X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=doc%2Fexamples%2Fwfcqueue%2Fcds_wfcq_dequeue.c;fp=doc%2Fexamples%2Fwfcqueue%2Fcds_wfcq_dequeue.c;h=6488d5363ad1a258126f0c049bd26492f2c49594;hp=0000000000000000000000000000000000000000;hb=c83da169e62137d669d458a03fce1ed7b76fb0c2;hpb=c5e05e2de62537a07d83e8309bf071258867b706

diff --git a/doc/examples/wfcqueue/cds_wfcq_dequeue.c b/doc/examples/wfcqueue/cds_wfcq_dequeue.c
new file mode 100644
index 0000000..6488d53
--- /dev/null
+++ b/doc/examples/wfcqueue/cds_wfcq_dequeue.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2013  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program for any
+ * purpose,  provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is
+ * granted, provided the above notices are retained, and a notice that
+ * the code was modified is included with the above copyright notice.
+ *
+ * This example shows how to dequeue nodes from a wfcqueue.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <urcu/wfcqueue.h>	/* Wait-free concurrent queue */
+#include <urcu/compiler.h>	/* For CAA_ARRAY_SIZE */
+
+/*
+ * Nodes populated into the queue.
+ */
+struct mynode {
+	int value;			/* Node content */
+	struct cds_wfcq_node node;	/* Chaining in queue */
+};
+
+int main(int argc, char **argv)
+{
+	int values[] = { -5, 42, 36, 24, };
+	struct cds_wfcq_head myqueue_head;	/* Queue head */
+	struct cds_wfcq_tail myqueue_tail;	/* Queue tail */
+	unsigned int i;
+	int ret = 0;
+
+	cds_wfcq_init(&myqueue_head, &myqueue_tail);
+
+	/*
+	 * Adding nodes to the linked-list. Safe against concurrent
+	 * RCU traversals, require mutual exclusion with list updates.
+	 */
+	for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
+		struct mynode *node;
+
+		node = malloc(sizeof(*node));
+		if (!node) {
+			ret = -1;
+			goto end;
+		}
+
+		cds_wfcq_node_init(&node->node);
+		node->value = values[i];
+		cds_wfcq_enqueue(&myqueue_head, &myqueue_tail,
+				&node->node);
+	}
+
+	/*
+	 * Dequeue each node from the queue. Those will be dequeued from
+	 * the oldest (first enqueued) to the newest (last enqueued).
+	 */
+	printf("dequeued content:");
+	for (;;) {
+		struct cds_wfcq_node *qnode;
+		struct mynode *node;
+
+		qnode = cds_wfcq_dequeue_blocking(&myqueue_head, &myqueue_tail);
+		if (!qnode) {
+			break;	/* Queue is empty. */
+		}
+		/* Getting the container structure from the node */
+		node = caa_container_of(qnode, struct mynode, node);
+		printf(" %d", node->value);
+		free(node);
+	}
+	printf("\n");
+end:
+	return ret;
+}