X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=README;h=659511f7c46eba7260e1297ae247efceaa88b7bf;hb=ef84facf4b0c23bd695ca9300055e3ffc9b56006;hp=10406f79f9b33b797e794ca463d97a5c7cf0378f;hpb=ac6454bc2a7d1acc6fbda969929b89b148f03a11;p=urcu.git

diff --git a/README b/README
index 10406f7..659511f 100644
--- a/README
+++ b/README
@@ -190,3 +190,24 @@ SMP support
 		./configure --disable-smp-support
 
 	theoretically yielding slightly better performance.
+
+Interaction with fork()
+
+	Special care must be taken for applications performing fork() without
+	any following exec(). This is caused by the fact that Linux only clones
+	the thread calling fork(), and thus never replicates any of the other
+	parent thread into the child process. Most liburcu implementations
+	require that all registrations (as reader, defer_rcu and call_rcu
+	threads) should be released before a fork() is performed, except for the
+	rather common scenario where fork() is immediately followed by exec() in
+	the child process. The only implementation not subject to that rule is
+	liburcu-bp, which is designed to handle fork() by calling
+	rcu_bp_before_fork, rcu_bp_after_fork_parent and
+	rcu_bp_after_fork_child.
+
+	Applications that use call_rcu() and that fork() without
+	doing an immediate exec() must take special action.  The parent
+	must invoke call_rcu_before_fork() before the fork() and
+	call_rcu_after_fork_parent() after the fork().  The child
+	process must invoke call_rcu_after_fork_child().
+	These three APIs are suitable for passing to pthread_atfork().