From: Mathieu Desnoyers Date: Fri, 21 Jun 2013 19:32:14 +0000 (-0400) Subject: doc/examples: add cds_wfcq_dequeue X-Git-Tag: v0.8.0~46 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=c83da169e62137d669d458a03fce1ed7b76fb0c2;p=urcu.git doc/examples: add cds_wfcq_dequeue Signed-off-by: Mathieu Desnoyers --- diff --git a/.gitignore b/.gitignore index b3bce57..01f9e92 100644 --- a/.gitignore +++ b/.gitignore @@ -83,6 +83,7 @@ doc/examples/list/cds_list_for_each_entry_rcu doc/examples/list/cds_list_replace_rcu doc/examples/wfcqueue/cds_wfcq_enqueue +doc/examples/wfcqueue/cds_wfcq_dequeue #automake /config.h diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am index e117f97..5425ed2 100644 --- a/doc/examples/Makefile.am +++ b/doc/examples/Makefile.am @@ -30,7 +30,9 @@ doc_examples_wfcqueuedir = ${doc_examplesdir}/wfcqueue dist_doc_examples_wfcqueue_DATA = \ wfcqueue/Makefile.cds_wfcq_enqueue \ - wfcqueue/cds_wfcq_enqueue.c + wfcqueue/Makefile.cds_wfcq_dequeue \ + wfcqueue/cds_wfcq_enqueue.c \ + wfcqueue/cds_wfcq_dequeue.c if NO_SHARED # Don't build examples if shared libraries support was explicitly diff --git a/doc/examples/wfcqueue/Makefile b/doc/examples/wfcqueue/Makefile new file mode 100644 index 0000000..8256128 --- /dev/null +++ b/doc/examples/wfcqueue/Makefile @@ -0,0 +1,21 @@ +# Copyright (C) 2013 Mathieu Desnoyers +# +# 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 makefile is purposefully kept simple to support GNU and BSD make. + +all: + $(MAKE) -f Makefile.cds_wfcq_enqueue + $(MAKE) -f Makefile.cds_wfcq_dequeue + +.PHONY: clean +clean: + $(MAKE) -f Makefile.cds_wfcq_enqueue clean + $(MAKE) -f Makefile.cds_wfcq_dequeue clean diff --git a/doc/examples/wfcqueue/Makefile.cds_wfcq_dequeue b/doc/examples/wfcqueue/Makefile.cds_wfcq_dequeue new file mode 100644 index 0000000..4f80a71 --- /dev/null +++ b/doc/examples/wfcqueue/Makefile.cds_wfcq_dequeue @@ -0,0 +1,21 @@ +# Copyright (C) 2013 Mathieu Desnoyers +# +# 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 makefile is purposefully kept simple to support GNU and BSD make. + +EXAMPLE_NAME = cds_wfcq_dequeue + +SOURCES = $(EXAMPLE_NAME).c +OBJECTS = $(EXAMPLE_NAME).o +BINARY = $(EXAMPLE_NAME) +LIBS = -lurcu-common + +include ../Makefile.examples.template 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 + * + * 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 +#include + +#include /* Wait-free concurrent queue */ +#include /* 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; +}