3 files changed, 19 insertions, 35 deletions

diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index 06f801764b6..6323a35c91c 100644
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -240,7 +240,7 @@ NoticeProcessor(void *arg, const char *message)
  * fgets are coded to handle possible interruption.
  *
  * On Windows, currently this does not work, so control-C is less useful
- * there, and the callback is just a no-op.
+ * there.
  */
 volatile bool sigint_interrupt_enabled = false;
 
diff --git a/src/bin/scripts/scripts_parallel.c b/src/bin/scripts/scripts_parallel.c
index 45c69b8d192..01bc6dfeffc 100644
--- a/src/bin/scripts/scripts_parallel.c
+++ b/src/bin/scripts/scripts_parallel.c
@@ -28,7 +28,7 @@
 #include "scripts_parallel.h"
 
 static void init_slot(ParallelSlot *slot, PGconn *conn);
-static int	select_loop(int maxFd, fd_set *workerset, bool *aborting);
+static int	select_loop(int maxFd, fd_set *workerset);
 
 static void
 init_slot(ParallelSlot *slot, PGconn *conn)
@@ -39,25 +39,19 @@ init_slot(ParallelSlot *slot, PGconn *conn)
 }
 
 /*
- * Loop on select() until a descriptor from the given set becomes readable.
+ * Wait until a file descriptor from the given set becomes readable.
  *
- * If we get a cancel request while we're waiting, we forego all further
- * processing and set the *aborting flag to true.  The return value must be
- * ignored in this case.  Otherwise, *aborting is set to false.
+ * Returns the number of ready descriptors, or -1 on failure (including
+ * getting a cancel request).
  */
 static int
-select_loop(int maxFd, fd_set *workerset, bool *aborting)
+select_loop(int maxFd, fd_set *workerset)
 {
 	int			i;
 	fd_set		saveSet = *workerset;
 
 	if (CancelRequested)
-	{
-		*aborting = true;
 		return -1;
-	}
-	else
-		*aborting = false;
 
 	for (;;)
 	{
@@ -90,7 +84,7 @@ select_loop(int maxFd, fd_set *workerset, bool *aborting)
 		if (i < 0 && errno == EINTR)
 			continue;			/* ignore this */
 		if (i < 0 || CancelRequested)
-			*aborting = true;	/* but not this */
+			return -1;			/* but not this */
 		if (i == 0)
 			continue;			/* timeout (Win32 only) */
 		break;
@@ -135,7 +129,6 @@ ParallelSlotsGetIdle(ParallelSlot *slots, int numslots)
 	{
 		fd_set		slotset;
 		int			maxFd = 0;
-		bool		aborting;
 
 		/* We must reconstruct the fd_set for each call to select_loop */
 		FD_ZERO(&slotset);
@@ -157,19 +150,12 @@ ParallelSlotsGetIdle(ParallelSlot *slots, int numslots)
 		}
 
 		SetCancelConn(slots->connection);
-		i = select_loop(maxFd, &slotset, &aborting);
+		i = select_loop(maxFd, &slotset);
 		ResetCancelConn();
 
-		if (aborting)
-		{
-			/*
-			 * We set the cancel-receiving connection to the one in the zeroth
-			 * slot above, so fetch the error from there.
-			 */
-			consumeQueryResult(slots->connection);
+		/* failure? */
+		if (i < 0)
 			return NULL;
-		}
-		Assert(i != 0);
 
 		for (i = 0; i < numslots; i++)
 		{
diff --git a/src/fe_utils/cancel.c b/src/fe_utils/cancel.c
index eb4056a9a6c..51fb67d384a 100644
--- a/src/fe_utils/cancel.c
+++ b/src/fe_utils/cancel.c
@@ -43,11 +43,11 @@
 static PGcancel *volatile cancelConn = NULL;
 
 /*
- * CancelRequested tracks if a cancellation request has completed after
- * a signal interruption.  Note that if cancelConn is not set, in short
- * if SetCancelConn() was never called or if ResetCancelConn() freed
- * the cancellation object, then CancelRequested is switched to true after
- * all cancellation attempts.
+ * CancelRequested is set when we receive SIGINT (or local equivalent).
+ * There is no provision in this module for resetting it; but applications
+ * might choose to clear it after successfully recovering from a cancel.
+ * Note that there is no guarantee that we successfully sent a Cancel request,
+ * or that the request will have any effect if we did send it.
  */
 volatile sig_atomic_t CancelRequested = false;
 
@@ -148,6 +148,8 @@ handle_sigint(SIGNAL_ARGS)
 	int			save_errno = errno;
 	char		errbuf[256];
 
+	CancelRequested = true;
+
 	if (cancel_callback != NULL)
 		cancel_callback();
 
@@ -156,7 +158,6 @@ handle_sigint(SIGNAL_ARGS)
 	{
 		if (PQcancel(cancelConn, errbuf, sizeof(errbuf)))
 		{
-			CancelRequested = true;
 			write_stderr(_("Cancel request sent\n"));
 		}
 		else
@@ -165,8 +166,6 @@ handle_sigint(SIGNAL_ARGS)
 			write_stderr(errbuf);
 		}
 	}
-	else
-		CancelRequested = true;
 
 	errno = save_errno;			/* just in case the write changed it */
 }
@@ -193,6 +192,8 @@ consoleHandler(DWORD dwCtrlType)
 	if (dwCtrlType == CTRL_C_EVENT ||
 		dwCtrlType == CTRL_BREAK_EVENT)
 	{
+		CancelRequested = true;
+
 		if (cancel_callback != NULL)
 			cancel_callback();
 
@@ -203,7 +204,6 @@ consoleHandler(DWORD dwCtrlType)
 			if (PQcancel(cancelConn, errbuf, sizeof(errbuf)))
 			{
 				write_stderr(_("Cancel request sent\n"));
-				CancelRequested = true;
 			}
 			else
 			{
@@ -211,8 +211,6 @@ consoleHandler(DWORD dwCtrlType)
 				write_stderr(errbuf);
 			}
 		}
-		else
-			CancelRequested = true;
 
 		LeaveCriticalSection(&cancelConnLock);