diff options
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 107 |
1 files changed, 61 insertions, 46 deletions
@@ -1,40 +1,55 @@ -2004-10-15 Ross Johnson <rpj at callisto.canberra.edu.au> +2004-10-19 Ross Johnson <rpj at callisto.canberra.edu.au>
- * implement.h (othread_mutex_t_): Use an event in place of - the POSIX semaphore. - * pthread_mutex_init.c: Create the event; remove semaphore init. - * pthread_mutex_destroy.c: Delete the event. - * pthread_mutex_lock.c: Replace the semaphore wait with the event wait. - * pthread_mutex_trylock.c: Likewise. - * pthread_mutex_timedlock.c: Likewise. - * pthread_mutex_unlock.c: Set the event. - + * sem_init.c (sem_init): New semaphore model based on the same idea + as mutexes, i.e. user space interlocked check to avoid + unnecessarily entering kernel space. Wraps the Win32 semaphore and + keeps it's own counter. + * sem_wait.c (sem_wait): Implemented user space check model. + * sem_post.c (sem_post): Likewise. + * sem_trywait.c (sem_trywait): Likewise. + * sem_timedwait.c (sem_timedwait): Likewise. + * sem_post_multiple.c (sem_post_multiple): Likewise. + * sem_getvalue.c (sem_getvalue): Likewise. + * ptw32_semwait.c (ptw32_semwait): Likewise. + * implement.h (sem_t_): Add counter element. + +2004-10-15 Ross Johnson <rpj at callisto.canberra.edu.au>
+ + * implement.h (othread_mutex_t_): Use an event in place of
+ the POSIX semaphore.
+ * pthread_mutex_init.c: Create the event; remove semaphore init.
+ * pthread_mutex_destroy.c: Delete the event.
+ * pthread_mutex_lock.c: Replace the semaphore wait with the event wait.
+ * pthread_mutex_trylock.c: Likewise.
+ * pthread_mutex_timedlock.c: Likewise.
+ * pthread_mutex_unlock.c: Set the event.
+
2004-10-14 Ross Johnson <rpj at callisto.canberra.edu.au>
- * pthread_mutex_lock.c (pthread_mutex_lock): New algorithm using - Terekhov's xchg based variation of Drepper's cmpxchg model. - Theoretically, xchg uses fewer clock cycles than cmpxchg (using IA-32 - as a reference), however, in my opinion bus locking dominates the - equation on smp systems, so the model with the least number of bus - lock operations in the execution path should win, which is Terekhov's - variant. On IA-32 uni-processor systems, it's faster to use the - CMPXCHG instruction without locking the bus than to use the XCHG - instruction, which always locks the bus. This makes the two variants - equal for the non-contended lock (fast lane) execution path on up - IA-32. Testing shows that the xchg variant is faster on up IA-32 as - well if the test forces higher lock contention frequency, even though - kernel calls should be dominating the times (on up IA-32, both - variants used CMPXCHG instructions and neither locked the bus). + * pthread_mutex_lock.c (pthread_mutex_lock): New algorithm using
+ Terekhov's xchg based variation of Drepper's cmpxchg model.
+ Theoretically, xchg uses fewer clock cycles than cmpxchg (using IA-32
+ as a reference), however, in my opinion bus locking dominates the
+ equation on smp systems, so the model with the least number of bus
+ lock operations in the execution path should win, which is Terekhov's
+ variant. On IA-32 uni-processor systems, it's faster to use the
+ CMPXCHG instruction without locking the bus than to use the XCHG
+ instruction, which always locks the bus. This makes the two variants
+ equal for the non-contended lock (fast lane) execution path on up
+ IA-32. Testing shows that the xchg variant is faster on up IA-32 as
+ well if the test forces higher lock contention frequency, even though
+ kernel calls should be dominating the times (on up IA-32, both
+ variants used CMPXCHG instructions and neither locked the bus).
* pthread_mutex_timedlock.c pthread_mutex_timedlock(): Similarly.
* pthread_mutex_trylock.c (pthread_mutex_trylock): Similarly.
* pthread_mutex_unlock.c (pthread_mutex_unlock): Similarly.
- * ptw32_InterlockedCompareExchange.c (ptw32_InterlockExchange): New - function. - (PTW32_INTERLOCKED_EXCHANGE): Sets up macro to use inlined + * ptw32_InterlockedCompareExchange.c (ptw32_InterlockExchange): New
+ function.
+ (PTW32_INTERLOCKED_EXCHANGE): Sets up macro to use inlined
ptw32_InterlockedExchange.
