diff options
| -rw-r--r-- | ChangeLog | 107 | ||||
| -rw-r--r-- | Nmakefile.tests | 12 | ||||
| -rw-r--r-- | implement.h | 1 | ||||
| -rw-r--r-- | ptw32_semwait.c | 13 | ||||
| -rw-r--r-- | sem_getvalue.c | 60 | ||||
| -rw-r--r-- | sem_init.c | 3 | ||||
| -rw-r--r-- | sem_post.c | 3 | ||||
| -rw-r--r-- | sem_post_multiple.c | 6 | ||||
| -rw-r--r-- | sem_timedwait.c | 10 | ||||
| -rw-r--r-- | sem_trywait.c | 3 | ||||
| -rw-r--r-- | sem_wait.c | 10 | ||||
| -rw-r--r-- | tests/ChangeLog | 12 | ||||
| -rw-r--r-- | tests/GNUmakefile | 4 | ||||
| -rw-r--r-- | tests/Makefile | 8 | ||||
| -rw-r--r-- | tests/semaphore2.c | 2 | ||||
| -rw-r--r-- | tests/semaphore3.c | 120 | 
16 files changed, 255 insertions, 119 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>
 diff --git a/Nmakefile.tests b/Nmakefile.tests index 8f2f527..4647273 100644 --- a/Nmakefile.tests +++ b/Nmakefile.tests @@ -93,6 +93,7 @@ rwlock4::	rwlock4.c  rwlock5::	rwlock5.c
  rwlock6::	rwlock6.c
  rwlock7::	rwlock7.c
 +rwlock8::	rwlock8.c
  rwlock2_t::	rwlock2_t.c
  rwlock3_t::	rwlock3_t.c
  rwlock4_t::	rwlock4_t.c
 @@ -101,6 +102,7 @@ rwlock6_t::	rwlock6_t.c  rwlock6_t2::	rwlock6_t2.c
  semaphore1::	semaphore1.c
  semaphore2::	semaphore2.c
 +semaphore3::	semaphore3.c
  context1::	context1.c
  cancel3::	cancel3.c
  cancel4::	cancel4.c
 @@ -138,10 +140,14 @@ cancel9::	cancel9.c  sizes:		:test:	sizes
  loadfree:	:test:
 -semaphore1	:test:	loadfree
 -semaphore2	:test:	loadfree
  mutex5		:test:	loadfree
  mutex1		:test:	loadfree
 +mutex1n		:test:	loadfree
 +mutex1r		:test:	loadfree
 +mutex1e		:test:	loadfree
 +semaphore1	:test:	loadfree
 +semaphore2	:test:	loadfree
 +semaphore3	:test:	loadfree
  mutex2		:test:	loadfree
  mutex2r		:test:	loadfree
  mutex2e		:test:	loadfree
 @@ -209,6 +215,8 @@ rwlock3		:test:	rwlock2  rwlock4		:test:	rwlock3
  rwlock5		:test:	rwlock4
  rwlock6		:test:	rwlock5
 +rwlock7		:test:	rwlock6
 +rwlock8		:test:	rwlock7
  rwlock2_t	:test:	rwlock2
  rwlock3_t	:test:	rwlock2_t
  rwlock4_t	:test:	rwlock3_t
 diff --git a/implement.h b/implement.h index f71f506..9cb3cb3 100644 --- a/implement.h +++ b/implement.h @@ -172,6 +172,7 @@ struct sem_t_    CRITICAL_SECTION sem_lock_cs;    HANDLE event;  #else				/* NEED_SEM */ +  int value;    HANDLE sem;  #endif				/* NEED_SEM */  }; diff --git a/ptw32_semwait.c b/ptw32_semwait.c index 38f31f5..2e9c883 100644 --- a/ptw32_semwait.c +++ b/ptw32_semwait.c @@ -83,7 +83,15 @@ ptw32_semwait (sem_t * sem)  #else /* NEED_SEM */ -      status = WaitForSingleObject ((*sem)->sem, INFINITE); +      if (InterlockedDecrement((LPLONG) &(*sem)->value) < 0) +        { +          /* Must wait */ +          status = WaitForSingleObject ((*sem)->sem, INFINITE); +        } +      else +	{ +	  return 0; +	}  #endif @@ -100,6 +108,9 @@ ptw32_semwait (sem_t * sem)  	}        else  	{ +#ifndef NEED_SEM +	  (void) InterlockedIncrement((LPLONG) &(*sem)->value); +#endif  	  result = EINVAL;  	}      } diff --git a/sem_getvalue.c b/sem_getvalue.c index c34739a..be80bea 100644 --- a/sem_getvalue.c +++ b/sem_getvalue.c @@ -77,15 +77,14 @@ sem_getvalue (sem_t * sem, int *sval)        *      pointed to by sem in the int pointed to by sval.        */  { -  int result = 0; -  long value; -    if (sem == NULL || *sem == NULL || sval == NULL)      { -      result = EINVAL; +      errno = EINVAL; +      return -1;      }    else      { +      long value;        register sem_t s = *sem;  #ifdef NEED_SEM @@ -96,59 +95,12 @@ sem_getvalue (sem_t * sem, int *sval)  #else -      /* -       * There appears to be NO atomic means of determining the -       * value of the semaphore. Using only ReleaseSemaphore() -       * with either a zero or oversized count parameter has been -       * suggested but this trick doesn't produce consistent results -       * across Windows versions (the technique uses values that are -       * knowingly illegal but hopes to extract the current value -       * anyway - the zero parameter appears to work for Win9x but -       * neither work reliably for WinNT). -       * -       * The intrusive method below will give false results -       * at times but it at least errs on the side of -       * caution. Competing threads might occasionally believe -       * the semaphore has a count of one less than it actually -       * would have and possibly block momentarily unecessarily, -       * but they will never see a higher semaphore value than -       * there should be. -       * -       * -       * Multiple threads calling sem_getvalue() at the same time -       * may not all return the same value (assuming no calls to -       * other semaphore routines). They will always return the -       * correct value or a lesser value. This problem could be fixed -       * with a global or a per-semaphore critical section here. -       * -       * An equally approximate but IMO slightly riskier approach -       * would be to keep a separate per-semaphore counter and -       * decrement/increment it inside of sem_wait() and sem_post() -       * etc using the Interlocked* functions. -       */ -      if (WaitForSingleObject (s->sem, 0) == WAIT_TIMEOUT) -	{ -	  /* Failed - must be zero */ -	  value = 0; -	} -      else -	{ -	  /* Decremented semaphore - release it and note the value */ -	  (void) ReleaseSemaphore (s->sem, 1L, &value); -	  value++; -	} +      value = s->value;  #endif -    } - -  if (result != 0) -    { -      errno = result; -      return -1; +      *sval = value; +      return 0;      } -  *sval = value; -  return 0; -  }				/* sem_getvalue */ @@ -127,8 +127,9 @@ sem_init (sem_t * sem, int pshared, unsigned int value)  #else /* NEED_SEM */ +	  s->value = value;  	  s->sem = CreateSemaphore (NULL,	/* Always NULL */ -				    (long) value,	/* Initial value */ +				    (long) 0,	/* Force threads to wait */  				    (long) _POSIX_SEM_VALUE_MAX,	/* Maximum value */  				    NULL);	/* Name */ @@ -85,7 +85,8 @@ sem_post (sem_t * sem)  #else /* NEED_SEM */ -  else if (!ReleaseSemaphore ((*sem)->sem, 1, 0)) +    else if (InterlockedExchangeAdd((LPLONG) &(*sem)->value, (LONG) 1) < 0 +	     && !ReleaseSemaphore((*sem)->sem, 1, NULL))  #endif /* NEED_SEM */ diff --git a/sem_post_multiple.c b/sem_post_multiple.c index 43c71a6..e30e01a 100644 --- a/sem_post_multiple.c +++ b/sem_post_multiple.c @@ -76,6 +76,9 @@ sem_post_multiple (sem_t * sem, int count)        */  {    int result = 0; +#ifndef NEED_SEM +  long waiters; +#endif    if (sem == NULL || *sem == NULL || count <= 0)      { @@ -88,7 +91,8 @@ sem_post_multiple (sem_t * sem, int count)  #else /* NEED_SEM */ -  else if (!ReleaseSemaphore ((*sem)->sem, count, 0)) +    else if ((waiters = -InterlockedExchangeAdd((LPLONG) &(*sem)->value, (LONG) count)) > 0 +	     && !ReleaseSemaphore((*sem)->sem,  (waiters<=count)?waiters:count, 0))  #endif /* NEED_SEM */ diff --git a/sem_timedwait.c b/sem_timedwait.c index e374006..e7fa55c 100644 --- a/sem_timedwait.c +++ b/sem_timedwait.c @@ -189,7 +189,15 @@ sem_timedwait (sem_t * sem, const struct timespec *abstime)  #else /* NEED_SEM */ -      result = (pthreadCancelableTimedWait ((*sem)->sem, milliseconds)); +      if (InterlockedDecrement((LPLONG) &(*sem)->value) < 0) +        { +          /* Must wait */ +	  result = pthreadCancelableTimedWait ((*sem)->sem, milliseconds); +	  if (result != 0) +	    { +              (void) InterlockedIncrement((LPLONG) &(*sem)->value); +	    } +        }  #endif diff --git a/sem_trywait.c b/sem_trywait.c index 342ee06..253c10e 100644 --- a/sem_trywait.c +++ b/sem_trywait.c @@ -92,8 +92,9 @@ sem_trywait (sem_t * sem)      {        result = EINVAL;      } -  else if (WaitForSingleObject ((*sem)->sem, 0) == WAIT_TIMEOUT) +  else if (InterlockedDecrement((LPLONG) &(*sem)->value) < 0)      { +      (void) InterlockedIncrement((LPLONG) &(*sem)->value);        result = EAGAIN;      } @@ -92,8 +92,14 @@ sem_wait (sem_t * sem)  #else /* NEED_SEM */ -      result = pthreadCancelableWait ((*sem)->sem); - +      sem_t s = *sem; + +      if (InterlockedDecrement((LPLONG) &s->value) < 0) +	{ +	  /* Must wait */ +	  result = pthreadCancelableWait (s->sem); +	} +       #endif /* NEED_SEM */      } diff --git a/tests/ChangeLog b/tests/ChangeLog index f55b2b6..65d52f1 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,8 +1,12 @@ -2004-10-14  Ross Johnson  <rpj@callisto.canberra.edu.au> +2004-10-19  Ross Johnson  <rpj@callisto.canberra.edu.au>
 -	* rwlock7.c (main): Tidy up statistics reporting; randomise -	update accesses. -	* rwlock8.c: New test. +	* semaphore3.c: New test. + +2004-10-14  Ross Johnson  <rpj@callisto.canberra.edu.au>
 + +	* rwlock7.c (main): Tidy up statistics reporting; randomise
 +	update accesses.
 +	* rwlock8.c: New test.
  2004-09-08  Alexandre Girao  <alexgirao@gmail.com>
 diff --git a/tests/GNUmakefile b/tests/GNUmakefile index 0979fda..aecd718 100644 --- a/tests/GNUmakefile +++ b/tests/GNUmakefile @@ -70,7 +70,8 @@ COPYFILES	= $(HDR) $(LIB) $(DLL) $(QAPC)  # stop.  TESTS	= sizes loadfree \ -	  self1 mutex5 mutex1 mutex1e mutex1n mutex1r semaphore1 semaphore2 \ +	  self1 mutex5 mutex1 mutex1e mutex1n mutex1r \ +	  semaphore1 semaphore2 semaphore3 \  	  condvar1 condvar1_1 condvar1_2 condvar2 condvar2_1 exit1 \  	  create1 create2 reuse1 reuse2 equal1 \  	  kill1 valid1 valid2 \ @@ -251,6 +252,7 @@ self1.pass:  self2.pass: create1.pass  semaphore1.pass:  semaphore2.pass: +semaphore3.pass: semaphore2.pass  sizes.pass:  spin1.pass:  spin2.pass: spin1.pass diff --git a/tests/Makefile b/tests/Makefile index 535347f..71154b3 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -80,8 +80,10 @@ EHFLAGS	=  # stop.
