Make defer_rcu() usable from library using multiple URCU implementations

[urcu.git] / README

diff --git a/README b/README
index 56e98d768e960ede0a80245a8a1a725218de33d4..7d97f1964674407ddb23c069e3024ea7dc2cfdd7 100644 (file)
--- a/README
+++ b/README
@@ -124,16 +124,15 @@ Writing
 
 Usage of liburcu-defer
 
-       * #include <urcu-defer.h>
-       * Link with "-lurcu-defer", and also with one of the urcu library
-         (either urcu, urcu-bp, urcu-mb or urcu-qsbr).
+       * Follow instructions for either liburcu, liburcu-qsbr,
+         liburcu-mb, liburcu-signal, or liburcu-bp above.
+         The liburcu-defer functionality is pulled into each of
+         those library modules.
        * Provides defer_rcu() primitive to enqueue delayed callbacks. Queued
          callbacks are executed in batch periodically after a grace period.
          Do _not_ use defer_rcu() within a read-side critical section, because
          it may call synchronize_rcu() if the thread queue is full.
-       * Provides defer_rcu_ratelimit() primitive, which acts just like
-         defer_rcu(), but takes an additional rate limiter callback forcing
-         synchronized callback execution of the limiter returns non-zero.
+         This can lead to deadlock or worse.
        * Requires that rcu_defer_barrier() must be called in library destructor
          if a library queues callbacks and is expected to be unloaded with
          dlclose().
@@ -205,6 +204,9 @@ Interaction with fork()
        rcu_bp_before_fork, rcu_bp_after_fork_parent and
        rcu_bp_after_fork_child.
 
-       Applications that use call_rcu() are required to invoke
-       call_rcu_after_fork_child() from the child process after a
-       successful fork() system call that is not followed by exec().
+       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().