp.sched_priority = sched_get_priority_min(SCHED_FIFO) + this->PriorityDelta;
142			}
143
144			if (sched_setscheduler(0, SCHED_FIFO, &schp) != 0) {
145	schoenebeck	392	perror("Thread: WARNING, can't assign realtime scheduling to thread!");
146	schoenebeck	53	return -1;
147			}
148	schoenebeck	361	#endif
149	schoenebeck	53	return 0;
150			}
151
152			/**
153	schoenebeck	392	* Locks the memory so it will not be swapped out by the operating system.
154			*/
155			int Thread::LockMemory() {
156	letz	399	#if !defined(__APPLE__)
157	schoenebeck	392	if (!bLockedMemory) return 0;
158			if (mlockall(MCL_CURRENT \| MCL_FUTURE) < 0) {
159			perror("Thread: WARNING, can't mlockall() memory!");
160			return -1;
161			}
162	letz	399	#endif
163	schoenebeck	392	return 0;
164			}
165
166			/**
167	schoenebeck	53	* Registers thread destructor callback function which will be executed when
168			* the thread stops it's execution and sets the 'Running' flag to true. This
169			* method will be called by the __pthread_launcher callback function, DO NOT
170			* CALL THIS METHOD YOURSELF!
171			*/
172			void Thread::EnableDestructor() {
173			pthread_mutex_lock(&__thread_state_mutex);
174			pthread_key_create(&__thread_destructor_key, __pthread_destructor);
175			pthread_setspecific(__thread_destructor_key, this);
176			Running = true;
177			pthread_mutex_unlock(&__thread_state_mutex);
178	schoenebeck	57	pthread_cond_broadcast(&__thread_start_condition);
179	schoenebeck	53	}
180
181			/**
182			* Will be called by the kernel when the thread stops it's execution.
183			*/
184			int Thread::Destructor() {
185			pthread_key_delete(__thread_destructor_key);
186			pthread_mutex_lock(&__thread_state_mutex);
187			Running = false;
188			pthread_mutex_unlock(&__thread_state_mutex);
189			pthread_cond_broadcast(&__thread_exit_condition);
190			}
191
192			/// Callback function for the POSIX thread API
193			void* __pthread_launcher(void* thread) {
194	schoenebeck	63	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL); // let the thread be killable under any circumstances
195	schoenebeck	53	Thread* t;
196			t = (Thread*) thread;
197	schoenebeck	57	t->SetSchedulingPriority();
198	schoenebeck	392	t->LockMemory();
199	schoenebeck	53	t->EnableDestructor();
200			t->Main();
201			}
202
203			/// Callback function for the POSIX thread API
204			void __pthread_destructor(void* thread) {
205			Thread* t;
206			t = (Thread*) thread;
207			t->Destructor();
208			}