Initial VES for DANOS vRouter

[demo.git] / vnfs / VESreporting_vFW5.0_DANOS / evel / evel-library / code / evel_library / ring_buffer.h

diff --git a/vnfs/VESreporting_vFW5.0_DANOS/evel/evel-library/code/evel_library/ring_buffer.h b/vnfs/VESreporting_vFW5.0_DANOS/evel/evel-library/code/evel_library/ring_buffer.h
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+++ b/vnfs/VESreporting_vFW5.0_DANOS/evel/evel-library/code/evel_library/ring_buffer.h
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+/*************************************************************************//**
+ *
+ * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
+ *
+ * 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 RING_BUFFER_INCLUDED
+#define RING_BUFFER_INCLUDED
+
+/**************************************************************************//**
+ * @file
+ * Ring  buffer to handle message requests.
+ *
+ ****************************************************************************/
+
+#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