/* *------------------------------------------------------------------ * svm_queue.c - unidirectional shared-memory queues * * Copyright (c) 2009-2019 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *------------------------------------------------------------------ */ #include #include #include #include #include #include #include #include #include #include svm_queue_t * svm_queue_init (void *base, int nels, int elsize) { svm_queue_t *q; pthread_mutexattr_t attr; pthread_condattr_t cattr; q = (svm_queue_t *) base; clib_memset (q, 0, sizeof (*q)); q->elsize = elsize; q->maxsize = nels; q->producer_evtfd = -1; q->consumer_evtfd = -1; clib_memset (&attr, 0, sizeof (attr)); clib_memset (&cattr, 0, sizeof (cattr)); if (pthread_mutexattr_init (&attr)) clib_unix_warning ("mutexattr_init"); if (pthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED)) clib_unix_warning ("pthread_mutexattr_setpshared"); if (pthread_mutexattr_setrobust (&attr, PTHREAD_MUTEX_ROBUST)) clib_unix_warning ("setrobust"); if (pthread_mutex_init (&q->mutex, &attr)) clib_unix_warning ("mutex_init"); if (pthread_mutexattr_destroy (&attr)) clib_unix_warning ("mutexattr_destroy"); if (pthread_condattr_init (&cattr)) clib_unix_warning ("condattr_init"); /* prints funny-looking messages in the Linux target */ if (pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED)) clib_unix_warning ("condattr_setpshared"); if (pthread_cond_init (&q->condvar, &cattr)) clib_unix_warning ("cond_init1"); if (pthread_condattr_destroy (&cattr)) clib_unix_warning ("cond_init2"); return (q); } svm_queue_t * svm_queue_alloc_and_init (int nels, int elsize, int consumer_pid) { svm_queue_t *q; q = clib_mem_alloc_aligned (sizeof (svm_queue_t) + nels * elsize, CLIB_CACHE_LINE_BYTES); clib_memset (q, 0, sizeof (*q)); q = svm_queue_init (q, nels, elsize); q->consumer_pid = consumer_pid; return q; } /* * svm_queue_free */ void svm_queue_free (svm_queue_t * q) { (void) pthread_mutex_destroy (&q->mutex); (void) pthread_cond_destroy (&q->condvar); clib_mem_free (q); } void svm_queue_lock (svm_queue_t * q) { int rv = pthread_mutex_lock (&q->mutex); if (PREDICT_FALSE (rv == EOWNERDEAD)) pthread_mutex_consistent (&q->mutex); } static int svm_queue_trylock (svm_queue_t * q) { int rv = pthread_mutex_trylock (&q->mutex); if (PREDICT_FALSE (rv == EOWNERDEAD)) rv = pthread_mutex_consistent (&q->mutex); return rv; } void svm_queue_unlock (svm_queue_t * q) { pthread_mutex_unlock (&q->mutex); } int svm_queue_is_full (svm_queue_t * q) { return q->cursize == q->maxsize; } static inline void svm_queue_send_signal_inline (svm_queue_t * q, u8 is_prod) { if (q->producer_evtfd == -1) { (void) pthread_cond_broadcast (&q->condvar); } else { int __clib_unused rv, fd; u64 data = 1; ASSERT (q->consumer_evtfd > 0 && q->producer_evtfd > 0); fd = is_prod ? q->producer_evtfd : q->consumer_evtfd; rv = write (fd, &data, sizeof (data)); if (PREDICT_FALSE (rv < 0)) clib_unix_warning ("signal write on %d returned %d", fd, rv); } } void svm_queue_send_signal (svm_queue_t * q, u8 is_prod) { svm_queue_send_signal_inline (q, is_prod); } static inline void svm_queue_wait_inline (svm_queue_t * q) { if (q->producer_evtfd == -1) { pthread_cond_wait (&q->condvar, &q->mutex); } else { /* Fake a wait for event. We could use epoll but that would mean * using yet another fd. Should do for now */ u32 cursize = q->cursize; svm_queue_unlock (q); while (q->cursize == cursize) CLIB_PAUSE (); svm_queue_lock (q); } } void svm_queue_wait (svm_queue_t * q) { svm_queue_wait_inline (q); } static inline int svm_queue_timedwait_inline (svm_queue_t * q, double timeout) { struct timespec ts; ts.tv_sec = unix_time_now () + (u32) timeout; ts.tv_nsec = (timeout - (u32) timeout) * 1e9; if (q->producer_evtfd == -1) { return pthread_cond_timedwait (&q->condvar, &q->mutex, &ts); } else { double max_time = unix_time_now () + timeout; u32 cursize = q->cursize; int rv; svm_queue_unlock (q); while (q->cursize == cursize && unix_time_now () < max_time) CLIB_PAUSE (); rv = unix_time_now () < max_time ? 0 : ETIMEDOUT; svm_queue_lock (q); return rv; } } int svm_queue_timedwait (svm_queue_t * q, double timeout) { return svm_queue_timedwait_inline (q, timeout); } /* * svm_queue_add_nolock */ int svm_queue_add_nolock (svm_queue_t * q, u8 * elem) { i8 *tailp; int need_broadcast = 0; if (PREDICT_FALSE (q->cursize == q->maxsize))