An attempt to get sem_getvalue working properly.

9 files changed, 218 insertions, 78 deletions

diff --git a/ChangeLog b/ChangeLog
index 9a2413d..693e04d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2002-06-03  Ross Johnson  <rpj@digit.ise.canberra.edu.au>

+

+	* sem_init.c (sem_init): Initialise Win32 semaphores

+	to _POSIX_SEM_VALUE_MAX (which this implementation

+	defines in pthread.h) so that sem_getvalue() can use

+	the trick described in the comments in sem_getvalue().

+	* pthread.h (_POSIX_SEM_VALUE_MAX): Defined.

+	(_POSIX_SEM_NSEMS_MAX): Defined - not used but may be

+	useful for source code portability.

+

+2002-06-03  Rob Fanner  <rfanner@stonethree.com>

+

+	* sem_getvalue.c (sem_getvalue): Did not work on NT.

+	Use approach suggested by Johnson M. Hart in his book

+	"Win32 System Programming".

+

 2002-02-28  Ross Johnson  <rpj@setup1.ise.canberra.edu.au>

 

 	* errno.c: Compiler directive was incorrectly including code.

diff --git a/Nmakefile.tests b/Nmakefile.tests
index 5e1b37a..e914305 100644
--- a/Nmakefile.tests
+++ b/Nmakefile.tests
@@ -86,6 +86,7 @@ rwlock5_t::	rwlock5_t.c
 rwlock6_t::	rwlock6_t.c

 rwlock6_t2::	rwlock6_t2.c

 semaphore1::	semaphore1.c

+semaphore2::	semaphore2.c

 context1::	context1.c

 cancel3::	cancel3.c

 cancel4::	cancel4.c

@@ -119,6 +120,7 @@ benchtest5::    benchtest5.c
 

 loadfree:	:test:

