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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 parent fb627b7 commit 782eefc

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10 files changed

+112
-35
lines changed

10 files changed

+112
-35
lines changed

‎doc/src/sgml/func.sgml

Lines changed: 51 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.301 2005/12/28 01:29:58 tgl Exp $
2+
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.302 2006/01/11 20:12:38 tgl Exp $
33
PostgreSQL documentation
44
-->
55

@@ -6170,6 +6170,56 @@ SELECT TIMESTAMP 'now'; -- incorrect for use with DEFAULT
61706170
</para>
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</tip>
61726172
</sect2>
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<sect2 id="functions-datetime-delay">
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<title>Delaying Execution</title>
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<indexterm>
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<primary>pg_sleep</primary>
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</indexterm>
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<indexterm>
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<primary>sleep</primary>
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</indexterm>
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<indexterm>
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<primary>delay</primary>
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</indexterm>
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<para>
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The following function is available to delay execution of the server
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process:
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<synopsis>
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pg_sleep(<replaceable>seconds</replaceable>)
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</synopsis>
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<function>pg_sleep</function> makes the current session's process
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sleep until <replaceable>seconds</replaceable> seconds have
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elapsed. <replaceable>seconds</replaceable> is a value of type
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<type>double precision</>, so fractional-second delays can be specified.
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For example:
6199+
6200+
<programlisting>
6201+
SELECT pg_sleep(1.5);
6202+
</programlisting>
6203+
</para>
6204+
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<note>
6206+
<para>
6207+
The effective resolution of the sleep interval is platform-specific;
6208+
0.01 seconds is a common value. The sleep delay will be at least as long
6209+
as specified. It may be longer depending on factors such as server load.
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</para>
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</note>
6212+
6213+
<warning>
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<para>
6215+
Make sure that your session does not hold more locks than necessary
6216+
when calling <function>pg_sleep</function>. Otherwise other sessions
6217+
might have to wait for your sleeping process, slowing down the entire
6218+
system.
6219+
</para>
6220+
</warning>
6221+
</sect2>
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61736223
</sect1>
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‎src/backend/utils/adt/misc.c

Lines changed: 50 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.49 2005/10/15 02:49:29 momjian Exp $
11+
* $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.50 2006/01/11 20:12:39 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -17,6 +17,7 @@
1717
#include <sys/file.h>
1818
#include <signal.h>
1919
#include <dirent.h>
20+
#include <math.h>
2021

2122
#include "catalog/pg_tablespace.h"
2223
#include "catalog/pg_type.h"
@@ -259,3 +260,51 @@ pg_tablespace_databases(PG_FUNCTION_ARGS)
259260
FreeDir(fctx->dirdesc);
260261
SRF_RETURN_DONE(funcctx);
261262
}
263+
264+
265+
/*
266+
* pg_sleep - delay for N seconds
267+
*/
268+
Datum
269+
pg_sleep(PG_FUNCTION_ARGS)
270+
{
271+
float8 secs = PG_GETARG_FLOAT8(0);
272+
float8 endtime;
273+
274+
/*
275+
* We break the requested sleep into segments of no more than 1 second,
276+
* to put an upper bound on how long it will take us to respond to a
277+
* cancel or die interrupt. (Note that pg_usleep is interruptible by
278+
* signals on some platforms but not others.) Also, this method avoids
279+
* exposing pg_usleep's upper bound on allowed delays.
280+
*
281+
* By computing the intended stop time initially, we avoid accumulation
282+
* of extra delay across multiple sleeps. This also ensures we won't
283+
* delay less than the specified time if pg_usleep is interrupted
284+
* by other signals such as SIGHUP.
285+
*/
286+
287+
#ifdef HAVE_INT64_TIMESTAMP
288+
#define GetNowFloat() ((float8) GetCurrentTimestamp() / 1000000.0)
289+
#else
290+
#define GetNowFloat() GetCurrentTimestamp()
291+
#endif
292+
293+
endtime = GetNowFloat() + secs;
294+
295+
for (;;)
296+
{
297+
float8 delay;
298+
299+
CHECK_FOR_INTERRUPTS();
300+
delay = endtime - GetNowFloat();
301+
if (delay >= 1.0)
302+
pg_usleep(1000000L);
303+
else if (delay > 0.0)
304+
pg_usleep((long) ceil(delay * 1000000.0));
305+
else
306+
break;
307+
}
308+
309+
PG_RETURN_VOID();
310+
}

‎src/include/catalog/catversion.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,7 @@
3737
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
3838
* Portions Copyright (c) 1994, Regents of the University of California
3939
*
40-
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.309 2006/01/08 07:00:25 neilc Exp $
40+
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.310 2006/01/11 20:12:39 tgl Exp $
4141
*
4242
*-------------------------------------------------------------------------
4343
*/
@@ -53,6 +53,6 @@
5353
*/
5454

5555
/* yyyymmddN */
56-
#define CATALOG_VERSION_NO 200601081
56+
#define CATALOG_VERSION_NO 200601111
5757

