I noticed several months ago, and came across it again today, that
libpq's pthread-win32.c implementation is using CreateMutex rather than
CRITICAL_SECTION. CreateMutex is like a semaphore in that it is
designed to be accessible via name system-wide. Even when you don't
give it a name, thus bound to process that created it, it still carries
significant overhead compared to using win32 CRITICAL_SECTIONs.
The attached patch replaces the win32 mutex calls with critical section
calls. The change will not affect the behavior of the windows
pthread_xxx functions.
--
Andrew Chernow
eSilo, LLC
every bit counts
http://www.esilo.com/
Index: src/port/pthread-win32.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/port/pthread-win32.h,v
retrieving revision 1.2
diff -c -r1.2 pthread-win32.h
*** src/port/pthread-win32.h 18 Apr 2007 08:32:40 -0000 1.2
--- src/port/pthread-win32.h 11 Apr 2008 18:35:33 -0000
***************
*** 2,8 ****
#define __PTHREAD_H
typedef ULONG pthread_key_t;
! typedef HANDLE pthread_mutex_t;
typedef int pthread_once_t;
DWORD pthread_self(void);
--- 2,8 ----
#define __PTHREAD_H
typedef ULONG pthread_key_t;
! typedef CRITICAL_SECTION *pthread_mutex_t;
typedef int pthread_once_t;
DWORD pthread_self(void);
Index: src/interfaces/libpq/pthread-win32.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/interfaces/libpq/pthread-win32.c,v
retrieving revision 1.15
diff -c -r1.15 pthread-win32.c
*** src/interfaces/libpq/pthread-win32.c 1 Jan 2008 19:46:00 -0000
1.15
--- src/interfaces/libpq/pthread-win32.c 11 Apr 2008 18:35:33 -0000
***************
*** 35,51 ****
void
pthread_mutex_init(pthread_mutex_t *mp, void *attr)
{
! *mp = CreateMutex(0, 0, 0);
}
void
pthread_mutex_lock(pthread_mutex_t *mp)
{
! WaitForSingleObject(*mp, INFINITE);
}
void
pthread_mutex_unlock(pthread_mutex_t *mp)
{
! ReleaseMutex(*mp);
}
--- 35,69 ----
void
pthread_mutex_init(pthread_mutex_t *mp, void *attr)
{
! if(mp)
! {
! *mp = (CRITICAL_SECTION *)malloc(sizeof(CRITICAL_SECTION));
! if(*mp)
! InitializeCriticalSection(*mp);
! }
}
void
pthread_mutex_lock(pthread_mutex_t *mp)
{
! if(mp && *mp)
! EnterCriticalSection(*mp);
}
void
pthread_mutex_unlock(pthread_mutex_t *mp)
{
! if(mp && *mp)
! LeaveCriticalSection(*mp);
}
+
+ /* If ever needed
+ pthread_mutex_destroy(pthread_mutex_t *mp)
+ {
+ if(mp && *mp)
+ {
+ DeleteCriticalSection(*mp);
+ *mp = NULL;
+ }
+ }
+ */
\ No newline at end of file
--
Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-patches
