Restrict supported arch ot P6+ on Intel x86 32.

[urcu.git] / README

diff --git a/README b/README
index 7753c8f957dfbf6acd9244b2fa2d9759879bc3f3..f9437dba2857856b726cc4539b6deeafaf09f668 100644 (file)
--- a/README
+++ b/README
@@ -4,9 +4,25 @@ by Mathieu Desnoyers and Paul E. McKenney
 BUILDING
 --------
 
 BUILDING
 --------
 

+       ./bootstrap (skip if using tarball)
+       ./configure

        make
        make install
        make
        make install

-       
+
+       Note:   Forcing 32-bit build:
+               * CFLAGS=-m32 ./configure
+
+               Forcing 64-bit build:
+               * CFLAGS=-m64 ./configure
+
+ARCHITECTURES SUPPORTED
+-----------------------
+
+Currently, x86 (only P6+), x86 64, PowerPC 32/64 and S390 are
+supported. The current use of sys_futex() makes it Linux-dependent, although
+this portability limitation might go away in a near future by using the pthread
+cond vars. Also, the restriction against i386, i486 and Pentium might go away if
+we integrate some of glibc runtime CPU-detection tests.

 
 QUICK START GUIDE
 -----------------
 
 QUICK START GUIDE
 -----------------


@@ -31,7 +47,7 @@ Usage of liburcu
 Usage of liburcu-mb
 
        * #include <urcu.h>
 Usage of liburcu-mb
 
        * #include <urcu.h>

-       * Compile code with "-DURCU_MB"
+       * Compile any _LGPL_SOURCE code using this library with "-DURCU_MB".

        * Link with "-lurcu-mb".
        * This version of the urcu library does not need to
          reserve a signal number. URCU_MB uses full memory barriers for
        * Link with "-lurcu-mb".
        * This version of the urcu library does not need to
          reserve a signal number. URCU_MB uses full memory barriers for


@@ -48,11 +64,24 @@ Usage of liburcu-qsbr
          the threads are not active. It provides the fastest read-side at the
          expense of more intrusiveness in the application code.
 
          the threads are not active. It provides the fastest read-side at the
          expense of more intrusiveness in the application code.
 

+Usage of liburcu-bp
+
+       * #include <urcu-bp.h>
+       * Link with "-lurcu-bp".
+       * The BP library flavor stands for "bulletproof". It is specifically
+         designed to help tracing library to hook on applications without
+         requiring to modify these applications. urcu_init(),
+         rcu_register_thread() and rcu_unregister_thread() all become nops.
+         The state is dealt with by the library internally at the expense of
+         read-side and write-side performance.
+

 Initialization
 
        Each thread that has reader critical sections (that uses
        rcu_read_lock()/rcu_read_unlock() must first register to the URCU
 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().
+       library. This is done by calling rcu_register_thread(). Unregistration
+       must be performed before exiting the thread by using
+       rcu_unregister_thread().

 
 Reading
 
 
 Reading
 


@@ -66,6 +95,15 @@ Writing
        After, synchronize_rcu() must be called. When it returns, the old
        values are not in usage anymore.
 
        After, synchronize_rcu() must be called. When it returns, the old
        values are not in usage anymore.
 

+Usage of liburcu-defer
+
+       * #include <urcu-defer.h>
+       * Link with "-lurcu-defer"
+       * Provides call_rcu() primitive to enqueue delayed callbacks. Queued
+         callbacks are executed in batch periodically after a grace period.
+         Do _not_ use call_rcu() within a read-side critical section, because
+         it may call synchronize_rcu() if the thread queue is full.
+

 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