Initial OpenECOMP Demo commit

[demo.git] / vnfs / VES / code / evel_library / ring_buffer.h

diff --git a/vnfs/VES/code/evel_library/ring_buffer.h b/vnfs/VES/code/evel_library/ring_buffer.h
new file mode 100644 (file)
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+#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