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Diffstat (limited to 'src/svm/queue.c')
| -rw-r--r-- | src/svm/queue.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/src/svm/queue.c b/src/svm/queue.c new file mode 100644 index 00000000000..aef409277db --- /dev/null +++ b/src/svm/queue.c @@ -0,0 +1,410 @@ +/* + *------------------------------------------------------------------ + * svm_queue.c - unidirectional shared-memory queues + * + * Copyright (c) 2009 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 <signal.h> + +/* + * svm_queue_init + * + * nels = number of elements on the queue + * elsize = element size, presumably 4 and cacheline-size will + * be popular choices. + * pid = consumer pid + * + * The idea is to call this function in the queue consumer, + * and e-mail the queue pointer to the producer(s). + * + * The vpp process / main thread allocates one of these + * at startup; its main input queue. The vpp main input queue + * has a pointer to it in the shared memory segment header. + * + * You probably want to be on an svm data heap before calling this + * function. + */ +svm_queue_t * +svm_queue_init (int nels, + int elsize, int consumer_pid, int signal_when_queue_non_empty) +{ + svm_queue_t *q; + pthread_mutexattr_t attr; + pthread_condattr_t cattr; + + q = clib_mem_alloc_aligned (sizeof (svm_queue_t) + + nels * elsize, CLIB_CACHE_LINE_BYTES); + memset (q, 0, sizeof (*q)); + + q->elsize = elsize; + q->maxsize = nels; + q->consumer_pid = consumer_pid; + q->signal_when_queue_non_empty = signal_when_queue_non_empty; + + memset (&attr, 0, sizeof (attr)); + 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_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; +} + +/* + * 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) + { + (void) pthread_cond_wait (&q->condvar, &q->mutex); + } + } + + tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); + clib_memcpy (tailp, elem, q->elsize); + + q->tail++; + q->cursize++; + + need_broadcast = (q->cursize == 1); + + if (q->tail == q->maxsize) + q->tail = 0; + + if (need_broadcast) + { + (void) pthread_cond_broadcast (&q->condvar); + if (q->signal_when_queue_non_empty) + kill (q->consumer_pid, q->signal_when_queue_non_empty); + } + return 0; +} + +int +svm_queue_add_raw (svm_queue_t * q, u8 * elem) +{ + i8 *tailp; + + if (PREDICT_FALSE (q->cursize == q->maxsize)) + { + while (q->cursize == q->maxsize) + ; + } + + tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); + clib_memcpy (tailp, elem, q->elsize); + + q->tail++; + q->cursize++; + + if (q->tail == q->maxsize) + q->tail = 0; + return 0; +} + + +/* + * 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 + pthread_mutex_lock (&q->mutex); + + if (PREDICT_FALSE (q->cursize == q->maxsize)) + { + if (nowait) + { + pthread_mutex_unlock (&q->mutex); + return (-2); + } + while (q->cursize == q->maxsize) + { + (void) pthread_cond_wait (&q->condvar, &q->mutex); + } + } + + tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); + clib_memcpy (tailp, elem, q->elsize); + + q->tail++; + q->cursize++; + + need_broadcast = (q->cursize == 1); + + if (q->tail == q->maxsize) + q->tail = 0; + + if (need_broadcast) + { + (void) pthread_cond_broadcast (&q->condvar); + if (q->signal_when_queue_non_empty) + kill (q->consumer_pid, q->signal_when_queue_non_empty); + } + pthread_mutex_unlock (&q->mutex); + + 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 + pthread_mutex_lock (&q->mutex); + + if (PREDICT_FALSE (q->cursize + 1 == q->maxsize)) + { + if (nowait) + { + pthread_mutex_unlock (&q->mutex); + return (-2); + } + while (q->cursize + 1 == q->maxsize) + { + (void) pthread_cond_wait (&q->condvar, &q->mutex); + } + } + + tailp = (i8 *) (&q->data[0] + q->elsize * q->tail); + clib_memcpy (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 (tailp, elem2, q->elsize); + + q->tail++; + q->cursize++; + + if (q->tail == q->maxsize) + q->tail = 0; + + if (need_broadcast) + { + (void) pthread_cond_broadcast (&q->condvar); + if (q->signal_when_queue_non_empty) + kill (q->consumer_pid, q->signal_when_queue_non_empty); + } + pthread_mutex_unlock (&q->mutex); + + return 0; +} + +/* + * svm_queue_sub + */ +int +svm_queue_sub (svm_queue_t * q, u8 * elem, int nowait) +{ + i8 *headp; + int need_broadcast = 0; + + if (nowait) + { + /* zero on success */ + if (pthread_mutex_trylock (&q->mutex)) + { + return (-1); + } + } + else + pthread_mutex_lock (&q->mutex); + + if (PREDICT_FALSE (q->cursize == 0)) + { + if (nowait) + { + pthread_mutex_unlock (&q->mutex); + return (-2); + } + while (q->cursize == 0) + { + (void) pthread_cond_wait (&q->condvar, &q->mutex); + } + } + + headp = (i8 *) (&q->data[0] + q->elsize * q->head); + clib_memcpy (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) + (void) pthread_cond_broadcast (&q->condvar); + + pthread_mutex_unlock (&q->mutex); + + return 0; +} + +int +svm_queue_sub2 (svm_queue_t * q, u8 * elem) +{ + int need_broadcast; + i8 *headp; + + pthread_mutex_lock (&q->mutex); + if (q->cursize == 0) + { + pthread_mutex_unlock (&q->mutex); + return -1; + } + + headp = (i8 *) (&q->data[0] + q->elsize * q->head); + clib_memcpy (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; + pthread_mutex_unlock (&q->mutex); + + if (need_broadcast) + (void) pthread_cond_broadcast (&q->condvar); + + 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 (elem, headp, q->elsize); + + q->head++; + q->cursize--; + + if (q->head == q->maxsize) + q->head = 0; + return 0; +} + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |