Create a standard function pg_sleep() to sleep for a specified amount of time.

Replace the former ad-hoc implementation used in the regression tests.
Joachim Wieland

1 files changed, 50 insertions, 1 deletions

diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index 14bb593c2c2..2ceea8969a5 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.49 2005/10/15 02:49:29 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.50 2006/01/11 20:12:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,6 +17,7 @@
 #include <sys/file.h>
 #include <signal.h>
 #include <dirent.h>
+#include <math.h>
 
 #include "catalog/pg_tablespace.h"
 #include "catalog/pg_type.h"
@@ -259,3 +260,51 @@ pg_tablespace_databases(PG_FUNCTION_ARGS)
 	FreeDir(fctx->dirdesc);
 	SRF_RETURN_DONE(funcctx);
 }
+
+
+/*
+ * pg_sleep - delay for N seconds
+ */
+Datum
+pg_sleep(PG_FUNCTION_ARGS)
+{
+	float8		secs = PG_GETARG_FLOAT8(0);
+	float8		endtime;
+
+	/*
+	 * We break the requested sleep into segments of no more than 1 second,
+	 * to put an upper bound on how long it will take us to respond to a
+	 * cancel or die interrupt.  (Note that pg_usleep is interruptible by
+	 * signals on some platforms but not others.)  Also, this method avoids
+	 * exposing pg_usleep's upper bound on allowed delays.
+	 *
+	 * By computing the intended stop time initially, we avoid accumulation
+	 * of extra delay across multiple sleeps.  This also ensures we won't
+	 * delay less than the specified time if pg_usleep is interrupted
+	 * by other signals such as SIGHUP.
+	 */
+
+#ifdef HAVE_INT64_TIMESTAMP
+#define GetNowFloat()	((float8) GetCurrentTimestamp() / 1000000.0)
+#else
+#define GetNowFloat()	GetCurrentTimestamp()
+#endif
+
+	endtime = GetNowFloat() + secs;
+
+	for (;;)
+	{
+		float8		delay;
+
+		CHECK_FOR_INTERRUPTS();
+		delay = endtime - GetNowFloat();
+		if (delay >= 1.0)
+			pg_usleep(1000000L);
+		else if (delay > 0.0)
+			pg_usleep((long) ceil(delay * 1000000.0));
+		else
+			break;
+	}
+
+	PG_RETURN_VOID();
+}