mutex.h

00001 /*------------------------------------------------------------------------
00002  *  Copyright 2007-2009 (c) Jeff Brown <spadix@users.sourceforge.net>
00003  *
00004  *  This file is part of the ZBar Bar Code Reader.
00005  *
00006  *  The ZBar Bar Code Reader is free software; you can redistribute it
00007  *  and/or modify it under the terms of the GNU Lesser Public License as
00008  *  published by the Free Software Foundation; either version 2.1 of
00009  *  the License, or (at your option) any later version.
00010  *
00011  *  The ZBar Bar Code Reader is distributed in the hope that it will be
00012  *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
00013  *  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *  GNU Lesser Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU Lesser Public License
00017  *  along with the ZBar Bar Code Reader; if not, write to the Free
00018  *  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
00019  *  Boston, MA  02110-1301  USA
00020  *
00021  *  http://sourceforge.net/projects/zbar
00022  *------------------------------------------------------------------------*/
00023 #ifndef _ZBAR_MUTEX_H_
00024 #define _ZBAR_MUTEX_H_
00025 
00026 #include <config.h>
00027 
00028 /* simple platform mutex abstraction
00029  */
00030 
00031 #if defined(_WIN32)
00032 
00033 # include <windows.h>
00034 
00035 # define DEBUG_LOCKS
00036 # ifdef DEBUG_LOCKS
00037 
00038 typedef struct zbar_mutex_s {
00039     int count;
00040     CRITICAL_SECTION mutex;
00041 } zbar_mutex_t;
00042 
00043 static inline int _zbar_mutex_init (zbar_mutex_t *lock)
00044 {
00045     lock->count = 1;
00046     InitializeCriticalSection(&lock->mutex);
00047     return(0);
00048 }
00049 
00050 static inline void _zbar_mutex_destroy (zbar_mutex_t *lock)
00051 {
00052     DeleteCriticalSection(&lock->mutex);
00053 }
00054 
00055 static inline int _zbar_mutex_lock (zbar_mutex_t *lock)
00056 {
00057     EnterCriticalSection(&lock->mutex);
00058     if(lock->count++ < 1)
00059         assert(0);
00060     return(0);
00061 }
00062 
00063 static inline int _zbar_mutex_unlock (zbar_mutex_t *lock)
00064 {
00065     if(lock->count-- <= 1)
00066         assert(0);
00067     LeaveCriticalSection(&lock->mutex);
00068     return(0);
00069 }
00070 
00071 # else
00072 
00073 typedef CRITICAL_SECTION zbar_mutex_t;
00074 
00075 static inline int _zbar_mutex_init (zbar_mutex_t *lock)
00076 {
00077     InitializeCriticalSection(lock);
00078     return(0);
00079 }
00080 
00081 static inline void _zbar_mutex_destroy (zbar_mutex_t *lock)
00082 {
00083     DeleteCriticalSection(lock);
00084 }
00085 
00086 static inline int _zbar_mutex_lock (zbar_mutex_t *lock)
00087 {
00088     EnterCriticalSection(lock);
00089     return(0);
00090 }
00091 
00092 static inline int _zbar_mutex_unlock (zbar_mutex_t *lock)
00093 {
00094     LeaveCriticalSection(lock);
00095     return(0);
00096 }
00097 
00098 # endif
00099 
00100 
00101 #elif defined(HAVE_LIBPTHREAD)
00102 
00103 # include <pthread.h>
00104 
00105 typedef pthread_mutex_t zbar_mutex_t;
00106 
00107 static inline int _zbar_mutex_init (zbar_mutex_t *lock)
00108 {
00109 # ifdef DEBUG_LOCKS
00110     pthread_mutexattr_t attr;
00111     pthread_mutexattr_init(&attr);
00112     pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
00113     int rc = pthread_mutex_init(lock, &attr);
00114     pthread_mutexattr_destroy(&attr);
00115     return(rc);
00116 # else
00117     return(pthread_mutex_init(lock, NULL));
00118 # endif
00119 }
00120 
00121 static inline void _zbar_mutex_destroy (zbar_mutex_t *lock)
00122 {
00123     pthread_mutex_destroy(lock);
00124 }
00125 
00126 static inline int _zbar_mutex_lock (zbar_mutex_t *lock)
00127 {
00128     int rc = pthread_mutex_lock(lock);
00129 # ifdef DEBUG_LOCKS
00130     assert(!rc);
00131 # endif
00132     /* FIXME save system code */
00133     /*rc = err_capture(proc, SEV_ERROR, ZBAR_ERR_LOCKING, __func__,
00134                        "unable to lock processor");*/
00135     return(rc);
00136 }
00137 
00138 static inline int _zbar_mutex_unlock (zbar_mutex_t *lock)
00139 {
00140     int rc = pthread_mutex_unlock(lock);
00141 # ifdef DEBUG_LOCKS
00142     assert(!rc);
00143 # endif
00144     /* FIXME save system code */
00145     return(rc);
00146 }
00147 
00148 
00149 #else
00150 
00151 typedef int zbar_mutex_t[0];
00152 
00153 #define _zbar_mutex_init(l) -1
00154 #define _zbar_mutex_destroy(l)
00155 #define _zbar_mutex_lock(l) 0
00156 #define _zbar_mutex_unlock(l) 0
00157 
00158 #endif
00159 
00160 #endif
00161