Add a pkg-config file for the new liburcu-cds

[urcu.git] / README

diff --git a/README b/README
index 659511f7c46eba7260e1297ae247efceaa88b7bf..a6e29c875de973ec9020cad76de9e28aa564fdf2 100644 (file)
--- a/README
+++ b/README
@@ -124,22 +124,37 @@ Writing
 
 Usage of liburcu-defer
 
 
 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() 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().
        * Its API is currently experimental. It may change in future library
          releases.
 
        * Requires that rcu_defer_barrier() must be called in library destructor
          if a library queues callbacks and is expected to be unloaded with
          dlclose().
        * Its API is currently experimental. It may change in future library
          releases.
 

+Usage of urcu-call-rcu
+
+       * Follow instructions for either liburcu, liburcu-qsbr,
+         liburcu-mb, liburcu-signal, or liburcu-bp above.
+         The urcu-call-rcu functionality is provided for each of
+         these library modules.
+       * Provides the call_rcu() primitive to enqueue delayed callbacks
+         in a manner similar to defer_rcu(), but without ever delaying
+         for a grace period.  On the other hand, call_rcu()'s best-case
+         overhead is not quite as good as that of defer_rcu().
+       * Provides call_rcu() to allow asynchronous handling of RCU
+         grace periods.  A number of additional functions are provided
+         to manage the helper threads used by call_rcu(), but reasonable
+         defaults are used if these additional functions are not invoked.
+         See API.txt for more details.
+

 Being careful with signals
 
        The liburcu library uses signals internally. The signal handler is
 Being careful with signals
 
        The liburcu library uses signals internally. The signal handler is