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| author | dimitri staessens <dimitri.staessens@intec.ugent.be> | 2016-08-08 19:08:25 +0200 |
|---|---|---|
| committer | dimitri staessens <dimitri.staessens@intec.ugent.be> | 2016-08-08 19:24:18 +0200 |
| commit | 9294c0727d7381fcd1bac3f355501a85ed13baff (patch) | |
| tree | 3989018ce89ec1313932c27b4311e907d4ff56ad /src/lib | |
| parent | 3220cd99c42f08bbd959cf73b9fc7b3ca8375676 (diff) | |
| download | ouroboros-9294c0727d7381fcd1bac3f355501a85ed13baff.tar.gz ouroboros-9294c0727d7381fcd1bac3f355501a85ed13baff.zip | |
lib: shm_ap_rbuff: Fix endless wait
When the rbuff was empty, the blocking read would wait forever for a
read.
Diffstat (limited to 'src/lib')
| -rw-r--r-- | src/lib/shm_ap_rbuff.c | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/src/lib/shm_ap_rbuff.c b/src/lib/shm_ap_rbuff.c index e9c51533..683d0185 100644 --- a/src/lib/shm_ap_rbuff.c +++ b/src/lib/shm_ap_rbuff.c @@ -42,11 +42,11 @@ #define PTHREAD_COND_CLOCK CLOCK_MONOTONIC -#define SHM_RBUFF_FILE_SIZE (SHM_BUFFER_SIZE * sizeof(struct rb_entry) \ +#define SHM_RBUFF_FILE_SIZE (SHM_BUFFER_SIZE * sizeof(struct rb_entry) \ + 2 * sizeof(size_t) + sizeof(pthread_mutex_t) \ + 2 * sizeof (pthread_cond_t)) -#define shm_rbuff_used(rb)((*rb->ptr_head + SHM_BUFFER_SIZE - *rb->ptr_tail) \ +#define shm_rbuff_used(rb)((*rb->ptr_head + SHM_BUFFER_SIZE - *rb->ptr_tail) \ & (SHM_BUFFER_SIZE - 1)) #define shm_rbuff_free(rb)(shm_rbuff_used(rb) + 1 < SHM_BUFFER_SIZE) #define shm_rbuff_empty(rb) (*rb->ptr_head == *rb->ptr_tail) @@ -421,25 +421,45 @@ ssize_t shm_ap_rbuff_read_port_b(struct shm_ap_rbuff * rb, pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock, (void *) rb->lock); - while (tail_el_ptr(rb)->port_id != port_id) { - if (timeout != NULL) - ret = pthread_cond_timedwait(rb->del, - rb->lock, - &abstime); - else - ret = pthread_cond_wait(rb->del, rb->lock); - - if (ret == EOWNERDEAD) { - LOG_DBG("Recovering dead mutex."); - pthread_mutex_consistent(rb->lock); + while (shm_rbuff_empty(rb) || tail_el_ptr(rb)->port_id != port_id) { + while (shm_rbuff_empty(rb)) { + if (timeout != NULL) + ret = pthread_cond_timedwait(rb->add, + rb->lock, + &abstime); + else + ret = pthread_cond_wait(rb->add, rb->lock); + + if (ret == EOWNERDEAD) { + LOG_DBG("Recovering dead mutex."); + pthread_mutex_consistent(rb->lock); + } + + if (ret == ETIMEDOUT) { + pthread_mutex_unlock(rb->lock); + return -ret; + } } - if (ret == ETIMEDOUT) { - pthread_mutex_unlock(rb->lock); - return -ret; + while (tail_el_ptr(rb)->port_id != port_id) { + if (timeout != NULL) + ret = pthread_cond_timedwait(rb->del, + rb->lock, + &abstime); + else + ret = pthread_cond_wait(rb->del, rb->lock); + + if (ret == EOWNERDEAD) { + LOG_DBG("Recovering dead mutex."); + pthread_mutex_consistent(rb->lock); + } + + if (ret == ETIMEDOUT) { + pthread_mutex_unlock(rb->lock); + return -ret; + } } } - idx = tail_el_ptr(rb)->index; *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_BUFFER_SIZE -1); |