From 782eefc580a503db4773cd177b17dcc6fd33b058 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 11 Jan 2006 20:12:43 +0000 Subject: [PATCH] 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 --- doc/src/sgml/func.sgml | 52 ++++++++++++++++++- src/backend/utils/adt/misc.c | 51 +++++++++++++++++- src/include/catalog/catversion.h | 4 +- src/include/catalog/pg_proc.h | 4 +- src/include/utils/builtins.h | 3 +- src/test/regress/expected/stats.out | 4 +- .../regress/input/create_function_1.source | 5 -- .../regress/output/create_function_1.source | 4 -- src/test/regress/regress.c | 18 +------ src/test/regress/sql/stats.sql | 2 +- 10 files changed, 112 insertions(+), 35 deletions(-) diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index d90bc15d41..a3eadb4bc4 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,5 +1,5 @@ @@ -6170,6 +6170,56 @@ SELECT TIMESTAMP 'now'; -- incorrect for use with DEFAULT + + + Delaying Execution + + + pg_sleep + + + sleep + + + delay + + + + The following function is available to delay execution of the server + process: + +pg_sleep(seconds) + + + pg_sleep makes the current session's process + sleep until seconds seconds have + elapsed. seconds is a value of type + double precision, so fractional-second delays can be specified. + For example: + + +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 may be longer depending on factors such as server load. + + + + + + Make sure that your session does not hold more locks than necessary + when calling pg_sleep. Otherwise other sessions + might have to wait for your sleeping process, slowing down the entire + system. + + + + diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c index 14bb593c2c..2ceea8969a 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 #include #include +#include #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(); +} diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index 6eb5f72d9f..258a9956f4 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -37,7 +37,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.309 2006/01/08 07:00:25 neilc Exp $ + * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.310 2006/01/11 20:12:39 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -53,6 +53,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 200601081 +#define CATALOG_VERSION_NO 200601111 #endif diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h index 7b78e78fcc..6f5ec17c45 100644 --- a/src/include/catalog/pg_proc.h +++ b/src/include/catalog/pg_proc.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.390 2006/01/08 07:00:25 neilc Exp $ + * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.391 2006/01/11 20:12:39 tgl Exp $ * * NOTES * 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" DESCR("Read text from a file"); 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_ )); DESCR("List all files in a directory"); +DATA(insert OID = 2626 ( pg_sleep PGNSP PGUID 12 f f t f v 1 2278 "701" _null_ _null_ _null_ pg_sleep - _null_ )); +DESCR("Sleep for the specified time in seconds"); /* Aggregates (moved here from pg_aggregate for 7.3) */ diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h index 97fbfdc341..8ca212852c 100644 --- a/src/include/utils/builtins.h +++ b/src/include/utils/builtins.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.269 2006/01/08 07:00:26 neilc Exp $ + * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.270 2006/01/11 20:12:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -387,6 +387,7 @@ extern Datum pg_cancel_backend(PG_FUNCTION_ARGS); extern Datum pg_reload_conf(PG_FUNCTION_ARGS); extern Datum pg_tablespace_databases(PG_FUNCTION_ARGS); extern Datum pg_rotate_logfile(PG_FUNCTION_ARGS); +extern Datum pg_sleep(PG_FUNCTION_ARGS); /* not_in.c */ extern Datum int4notin(PG_FUNCTION_ARGS); diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index bd2e1328f8..d3495ffb48 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -36,8 +36,8 @@ SELECT count(*) FROM tenk2 WHERE unique1 = 1; (1 row) -- let stats collector catch up -SELECT do_sleep(2); - do_sleep +SELECT pg_sleep(2.0); + pg_sleep ---------- (1 row) diff --git a/src/test/regress/input/create_function_1.source b/src/test/regress/input/create_function_1.source index 14b90ca1a1..faa73156dc 100644 --- a/src/test/regress/input/create_function_1.source +++ b/src/test/regress/input/create_function_1.source @@ -52,11 +52,6 @@ CREATE FUNCTION set_ttdummy (int4) AS '@abs_builddir@/regress@DLSUFFIX@' LANGUAGE 'C' STRICT; -CREATE FUNCTION do_sleep (int4) - RETURNS void - AS '@abs_builddir@/regress@DLSUFFIX@' - LANGUAGE 'C' STRICT; - -- Things that shouldn't work: CREATE FUNCTION test1 (int) RETURNS int LANGUAGE sql diff --git a/src/test/regress/output/create_function_1.source b/src/test/regress/output/create_function_1.source index 7511c3f8d6..ed275b1f48 100644 --- a/src/test/regress/output/create_function_1.source +++ b/src/test/regress/output/create_function_1.source @@ -47,10 +47,6 @@ CREATE FUNCTION set_ttdummy (int4) RETURNS int4 AS '@abs_builddir@/regress@DLSUFFIX@' LANGUAGE 'C' STRICT; -CREATE FUNCTION do_sleep (int4) - RETURNS void - AS '@abs_builddir@/regress@DLSUFFIX@' - LANGUAGE 'C' STRICT; -- Things that shouldn't work: CREATE FUNCTION test1 (int) RETURNS int LANGUAGE sql AS 'SELECT ''not an integer'';'; diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c index 97fe608602..7c58f950cb 100644 --- a/src/test/regress/regress.c +++ b/src/test/regress/regress.c @@ -1,5 +1,5 @@ /* - * $PostgreSQL: pgsql/src/test/regress/regress.c,v 1.64 2005/10/15 02:49:51 momjian Exp $ + * $PostgreSQL: pgsql/src/test/regress/regress.c,v 1.65 2006/01/11 20:12:43 tgl Exp $ */ #include "postgres.h" @@ -26,7 +26,6 @@ extern char *reverse_name(char *string); extern int oldstyle_length(int n, text *t); extern Datum int44in(PG_FUNCTION_ARGS); extern Datum int44out(PG_FUNCTION_ARGS); -extern Datum do_sleep(PG_FUNCTION_ARGS); /* @@ -735,18 +734,3 @@ int44out(PG_FUNCTION_ARGS) *--walk = '\0'; PG_RETURN_CSTRING(result); } - -/* - * do_sleep - delay for N seconds - */ -PG_FUNCTION_INFO_V1(do_sleep); - -Datum -do_sleep(PG_FUNCTION_ARGS) -{ - int32 secs = PG_GETARG_INT32(0); - - pg_usleep(secs * 1000000L); - - PG_RETURN_VOID(); -} diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 3589a0cf5d..75acee647d 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -26,7 +26,7 @@ SELECT count(*) FROM tenk2; SELECT count(*) FROM tenk2 WHERE unique1 = 1; -- let stats collector catch up -SELECT do_sleep(2); +SELECT pg_sleep(2.0); -- check effects SELECT st.seq_scan >= pr.seq_scan + 1, -- 2.40.0