 semaphore1	:test:	loadfree

+semaphore2	:test:	loadfree

 mutex5		:test:	loadfree

 mutex1		:test:	loadfree

 mutex2		:test:	loadfree

diff --git a/pthread.h b/pthread.h
index 3e37f81..253888b 100644
--- a/pthread.h
+++ b/pthread.h
@@ -1,4 +1,4 @@
-/* This is the POSIX thread API (POSIX 1003).
+/* This is an implementation of the threads API of POSIX 1003.1-2001.
  *
  * --------------------------------------------------------------------------
  *
@@ -76,12 +76,14 @@
  *	Provides an implementation of PThreads based upon the
  *	standard:
  *
- *		POSIX 1003.1c-1995	(POSIX.1c)
+ *		POSIX 1003.1-2001
+ *  and
+ *    The Single Unix Specification version 3
  *
- *	Parts of the implementation also comply with the
- *	Open Group Unix 98 specification in order to enhance
- *	code portability between Windows, various commercial
- *	Unix implementations, and Linux.
+ *    (these two are equivalent)
+ *
+ *	in order to enhance code portability between Windows,
+ *  various commercial Unix implementations, and Linux.
  *
  *	See the ANNOUNCE file for a full list of conforming
  *	routines and defined constants, and a list of missing
@@ -283,8 +285,8 @@ extern "C"
 /*
  * -------------------------------------------------------------
  *
- * POSIX 1003.1c-1995 Options
- * ===========================
+ * POSIX 1003.1-2001 Options
+ * =========================
  *
  * _POSIX_THREADS (set)
  *			If set, you can use threads
@@ -350,11 +352,20 @@ extern "C"
  *			If set you can use the special *_r library
  *			functions that provide thread-safe behaviour
  *
+ * _POSIX_READER_WRITER_LOCKS (set)
+ *			If set, you can use read/write locks
+ *
+ * _POSIX_SPIN_LOCKS (set)
+ *			If set, you can use spin locks
+ *
+ * _POSIX_BARRIERS (set)
+ *			If set, you can use barriers
+ *
  *	+ These functions provide both 'inherit' and/or
  *	  'protect' protocol, based upon these macro
  *	  settings.
  *
- * POSIX 1003.1c-1995 Limits
+ * POSIX 1003.1-2001 Limits
  * ===========================
  *
  * PTHREAD_DESTRUCTOR_ITERATIONS
@@ -373,18 +384,13 @@ extern "C"
  *			Maximum number of threads supported per
  *			process (must be at least 64).
  *
+ * _POSIX_SEM_NSEMS_MAX
+ *      The maximum number of semaphores a process can have.
+ *      (only defined if not already defined)
  *
- * POSIX 1003.1j/D10-1999 Options
- * ==============================
- *
- * _POSIX_READER_WRITER_LOCKS (set)
- *			If set, you can use read/write locks
- *
- * _POSIX_SPIN_LOCKS (set)
- *			If set, you can use spin locks
- *
- * _POSIX_BARRIERS (set)
- *			If set, you can use barriers
+ * _POSIX_SEM_VALUE_MAX
+ *      The maximum value a semaphore can have.
+ *      (only defined if not already defined)
  *
  * -------------------------------------------------------------
  */
@@ -452,11 +458,16 @@ extern "C"
  *		constant should be set at DLL load time.
  *
  */
-#define PTHREAD_DESTRUCTOR_ITERATIONS			   4
-#define PTHREAD_KEYS_MAX				  64
-#define PTHREAD_STACK_MIN				   0
-#define PTHREAD_THREADS_MAX				2019
-
+#define PTHREAD_DESTRUCTOR_ITERATIONS			       4
+#define PTHREAD_KEYS_MAX                        64
+#define PTHREAD_STACK_MIN                        0
+#define PTHREAD_THREADS_MAX                   2019
+#ifndef _POSIX_SEM_NSEMS_MAX
+#  define _POSIX_SEM_NSEMS_MAX           (INT_MAX)
+#endif
+#ifndef _POSIX_SEM_VALUE_MAX
+#  define _POSIX_SEM_VALUE_MAX       (INT_MAX - 1)
+#endif
 
 #if __GNUC__ && ! defined (__declspec)
 # error Please upgrade your GNU compiler to one that supports __declspec.
diff --git a/sem_getvalue.c b/sem_getvalue.c
index abc76c0..b3033d3 100644
--- a/sem_getvalue.c
+++ b/sem_getvalue.c
@@ -4,15 +4,13 @@
  * Module: sem_getvalue.c
  *
  * Purpose:
- *	Semaphores aren't actually part of the PThreads standard.
+ *	Semaphores aren't actually part of PThreads.
  *	They are defined by the POSIX Standard:
  *
- *		POSIX 1003.1b-1993	(POSIX.1b)
+ *		POSIX 1003.1-2001
  *
  * -------------------------------------------------------------
  *
- * --------------------------------------------------------------------------
- *
  *      Pthreads-win32 - POSIX Threads Library for Win32
  *      Copyright(C) 1998 John E. Bossom
  *      Copyright(C) 1999,2002 Pthreads-win32 contributors
@@ -93,19 +91,24 @@ sem_getvalue(sem_t * sem, int * sval)
 #else
       long value = *sval;
  
-      /* Note:
-       *  The windows NT documentation says that the increment must be
-       *  greater than zero, but it is set to zero here. If this works,
-       *  the function will return true. If not, we can't do it this way
-       *  so flag it as not implemented.
-       */
+			/* From "Win32 System Programming - Second Edition"
+			 * by Johnson M Hart, chapter 9, page 256 :
+			 *
+			 * "The release count must be greater than zero, but if it
+			 * would cause the semaphore count to exceed the maximum,
+			 * the call will fail, returning FALSE, and the count will
+			 * remain unchanged. Releasing a semaphore with a large count
+			 * is a method used to obtain the current count atomically
+			 * (of course, another thread might change the value immediately)."
+			 */
 
