X-Git-Url: https://git.lttng.org/?p=urcu.git;a=blobdiff_plain;f=README;h=ae8b6619cb5645dfcab48f3bf96d257b20b42973;hp=d47e5df9465070010a15797671ed48195dcf0628;hb=538d7df5086144837beb7a9c1e2a94eb637b9904;hpb=6991f61a6a02d95a4275bcc90aa9bb7037a9e69e

diff --git a/README b/README
index d47e5df..ae8b661 100644
--- a/README
+++ b/README
@@ -1,11 +1,51 @@
-build instructions for userspace-rcu library :
+Userspace RCU Implementatation
+by Mathieu Desnoyers and Paul E. McKenney
 
-make pthreads-x86
-or
-make pthreads-ppc
+BUILDING
+--------
 
-make
-make install
+	make
+	make install
+	
 
+QUICK START GUIDE
+-----------------
 
-     Mathieu Desnoyers
+Initialization
+
+	Each thread that has reader critical sections (that uses
+	rcu_read_lock()/rcu_read_unlock() must first register to the URCU
+	library. This is done by calling rcu_register_thread().
+
+Reading
+
+	Reader critical sections must be protected by locating them between
+	calls to rcu_read_lock() and rcu_read_unlock(). Inside that lock,
+	rcu_dereference() may be called to read an RCU protected pointer.
+
+Writing
+
+	rcu_assign_pointer() and rcu_xchg_pointer() may be called anywhere.
+	After, synchronize_rcu() must be called. When it returns, the old
+	values are not in usage anymore.
+
+Being careful with signals
+
+	The library uses signals internally. The signal handler is
+	registered with the SA_RESTART flag. However, these signals may cause
+	some non-restartable system calls to fail with errno = EINTR. Care
+	should be taken to restart system calls manually if they fail with this
+	error. A list of non-restartable system calls may be found in
+	signal(7). To ensure the Userspace RCU library does not use signals,
+	define CONFIG_URCU_AVOID_SIGNALS at compile-time.
+
+Usage of CONFIG_URCU_AVOID_SIGNALS
+
+	CONFIG_URCU_AVOID_SIGNALS uses full SMP barriers for readers. This
+	eliminates the need for signals but results in slower reads.
+
+
+Usage of DEBUG_YIELD
+
+	DEBUG_YIELD is used to add random delays in the code for testing
+	purposes.