From e79f151adc07538fbb1057442df2c1fe6ac01836 Mon Sep 17 00:00:00 2001 From: dimitri staessens Date: Sun, 15 May 2016 02:31:54 +0200 Subject: lib: shm_ap_rbuff: simplified file offsets Used simpler pointer arithmetic to calculate the file offset pointers. --- src/lib/shm_ap_rbuff.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) (limited to 'src/lib/shm_ap_rbuff.c') diff --git a/src/lib/shm_ap_rbuff.c b/src/lib/shm_ap_rbuff.c index da6f0e33..0524a96c 100644 --- a/src/lib/shm_ap_rbuff.c +++ b/src/lib/shm_ap_rbuff.c @@ -38,7 +38,7 @@ #define SHM_RBUFF_FILE_SIZE (SHM_RBUFF_SIZE * sizeof(struct rb_entry) \ + 2 * sizeof(size_t) + sizeof(pthread_mutex_t)) -#define shm_rbuff_used(rb)((*rb->ptr_head + SHM_RBUFF_SIZE - *rb->ptr_tail)\ +#define shm_rbuff_used(rb)((*rb->ptr_head + SHM_RBUFF_SIZE - *rb->ptr_tail) \ & (SHM_RBUFF_SIZE - 1)) #define shm_rbuff_free(rb)(shm_rbuff_used(rb) + 1 < SHM_RBUFF_SIZE) @@ -105,12 +105,10 @@ struct shm_ap_rbuff * shm_ap_rbuff_create() return NULL; } - rb->shm_base = shm_base; - rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE); - rb->ptr_tail = (size_t *) - ((uint8_t *) rb->ptr_head + sizeof(size_t)); - rb->shm_mutex = (pthread_mutex_t *) - ((uint8_t *) rb->ptr_tail + sizeof(size_t)); + rb->shm_base = shm_base; + rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE); + rb->ptr_tail = rb->ptr_head + 1; + rb->shm_mutex = (pthread_mutex_t *) (rb->ptr_tail + 1); pthread_mutexattr_init(&attr); pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED); @@ -165,12 +163,10 @@ struct shm_ap_rbuff * shm_ap_rbuff_open(pid_t pid) return NULL; } - rb->shm_base = shm_base; - rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE); - rb->ptr_tail = (size_t *) - ((uint8_t *) rb->ptr_head + sizeof(size_t)); - rb->shm_mutex = (pthread_mutex_t *) - ((uint8_t *) rb->ptr_tail + sizeof(size_t)); + rb->shm_base = shm_base; + rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE); + rb->ptr_tail = rb->ptr_head + 1; + rb->shm_mutex = (pthread_mutex_t *) (rb->ptr_tail + 1); rb->fd = shm_fd; rb->pid = pid; -- cgit v1.2.3