-      if ( ReleaseSemaphore( (*sem)->sem, 0L, &value) )
+      if ( ! ReleaseSemaphore( (*sem)->sem, _POSIX_SEM_VALUE_MAX + 1, &value) )
         {
           *sval = value;
         }
       else
         {
+					/* This should NEVER occur. */
           result = ENOSYS;
         }
  
diff --git a/sem_init.c b/sem_init.c
index e36678c..78e9770 100644
--- a/sem_init.c
+++ b/sem_init.c
@@ -4,15 +4,13 @@
  * Module: sem_init.c
  *
  * Purpose:
- *	Semaphores aren't actually part of the PThreads standard.
+ *	Semaphores aren't actually part of PThreads.
  *	They are defined by the POSIX Standard:
  *
- *		POSIX 1003.1b-1993	(POSIX.1b)
+ *		POSIX 1003.1-2001
  *
  * -------------------------------------------------------------
  *
- * --------------------------------------------------------------------------
- *
  *      Pthreads-win32 - POSIX Threads Library for Win32
  *      Copyright(C) 1998 John E. Bossom
  *      Copyright(C) 1999,2002 Pthreads-win32 contributors
@@ -49,14 +47,12 @@
 #include "semaphore.h"
 #include "implement.h"
 
-#include <limits.h>
-
 int
 sem_init (sem_t * sem, int pshared, unsigned int value)
      /*
       * ------------------------------------------------------
       * DOCPUBLIC
-      *      This function initializes an unnamed semaphore. the
+      *      This function initializes a semaphore. The
       *      initial value of the semaphore is 'value'
       *
       * PARAMETERS
@@ -73,7 +69,7 @@ sem_init (sem_t * sem, int pshared, unsigned int value)
       * 	     initial value of the semaphore counter
       *
       * DESCRIPTION
-      *      This function initializes an unnamed semaphore. The
+      *      This function initializes a semaphore. The
       *      initial value of the semaphore is set to 'value'.
       *
       * RESULTS
@@ -106,45 +102,46 @@ sem_init (sem_t * sem, int pshared, unsigned int value)
       s = (sem_t) calloc (1, sizeof (*s));
 
       if (NULL == s)
-	{
-	  result = ENOMEM;
-	}
+				{
+					result = ENOMEM;
+				}
 
 #ifdef NEED_SEM
 
       else
-	{
-	  s->value = value;
-	  s->event = CreateEvent (NULL,
-				  FALSE,	/* manual reset */
-				  FALSE,	/* initial state */
-				  NULL);
-	  if (0 == s->event)
-	    {
-	      result = ENOSPC;
-	    }
-	  else
-	    {
-	      if (value != 0)
-		{
-		  SetEvent(s->event);
-		}
-
-	      InitializeCriticalSection(&s->sem_lock_cs);
-	    }
-	}
-
+				{
+					s->value = value;
+					s->event = CreateEvent (NULL,
+						FALSE,	/* manual reset */
+						FALSE,	/* initial state */
+						NULL);
+
+					if (0 == s->event)
+						{
+							result = ENOSPC;
+						}
+					else
+						{
+							if (value != 0)
+								{
+									SetEvent(s->event);
+								}
+							
+							InitializeCriticalSection(&s->sem_lock_cs);
+						}
+				}
+			
 #else /* NEED_SEM */
 
       s->sem = CreateSemaphore (NULL,	     /* Always NULL */
-				value,	     /* Initial value */
-				INT_MAX,     /* Maximum value */
-				NULL);	     /* Name */
-
+				value,	              /* Initial value */
+				_POSIX_SEM_VALUE_MAX, /* Maximum value */
+				NULL);	              /* Name */
+			
       if (0 == s->sem)
-	{
-	  result = ENOSPC;
-	}
+				{
+					result = ENOSPC;
+				}
 
 #endif /* NEED_SEM */
 
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 6c8deed..e9266a5 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,7 @@
+2002-06-03  Ross Johnson  <rpj@digit.ise.canberra.edu.au>

+

+	* semaphore2.c: New test.

