1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
22 * @brief Thread Safe FIFO bounded queue
23 * @note Since most implementations of the queue are backed by a condition
24 * variable implementation, it isn't available on systems without threads.
25 * Although condition variables are some times available without threads.
29 #include "apr_errno.h"
30 #include "apr_pools.h"
36 #endif /* __cplusplus */
39 * @defgroup APR_Util_FIFO Thread Safe FIFO bounded queue
47 typedef struct apr_queue_t apr_queue_t
;
51 * @param queue The new queue
52 * @param queue_capacity maximum size of the queue
53 * @param a pool to allocate queue from
55 APU_DECLARE(apr_status_t
) apr_queue_create(apr_queue_t
**queue
,
56 unsigned int queue_capacity
,
60 * push/add a object to the queue, blocking if the queue is already full
62 * @param queue the queue
63 * @param data the data
64 * @returns APR_EINTR the blocking was interrupted (try again)
65 * @returns APR_EOF the queue has been terminated
66 * @returns APR_SUCCESS on a successfull push
68 APU_DECLARE(apr_status_t
) apr_queue_push(apr_queue_t
*queue
, void *data
);
71 * pop/get an object from the queue, blocking if the queue is already empty
73 * @param queue the queue
74 * @param data the data
75 * @returns APR_EINTR the blocking was interrupted (try again)
76 * @returns APR_EOF if the queue has been terminated
77 * @returns APR_SUCCESS on a successfull pop
79 APU_DECLARE(apr_status_t
) apr_queue_pop(apr_queue_t
*queue
, void **data
);
82 * push/add a object to the queue, returning immediatly if the queue is full
84 * @param queue the queue
85 * @param data the data
86 * @returns APR_EINTR the blocking operation was interrupted (try again)
87 * @returns APR_EAGAIN the queue is full
88 * @returns APR_EOF the queue has been terminated
89 * @returns APR_SUCCESS on a successfull push
91 APU_DECLARE(apr_status_t
) apr_queue_trypush(apr_queue_t
*queue
, void *data
);
94 * pop/get an object to the queue, returning immediatly if the queue is empty
96 * @param queue the queue
97 * @param data the data
98 * @returns APR_EINTR the blocking operation was interrupted (try again)
99 * @returns APR_EAGAIN the queue is empty
100 * @returns APR_EOF the queue has been terminated
101 * @returns APR_SUCCESS on a successfull push
103 APU_DECLARE(apr_status_t
) apr_queue_trypop(apr_queue_t
*queue
, void **data
);
106 * returns the size of the queue.
108 * @warning this is not threadsafe, and is intended for reporting/monitoring
110 * @param queue the queue
111 * @returns the size of the queue
113 APU_DECLARE(unsigned int) apr_queue_size(apr_queue_t
*queue
);
116 * interrupt all the threads blocking on this queue.
118 * @param queue the queue
120 APU_DECLARE(apr_status_t
) apr_queue_interrupt_all(apr_queue_t
*queue
);
123 * terminate all queue, sendinging a interupt to all the
126 * @param queue the queue
128 APU_DECLARE(apr_status_t
) apr_queue_term(apr_queue_t
*queue
);
136 #endif /* APR_HAS_THREADS */
138 #endif /* APRQUEUE_H */