/* 
 *------------------------------------------------------------------
 * unix_shared_memory_queue.h - 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.
 *------------------------------------------------------------------
 */

#ifndef included_unix_shared_memory_queue_h
#define included_unix_shared_memory_queue_h

#include <pthread.h>
#include <vppinfra/mem.h>

typedef struct _unix_shared_memory_queue {
    pthread_mutex_t mutex;      /* 8 bytes */
    pthread_cond_t condvar;     /* 8 bytes */
    int head;
    int tail;
    int cursize;
    int maxsize;
    int elsize;
    int consumer_pid;
    int signal_when_queue_non_empty;
    char data[0];
} unix_shared_memory_queue_t;

unix_shared_memory_queue_t *
unix_shared_memory_queue_init(int nels, 
                              int elsize, 
                              int consumer_pid,
                              int signal_when_queue_non_empty);
void unix_shared_memory_queue_free(unix_shared_memory_queue_t *q);
int unix_shared_memory_queue_add (unix_shared_memory_queue_t *q, 
                                  u8 *elem, int nowait);
int unix_shared_memory_queue_sub(unix_shared_memory_queue_t *q, 
                                 u8 *elem, int nowait);
void unix_shared_memory_queue_lock (unix_shared_memory_queue_t *q);
void unix_shared_memory_queue_unlock (unix_shared_memory_queue_t *q);
int unix_shared_memory_queue_is_full (unix_shared_memory_queue_t *q);
int unix_shared_memory_queue_add_nolock (unix_shared_memory_queue_t *q, 
                                         u8 *elem);

int unix_shared_memory_queue_sub_raw (unix_shared_memory_queue_t *q, 
                                      u8 *elem);
int unix_shared_memory_queue_add_raw (unix_shared_memory_queue_t *q, 
                                      u8 *elem);

#endif /* included_unix_shared_memory_queue_h */