+

 2002-03-02  Ross Johnson  <rpj@special.ise.canberra.edu.au>

 

 	* Makefile (CFLAGS): Changed /MT to /MD to link with

diff --git a/tests/GNUmakefile b/tests/GNUmakefile
index cdae2d9..15b77b6 100644
--- a/tests/GNUmakefile
+++ b/tests/GNUmakefile
@@ -65,7 +65,7 @@ COPYFILES	= $(HDR) $(LIB) $(DLL)
 # stop.
 
 TESTS	= loadfree \
-	  semaphore1 self1 mutex5 mutex1 mutex1e mutex1n mutex1r \
+	  semaphore1 semaphore2 self1 mutex5 mutex1 mutex1e mutex1n mutex1r \
 	  condvar1 condvar1_1 condvar1_2 condvar2 condvar2_1 exit1 create1 equal1 \
 	  exit2 exit3 \
 	  join0 join1 join2 \
@@ -221,6 +221,7 @@ rwlock6_t2.pass: rwlock6_t.pass
 self1.pass:
 self2.pass: create1.pass
 semaphore1.pass:
+semaphore2.pass:
 spin1.pass:
 spin2.pass: spin1.pass
 spin3.pass: spin2.pass
diff --git a/tests/Makefile b/tests/Makefile
index a3fa7f3..014b767 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -71,7 +71,7 @@ EHFLAGS	=
 # stop.

 

 PASSES= loadfree.pass \

-	  semaphore1.pass  self1.pass  mutex5.pass  \

+	  semaphore1.pass  semaphore2.pass  self1.pass  mutex5.pass  \

 	  mutex1.pass  mutex1n.pass  mutex1e.pass  mutex1r.pass  mutex2.pass  mutex3.pass  \

 	  condvar1.pass  condvar1_1.pass  condvar1_2.pass  condvar2.pass  condvar2_1.pass  \

 	  exit1.pass  create1.pass  equal1.pass  \

@@ -286,7 +286,8 @@ rwlock6_t.pass: rwlock5_t.pass
 rwlock6_t2.pass: rwlock6_t.pass

 self1.pass:

 self2.pass: create1.pass

-semaphore.pass:

+semaphore1.pass:

+semaphore2.pass:

 spin1.pass:

 spin2.pass: spin1.pass

 spin3.pass: spin2.pass

diff --git a/tests/semaphore2.c b/tests/semaphore2.c
new file mode 100644
index 0000000..133443c
--- /dev/null
+++ b/tests/semaphore2.c
@@ -0,0 +1,105 @@
+/*
+ * File: semaphore2.c
+ *
+ *
+ * --------------------------------------------------------------------------
+ *
+ *	Pthreads-win32 - POSIX Threads Library for Win32
+ *	Copyright(C) 1998 John E. Bossom
+ *	Copyright(C) 1999,2002 Pthreads-win32 contributors
+ *
+ *	Contact Email: rpj@ise.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 value.
+ * - 
+ *
+ * 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 BIG_NUM 10000
+
+int
+main()
+{
+  sem_t s;
+	int value = 0;
+  int result;
+
+  assert(sem_init(&s, PTHREAD_PROCESS_PRIVATE, BIG_NUM) == 0);
+	assert((result = sem_getvalue(&s, &value)) == 0);
+	assert(value == BIG_NUM);
+
+	for (i = BIG_NUM - 1; i >= 0; i--)
+		{
+			assert(sem_wait(&s) == 0);
+			assert((result = sem_getvalue(&s, &value)) == 0);
+			assert(value == i);
+		}
+
+	for (i = 1; i <= BIG_NUM; i--)
+		{
+			assert(sem_post(&s) == 0);
+			assert((result = sem_getvalue(&s, &value)) == 0);
+			assert(value == i);
+		}
+
+  return 0;
+}
+