From 760c770ff66b5c2f77f2e17750a2e263a74d82b3 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Thu, 30 Jan 2014 15:45:14 -0500
Subject: [PATCH] Add convenience functions pg_sleep_for and pg_sleep_until.
Vik Fearing, reviewed by Pavel Stehule and myself
---
doc/src/sgml/func.sgml | 18 ++++++++++++++----
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_proc.h | 4 ++++
src/test/regress/expected/stats.out | 6 +++---
src/test/regress/sql/stats.sql | 2 +-
5 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 9816163354d..3802fbcbb0a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -7664,20 +7664,28 @@ SELECT TIMESTAMP 'now'; -- incorrect for use with DEFAULT
</indexterm>
<para>
- The following function is available to delay execution of the server
+ The following functions are available to delay execution of the server
process:
<synopsis>
pg_sleep(<replaceable>seconds</replaceable>)
+pg_sleep_for(<type>interval</>)
+pg_sleep_until(<type>timestamp with time zone</>)
</synopsis>
<function>pg_sleep</function> makes the current session's process
sleep until <replaceable>seconds</replaceable> seconds have
elapsed. <replaceable>seconds</replaceable> is a value of type
<type>double precision</>, so fractional-second delays can be specified.
+ <function>pg_sleep_for</function> is a convenience function for larger
+ sleep times specified as an <type>interval</>.
+ <function>pg_sleep_until</function> is a convenience function for when
+ a specific wake-up time is desired.
For example:
<programlisting>
SELECT pg_sleep(1.5);
+SELECT pg_sleep_for('5 minutes');
+SELECT pg_sleep_until('tomorrow 03:00');
</programlisting>
</para>
@@ -7686,15 +7694,17 @@ SELECT pg_sleep(1.5);
The effective resolution of the sleep interval is platform-specific;
0.01 seconds is a common value. The sleep delay will be at least as long
as specified. It might be longer depending on factors such as server load.
+ In particular, <function>pg_sleep_until</function> is not guaranteed to
+ wake up exactly at the specified time, but it will not wake up any earlier.
</para>
</note>
<warning>
<para>
Make sure that your session does not hold more locks than necessary
- when calling <function>pg_sleep</function>. Otherwise other sessions
- might have to wait for your sleeping process, slowing down the entire
- system.
+ when calling <function>pg_sleep</function> or its variants. Otherwise
+ other sessions might have to wait for your sleeping process, slowing down
+ the entire system.
</para>
</warning>
</sect2>
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 404787c90ce..c4661a8a66b 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201401291
+#define CATALOG_VERSION_NO 201401301
#endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 9fc61ebed62..1682fa9f999 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -3034,6 +3034,10 @@ DATA(insert OID = 2625 ( pg_ls_dir PGNSP PGUID 12 1 1000 0 0 f f f f t t v 1 0
DESCR("list all files in a directory");
DATA(insert OID = 2626 ( pg_sleep PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 2278 "701" _null_ _null_ _null_ _null_ pg_sleep _null_ _null_ _null_ ));
DESCR("sleep for the specified time in seconds");
+DATA(insert OID = 3935 ( pg_sleep_for PGNSP PGUID 14 1 0 0 0 f f f f t f v 1 0 2278 "1186" _null_ _null_ _null_ _null_ "select pg_catalog.pg_sleep(extract(epoch from pg_catalog.now() operator(pg_catalog.+) $1) operator(pg_catalog.-) extract(epoch from pg_catalog.now()))" _null_ _null_ _null_ ));
+DESCR("sleep for the specified interval");
+DATA(insert OID = 3936 ( pg_sleep_until PGNSP PGUID 14 1 0 0 0 f f f f t f v 1 0 2278 "1184" _null_ _null_ _null_ _null_ "select pg_catalog.pg_sleep(extract(epoch from $1) operator(pg_catalog.-) extract(epoch from pg_catalog.now()))" _null_ _null_ _null_ ));
+DESCR("sleep until the specified time");
DATA(insert OID = 2971 ( text PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "16" _null_ _null_ _null_ _null_ booltext _null_ _null_ _null_ ));
DESCR("convert boolean to text");
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 56bace1187b..ec0ff6589b8 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -18,9 +18,9 @@ SET enable_indexscan TO on;
SET enable_indexonlyscan TO off;
-- wait to let any prior tests finish dumping out stats;
-- else our messages might get lost due to contention
-SELECT pg_sleep(2.0);
- pg_sleep
-----------
+SELECT pg_sleep_for('2 seconds');
+ pg_sleep_for
+--------------
(1 row)
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index bb349b2dfa6..646b9ac6869 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -16,7 +16,7 @@ SET enable_indexonlyscan TO off;
-- wait to let any prior tests finish dumping out stats;
-- else our messages might get lost due to contention
-SELECT pg_sleep(2.0);
+SELECT pg_sleep_for('2 seconds');
-- save counters
CREATE TEMP TABLE prevstats AS
--
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