Win32 CHECK_FOR_INTERRUPTS() performance tweak - Mailing list pgsql-patches

From Qingqing Zhou
Subject Win32 CHECK_FOR_INTERRUPTS() performance tweak
Date
Msg-id Pine.LNX.4.58.0510210222310.13224@eon.cs
Whole thread Raw
List pgsql-patches
This patch improves the win32 CHECK_FOR_INTERRUPTS() performance by
testing if any unblocked signals are queued before check
pgwin32_signal_event. This avoids an unnecessary system call.

Regards,
Qingqing

---

Index: backend/port/win32/signal.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/port/win32/signal.c,v
retrieving revision 1.12
diff -u -r1.12 signal.c
--- backend/port/win32/signal.c    15 Oct 2005 02:49:23 -0000    1.12
+++ backend/port/win32/signal.c    21 Oct 2005 05:32:52 -0000
@@ -19,11 +19,12 @@
 /* pg_signal_crit_sec is used to protect only pg_signal_queue. That is the only
  * variable that can be accessed from the signal sending threads! */
 static CRITICAL_SECTION pg_signal_crit_sec;
-static int    pg_signal_queue;

 static pqsigfunc pg_signal_array[PG_SIGNAL_COUNT];
 static pqsigfunc pg_signal_defaults[PG_SIGNAL_COUNT];
-static int    pg_signal_mask;
+
+int    pg_signal_queue;
+int    pg_signal_mask;

 DLLIMPORT HANDLE pgwin32_signal_event;
 HANDLE        pgwin32_initial_signal_pipe = INVALID_HANDLE_VALUE;
@@ -91,11 +92,10 @@
     int            i;

     EnterCriticalSection(&pg_signal_crit_sec);
-    while (pg_signal_queue & ~pg_signal_mask)
+    while (UNBLOCKED_SIGNAL_QUEUE())
     {
         /* One or more unblocked signals queued for execution */
-
-        int            exec_mask = pg_signal_queue & ~pg_signal_mask;
+        int            exec_mask = UNBLOCKED_SIGNAL_QUEUE();

         for (i = 0; i < PG_SIGNAL_COUNT; i++)
         {
Index: include/port/win32.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/port/win32.h,v
retrieving revision 1.47
diff -u -r1.47 win32.h
--- include/port/win32.h    15 Oct 2005 02:49:45 -0000    1.47
+++ include/port/win32.h    21 Oct 2005 05:33:26 -0000
@@ -214,6 +214,12 @@


 /* In backend/port/win32/signal.c */
+extern int    pg_signal_queue;
+extern int    pg_signal_mask;
+
+#define UNBLOCKED_SIGNAL_QUEUE()    \
+        (pg_signal_queue & ~pg_signal_mask)
+
 extern DLLIMPORT HANDLE pgwin32_signal_event;
 extern HANDLE pgwin32_initial_signal_pipe;

Index: include/miscadmin.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/miscadmin.h,v
retrieving revision 1.180
diff -u -r1.180 miscadmin.h
--- include/miscadmin.h    15 Oct 2005 02:49:41 -0000    1.180
+++ include/miscadmin.h    21 Oct 2005 05:33:56 -0000
@@ -87,8 +87,10 @@

 #define CHECK_FOR_INTERRUPTS() \
 do { \
-    if (WaitForSingleObjectEx(pgwin32_signal_event,0,TRUE) == WAIT_OBJECT_0) \
-        pgwin32_dispatch_queued_signals(); \
+    if (UNBLOCKED_SIGNAL_QUEUE())    { \
+        if (WaitForSingleObjectEx(pgwin32_signal_event,0,TRUE) == WAIT_OBJECT_0) \
+            pgwin32_dispatch_queued_signals(); \
+    }    \
     if (InterruptPending) \
         ProcessInterrupts(); \
 } while(0)

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