5858
#endif

‎src/include/catalog/pg_proc.h

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Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.390 2006/01/08 07:00:25 neilc Exp $
10+
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.391 2006/01/11 20:12:39 tgl Exp $
1111
*
1212
* NOTES
1313
* The script catalog/genbki.sh reads this file and generates .bki
@@ -3025,6 +3025,8 @@ DATA(insert OID = 2624 ( pg_read_file PGNSP PGUID 12 f f t f v 3 25 "25 20 20"
30253025
DESCR("Read text from a file");
30263026
DATA(insert OID = 2625 ( pg_ls_dir PGNSP PGUID 12 f f t t v 1 25 "25" _null_ _null_ _null_ pg_ls_dir - _null_ ));
30273027
DESCR("List all files in a directory");
3028+
DATA(insert OID = 2626 ( pg_sleep PGNSP PGUID 12 f f t f v 1 2278 "701" _null_ _null_ _null_ pg_sleep - _null_ ));
3029+
DESCR("Sleep for the specified time in seconds");
30283030

30293031

30303032
/* Aggregates (moved here from pg_aggregate for 7.3) */

‎src/include/utils/builtins.h

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.269 2006/01/08 07:00:26 neilc Exp $
10+
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.270 2006/01/11 20:12:42 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -387,6 +387,7 @@ extern Datum pg_cancel_backend(PG_FUNCTION_ARGS);
387387
extern Datum pg_reload_conf(PG_FUNCTION_ARGS);
388388
extern Datum pg_tablespace_databases(PG_FUNCTION_ARGS);
389389
extern Datum pg_rotate_logfile(PG_FUNCTION_ARGS);
390+
extern Datum pg_sleep(PG_FUNCTION_ARGS);
390391

391392
/* not_in.c */
392393
extern Datum int4notin(PG_FUNCTION_ARGS);

‎src/test/regress/expected/stats.out

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -36,8 +36,8 @@ SELECT count(*) FROM tenk2 WHERE unique1 = 1;
3636
(1 row)
3737

3838
-- let stats collector catch up
39-
SELECT do_sleep(2);
40-
do_sleep
39+
SELECT pg_sleep(2.0);
40+
pg_sleep
4141
----------
4242

4343
(1 row)

‎src/test/regress/input/create_function_1.source

Lines changed: 0 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -52,11 +52,6 @@ CREATE FUNCTION set_ttdummy (int4)
5252
AS '@abs_builddir@/regress@DLSUFFIX@'
5353
LANGUAGE 'C' STRICT;
5454

55-
CREATE FUNCTION do_sleep (int4)
56-
RETURNS void
57-
AS '@abs_builddir@/regress@DLSUFFIX@'
58-
LANGUAGE 'C' STRICT;
59-
6055
-- Things that shouldn't work:
6156

6257
CREATE FUNCTION test1 (int) RETURNS int LANGUAGE sql

‎src/test/regress/output/create_function_1.source

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -47,10 +47,6 @@ CREATE FUNCTION set_ttdummy (int4)
4747
RETURNS int4
4848
AS '@abs_builddir@/regress@DLSUFFIX@'
4949
LANGUAGE 'C' STRICT;
50-
CREATE FUNCTION do_sleep (int4)
51-
RETURNS void
52-
AS '@abs_builddir@/regress@DLSUFFIX@'
53-
LANGUAGE 'C' STRICT;
5450
-- Things that shouldn't work:
5551
CREATE FUNCTION test1 (int) RETURNS int LANGUAGE sql
5652
AS 'SELECT ''not an integer'';';

‎src/test/regress/regress.c

Lines changed: 1 addition & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
/*
2-
* $PostgreSQL: pgsql/src/test/regress/regress.c,v 1.64 2005/10/15 02:49:51 momjian Exp $
2+
* $PostgreSQL: pgsql/src/test/regress/regress.c,v 1.65 2006/01/11 20:12:43 tgl Exp $
33
*/
44

55
#include "postgres.h"
@@ -26,7 +26,6 @@ extern char *reverse_name(char *string);
2626
extern int oldstyle_length(int n, text *t);
2727
extern Datum int44in(PG_FUNCTION_ARGS);
2828
extern Datum int44out(PG_FUNCTION_ARGS);
29-
extern Datum do_sleep(PG_FUNCTION_ARGS);
3029

3130

3231
/*
@@ -735,18 +734,3 @@ int44out(PG_FUNCTION_ARGS)
735734
*--walk = '\0';
736735
PG_RETURN_CSTRING(result);
737736
}
738-
739-
/*
740-
* do_sleep - delay for N seconds
741-
*/
742-
PG_FUNCTION_INFO_V1(do_sleep);
743-
744-
Datum
745-
do_sleep(PG_FUNCTION_ARGS)
746-
{
747-
int32 secs = PG_GETARG_INT32(0);
748-
749-
pg_usleep(secs * 1000000L);
750-
751-
PG_RETURN_VOID();
752-
}

‎src/test/regress/sql/stats.sql

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -26,7 +26,7 @@ SELECT count(*) FROM tenk2;
2626
SELECT count(*) FROM tenk2 WHERE unique1 = 1;
2727

2828
-- let stats collector catch up
29-
SELECT do_sleep(2);
29+
SELECT pg_sleep(2.0);
3030

3131
-- check effects
3232
SELECT st.seq_scan >= pr.seq_scan + 1,

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