--- /dev/null
+/*
+ *------------------------------------------------------------------
+ * 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:
+ */
Code Review / vpp.git / blobdiff