From: Mathieu Desnoyers Date: Fri, 21 Jun 2013 15:46:17 +0000 (-0400) Subject: doc/examples: cds_list_add_rcu X-Git-Tag: v0.8.0~58 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=f37f1d93b55ca5f03761a840a8736613eb04f90b;p=userspace-rcu.git doc/examples: cds_list_add_rcu Signed-off-by: Mathieu Desnoyers --- diff --git a/.gitignore b/.gitignore index 3cd26f1..2fdfc1c 100644 --- a/.gitignore +++ b/.gitignore @@ -73,6 +73,8 @@ tests/test_urcu_wfcq_dynlink tests/*.log *.so +doc/examples/list/cds_list_add_rcu + #automake /config.h .deps/ diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am index 0d0c021..c06a816 100644 --- a/doc/examples/Makefile.am +++ b/doc/examples/Makefile.am @@ -6,11 +6,21 @@ dist_doc_examples_qsbr_minimal_DATA = \ qsbr-minimal/Makefile \ qsbr-minimal/qsbr-minimal.c +dist_doc_examples_DATA = \ + Makefile.examples.template + +doc_examples_listdir = ${doc_examplesdir}/list + +dist_doc_examples_list_DATA = \ + list/Makefile \ + list/Makefile.cds_list_add_rcu \ + list/cds_list_add_rcu.c + if NO_SHARED # Don't build examples if shared libraries support was explicitly # disabled. else -SUBDIRS_PROXY = qsbr-minimal +SUBDIRS_PROXY = qsbr-minimal list all-local: for subdir in $(SUBDIRS_PROXY); do \ diff --git a/doc/examples/Makefile.examples.template b/doc/examples/Makefile.examples.template new file mode 100644 index 0000000..cb0275d --- /dev/null +++ b/doc/examples/Makefile.examples.template @@ -0,0 +1,30 @@ +# 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. + +CC = gcc +LIBS = -lurcu +CFLAGS = -g -O2 -Wall + +all: $(BINARY) + +$(BINARY): $(OBJECTS) + $(CC) $(CFLAGS) $(LDFLAGS) $(AM_CFLAGS) $(AM_LDFLAGS) \ + $(LIBS) -o $@ $(OBJECTS) + +$(OBJECTS): $(SOURCES) + $(CC) $(CPPFLAGS) $(CFLAGS) $(AM_CPPFLAGS) $(AM_CFLAGS) \ + -c -o $@ $(SOURCES) + +.PHONY: clean +clean: + rm -f *.o $(BINARY) diff --git a/doc/examples/list/Makefile b/doc/examples/list/Makefile new file mode 100644 index 0000000..122417d --- /dev/null +++ b/doc/examples/list/Makefile @@ -0,0 +1,14 @@ +# 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. + +include Makefile.cds_list_add_rcu diff --git a/doc/examples/list/Makefile.cds_list_add_rcu b/doc/examples/list/Makefile.cds_list_add_rcu new file mode 100644 index 0000000..af83c01 --- /dev/null +++ b/doc/examples/list/Makefile.cds_list_add_rcu @@ -0,0 +1,20 @@ +# 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_list_add_rcu + +SOURCES = $(EXAMPLE_NAME).c +OBJECTS = $(EXAMPLE_NAME).o +BINARY = $(EXAMPLE_NAME) + +include ../Makefile.examples.template diff --git a/doc/examples/list/cds_list_add_rcu.c b/doc/examples/list/cds_list_add_rcu.c new file mode 100644 index 0000000..ad1d909 --- /dev/null +++ b/doc/examples/list/cds_list_add_rcu.c @@ -0,0 +1,64 @@ +/* + * 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 add into a linked-list safely against + * concurrent RCU traversals. + */ + +#include + +#include /* Userspace RCU flavor */ +#include /* RCU list */ +#include /* For CAA_ARRAY_SIZE */ + +/* + * Nodes populated into the list. + */ +struct mynode { + int value; /* Node content */ + struct cds_list_head node; /* Linked-list chaining */ +}; + +int main(int argc, char **argv) +{ + int values[] = { -5, 42, 36, 24, }; + CDS_LIST_HEAD(mylist); /* Defines an empty list head */ + unsigned int i; + int ret = 0; + struct mynode *node; + + /* + * 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++) { + node = malloc(sizeof(*node)); + if (!node) { + ret = -1; + goto end; + } + node->value = values[i]; + cds_list_add_rcu(&node->node, &mylist); + } + + /* + * Just show the list content. This is _not_ an RCU-safe + * iteration on the list. + */ + printf("mylist content:"); + cds_list_for_each_entry(node, &mylist, node) { + printf(" %d", node->value); + } + printf("\n"); +end: + return ret; +}