src/ppmutex.c

   1 /* This file is part of Pazpar2.
   2    Copyright (C) 2006-2013 Index Data
   3
   4 Pazpar2 is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Pazpar2 is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17
  18 */
  19
  20 /** \file
  21     \brief control MUTEX debugging
  22 */
  23
  24 #if HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <assert.h>
  29 #include <yaz/log.h>
  30 #include "ppmutex.h"
  31
  32 static int ppmutex_level = 0;
  33
  34 void pazpar2_mutex_init(void)
  35 {
  36     ppmutex_level = yaz_log_module_level("mutex");
  37 }
  38
  39 void pazpar2_mutex_create(YAZ_MUTEX *p, const char *name)
  40 {
  41     assert(p);
  42     yaz_mutex_create(p);
  43     yaz_mutex_set_name(*p, ppmutex_level, name);
  44 }
  45
  46 void pazpar2_lock_rdwr_init(Pazpar2_lock_rdwr *p)
  47 {
  48     p->readers_reading = 0;
  49     p->writers_writing = 0;
  50 #if YAZ_POSIX_THREADS
  51     pthread_mutex_init(&p->mutex, 0);
  52     pthread_cond_init(&p->lock_free, 0);
  53 #endif
  54 }
  55
  56 void pazpar2_lock_rdwr_destroy(Pazpar2_lock_rdwr *p)
  57 {
  58     assert (p->readers_reading == 0);
  59     assert (p->writers_writing == 0);
  60 #if YAZ_POSIX_THREADS
  61     pthread_mutex_destroy(&p->mutex);
  62     pthread_cond_destroy(&p->lock_free);
  63 #endif
  64 }
  65
  66 void pazpar2_lock_rdwr_rlock(Pazpar2_lock_rdwr *p)
  67 {
  68 #if YAZ_POSIX_THREADS
  69     pthread_mutex_lock(& p->mutex);
  70     while (p->writers_writing)
  71         pthread_cond_wait(&p->lock_free, &p->mutex);
  72     p->readers_reading++;
  73     pthread_mutex_unlock(&p->mutex);
  74 #endif
  75 }
  76
  77 void pazpar2_lock_rdwr_wlock(Pazpar2_lock_rdwr *p)
  78 {
  79 #if YAZ_POSIX_THREADS
  80     pthread_mutex_lock(&p->mutex);
  81     while (p->writers_writing || p->readers_reading)
  82         pthread_cond_wait(&p->lock_free, &p->mutex);
  83     p->writers_writing++;
  84     pthread_mutex_unlock(&p->mutex);
  85 #endif
  86 }
  87
  88 void pazpar2_lock_rdwr_upgrade(Pazpar2_lock_rdwr *p)
  89 {
  90 #if YAZ_POSIX_THREADS
  91     assert(p->readers_reading > 0);
  92     pthread_mutex_lock(&p->mutex);
  93     --p->readers_reading;
  94     while (p->writers_writing || p->readers_reading)
  95         pthread_cond_wait(&p->lock_free, &p->mutex);
  96     p->writers_writing++;
  97     pthread_mutex_unlock(&p->mutex);
  98 #endif
  99 }
 100
 101 void pazpar2_lock_rdwr_downgrade(Pazpar2_lock_rdwr *p)
 102 {
 103 #if YAZ_POSIX_THREADS
 104     assert(p->writers_writing == 1);
 105     pthread_mutex_lock(&p->mutex);
 106     p->writers_writing--;
 107     p->readers_reading++;
 108     pthread_cond_broadcast(&p->lock_free);
 109     pthread_mutex_unlock(&p->mutex);
 110 #endif
 111 }
 112
 113 void pazpar2_lock_rdwr_runlock(Pazpar2_lock_rdwr *p)
 114 {
 115 #if YAZ_POSIX_THREADS
 116     assert(p->readers_reading > 0);
 117     pthread_mutex_lock(&p->mutex);
 118     p->readers_reading--;
 119     if (p->readers_reading == 0)
 120         pthread_cond_signal(&p->lock_free);
 121     pthread_mutex_unlock(&p->mutex);
 122 #endif
 123 }
 124
 125 void pazpar2_lock_rdwr_wunlock(Pazpar2_lock_rdwr *p)
 126 {
 127 #if YAZ_POSIX_THREADS
 128     assert(p->writers_writing == 1);
 129     pthread_mutex_lock(&p->mutex);
 130     p->writers_writing--;
 131     pthread_cond_broadcast(&p->lock_free);
 132     pthread_mutex_unlock(&p->mutex);
 133 #endif
 134 }
 135
 136 /*
 137  * Local variables:
 138  * c-basic-offset: 4
 139  * c-file-style: "Stroustrup"
 140  * indent-tabs-mode: nil
 141  * End:
 142  * vim: shiftwidth=4 tabstop=8 expandtab
 143  */
 144