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