2 *------------------------------------------------------------------
3 * svm_queue.c - unidirectional shared-memory queues
5 * Copyright (c) 2009 Cisco and/or its affiliates.
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at:
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *------------------------------------------------------------------
25 #include <vppinfra/mem.h>
26 #include <vppinfra/format.h>
27 #include <vppinfra/cache.h>
28 #include <svm/queue.h>
29 #include <vppinfra/time.h>
32 svm_queue_init (void *base, int nels, int elsize)
35 pthread_mutexattr_t attr;
36 pthread_condattr_t cattr;
38 q = (svm_queue_t *) base;
39 memset (q, 0, sizeof (*q));
43 q->producer_evtfd = -1;
44 q->consumer_evtfd = -1;
46 memset (&attr, 0, sizeof (attr));
47 memset (&cattr, 0, sizeof (cattr));
49 if (pthread_mutexattr_init (&attr))
50 clib_unix_warning ("mutexattr_init");
51 if (pthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED))
52 clib_unix_warning ("pthread_mutexattr_setpshared");
53 if (pthread_mutex_init (&q->mutex, &attr))
54 clib_unix_warning ("mutex_init");
55 if (pthread_mutexattr_destroy (&attr))
56 clib_unix_warning ("mutexattr_destroy");
57 if (pthread_condattr_init (&cattr))
58 clib_unix_warning ("condattr_init");
59 /* prints funny-looking messages in the Linux target */
60 if (pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED))
61 clib_unix_warning ("condattr_setpshared");
62 if (pthread_cond_init (&q->condvar, &cattr))
63 clib_unix_warning ("cond_init1");
64 if (pthread_condattr_destroy (&cattr))
65 clib_unix_warning ("cond_init2");
71 svm_queue_alloc_and_init (int nels, int elsize, int consumer_pid)
75 q = clib_mem_alloc_aligned (sizeof (svm_queue_t)
76 + nels * elsize, CLIB_CACHE_LINE_BYTES);
77 memset (q, 0, sizeof (*q));
78 q = svm_queue_init (q, nels, elsize);
79 q->consumer_pid = consumer_pid;
88 svm_queue_free (svm_queue_t * q)
90 (void) pthread_mutex_destroy (&q->mutex);
91 (void) pthread_cond_destroy (&q->condvar);
96 svm_queue_lock (svm_queue_t * q)
98 pthread_mutex_lock (&q->mutex);
102 svm_queue_unlock (svm_queue_t * q)
104 pthread_mutex_unlock (&q->mutex);
108 svm_queue_is_full (svm_queue_t * q)
110 return q->cursize == q->maxsize;
114 svm_queue_send_signal (svm_queue_t * q, u8 is_prod)
116 if (q->producer_evtfd == -1)
118 (void) pthread_cond_broadcast (&q->condvar);
122 int __clib_unused rv, fd;
124 ASSERT (q->consumer_evtfd != -1);
125 fd = is_prod ? q->producer_evtfd : q->consumer_evtfd;
126 rv = write (fd, &data, sizeof (data));
131 * svm_queue_add_nolock
134 svm_queue_add_nolock (svm_queue_t * q, u8 * elem)
137 int need_broadcast = 0;
139 if (PREDICT_FALSE (q->cursize == q->maxsize))
141 while (q->cursize == q->maxsize)
143 (void) pthread_cond_wait (&q->condvar, &q->mutex);
147 tailp = (i8 *) (&q->data[0] + q->elsize * q->tail);
148 clib_memcpy (tailp, elem, q->elsize);
153 need_broadcast = (q->cursize == 1);
155 if (q->tail == q->maxsize)
159 svm_queue_send_signal (q, 1);
164 svm_queue_add_raw (svm_queue_t * q, u8 * elem)
168 tailp = (i8 *) (&q->data[0] + q->elsize * q->tail);
169 clib_memcpy (tailp, elem, q->elsize);
171 q->tail = (q->tail + 1) % q->maxsize;
