Add a new ring_buffer class

This commit was SVN r22615.

opal/class/Makefile.am

@@ -29,7 +29,8 @@ headers += \
         class/opal_graph.h\
         class/opal_atomic_lifo.h \
         class/opal_pointer_array.h \
-        class/opal_value_array.h
+        class/opal_value_array.h \
+        class/opal_ring_buffer.h
 
 libopen_pal_la_SOURCES += \
         class/opal_bitmap.c \
@@ -40,4 +41,6 @@ libopen_pal_la_SOURCES += \
         class/opal_graph.c\
         class/opal_atomic_lifo.c \
         class/opal_pointer_array.c \
-        class/opal_value_array.c
+        class/opal_value_array.c \
+        class/opal_ring_buffer.c
+

opal/class/opal_ring_buffer.c

@@ -0,0 +1,85 @@
+/* -*- Mode: C; c-basic-offset:4 ; -*- */
+/*
+ * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
+ *                         University Research and Technology
+ *                         Corporation.  All rights reserved.
+ * Copyright (c) 2004-2007 The University of Tennessee and The University
+ *                         of Tennessee Research Foundation.  All rights
+ *                         reserved.
+ * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
+ *                         University of Stuttgart.  All rights reserved.
+ * Copyright (c) 2004-2005 The Regents of the University of California.
+ *                         All rights reserved.
+ * Copyright (c) 2010      Cisco Systems, Inc. All rights reserved.
+ * $COPYRIGHT$
+ * 
+ * Additional copyrights may follow
+ * 
+ * $HEADER$
+ */
+
+#include "opal_config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+
+#include "opal/constants.h"
+#include "opal/class/opal_ring_buffer.h"
+#include "opal/util/output.h"
+
+static void opal_ring_buffer_construct(opal_ring_buffer_t *);
+static void opal_ring_buffer_destruct(opal_ring_buffer_t *);
+
+OBJ_CLASS_INSTANCE(opal_ring_buffer_t, opal_object_t,
+                   opal_ring_buffer_construct,
+                   opal_ring_buffer_destruct);
+
+/*
+ * opal_ring_buffer constructor
+ */
+static void opal_ring_buffer_construct(opal_ring_buffer_t *ring)
+{
+    OBJ_CONSTRUCT(&ring->lock, opal_mutex_t);
+    ring->head = NULL;
+    ring->tail = NULL;
+    ring->size = 0;
+    ring->addr = NULL;
+}
+
+/*
+ * opal_ring_buffer destructor
+ */
+static void opal_ring_buffer_destruct(opal_ring_buffer_t *ring)
+{
+    if( NULL != ring->addr) {
+        free(ring->addr);
+        ring->addr = NULL;
+    }
+
+    ring->size = 0;
+
+    OBJ_DESTRUCT(&ring->lock);
+}
+
+/**
+ * initialize a ring object
+ */
+int opal_ring_buffer_init(opal_ring_buffer_t* ring, int size)
+{
+    /* check for errors */
+    if (NULL == ring) {
+        return OPAL_ERR_BAD_PARAM;
+    }
+    
+    /* Allocate and set the ring to NULL */   
+    ring->addr = (char **)calloc(size * sizeof(char*), 1);
+    if (NULL == ring->addr) { /* out of memory */
+        return OPAL_ERR_OUT_OF_RESOURCE;
+    }
+    ring->size = size;
+    /* point the head to the first location */
+    ring->head = &ring->addr[0];
+
+    return OPAL_SUCCESS;
+}