- * implement.h (PTW32_INTERLOCKED_EXCHANGE): Set default to + * implement.h (PTW32_INTERLOCKED_EXCHANGE): Set default to
InterlockedExchange().
- * Makefile: Building using /Ob2 so that asm sections within inline + * Makefile: Building using /Ob2 so that asm sections within inline
functions are inlined.
2004-10-08 Ross Johnson <rpj at callisto.canberra.edu.au>
@@ -42,16 +57,16 @@ * pthread_mutex_destroy.c (pthread_mutex_destroy): Critical Section
element is no longer required.
* pthread_mutex_init.c (pthread_mutex_init): Likewise.
- * pthread_mutex_lock.c (pthread_mutex_lock): New algorithm following - Drepper's paper at http://people.redhat.com/drepper/futex.pdf, but - using the existing semaphore in place of the futex described in the + * pthread_mutex_lock.c (pthread_mutex_lock): New algorithm following
+ Drepper's paper at http://people.redhat.com/drepper/futex.pdf, but
+ using the existing semaphore in place of the futex described in the
paper. Idea suggested by Alexander Terekhov - see:
http://sources.redhat.com/ml/pthreads-win32/2003/msg00108.html
* pthread_mutex_timedlock.c pthread_mutex_timedlock(): Similarly.
* pthread_mutex_trylock.c (pthread_mutex_trylock): Similarly.
* pthread_mutex_unlock.c (pthread_mutex_unlock): Similarly.
- * pthread_barrier_wait.c (pthread_barrier_wait): Use inlined version - of InterlockedCompareExchange() if possible - determined at + * pthread_barrier_wait.c (pthread_barrier_wait): Use inlined version
+ of InterlockedCompareExchange() if possible - determined at
build-time.
* pthread_spin_destroy.c pthread_spin_destroy(): Likewise.
* pthread_spin_lock.c pthread_spin_lock():Likewise.
@@ -59,29 +74,29 @@ * pthread_spin_unlock.c (pthread_spin_unlock):Likewise.
* ptw32_InterlockedCompareExchange.c: Sets up macro for inlined use.
* implement.h (pthread_mutex_t_): Remove Critical Section element.
- (PTW32_INTERLOCKED_COMPARE_EXCHANGE): Set to default non-inlined + (PTW32_INTERLOCKED_COMPARE_EXCHANGE): Set to default non-inlined
version of InterlockedCompareExchange().
- * private.c: Include ptw32_InterlockedCompareExchange.c first for + * private.c: Include ptw32_InterlockedCompareExchange.c first for
inlining.
- * GNUmakefile: Add commandline option to use inlined + * GNUmakefile: Add commandline option to use inlined
InterlockedCompareExchange().
* Makefile: Likewise.
2004-09-27 Ross Johnson <rpj at callisto.canberra.edu.au>
- * pthread_mutex_lock.c (pthread_mutex_lock): Separate - PTHREAD_MUTEX_NORMAL logic since we do not need to keep or check some - state required by other mutex types; do not check mutex pointer arg - for validity - leave this to the system since we are only checking - for NULL pointers. This should improve speed of NORMAL mutexes and + * pthread_mutex_lock.c (pthread_mutex_lock): Separate
+ PTHREAD_MUTEX_NORMAL logic since we do not need to keep or check some
+ state required by other mutex types; do not check mutex pointer arg
+ for validity - leave this to the system since we are only checking
+ for NULL pointers. This should improve speed of NORMAL mutexes and
marginally improve speed of other type.
* pthread_mutex_trylock.c (pthread_mutex_trylock): Likewise.
* pthread_mutex_unlock.c (pthread_mutex_unlock): Likewise; also avoid
- entering the critical section for the no-waiters case, with approx. + entering the critical section for the no-waiters case, with approx.
30% reduction in lock/unlock overhead for this case.
* pthread_mutex_timedlock.c (pthread_mutex_timedlock): Likewise; also
- no longer keeps mutex if post-timeout second attempt succeeds - this - will assist applications that wish to impose strict lock deadlines, + no longer keeps mutex if post-timeout second attempt succeeds - this
+ will assist applications that wish to impose strict lock deadlines,
rather than simply to escape from frozen locks.
2004-09-09 Tristan Savatier <tristan at mpegtv.com>
@@ -92,7 +107,7 @@ [Maintainer's note: the race condition is harmless on SPU systems
and only a problem on MPU systems if concurrent access results in an
exception (presumably generated by a hardware interrupt). There are
- other instances of similar harmless race conditions that have not + other instances of similar harmless race conditions that have not
been identified as issues.]
2004-09-09 Ross Johnson <rpj at callisto.canberra.edu.au>
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