  PASSES= sizes.pass  loadfree.pass \
 -	  semaphore1.pass  semaphore2.pass  self1.pass  mutex5.pass  \
 -	  mutex1.pass  mutex1n.pass  mutex1e.pass  mutex1r.pass  mutex2.pass  mutex3.pass  \
 +	  self1.pass  mutex5.pass  \
 +	  mutex1.pass  mutex1n.pass  mutex1e.pass  mutex1r.pass  \ +	  semaphore1.pass  semaphore2.pass  semaphore3.pass  \ +	  mutex2.pass  mutex3.pass  \
  	  mutex2r.pass  mutex2e.pass  mutex3r.pass  mutex3e.pass  \
  	  condvar1.pass  condvar1_1.pass  condvar1_2.pass  condvar2.pass  condvar2_1.pass  \
  	  exit1.pass  create1.pass  create2.pass  reuse1.pass  reuse2.pass  equal1.pass  \
 @@ -100,7 +102,7 @@ PASSES= sizes.pass  loadfree.pass \  	  condvar4.pass  condvar5.pass  condvar6.pass  \
  	  condvar7.pass  condvar8.pass  condvar9.pass  \
  	  errno1.pass  \
 -	  rwlock1.pass  rwlock2.pass  rwlock3.pass  rwlock4.pass  \ +	  rwlock1.pass  rwlock2.pass  rwlock3.pass  rwlock4.pass  \
  	  rwlock5.pass  rwlock6.pass  rwlock7.pass  rwlock8.pass  \
  	  rwlock2_t.pass  rwlock3_t.pass  rwlock4_t.pass  rwlock5_t.pass  rwlock6_t.pass  rwlock6_t2.pass  \
  	  context1.pass  \
 diff --git a/tests/semaphore2.c b/tests/semaphore2.c index 8e264ea..e3663d9 100644 --- a/tests/semaphore2.c +++ b/tests/semaphore2.c @@ -73,7 +73,7 @@  #include "test.h" -#define MAX_COUNT 100000 +#define MAX_COUNT 100  int  main() diff --git a/tests/semaphore3.c b/tests/semaphore3.c new file mode 100644 index 0000000..c6570f8 --- /dev/null +++ b/tests/semaphore3.c @@ -0,0 +1,120 @@ +/* + * File: semaphore3.c + * + * + * -------------------------------------------------------------------------- + * + *      Pthreads-win32 - POSIX Threads Library for Win32 + *      Copyright(C) 1998 John E. Bossom + *      Copyright(C) 1999,2003 Pthreads-win32 contributors + *  + *      Contact Email: rpj@callisto.canberra.edu.au + *  + *      The current list of contributors is contained + *      in the file CONTRIBUTORS included with the source + *      code distribution. The list can also be seen at the + *      following World Wide Web location: + *      http://sources.redhat.com/pthreads-win32/contributors.html + *  + *      This library is free software; you can redistribute it and/or + *      modify it under the terms of the GNU Lesser General Public + *      License as published by the Free Software Foundation; either + *      version 2 of the License, or (at your option) any later version. + *  + *      This library is distributed in the hope that it will be useful, + *      but WITHOUT ANY WARRANTY; without even the implied warranty of + *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU + *      Lesser General Public License for more details. + *  + *      You should have received a copy of the GNU Lesser General Public + *      License along with this library in the file COPYING.LIB; + *      if not, write to the Free Software Foundation, Inc., + *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + * + * -------------------------------------------------------------------------- + * + * Test Synopsis: Verify sem_getvalue returns the correct number of waiters. + * -  + * + * Test Method (Validation or Falsification): + * - Validation + * + * Requirements Tested: + * -  + * + * Features Tested: + * -  + * + * Cases Tested: + * - + * + * Description: + * - + * + * Environment: + * - + * + * Input: + * - None. + * + * Output: + * - File name, Line number, and failed expression on failure. + * - No output on success. + * + * Assumptions: + * - + * + * Pass Criteria: + * - Process returns zero exit status. + * + * Fail Criteria: + * - Process returns non-zero exit status. + */ + +#include "test.h" + +#define MAX_COUNT 100 + +sem_t s; + +void * +thr (void * arg) +{ +  assert(pthread_detach(pthread_self()) == 0); +  assert(sem_wait(&s) == 0); + +  return NULL; +} + +int +main() +{ +	int value = 0; +	int i; +	pthread_t t[MAX_COUNT]; + +  assert(sem_init(&s, PTHREAD_PROCESS_PRIVATE, 0) == 0); +	assert(sem_getvalue(&s, &value) == 0); +	assert(value == 0); +//	  printf("Value = %ld\n", value); + +	for (i = 1; i <= MAX_COUNT; i++) +		{ +			assert(pthread_create(&t[i-1], NULL, thr, NULL) == 0); +			sched_yield(); +			assert(sem_getvalue(&s, &value) == 0); +//			  printf("Value = %ld\n", value); +			assert(-value == i); +		} + +	for (i = MAX_COUNT - 1; i >= 0; i--) +		{ +			assert(sem_post(&s) == 0); +			assert(sem_getvalue(&s, &value) == 0); +//			  printf("Value = %ld\n", value); +			assert(-value == i); +		} + +  return 0; +} + | 