180 svm_queue_add (svm_queue_t * q, u8 * elem, int nowait)
183 int need_broadcast = 0;
187 /* zero on success */
188 if (pthread_mutex_trylock (&q->mutex))
194 pthread_mutex_lock (&q->mutex);
196 if (PREDICT_FALSE (q->cursize == q->maxsize))
200 pthread_mutex_unlock (&q->mutex);
203 while (q->cursize == q->maxsize)
205 (void) pthread_cond_wait (&q->condvar, &q->mutex);
209 tailp = (i8 *) (&q->data[0] + q->elsize * q->tail);
210 clib_memcpy (tailp, elem, q->elsize);
215 need_broadcast = (q->cursize == 1);
217 if (q->tail == q->maxsize)
221 svm_queue_send_signal (q, 1);
223 pthread_mutex_unlock (&q->mutex);
232 svm_queue_add2 (svm_queue_t * q, u8 * elem, u8 * elem2, int nowait)
235 int need_broadcast = 0;
239 /* zero on success */
240 if (pthread_mutex_trylock (&q->mutex))
246 pthread_mutex_lock (&q->mutex);
248 if (PREDICT_FALSE (q->cursize + 1 == q->maxsize))
252 pthread_mutex_unlock (&q->mutex);
255 while (q->cursize + 1 == q->maxsize)
257 (void) pthread_cond_wait (&q->condvar, &q->mutex);
261 tailp = (i8 *) (&q->data[0] + q->elsize * q->tail);
262 clib_memcpy (tailp, elem, q->elsize);
267 if (q->tail == q->maxsize)
270 need_broadcast = (q->cursize == 1);
272 tailp = (i8 *) (&q->data[0] + q->elsize * q->tail);
273 clib_memcpy (tailp, elem2, q->elsize);
278 if (q->tail == q->maxsize)
282 svm_queue_send_signal (q, 1);
284 pthread_mutex_unlock (&q->mutex);
293 svm_queue_sub (svm_queue_t * q, u8 * elem, svm_q_conditional_wait_t cond,
297 int need_broadcast = 0;
300 if (cond == SVM_Q_NOWAIT)
302 /* zero on success */
303 if (pthread_mutex_trylock (&q->mutex))
309 pthread_mutex_lock (&q->mutex);
311 if (PREDICT_FALSE (q->cursize == 0))
313 if (cond == SVM_Q_NOWAIT)
315 pthread_mutex_unlock (&q->mutex);
318 else if (cond == SVM_Q_TIMEDWAIT)
321 ts.tv_sec = unix_time_now () + time;
323 while (q->cursize == 0 && rc == 0)
325 rc = pthread_cond_timedwait (&q->condvar, &q->mutex, &ts);
329 pthread_mutex_unlock (&q->mutex);
335 while (q->cursize == 0)
337 (void) pthread_cond_wait (&q->condvar, &q->mutex);
342 headp = (i8 *) (&q->data[0] + q->elsize * q->head);
343 clib_memcpy (elem, headp, q->elsize);
346 /* $$$$ JFC shouldn't this be == 0? */
347 if (q->cursize == q->maxsize)
352 if (q->head == q->maxsize)
356 svm_queue_send_signal (q, 0);
358 pthread_mutex_unlock (&q->mutex);
364 svm_queue_sub2 (svm_queue_t * q, u8 * elem)
369 pthread_mutex_lock (&q->mutex);
372 pthread_mutex_unlock (&q->mutex);
376 headp = (i8 *) (&q->data[0] + q->elsize * q->head);
377 clib_memcpy (elem, headp, q->elsize);
380 need_broadcast = (q->cursize == q->maxsize / 2);
383 if (PREDICT_FALSE (q->head == q->maxsize))
385 pthread_mutex_unlock (&q->mutex);
388 svm_queue_send_signal (q, 0);
394 svm_queue_sub_raw (svm_queue_t * q, u8 * elem)
398 if (PREDICT_FALSE (q->cursize == 0))
400 while (q->cursize == 0)
404 headp = (i8 *) (&q->data[0] + q->elsize * q->head);
405 clib_memcpy (elem, headp, q->elsize);
407 q->head = (q->head + 1) % q->maxsize;
414 svm_queue_set_producer_event_fd (svm_queue_t * q, int fd)
416 q->producer_evtfd = fd;
420 svm_queue_set_consumer_event_fd (svm_queue_t * q, int fd)
422 q->consumer_evtfd = fd;
426 * fd.io coding-style-patch-verification: ON
429 * eval: (c-set-style "gnu")