src/common/Condition.h

/***************************************************************************
 *                                                                         *
 *   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                                                   *
 ***************************************************************************/

#ifndef __CONDITION_H__
#define __CONDITION_H__

#include "Mutex.h"

/**
 * Thread safe boolean condition.
 *
 * This is not meant to be used for real time operation!
 */
class Condition : public Mutex {
    public:
        /**
         * Constructor
         *
         * @param bInitialCondition - optional: starting condition
         *                            (default = false)
         */
        Condition(bool bInitialCondition = false);

        /**
         * Destructor
         */
        ~Condition();

        /**
         * Blocks the calling thread if current condition equals
         * \a bCondition, in this case the calling thread will be blocked
         * until condition turns. Upon successful return the Condition
         * object is locked, so the calling thread can safely run it's
         * critical section and has to explicitly call Unlock() right after
         * it left it's critcal section.
         *
         * @param bCondition         - block in case of this condition
         * @param TimeoutSeconds     - optional: max. wait time in seconds
         *                             (default: 0s)
         * @param TimeoutNanoSeconds - optional: max wait time in nano
         *                             seconds (default: 0ns)
         * @returns  0 on success, a value less than 0 if timeout exceeded
         */
        int WaitIf(bool bCondition, long TimeoutSeconds = 0L, long TimeoutNanoSeconds = 0L);

        /**
         * Same as WaitIf(), except that WaitAndUnlockIf() will unlock the
         * Condition object, so only use this call if you don't need to
         * enter a thread critical section, otherwise use WaitIf() instead!
         *
         * @param bCondition         - block in case of this condition
         * @param TimeoutSeconds     - optional: max. wait time in seconds
         *                             (default: 0s)
         * @param TimeoutNanoSeconds - optional: max wait time in nano
         *                             seconds (default: 0ns)
         * @returns  0 on success, a value less than 0 if timeout exceeded
         * @see WaitIf()
         */
        int WaitAndUnlockIf(bool bCondition, long TimeoutSeconds = 0L, long TimeoutNanoSeconds = 0L);

        /**
         * Set Condition object to \a bCondition. Upon change of the
         * condition, other threads waiting for \a bCondition will be
         * awakened.
         *
         * @param bCondition - new condition
         */
        void Set(bool bCondition);

    protected:
        pthread_cond_t __posix_true_condition;
        pthread_cond_t __posix_false_condition;
        bool bCondition;
};

#endif // __CONDITION_H__
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			#ifndef __CONDITION_H__
24			#define __CONDITION_H__
25
26			#include "Mutex.h"
27
28			/**
29			* Thread safe boolean condition.
30			*
31			* This is not meant to be used for real time operation!
32			*/
33			class Condition : public Mutex {
34			public:
35			/**
36			* Constructor
37			*
38			* @param bInitialCondition - optional: starting condition
39			* (default = false)
40			*/
41			Condition(bool bInitialCondition = false);
42
43			/**
44			* Destructor
45			*/
46			~Condition();
47
48			/**
49			* Blocks the calling thread if current condition equals
50			* \a bCondition, in this case the calling thread will be blocked
51			* until condition turns. Upon successful return the Condition
52			* object is locked, so the calling thread can safely run it's
53			* critical section and has to explicitly call Unlock() right after
54			* it left it's critcal section.
55			*
56			* @param bCondition - block in case of this condition
57			* @param TimeoutSeconds - optional: max. wait time in seconds
58			* (default: 0s)
59			* @param TimeoutNanoSeconds - optional: max wait time in nano
60			* seconds (default: 0ns)
61			* @returns 0 on success, a value less than 0 if timeout exceeded
62			*/
63			int WaitIf(bool bCondition, long TimeoutSeconds = 0L, long TimeoutNanoSeconds = 0L);
64
65			/**
66			* Same as WaitIf(), except that WaitAndUnlockIf() will unlock the
67			* Condition object, so only use this call if you don't need to
68			* enter a thread critical section, otherwise use WaitIf() instead!
69			*
70			* @param bCondition - block in case of this condition
71			* @param TimeoutSeconds - optional: max. wait time in seconds
72			* (default: 0s)
73			* @param TimeoutNanoSeconds - optional: max wait time in nano
74			* seconds (default: 0ns)
75			* @returns 0 on success, a value less than 0 if timeout exceeded
76			* @see WaitIf()
77			*/
78			int WaitAndUnlockIf(bool bCondition, long TimeoutSeconds = 0L, long TimeoutNanoSeconds = 0L);
79
80			/**
81			* Set Condition object to \a bCondition. Upon change of the
82			* condition, other threads waiting for \a bCondition will be
83			* awakened.
84			*
85			* @param bCondition - new condition
86			*/
87			void Set(bool bCondition);
88
89			protected:
90			pthread_cond_t __posix_true_condition;
91			pthread_cond_t __posix_false_condition;
92			bool bCondition;
93			};
94
95			#endif // __CONDITION_H__