From ab588700c2d55e427f776c03ae9b7ae5e008f2c1 Mon Sep 17 00:00:00 2001 From: dimitri staessens Date: Sat, 1 Apr 2017 21:19:04 +0200 Subject: lib: Fix some issues in lockless rbuff --- src/lib/shm_rbuff_ll.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'src/lib/shm_rbuff_ll.c') diff --git a/src/lib/shm_rbuff_ll.c b/src/lib/shm_rbuff_ll.c index b5b8bed2..d777de8b 100644 --- a/src/lib/shm_rbuff_ll.c +++ b/src/lib/shm_rbuff_ll.c @@ -228,6 +228,8 @@ int shm_rbuff_write(struct shm_rbuff * rb, size_t ohead; size_t nhead; + bool was_empty = false; + assert(rb); assert(idx < SHM_BUFFER_SIZE); @@ -238,11 +240,9 @@ int shm_rbuff_write(struct shm_rbuff * rb, return -EAGAIN; if (shm_rbuff_empty(rb)) - pthread_cond_broadcast(rb->add); + was_empty = true; - ohead = RB_HEAD; - - *head_el_ptr(rb) = (ssize_t) idx; + nhead = RB_HEAD; do { ohead = nhead; @@ -250,6 +250,11 @@ int shm_rbuff_write(struct shm_rbuff * rb, nhead = __sync_val_compare_and_swap(rb->head, ohead, nhead); } while (nhead != ohead); + *(rb->shm_base + nhead) = (ssize_t) idx; + + if (was_empty) + pthread_cond_broadcast(rb->add); + return 0; } @@ -263,7 +268,7 @@ ssize_t shm_rbuff_read(struct shm_rbuff * rb) if (shm_rbuff_empty(rb)) return -EAGAIN; - otail = RB_TAIL; + ntail = RB_TAIL; do { otail = ntail; @@ -273,7 +278,7 @@ ssize_t shm_rbuff_read(struct shm_rbuff * rb) pthread_cond_broadcast(rb->del); - return *tail_el_ptr(rb); + return *(rb->shm_base + ntail); } ssize_t shm_rbuff_read_b(struct shm_rbuff * rb, @@ -348,7 +353,7 @@ void shm_rbuff_fini(struct shm_rbuff * rb) assert(__sync_fetch_and_add(rb->acl, 0) == RB_CLOSED); - if (shm_rbuff_empty) + if (shm_rbuff_empty(rb)) return; #ifdef __APPLE__ -- cgit v1.2.3