From 80d100cd59015d91c4f0abfaf07b6876088ecbf1 Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Tue, 19 Apr 2022 18:57:24 -0700 Subject: session svm: fix mq producer wait on q and ring Make sure producer drops lock when it waits for empty ring slot. Type: fix Signed-off-by: Florin Coras Change-Id: Id77d54ee8c01bed20c9eaf5ad372ed4b1e9fa712 --- src/svm/message_queue.c | 37 ++++++++++++++++++++++++++++++++----- src/svm/message_queue.h | 14 ++++++++++++++ 2 files changed, 46 insertions(+), 5 deletions(-) (limited to 'src/svm') diff --git a/src/svm/message_queue.c b/src/svm/message_queue.c index a6af7962f73..2880645b427 100644 --- a/src/svm/message_queue.c +++ b/src/svm/message_queue.c @@ -243,8 +243,7 @@ svm_msg_q_lock_and_alloc_msg_w_ring (svm_msg_q_t * mq, u32 ring_index, { if (svm_msg_q_try_lock (mq)) return -1; - if (PREDICT_FALSE (svm_msg_q_is_full (mq) - || svm_msg_q_ring_is_full (mq, ring_index))) + if (PREDICT_FALSE (svm_msg_q_or_ring_is_full (mq, ring_index))) { svm_msg_q_unlock (mq); return -2; @@ -254,9 +253,8 @@ svm_msg_q_lock_and_alloc_msg_w_ring (svm_msg_q_t * mq, u32 ring_index, else { svm_msg_q_lock (mq); - while (svm_msg_q_is_full (mq) - || svm_msg_q_ring_is_full (mq, ring_index)) - svm_msg_q_wait_prod (mq); + while (svm_msg_q_or_ring_is_full (mq, ring_index)) + svm_msg_q_or_ring_wait_prod (mq, ring_index); *msg = svm_msg_q_alloc_msg_w_ring (mq, ring_index); } return 0; @@ -568,6 +566,35 @@ svm_msg_q_wait_prod (svm_msg_q_t *mq) return 0; } +int +svm_msg_q_or_ring_wait_prod (svm_msg_q_t *mq, u32 ring_index) +{ + if (mq->q.evtfd == -1) + { + while (svm_msg_q_or_ring_is_full (mq, ring_index)) + pthread_cond_wait (&mq->q.shr->condvar, &mq->q.shr->mutex); + } + else + { + u64 buf; + int rv; + + while (svm_msg_q_or_ring_is_full (mq, ring_index)) + { + while ((rv = read (mq->q.evtfd, &buf, sizeof (buf))) < 0) + { + if (errno != EAGAIN) + { + clib_unix_warning ("read error"); + return rv; + } + } + } + } + + return 0; +} + int svm_msg_q_timedwait (svm_msg_q_t *mq, double timeout) { diff --git a/src/svm/message_queue.h b/src/svm/message_queue.h index bd76eda5d88..0780cca1c32 100644 --- a/src/svm/message_queue.h +++ b/src/svm/message_queue.h @@ -328,6 +328,12 @@ svm_msg_q_ring_is_full (svm_msg_q_t * mq, u32 ring_index) return (clib_atomic_load_relax_n (&ring->shr->cursize) >= ring->nitems); } +static inline u8 +svm_msg_q_or_ring_is_full (svm_msg_q_t *mq, u32 ring_index) +{ + return (svm_msg_q_is_full (mq) || svm_msg_q_ring_is_full (mq, ring_index)); +} + /** * Check if message queue is empty */ @@ -417,6 +423,14 @@ int svm_msg_q_wait (svm_msg_q_t *mq, svm_msg_q_wait_type_t type); */ int svm_msg_q_wait_prod (svm_msg_q_t *mq); +/** + * Wait for message queue or ring event as producer + * + * Similar to @ref svm_msg_q_wait but lock (mutex or spinlock) must + * be held. Should only be called by producers. + */ +int svm_msg_q_or_ring_wait_prod (svm_msg_q_t *mq, u32 ring_index); + /** * Timed wait for message queue event * -- cgit 1.2.3-korg