aboutsummaryrefslogtreecommitdiffstats
path: root/erts/include/internal/libatomic_ops
AgeCommit message (Collapse)Author
2011-05-20Update copyright yearsBjörn-Egil Dahlberg
2011-05-11Homogenize memory barriers on atomicsRickard Green
Atomic operations with specified barriers have specified barrier semantics. Set and read operations have undefined barrier semantics. All other atomic operations implied full memory barriers, except when using the libatomic_ops library and the tilera atomics api. Some code in the runtime system assumed that all operations used (except for set, read and specified) implied full memory barriers. The use of the libatomic_ops library and the tilera atomics api have therefore been modified to behave as the other implementations. Some atomic operations with specified barrier semantics on sparc32 have also been been relaxed in this commit.
2010-12-15Add support for 32-bit atomicsRickard Green
2010-12-14Move atomic API into own filesRickard Green
2010-12-11Introduce ethr_sint_t and use it for atomicsRickard Green
The atomic memory operations interface used the 'long' type and assumed that it was of the same size as 'void *'. This is true on most platforms, however, not on Windows 64.
2010-08-10Rewrite ethread libraryRickard Green
Large parts of the ethread library have been rewritten. The ethread library is an Erlang runtime system internal, portable thread library used by the runtime system itself. Most notable improvement is a reader optimized rwlock implementation which dramatically improve the performance of read-lock/read-unlock operations on multi processor systems by avoiding ping-ponging of the rwlock cache lines. The reader optimized rwlock implementation is used by miscellaneous rwlocks in the runtime system that are known to be read-locked frequently, and can be enabled on ETS tables by passing the `{read_concurrency, true}' option upon table creation. See the documentation of `ets:new/2' for more information. The ethread library can now also use the libatomic_ops library for atomic memory accesses. This makes it possible for the Erlang runtime system to utilize optimized atomic operations on more platforms than before. Use the `--with-libatomic_ops=PATH' configure command line argument when specifying where the libatomic_ops installation is located. The libatomic_ops library can be downloaded from: http://www.hpl.hp.com/research/linux/atomic_ops/ The changed API of the ethread library has also caused modifications in the Erlang runtime system. Preparations for the to come "delayed deallocation" feature has also been done since it depends on the ethread library. Note: When building for x86, the ethread library will now use instructions that first appeared on the pentium 4 processor. If you want the runtime system to be compatible with older processors (back to 486) you need to pass the `--enable-ethread-pre-pentium4-compatibility' configure command line argument when configuring the system.