Currently, the following architectures are supported:
- x86 (i386, i486, i586, i686)
- - amd64 / x86_64
+ - amd64 / x86\_64
- PowerPC 32/64
- S390, S390x
- ARM 32/64
therefore not compatible with `liburcu` on x86 32-bit
(i386, i486, i586, i686).
The problem has been reported to the GCC community:
- http://www.mail-archive.com/gcc-bugs@gcc.gnu.org/msg281255.html
+ <http://www.mail-archive.com/gcc-bugs@gcc.gnu.org/msg281255.html>
- GCC 3.3 cannot match the "xchg" instruction on 32-bit x86 build.
- See http://kerneltrap.org/node/7507
+ See <http://kerneltrap.org/node/7507>
- Alpha, ia64 and ARM architectures depend on GCC 4.x with atomic builtins
support. For ARM this was introduced with GCC 4.4:
- http://gcc.gnu.org/gcc-4.4/changes.html.
+ <http://gcc.gnu.org/gcc-4.4/changes.html>.
- Linux aarch64 depends on GCC 5.1 or better because prior versions
perform unsafe access to deallocated stack.
- GNU autotools (automake >=1.12, autoconf >=2.69)
(make sure your system wide `automake` points to a recent version!)
- GNU Libtool >=2.2
- (for more information, go to http://www.gnu.org/software/autoconf/)
+ (for more information, go to <http://www.gnu.org/software/autoconf/>)
If you get the tree from the repository, you will need to use the `bootstrap`
script in the root of the tree. It calls all the GNU tools needed to prepare
- `signal`,
- `bp`.
-The API members start with the prefix "urcu_<flavor>_", where
-<flavor> is the chosen flavor name.
+The API members start with the prefix `urcu_<flavor>_`, where
+`<flavor>` is the chosen flavor name.
### Usage of `liburcu-memb`
grace-period detection speed, read-side speed and flexibility.
Dynamically detects kernel support for `sys_membarrier()`. Falls back
on `urcu-mb` scheme if support is not present, which has slower
-read-side. Use the --disable-sys-membarrier-fallback configure option
+read-side. Use the `--disable-sys-membarrier-fallback` configure option
to disable the fall back, thus requiring `sys_membarrier()` to be
available. This gives a small speedup when `sys_membarrier()` is
supported by the kernel, and aborts in the library constructor if not
self-checks disabled.
For always-on debugging self-checks:
- ./configure --enable-rcu-debug
+
+ ./configure --enable-rcu-debug
For fine grained enabling of debugging self-checks, build
-userspace-rcu with DEBUG_RCU defined and compile dependent
-applications with DEBUG_RCU defined when necessary.
+userspace-rcu with `DEBUG_RCU` defined and compile dependent
+applications with `DEBUG_RCU` defined when necessary.
Warning: Enabling this feature result in a performance penalty.
By default the library is configured with extra debugging checks for
lock-free hash table iterator traversal disabled.
-Building liburcu with --enable-cds-lfht-iter-debug and rebuilding
+Building liburcu with `--enable-cds-lfht-iter-debug` and rebuilding
application to match the ABI change allows finding cases where the hash
table iterator is re-purposed to be used on a different hash table while
still being used to iterate on a hash table.
Userspace RCU 0.11 or 0.12 shared objects. The problem occurs as
follows:
- - An application executable is built with _LGPL_SOURCE defined, includes
+ - An application executable is built with `_LGPL_SOURCE` defined, includes
any of the Userspace RCU 0.10 urcu flavor headers, and is built
- without the -fpic compiler option.
+ without the `-fpic` compiler option.
- The Userspace RCU 0.10 library shared objects are updated to 0.11
or 0.12 without rebuilding the application.
- Rebuild the application against Userspace RCU 0.11+.
- - Rebuild the application with -fpic.
+ - Rebuild the application with `-fpic`.
- Upgrade Userspace RCU to 0.13+ without installing 0.11 nor 0.12.
Doubly-linked list, with single pointer list head.
Requires mutual exclusion on updates, allows RCU read traversals. Useful
-for implementing hash tables. Downside over rculist.h: lookup of tail in O(n).
+for implementing hash tables. Downside over `rculist.h`: lookup of tail in O(n).
### `urcu/wfstack.h`
-Stack with wait-free push and wait-free pop_all. Both
+Stack with wait-free push and wait-free pop\_all. Both
blocking and non-blocking pop and traversal operations are provided. This
stack does _not_ specifically rely on RCU. Various synchronization techniques
can be used to deal with pop ABA. Those are detailed in the API.
### `urcu/lfstack.h`
-Stack with lock-free push, lock-free pop, wait-free pop_all,
+Stack with lock-free push, lock-free pop, wait-free pop\_all,
wait-free traversal. Various synchronization techniques can be
used to deal with pop ABA. Those are detailed in the API.
This stack does _not_ specifically rely on RCU.
---
```c
-void uatomic_set(type *addr, type v)
+void uatomic_set(type *addr, type v);
```
Atomically write `v` into `addr`. By "atomically", we mean that no
```c
-type uatomic_read(type *addr)
+type uatomic_read(type *addr);
```
Atomically read `v` from `addr`. By "atomically", we mean that
```c
-type uatomic_cmpxchg(type *addr, type old, type new)
+type uatomic_cmpxchg(type *addr, type old, type new);
```
An atomic read-modify-write operation that performs this
```c
-type uatomic_xchg(type *addr, type new)
+type uatomic_xchg(type *addr, type new);
```
An atomic read-modify-write operation that performs this sequence
```c
-type uatomic_add_return(type *addr, type v)
-type uatomic_sub_return(type *addr, type v)
+type uatomic_add_return(type *addr, type v);
+type uatomic_sub_return(type *addr, type v);
```
An atomic read-modify-write operation that performs this
```c
-void uatomic_and(type *addr, type mask)
-void uatomic_or(type *addr, type mask)
+void uatomic_and(type *addr, type mask);
+void uatomic_or(type *addr, type mask);
```
Atomically write the result of bitwise "and"/"or" between the
```c
-void uatomic_add(type *addr, type v)
-void uatomic_sub(type *addr, type v)
+void uatomic_add(type *addr, type v);
+void uatomic_sub(type *addr, type v);
```
Atomically increment/decrement the content of `addr` by `v`.
```c
-void uatomic_inc(type *addr)
-void uatomic_dec(type *addr)
+void uatomic_inc(type *addr);
+void uatomic_dec(type *addr);
```
Atomically increment/decrement the content of `addr` by 1.
projects / userspace-rcu.git / commitdiff
