-----------------------
Currently, Linux x86 (i386, i486, i586, i686), x86 64-bit, PowerPC 32/64,
-S390, S390x, ARM, Alpha, ia64 and Sparcv9 32/64 are supported. Tested on
-Linux, FreeBSD 8.2/9.0, and Cygwin. Should also work on: Android, NetBSD 5,
-OpenBSD, Darwin (more testing needed before claiming support for these OS).
+S390, S390x, ARM, MIPS, Alpha, ia64 and Sparcv9 32/64 are supported.
+Tested on Linux, FreeBSD 8.2/8.3/9.0/9.1/10.0 i386/amd64, and Cygwin.
+Should also work on: Android, NetBSD 5, OpenBSD, Darwin (more testing
+needed before claiming support for these OS).
Linux ARM depends on running a Linux kernel 2.6.15 or better, GCC 4.4 or
better.
support. For ARM this was introduced with gcc 4.4:
http://gcc.gnu.org/gcc-4.4/changes.html
+Clang version 3.0 (based on LLVM 3.0) is supported.
+
For developers using the git tree:
This source tree is based on the autotools suite from GNU to simplify
See the relevant API documentation files in doc/. The APIs provided by
Userspace RCU are, by prefix:
-- rcu_ : Read-Copy Update
+- rcu_ : Read-Copy Update (see doc/rcu-api.txt)
- cmm_ : Concurrent Memory Model
- caa_ : Concurrent Architecture Abstraction
-- cds_ : Concurrent Data Structures
-- uatomic_: Userspace Atomic
+- cds_ : Concurrent Data Structures (see doc/cds-api.txt)
+- uatomic_: Userspace Atomic (see doc/uatomic-api.txt)
QUICK START GUIDE
should only be taken when the RCU reader thread is "offline"
(this can be performed by calling rcu_thread_offline()).
-Usage of DEBUG_RCU
-
- DEBUG_RCU is used to add internal debugging self-checks to the
- RCU library. This define adds a performance penalty when enabled.
- Can be enabled by uncommenting the corresponding line in
- Makefile.build.inc.
-
-Usage of DEBUG_YIELD
-
- DEBUG_YIELD is used to add random delays in the code for testing
- purposes.
-
-SMP support
-
- By default the library is configured to use synchronization primitives
- adequate for SMP systems. On uniprocessor systems, support for SMP
- systems can be disabled with:
-
- ./configure --disable-smp-support
-
- theoretically yielding slightly better performance.
-
Interaction with fork()
Special care must be taken for applications performing fork() without
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().
+ Even though these three APIs are suitable for passing to
+ pthread_atfork(), use of pthread_atfork() is *STRONGLY
+ DISCOURAGED* for programs calling the glibc memory allocator
+ (malloc(), calloc(), free(), ...) within call_rcu callbacks.
+ This is due to limitations in the way glibc memory allocator
+ handles calls to the memory allocator from concurrent threads
+ while the pthread_atfork() handlers are executing.
+ Combining e.g.:
+ * call to free() from callbacks executed within call_rcu worker
+ threads,
+ * executing call_rcu atfork handlers within the glibc pthread
+ atfork mechanism,
+ will sometimes trigger interesting process hangs. This usually
+ hangs on a memory allocator lock within glibc.
Thread Local Storage (TLS)
TLS variables on systems where it is not available. This behavior
can be forced by specifying --disable-compiler-tls as configure
argument.
+
+Usage of DEBUG_RCU
+
+ DEBUG_RCU is used to add internal debugging self-checks to the
+ RCU library. This define adds a performance penalty when enabled.
+ Can be enabled by uncommenting the corresponding line in
+ Makefile.build.inc.
+
+Usage of DEBUG_YIELD
+
+ DEBUG_YIELD is used to add random delays in the code for testing
+ purposes.
+
+SMP support
+
+ By default the library is configured to use synchronization primitives
+ adequate for SMP systems. On uniprocessor systems, support for SMP
+ systems can be disabled with:
+
+ ./configure --disable-smp-support
+
+ theoretically yielding slightly better performance.
projects / urcu.git / blobdiff