/* *------------------------------------------------------------------ * 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 <stdio.h> #include <stdlib.h> #include <string.h> #include <pthread.h> #include <vppinfra/mem.h> #include <vppinfra/format.h> #include <vppinfra/cache.h> #include <svm/queue.h> #include <vppinfra/time.h> #include <vppinfra/lock.h> 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_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) { pthread_mutex_lock (&q->mutex); } 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 (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)); } } 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)) { while (q->cursize == q->maxsize) svm_queue_wait_inline (q); } tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); clib_memcpy_fast (tailp, elem, q->elsize); q->tail++; q->cursize++; need_broadcast = (q->cursize == 1); if (q->tail == q->maxsize) q->tail = 0; if (need_broadcast) svm_queue_send_signal (q, 1); return 0; } void svm_queue_add_raw (svm_queue_t * q, u8 * elem) { i8 *tailp; tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); clib_memcpy_fast (tailp, elem, q->elsize); q->tail = (q->tail + 1) % q->maxsize; q->cursize++; if (q->cursize == 1) svm_queue_send_signal (q, 1); } /* * svm_queue_add */ int svm_queue_add (svm_queue_t * q, u8 * elem, int nowait) { i8 *tailp; int need_broadcast = 0; if (nowait) { /* zero on success */ if (pthread_mutex_trylock (&q->mutex)) { return (-1); } } else svm_queue_lock (q); if (PREDICT_FALSE (q->cursize == q->maxsize)) { if (nowait) { svm_queue_unlock (q); return (-2); } while (q->cursize == q->maxsize) svm_queue_wait_inline (q); } tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); clib_memcpy_fast (tailp, elem, q->elsize); q->tail++; q->cursize++; need_broadcast = (q->cursize == 1); if (q->tail == q->maxsize) q->tail = 0; if (need_broadcast) svm_queue_send_signal (q, 1); svm_queue_unlock (q); return 0; } /* * svm_queue_add2 */ int svm_queue_add2 (svm_queue_t * q, u8 * elem, u8 * elem2, int nowait) { i8 *tailp; int need_broadcast = 0; if (nowait) { /* zero on success */ if (pthread_mutex_trylock (&q->mutex)) { return (-1); } } else svm_queue_lock (q); if (PREDICT_FALSE (q->cursize + 1 == q->maxsize)) { if (nowait) { svm_queue_unlock (q); return (-2); } while (q->cursize + 1 == q->maxsize) svm_queue_wait_inline (q); } tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); clib_memcpy_fast (tailp, elem, q->elsize); q->tail++; q->cursize++; if (q->tail == q->maxsize) q->tail = 0; need_broadcast = (q->cursize == 1); tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); clib_memcpy_fast (tailp, elem2, q->elsize); q->tail++; q->cursize++; if (q->tail == q->maxsize) q->tail = 0; if (need_broadcast) svm_queue_send_signal (q, 1); svm_queue_unlock (q); return 0; } /* * svm_queue_sub */ int svm_queue_sub (svm_queue_t * q, u8 * elem, svm_q_conditional_wait_t cond, u32 time) { i8 *headp; int need_broadcast = 0; int rc = 0; if (cond == SVM_Q_NOWAIT) { /* zero on success */ if (pthread_mutex_trylock (&q->mutex)) { return (-1); } } else svm_queue_lock (q); if (PREDICT_FALSE (q->cursize == 0)) { if (cond == SVM_Q_NOWAIT) { svm_queue_unlock (q); return (-2); } else if (cond == SVM_Q_TIMEDWAIT) { while (q->cursize == 0 && rc == 0) rc = svm_queue_timedwait_inline (q, time); if (rc == ETIMEDOUT) { svm_queue_unlock (q); return ETIMEDOUT; } } else { while (q->cursize == 0) svm_queue_wait_inline (q); } } headp = (i8 *) (&q->data[0] + q->elsize * q->head); clib_memcpy_fast (elem, headp, q->elsize); q->head++; /* $$$$ JFC shouldn't this be == 0? */ if (q->cursize == q->maxsize) need_broadcast = 1; q->cursize--; if (q->head == q->maxsize) q->head = 0; if (need_broadcast) svm_queue_send_signal (q, 0); svm_queue_unlock (q); return 0; } int svm_queue_sub2 (svm_queue_t * q, u8 * elem) { int need_broadcast; i8 *headp; svm_queue_lock (q); if (q->cursize == 0) { svm_queue_unlock (q); return -1; } headp = (i8 *) (&q->data[0] + q->elsize * q->head); clib_memcpy_fast (elem, headp, q->elsize); q->head++; need_broadcast = (q->cursize == q->maxsize / 2); q->cursize--; if (PREDICT_FALSE (q->head == q->maxsize)) q->head = 0; svm_queue_unlock (q); if (need_broadcast) svm_queue_send_signal (q, 0); return 0; } int svm_queue_sub_raw (svm_queue_t * q, u8 * elem) { i8 *headp; if (PREDICT_FALSE (q->cursize == 0)) { while (q->cursize == 0) ; } headp = (i8 *) (&q->data[0] + q->elsize * q->head); clib_memcpy_fast (elem, headp, q->elsize); q->head = (q->head + 1) % q->maxsize; q->cursize--; return 0; } void svm_queue_set_producer_event_fd (svm_queue_t * q, int fd) { q->producer_evtfd = fd; } void svm_queue_set_consumer_event_fd (svm_queue_t * q, int fd) { q->consumer_evtfd = fd; } /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */