1 files changed, 291 insertions, 0 deletions
diff --git a/vlib-api/vlibmemory/unix_shared_memory_queue.c b/vlib-api/vlibmemory/unix_shared_memory_queue.c
new file mode 100644
index 00000000000..62fb240cc6c
--- /dev/null
+++ b/vlib-api/vlibmemory/unix_shared_memory_queue.c
@@ -0,0 +1,291 @@
+/* 
+ *------------------------------------------------------------------
+ * unix_shared_memory_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 <vlibmemory/unix_shared_memory_queue.h>
+#include <signal.h>
+
+/*
+ * unix_shared_memory_queue_init
+ * 
+ * nels = number of elements on the queue
+ * elsize = element size, presumably 4 and cacheline-size will
+ *          be popular choices.
+ * coid  = consumer coid, from ChannelCreate
+ * pid   = consumer pid
+ * pulse_code  = pulse code consumer expects
+ * pulse_value = pulse value consumer expects
+ * consumer_prio = consumer's priority, so pulses won't change
+ *                 the consumer's priority.
+ *
+ * The idea is to call this function in the queue consumer,
+ * and e-mail the queue pointer to the producer(s).
+ *
+ * The spp process / main thread allocates one of these
+ * at startup; its main input queue. The spp 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.
+ */
+unix_shared_memory_queue_t *
+unix_shared_memory_queue_init(int nels, 
+                              int elsize, 
+                              int consumer_pid,
+                              int signal_when_queue_non_empty)
+{
+    unix_shared_memory_queue_t *q;
+    pthread_mutexattr_t attr;
+    pthread_condattr_t cattr;
+
+    q = clib_mem_alloc_aligned(sizeof(unix_shared_memory_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(attr));
+    
+    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);
+}
+
+/*
+ * unix_shared_memory_queue_free
+ */
+void unix_shared_memory_queue_free(unix_shared_memory_queue_t *q)
+{
+    (void) pthread_mutex_destroy(&q->mutex);
+    (void) pthread_cond_destroy(&q->condvar);
+    clib_mem_free(q);
+}
+
+void unix_shared_memory_queue_lock (unix_shared_memory_queue_t *q)
+{
+    pthread_mutex_lock(&q->mutex);
+}
+
+void unix_shared_memory_queue_unlock (unix_shared_memory_queue_t *q)
+{
+    pthread_mutex_unlock(&q->mutex);
+}
+
+int unix_shared_memory_queue_is_full (unix_shared_memory_queue_t *q)
+{
+    return q->cursize == q->maxsize;
+}
+
+/*
+ * unix_shared_memory_queue_add_nolock
+ */
+int unix_shared_memory_queue_add_nolock (unix_shared_memory_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);
+    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 unix_shared_memory_queue_add_raw (unix_shared_memory_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);
+    memcpy(tailp, elem, q->elsize);
+
+    q->tail++;
+    q->cursize++;
+
+    if (q->tail == q->maxsize)
+        q->tail = 0;
+    return 0;
+}
+
+
+/*
+ * unix_shared_memory_queue_add
+ */
+int unix_shared_memory_queue_add (unix_shared_memory_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);
+    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;
+}
+
+/*
+ * unix_shared_memory_queue_sub
+ */
+int unix_shared_memory_queue_sub(unix_shared_memory_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);
+    memcpy(elem, headp, q->elsize);
+    
+    q->head++;
+    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 unix_shared_memory_queue_sub_raw (unix_shared_memory_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);
+    memcpy(elem, headp, q->elsize);
+    
+    q->head++;
+    q->cursize--;
+
+    if(q->head == q->maxsize)
+        q->head = 0;
+    return 0;
+}