From 05796604aee3ce40f4170b691b6126c89c2d09e6 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 21 Jun 2013 13:43:43 -0400 Subject: [PATCH] doc/examples: cds_list_add_tail_rcu Signed-off-by: Mathieu Desnoyers --- .gitignore | 1 + doc/examples/Makefile.am | 2 + doc/examples/list/Makefile | 2 + .../list/Makefile.cds_list_add_tail_rcu | 20 ++++++ doc/examples/list/cds_list_add_tail_rcu.c | 64 +++++++++++++++++++ 5 files changed, 89 insertions(+) create mode 100644 doc/examples/list/Makefile.cds_list_add_tail_rcu create mode 100644 doc/examples/list/cds_list_add_tail_rcu.c diff --git a/.gitignore b/.gitignore index ebacc52..c4c3bdd 100644 --- a/.gitignore +++ b/.gitignore @@ -74,6 +74,7 @@ tests/*.log *.so doc/examples/list/cds_list_add_rcu +doc/examples/list/cds_list_add_tail_rcu doc/examples/list/cds_list_del_rcu #automake diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am index 1d81287..cae3a02 100644 --- a/doc/examples/Makefile.am +++ b/doc/examples/Makefile.am @@ -14,8 +14,10 @@ doc_examples_listdir = ${doc_examplesdir}/list dist_doc_examples_list_DATA = \ list/Makefile \ list/Makefile.cds_list_add_rcu \ + list/Makefile.cds_list_add_tail_rcu \ list/Makefile.cds_list_del_rcu \ list/cds_list_add_rcu.c \ + list/cds_list_add_tail_rcu.c \ list/cds_list_del_rcu.c if NO_SHARED diff --git a/doc/examples/list/Makefile b/doc/examples/list/Makefile index 8e2279e..7507650 100644 --- a/doc/examples/list/Makefile +++ b/doc/examples/list/Makefile @@ -13,9 +13,11 @@ all: $(MAKE) -f Makefile.cds_list_add_rcu + $(MAKE) -f Makefile.cds_list_add_tail_rcu $(MAKE) -f Makefile.cds_list_del_rcu .PHONY: clean clean: $(MAKE) -f Makefile.cds_list_add_rcu clean + $(MAKE) -f Makefile.cds_list_add_tail_rcu clean $(MAKE) -f Makefile.cds_list_del_rcu clean diff --git a/doc/examples/list/Makefile.cds_list_add_tail_rcu b/doc/examples/list/Makefile.cds_list_add_tail_rcu new file mode 100644 index 0000000..a3b5a73 --- /dev/null +++ b/doc/examples/list/Makefile.cds_list_add_tail_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_tail_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_tail_rcu.c b/doc/examples/list/cds_list_add_tail_rcu.c new file mode 100644 index 0000000..53784c9 --- /dev/null +++ b/doc/examples/list/cds_list_add_tail_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 tail of 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_tail_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; +} -- 2.34.1