refcnt.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 _REFCNT_H_
00024 #define _REFCNT_H_
00025 
00026 #include <config.h>
00027 #include <assert.h>
00028 
00029 #if defined(_WIN32)
00030 # include <windows.h>
00031 
00032 typedef volatile LONG refcnt_t;  /* FIXME where did volatile come from? */
00033 
00034 static inline int _zbar_refcnt (refcnt_t *cnt,
00035                                 int delta)
00036 {
00037     int rc = -1;
00038     if(delta > 0)
00039         while(delta--)
00040             rc = InterlockedIncrement(cnt);
00041     else if(delta < 0)
00042         while(delta++)
00043             rc = InterlockedDecrement(cnt);
00044     assert(rc >= 0);
00045     return(rc);
00046 }
00047 
00048 
00049 #elif defined(HAVE_LIBPTHREAD)
00050 # include <pthread.h>
00051 
00052 typedef int refcnt_t;
00053 
00054 extern pthread_mutex_t _zbar_reflock;
00055 
00056 static inline int _zbar_refcnt (refcnt_t *cnt,
00057                                 int delta)
00058 {
00059     pthread_mutex_lock(&_zbar_reflock);
00060     int rc = (*cnt += delta);
00061     pthread_mutex_unlock(&_zbar_reflock);
00062     assert(rc >= 0);
00063     return(rc);
00064 }
00065 
00066 
00067 #else
00068 
00069 typedef int refcnt_t;
00070 
00071 static inline int _zbar_refcnt (refcnt_t *cnt,
00072                                 int delta)
00073 {
00074     int rc = (*cnt += delta);
00075     assert(rc >= 0);
00076     return(rc);
00077 }
00078 
00079 #endif
00080 
00081 
00082 void _zbar_refcnt_init(void);
00083 
00084 #endif
00085