opal/class/opal_ring_buffer.h

@@ -0,0 +1,139 @@
+/* -*- Mode: C; c-basic-offset:4 ; -*- */
+/*
+ * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
+ *                         University Research and Technology
+ *                         Corporation.  All rights reserved.
+ * Copyright (c) 2004-2008 The University of Tennessee and The University
+ *                         of Tennessee Research Foundation.  All rights
+ *                         reserved.
+ * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
+ *                         University of Stuttgart.  All rights reserved.
+ * Copyright (c) 2004-2005 The Regents of the University of California.
+ *                         All rights reserved.
+ * Copyright (c) 2010      Cisco Systems, Inc. All rights reserved.
+ * $COPYRIGHT$
+ * 
+ * Additional copyrights may follow
+ * 
+ * $HEADER$
+ */
+/** @file
+ *
+ */
+
+#ifndef OPAL_RING_BUFFER_H
+#define OPAL_RING_BUFFER_H
+
+#include "opal_config.h"
+
+#include "opal/threads/mutex.h"
+#include "opal/class/opal_object.h"
+#include "opal/util/output.h"
+
+BEGIN_C_DECLS
+
+/**
+ * dynamic pointer ring
+ */
+struct opal_ring_buffer_t {
+    /** base class */
+    opal_object_t super;
+    /** synchronization object */
+    opal_mutex_t lock;
+    /* head/tail indices */
+    char **head;
+    char **tail;
+    /** size of list, i.e. number of elements in addr */
+    int size;
+    /** pointer to ring */
+    char **addr;
+};
+/**
+ * Convenience typedef
+ */
+typedef struct opal_ring_buffer_t opal_ring_buffer_t;
+/**
+ * Class declaration
+ */
+OPAL_DECLSPEC OBJ_CLASS_DECLARATION(opal_ring_buffer_t);
+
+/**
+ * Initialize the ring buffer, defining its size.
+ *
+ * @param ring Pointer to a ring buffer (IN/OUT)
+ * @param size The number of elements in the ring (IN)
+ *
+ * @return OPAL_SUCCESS if all initializations were succesful. Otherwise,
+ *  the error indicate what went wrong in the function.
+ */
+OPAL_DECLSPEC int opal_ring_buffer_init(opal_ring_buffer_t* ring, int size);
+
+/**
+ * Push an item onto the ring buffer
+ *
+ * @param ring Pointer to ring (IN)
+ * @param ptr Pointer value (IN)
+ *
+ * @return OPAL_SUCCESS. Returns error if ring cannot take
+ *  another entry
+ */
+static inline void* opal_ring_buffer_push(opal_ring_buffer_t *ring, void *ptr)
+{
+    char *p=NULL;
+    
+    OPAL_THREAD_LOCK(&(ring->lock));
+    if (NULL != *ring->head) {
+        p = *ring->head;
+        if (ring->head == ring->tail) {
+            /* push the tail ahead of us */
+            if (ring->tail == &ring->addr[ring->size-1]) {
+                ring->tail = &ring->addr[0];
+            } else {
+                ring->tail++;
+            }
+        }
+    }
+    *ring->head = ptr;
+    if (ring->head == &ring->addr[ring->size-1]) {
+        ring->head = &ring->addr[0];
+    } else {
+        ring->head++;
+    }
+    OPAL_THREAD_UNLOCK(&(ring->lock));
+    return (void*)p;
+}
+
+
+/**
+ * Pop an item off of the ring. The head of the ring will be
+ * returned. If nothing on the ring, NULL is returned.
+ *
+ * @param ring          Pointer to ring (IN)
+ *
+ * @return Error code.  NULL indicates an error.
+ */
+
+static inline void* opal_ring_buffer_pop(opal_ring_buffer_t *ring)
+{
+    char *p;
+
+    OPAL_THREAD_LOCK(&(ring->lock));
+    if (NULL == ring->tail || ring->head == ring->tail) {
+        p = NULL;
+    } else {
+        p = *ring->tail;
+        *ring->tail = NULL;
+        if (ring->tail == &ring->addr[ring->size-1]) {
+            ring->tail = &ring->addr[0];
+        } else {
+            ring->tail++;
+        }
+    }
+    OPAL_THREAD_UNLOCK(&(ring->lock));
+    return (void*)p;
+}
+
+
+END_C_DECLS
+
+#endif /* OPAL_RING_BUFFER_H */