common/utils/cleanup.h

   1 /* nbdkit
   2  * Copyright Red Hat
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef NBDKIT_CLEANUP_H
  34 #define NBDKIT_CLEANUP_H
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 #include <pthread.h>
  41 #include <assert.h>
  42
  43 #include "unique-name.h"
  44
  45 /* Work around clang bug: https://bugs.llvm.org/show_bug.cgi?id=43482 */
  46 #ifdef __clang__
  47 #define CLANG_UNUSED_VARIABLE_WORKAROUND __attribute__ ((__unused__))
  48 #else
  49 #define CLANG_UNUSED_VARIABLE_WORKAROUND
  50 #endif
  51
  52 /* cleanup.c */
  53 extern void cleanup_free (void *ptr);
  54 #define CLEANUP_FREE __attribute__ ((cleanup (cleanup_free)))
  55
  56 extern void cleanup_mutex_unlock (pthread_mutex_t **ptr);
  57 #define CLEANUP_MUTEX_UNLOCK __attribute__ ((cleanup (cleanup_mutex_unlock)))
  58
  59 #define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \
  60   ACQUIRE_LOCK_FOR_CURRENT_SCOPE_1 ((mutex), NBDKIT_UNIQUE_NAME (_lock))
  61 #define ACQUIRE_LOCK_FOR_CURRENT_SCOPE_1(mutex, lock)                   \
  62   CLEANUP_MUTEX_UNLOCK pthread_mutex_t *lock = mutex;                   \
  63   do {                                                                  \
  64     int _r = pthread_mutex_lock (lock);                                 \
  65     assert (!_r);                                                       \
  66   } while (0)
  67
  68 extern void cleanup_rwlock_unlock (pthread_rwlock_t **ptr);
  69 #define CLEANUP_RWLOCK_UNLOCK __attribute__ ((cleanup (cleanup_rwlock_unlock)))
  70
  71 #define ACQUIRE_WRLOCK_FOR_CURRENT_SCOPE(rwlock) \
  72   ACQUIRE_WRLOCK_FOR_CURRENT_SCOPE_1 ((rwlock), NBDKIT_UNIQUE_NAME (_lock))
  73 #define ACQUIRE_WRLOCK_FOR_CURRENT_SCOPE_1(rwlock, lock)                \
  74   CLEANUP_RWLOCK_UNLOCK pthread_rwlock_t *lock = rwlock;                \
  75   do {                                                                  \
  76     int _r = pthread_rwlock_wrlock (lock);                              \
  77     assert (!_r);                                                       \
  78   } while (0)
  79
  80 #define ACQUIRE_RDLOCK_FOR_CURRENT_SCOPE(rwlock) \
  81   ACQUIRE_RDLOCK_FOR_CURRENT_SCOPE_1 ((rwlock), NBDKIT_UNIQUE_NAME (_lock))
  82 #define ACQUIRE_RDLOCK_FOR_CURRENT_SCOPE_1(rwlock, lock)                \
  83   CLEANUP_RWLOCK_UNLOCK pthread_rwlock_t *lock = rwlock;                \
  84   do {                                                                  \
  85     int _r = pthread_rwlock_rdlock (lock);                              \
  86     assert (!_r);                                                       \
  87   } while (0)
  88
  89 /* cleanup-nbdkit.c */
  90 struct nbdkit_extents;
  91 extern void cleanup_extents_free (struct nbdkit_extents **ptr);
  92 #define CLEANUP_EXTENTS_FREE __attribute__ ((cleanup (cleanup_extents_free)))
  93 struct nbdkit_exports;
  94 extern void cleanup_exports_free (struct nbdkit_exports **ptr);
  95 #define CLEANUP_EXPORTS_FREE __attribute__ ((cleanup (cleanup_exports_free)))
  96
  97 #ifdef __cplusplus
  98 } /* extern "C" */
  99 #endif
 100
 101 #endif /* NBDKIT_CLEANUP_H */