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Diffstat (limited to 'vnfs/VES/code/evel_library/ring_buffer.h')
| -rw-r--r-- | vnfs/VES/code/evel_library/ring_buffer.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/vnfs/VES/code/evel_library/ring_buffer.h b/vnfs/VES/code/evel_library/ring_buffer.h new file mode 100644 index 00000000..c6870508 --- /dev/null +++ b/vnfs/VES/code/evel_library/ring_buffer.h @@ -0,0 +1,109 @@ +#ifndef RING_BUFFER_INCLUDED +#define RING_BUFFER_INCLUDED + +/**************************************************************************//** + * @file + * A ring buffer. + * + * License + * ------- + * + * Copyright(c) <2016>, AT&T Intellectual Property. All other rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: This product includes + * software developed by the AT&T. + * 4. Neither the name of AT&T nor the names of its contributors may be used to + * endorse or promote products derived from this software without specific + * prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY AT&T INTELLECTUAL PROPERTY ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL AT&T INTELLECTUAL PROPERTY BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + *****************************************************************************/ + +#include <pthread.h> + +/**************************************************************************//** + * Ring buffer structure. + *****************************************************************************/ +typedef struct ring_buffer +{ + int size; + int next_write; + int next_read; + void ** ring; + pthread_cond_t ring_cv; + pthread_mutex_t ring_mutex; +} ring_buffer; + +/**************************************************************************//** + * Ring buffer initialization. + * + * Initialize the buffer supplied to the specified size. + * + * @param buffer Pointer to the ring-buffer to be initialized. + * @param size How many elements to be stored in the ring-buffer. + * + * @returns Nothing +******************************************************************************/ +void ring_buffer_initialize(ring_buffer * buffer, int size); + +/**************************************************************************//** + * Read an element from a ring_buffer. + * + * Reads an element from the ring_buffer, advancing the next-read position. + * Operation is synchronized and therefore MT-safe. Blocks if no data is + * available. + * + * @param buffer Pointer to the ring-buffer to be read. + * + * @returns Pointer to the element read from the buffer. +******************************************************************************/ +void * ring_buffer_read(ring_buffer * buffer); + +/**************************************************************************//** + * Write an element into a ring_buffer. + * + * Writes an element into the ring_buffer, advancing the next-write position. + * Operation is synchronized and therefore MT-safe. Fails if the buffer is + * full without blocking. + * + * @param buffer Pointer to the ring-buffer to be written. + * @param msg Pointer to data to be stored in the ring_buffer. + * + * @returns Number of items written. + * @retval 1 The data was written successfully. + * @retval 0 The ring_buffer was full so no data written. +******************************************************************************/ +int ring_buffer_write(ring_buffer * buffer, void * msg); + +/**************************************************************************//** + * Tests whether there is data in the ring_buffer. + * + * Tests whether there is currently data in the ring_buffer without blocking. + * + * @param buffer Pointer to the ring-buffer to be tested. + * + * @returns Whether there is data in the ring_buffer. + * @retval 0 There isn't any data in the ring_buffer. + * @retval 1 There is data in the ring_buffer. +******************************************************************************/ +int ring_buffer_is_empty(ring_buffer * buffer); + +#endif |