Do not accept interrupts in RESUME_INTERRUPTS() and END_CRIT_SECTION()

macros, but only at explicit CHECK_FOR_INTERRUPTS() calls.  Not clear
whether overenthusiastic acceptance of interrupts accounts for any real
bugs, but it definitely seems risky and unnecessary.

src/backend/tcop/postgres.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.243 2001/12/04 19:40:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.244 2002/01/01 23:16:22 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -1626,7 +1626,7 @@ PostgresMain(int argc, char *argv[], const char *username)
 	if (!IsUnderPostmaster)
 	{
 		puts("\nPOSTGRES backend interactive interface ");
-		puts("$Revision: 1.243 $ $Date: 2001/12/04 19:40:17 $\n");
+		puts("$Revision: 1.244 $ $Date: 2002/01/01 23:16:22 $\n");
 	}
 
 	/*
@@ -1703,7 +1703,6 @@ PostgresMain(int argc, char *argv[], const char *username)
 
 		/*
 		 * Exit interrupt holdoff section we implicitly established above.
-		 * (This could result in accepting a cancel or die interrupt.)
 		 */
 		RESUME_INTERRUPTS();
 	}

src/include/miscadmin.h

@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: miscadmin.h,v 1.97 2001/11/05 17:46:31 momjian Exp $
+ * $Id: miscadmin.h,v 1.98 2002/01/01 23:16:22 tgl Exp $
  *
  * NOTES
  *	  some of the information in this file should be moved to
@@ -43,7 +43,8 @@
  * or die interrupt.  The HOLD_INTERRUPTS() and RESUME_INTERRUPTS() macros
  * allow code to ensure that no cancel or die interrupt will be accepted,
  * even if CHECK_FOR_INTERRUPTS() gets called in a subroutine.	The interrupt
- * will be held off until the last matching RESUME_INTERRUPTS() occurs.
+ * will be held off until CHECK_FOR_INTERRUPTS() is done outside any
+ * HOLD_INTERRUPTS() ... RESUME_INTERRUPTS() section.
  *
  * Special mechanisms are used to let an interrupt be accepted when we are
  * waiting for a lock or when we are waiting for command input (but, of
@@ -85,8 +86,6 @@ extern void ProcessInterrupts(void);
 	do { \
 		Assert(InterruptHoldoffCount > 0); \
 		InterruptHoldoffCount--; \
-		if (InterruptPending) \
-			ProcessInterrupts(); \
 	} while(0)
 
 #define START_CRIT_SECTION()  (CritSectionCount++)
@@ -95,8 +94,6 @@ extern void ProcessInterrupts(void);
 	do { \
 		Assert(CritSectionCount > 0); \
 		CritSectionCount--; \
-		if (InterruptPending) \
-			ProcessInterrupts(); \
 	} while(0)