Re: [Libguestfs] [RFC: nbdkit PATCH] cleanup: Assert mutex sanity

Although we haven't always checked that pthread_mutex_[un]lock succeeded, it never hurts to avoid blatant programming bugs such as when EINVAL can detect use of an uninitialized mutex.

Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- Applies on top of my series to move cleanup.c to common/ Should I also go through and add checking to other bare pthread_mutex_[un]lock() calls?

common/utils/cleanup.h | 5 ++++- common/utils/cleanup.c | 3 ++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/common/utils/cleanup.h b/common/utils/cleanup.h index e6e6140..0ab9e65 100644 --- a/common/utils/cleanup.h +++ b/common/utils/cleanup.h @@ -43,6 +43,9 @@ extern void cleanup_unlock (pthread_mutex_t **ptr); #define CLEANUP_UNLOCK __attribute__((cleanup (cleanup_unlock))) #define ACQUIRE_LOCK_FOR_CURRENT_SCOPE(mutex) \ CLEANUP_UNLOCK pthread_mutex_t *_lock = mutex; \ - pthread_mutex_lock (_lock) + do { \ + int _r = pthread_mutex_lock (_lock); \ + assert (!_r); \ + } while (0) #endif /* NBDKIT_CLEANUP_H */ diff --git a/common/utils/cleanup.c b/common/utils/cleanup.c index 196d910..995f46c 100644 --- a/common/utils/cleanup.c +++ b/common/utils/cleanup.c @@ -53,5 +53,6 @@ cleanup_extents_free (void *ptr) void cleanup_unlock (pthread_mutex_t **ptr) { - pthread_mutex_unlock (*ptr); + int r = pthread_mutex_unlock (*ptr); + assert (!r); }