From 430cc8cb79c7cf3ea811760e8aadd53cab7ff9e3 Mon Sep 17 00:00:00 2001 From: bdrouvotAWS Date: Sat, 5 Aug 2023 12:39:42 +0000 Subject: [PATCH v9] Add catalog pg_wait_events Adding a new system view, namely pg_wait_events, that describes the wait events. --- doc/src/sgml/monitoring.sgml | 13 ++- doc/src/sgml/system-views.sgml | 64 +++++++++++++ src/backend/Makefile | 3 +- src/backend/catalog/system_views.sql | 3 + src/backend/utils/activity/.gitignore | 1 + src/backend/utils/activity/Makefile | 8 +- .../activity/generate-wait_event_types.pl | 54 ++++++++++- src/backend/utils/activity/meson.build | 1 + src/backend/utils/activity/wait_event.c | 44 +++++++++ src/backend/utils/activity/wait_event_funcs.c | 93 +++++++++++++++++++ src/include/catalog/pg_proc.dat | 6 ++ src/include/utils/meson.build | 4 +- src/include/utils/wait_event.h | 1 + .../modules/worker_spi/t/001_worker_spi.pl | 6 ++ src/test/regress/expected/rules.out | 4 + src/test/regress/expected/sysviews.out | 16 ++++ src/test/regress/sql/sysviews.sql | 4 + src/tools/msvc/Solution.pm | 3 +- src/tools/msvc/clean.bat | 1 + 19 files changed, 318 insertions(+), 11 deletions(-) 21.0% doc/src/sgml/ 59.5% src/backend/utils/activity/ 3.5% src/include/catalog/ 4.5% src/test/regress/expected/ 4.5% src/test/ 3.0% src/tools/msvc/ 3.6% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 70511a2388..6c53c1ed91 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1103,7 +1103,7 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser &wait_event_types; - Here is an example of how wait events can be viewed: + Here are examples of how wait events can be viewed: SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event is NOT NULL; @@ -1112,6 +1112,17 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i 2540 | Lock | relation 6644 | LWLock | ProcArray (2 rows) + + + +SELECT a.pid, a.wait_event, w.description +FROM pg_stat_activity a JOIN pg_wait_events w +ON (a.wait_event_type = w.type AND a.wait_event = w.name) +WHERE wait_event is NOT NULL and a.state = 'active'; +-[ RECORD 1 ]------------------------------------------------------------------ +pid | 686674 +wait_event | WALInitSync +description | Waiting for a newly initialized WAL file to reach durable storage diff --git a/doc/src/sgml/system-views.sgml b/doc/src/sgml/system-views.sgml index 57b228076e..2b35c2f91b 100644 --- a/doc/src/sgml/system-views.sgml +++ b/doc/src/sgml/system-views.sgml @@ -221,6 +221,11 @@ views + + pg_wait_events + wait events + + @@ -4825,4 +4830,63 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx + + + <structname>pg_wait_events</structname> + + + pg_wait_events + + + + The view pg_wait_events provides description about the + wait events. + + + + <structname>pg_wait_events</structname> Columns + + + + + Column Type + + + Description + + + + + + + + type text + + + Wait event type + + + + + + name text + + + Wait event name + + + + + + description text + + + Wait event description + + + + +
+ + diff --git a/src/backend/Makefile b/src/backend/Makefile index 1c929383c4..3e275ac759 100644 --- a/src/backend/Makefile +++ b/src/backend/Makefile @@ -134,7 +134,7 @@ storage/lmgr/lwlocknames.h: storage/lmgr/generate-lwlocknames.pl storage/lmgr/lw $(MAKE) -C storage/lmgr lwlocknames.h lwlocknames.c utils/activity/wait_event_types.h: utils/activity/generate-wait_event_types.pl utils/activity/wait_event_names.txt - $(MAKE) -C utils/activity wait_event_types.h pgstat_wait_event.c + $(MAKE) -C utils/activity wait_event_types.h pgstat_wait_event.c wait_event_funcs_data.c # run this unconditionally to avoid needing to know its dependencies here: submake-catalog-headers: @@ -311,6 +311,7 @@ maintainer-clean: distclean storage/lmgr/lwlocknames.c \ storage/lmgr/lwlocknames.h \ utils/activity/pgstat_wait_event.c \ + utils/activity/wait_event_funcs_data.c \ utils/activity/wait_event_types.h \ utils/adt/jsonpath_gram.c \ utils/adt/jsonpath_gram.h \ diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index af65af6bdd..362b1ea8d5 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -1342,3 +1342,6 @@ CREATE VIEW pg_stat_subscription_stats AS ss.stats_reset FROM pg_subscription as s, pg_stat_get_subscription_stats(s.oid) as ss; + +CREATE VIEW pg_wait_events AS + SELECT * FROM pg_get_wait_events() AS we; diff --git a/src/backend/utils/activity/.gitignore b/src/backend/utils/activity/.gitignore index d77079285b..bd0c0c7772 100644 --- a/src/backend/utils/activity/.gitignore +++ b/src/backend/utils/activity/.gitignore @@ -1,2 +1,3 @@ /pgstat_wait_event.c /wait_event_types.h +/wait_event_funcs_data.c diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile index f1117745d4..f57cf3958c 100644 --- a/src/backend/utils/activity/Makefile +++ b/src/backend/utils/activity/Makefile @@ -32,10 +32,14 @@ OBJS = \ pgstat_subscription.o \ pgstat_wal.o \ pgstat_xact.o \ - wait_event.o + wait_event.o \ + wait_event_funcs.o include $(top_srcdir)/src/backend/common.mk +wait_event_funcs.o: wait_event_funcs_data.c +wait_event_funcs_data.c: wait_event_types.h + wait_event.o: pgstat_wait_event.c pgstat_wait_event.c: wait_event_types.h touch $@ @@ -44,4 +48,4 @@ wait_event_types.h: $(top_srcdir)/src/backend/utils/activity/wait_event_names.tx $(PERL) $(srcdir)/generate-wait_event_types.pl --code $< maintainer-clean: clean - rm -f wait_event_types.h pgstat_wait_event.c + rm -f wait_event_types.h pgstat_wait_event.c wait_event_funcs_data.c diff --git a/src/backend/utils/activity/generate-wait_event_types.pl b/src/backend/utils/activity/generate-wait_event_types.pl index 56335e8730..9c4557d903 100644 --- a/src/backend/utils/activity/generate-wait_event_types.pl +++ b/src/backend/utils/activity/generate-wait_event_types.pl @@ -4,6 +4,7 @@ # Generate wait events support files from wait_event_names.txt: # - wait_event_types.h (if --code is passed) # - pgstat_wait_event.c (if --code is passed) +# - wait_event_funcs_data.c (if --code is passed) # - wait_event_types.sgml (if --docs is passed) # # Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group @@ -98,8 +99,10 @@ if ($gen_code) # multiple times. my $htmp = "$output_path/wait_event_types.h.tmp$$"; my $ctmp = "$output_path/pgstat_wait_event.c.tmp$$"; + my $wctmp = "$output_path/wait_event_funcs_data.c.tmp$$"; open my $h, '>', $htmp or die "Could not open $htmp: $!"; open my $c, '>', $ctmp or die "Could not open $ctmp: $!"; + open my $wc, '>', $wctmp or die "Could not open $wctmp: $!"; my $header_comment = '/*------------------------------------------------------------------------- @@ -129,12 +132,14 @@ if ($gen_code) printf $c $header_comment, 'pgstat_wait_event.c'; + printf $wc $header_comment, 'wait_event_funcs_data.c'; + + # Generate the pgstat_wait_event.c and wait_event_types.h files # uc() is being used to force the comparison to be case-insensitive. foreach my $waitclass (sort { uc($a) cmp uc($b) } keys %hashwe) { - - # Don't generate .c and .h files for Extension, LWLock and - # Lock, these are handled independently. + # Don't generate the pgstat_wait_event.c and wait_event_types.h files + # for Extension, LWLock and Lock, these are handled independently. next if ( $waitclass eq 'WaitEventExtension' || $waitclass eq 'WaitEventLWLock' @@ -183,14 +188,55 @@ if ($gen_code) printf $c "}\n\n"; } + # Generate wait_event_funcs_data.c, for the contents of static C + # structure holding all the information about the wait events. + # uc() is being used to force the comparison to be case-insensitive, + # even though it is not strictly mandatory here. + foreach my $waitclass (sort { uc($a) cmp uc($b) } keys %hashwe) + { + my $last = $waitclass; + $last =~ s/^WaitEvent//; + + foreach my $wev (@{ $hashwe{$waitclass} }) + { + my $new_desc = substr $wev->[2], 1, -2; + # Escape single quotes. + $new_desc =~ s/'/\\'/g; + + # Replace the "quote" markups by real ones. + $new_desc =~ s/(.*?)<\/quote>/\\"$1\\"/g; + + # Remove SGML markups. + $new_desc =~ s/<.*?>(.*?)<.*?>/$1/g; + + # Tweak contents about links on GUCs, + while (my ($capture) = + $new_desc =~ m//g) + { + $capture =~ s/-/_/g; + $new_desc =~ s//$capture/g; + } + # Then remove any reference to "see ". + $new_desc =~ s/; see.*$//; + + # One element to the C structure holding the wait event + # info, as of (type, name, description). + printf $wc "\t{\"%s\", \"%s\", \"%s\"},\n", $last, $wev->[1], + $new_desc; + } + } + printf $h "#endif /* WAIT_EVENT_TYPES_H */\n"; close $h; close $c; + close $wc; rename($htmp, "$output_path/wait_event_types.h") || die "rename: $htmp to $output_path/wait_event_types.h: $!"; rename($ctmp, "$output_path/pgstat_wait_event.c") || die "rename: $ctmp to $output_path/pgstat_wait_event.c: $!"; + rename($wctmp, "$output_path/wait_event_funcs_data.c") + || die "rename: $wctmp to $output_path/wait_event_funcs_data.c: $!"; } # Generate the .sgml file. elsif ($gen_docs) @@ -249,7 +295,7 @@ Usage: perl [--output ] [--code ] [ --sgml ] input_file Options: --outdir Output directory (default '.') - --code Generate wait_event_types.h and pgstat_wait_event.c. + --code Generate C and header files. --sgml Generate wait_event_types.sgml. generate-wait_event_types.pl generates the SGML documentation and code diff --git a/src/backend/utils/activity/meson.build b/src/backend/utils/activity/meson.build index 9633f3623c..46a27e7548 100644 --- a/src/backend/utils/activity/meson.build +++ b/src/backend/utils/activity/meson.build @@ -23,6 +23,7 @@ backend_sources += files( # seems nicer to not add that as an include path for the whole backend. waitevent_sources = files( 'wait_event.c', + 'wait_event_funcs.c', ) wait_event = static_library('wait_event_names', diff --git a/src/backend/utils/activity/wait_event.c b/src/backend/utils/activity/wait_event.c index 4b9b5c01cb..d31767df80 100644 --- a/src/backend/utils/activity/wait_event.c +++ b/src/backend/utils/activity/wait_event.c @@ -264,6 +264,50 @@ GetWaitEventExtensionIdentifier(uint16 eventId) } +/* + * Returns a list of currently defined custom wait event names for extensions. + * The result is a palloc'd array, with the number of elements returned into + * *nwaitevents. + */ +char ** +GetWaitEventExtensionNames(int *nwaitevents) +{ + char **waiteventnames; + WaitEventExtensionEntryByName *hentry; + HASH_SEQ_STATUS hash_seq; + int index; + int els; + + LWLockAcquire(WaitEventExtensionLock, LW_SHARED); + + /* Now we can safely count the number of entries */ + els = hash_get_num_entries(WaitEventExtensionHashByName); + + /* Allocate enough space for all entries */ + waiteventnames = palloc(els * sizeof(char[NAMEDATALEN])); + + /* Now scan the hash table to copy the data */ + hash_seq_init(&hash_seq, WaitEventExtensionHashByName); + + index = 0; + while ((hentry = (WaitEventExtensionEntryByName *) hash_seq_search(&hash_seq)) != NULL) + { + + waiteventnames[index] = palloc(sizeof(char[NAMEDATALEN])); + strlcpy(waiteventnames[index], hentry->wait_event_name, + sizeof(char[NAMEDATALEN])); + + index++; + } + + LWLockRelease(WaitEventExtensionLock); + + Assert(index == els); + + *nwaitevents = index; + return waiteventnames; +} + /* * Configure wait event reporting to report wait events to *wait_event_info. * *wait_event_info needs to be valid until pgstat_reset_wait_event_storage() diff --git a/src/backend/utils/activity/wait_event_funcs.c b/src/backend/utils/activity/wait_event_funcs.c new file mode 100644 index 0000000000..06992f04a9 --- /dev/null +++ b/src/backend/utils/activity/wait_event_funcs.c @@ -0,0 +1,93 @@ +/*------------------------------------------------------------------------ + * + * wait_event_funcs.c + * Functions for accessing wait event data. + * + * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/utils/activity/wait_event_funcs.c + * + *------------------------------------------------------------------------ + */ +#include "postgres.h" + +#include "funcapi.h" +#include "utils/builtins.h" +#include "utils/wait_event.h" + +/* + * Each wait event has one corresponding entry in this structure, fed to + * the SQL function of this file. + */ +static const struct +{ + const char *type; + const char *name; + const char *description; +} + +waitEventData[] = +{ +#include "wait_event_funcs_data.c" + /* end of list */ + {NULL, NULL, NULL} +}; + + +/* + * pg_get_wait_events + * + * List all the wait events type, name and description. + */ +Datum +pg_get_wait_events(PG_FUNCTION_ARGS) +{ +#define PG_GET_WAIT_EVENTS_COLS 3 + ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + char **waiteventnames; + int nbextwaitevents; + + /* Build tuplestore to hold the result rows */ + InitMaterializedSRF(fcinfo, 0); + + /* Iterate over the list of wait events */ + for (int idx = 0; waitEventData[idx].type != NULL; idx++) + { + Datum values[PG_GET_WAIT_EVENTS_COLS] = {0}; + bool nulls[PG_GET_WAIT_EVENTS_COLS] = {0}; + + values[0] = CStringGetTextDatum(waitEventData[idx].type); + values[1] = CStringGetTextDatum(waitEventData[idx].name); + values[2] = CStringGetTextDatum(waitEventData[idx].description); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + /* Handling extension custom wait events */ + waiteventnames = GetWaitEventExtensionNames(&nbextwaitevents); + + for (int idx = 0; idx < nbextwaitevents; idx++) + { + StringInfoData buf; + Datum values[PG_GET_WAIT_EVENTS_COLS] = {0}; + bool nulls[PG_GET_WAIT_EVENTS_COLS] = {0}; + + + values[0] = CStringGetTextDatum("Extension"); + values[1] = CStringGetTextDatum(waiteventnames[idx]); + + initStringInfo(&buf); + appendStringInfoString(&buf, "Waiting for custom wait event \""); + appendStringInfoString(&buf, waiteventnames[idx]); + appendStringInfoString(&buf, "\" defined by an extension module"); + + values[2] = CStringGetTextDatum(buf.data); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 6996073989..b2dab98a8d 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5417,6 +5417,12 @@ proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}', proargnames => '{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,gss_delegation,leader_pid,query_id}', prosrc => 'pg_stat_get_activity' }, +{ oid => '8403', descr => 'describe wait events', + proname => 'pg_get_wait_events', procost => '10', prorows => '250', + proretset => 't', provolatile => 's', prorettype => 'record', + proargtypes => '', proallargtypes => '{text,text,text}', + proargmodes => '{o,o,o}', proargnames => '{type,name,description}', + prosrc => 'pg_get_wait_events' }, { oid => '3318', descr => 'statistics: information about progress of backends running maintenance command', proname => 'pg_stat_get_progress_info', prorows => '100', proretset => 't', diff --git a/src/include/utils/meson.build b/src/include/utils/meson.build index 6de5d93799..c179478611 100644 --- a/src/include/utils/meson.build +++ b/src/include/utils/meson.build @@ -1,6 +1,6 @@ # Copyright (c) 2022-2023, PostgreSQL Global Development Group -wait_event_output = ['wait_event_types.h', 'pgstat_wait_event.c'] +wait_event_output = ['wait_event_types.h', 'pgstat_wait_event.c', 'wait_event_funcs_data.c'] wait_event_target = custom_target('wait_event_names', input: files('../../backend/utils/activity/wait_event_names.txt'), output: wait_event_output, @@ -11,7 +11,7 @@ wait_event_target = custom_target('wait_event_names', ], build_by_default: true, install: true, - install_dir: [dir_include_server / 'utils', false], + install_dir: [dir_include_server / 'utils', false, false], ) wait_event_types_h = wait_event_target[0] diff --git a/src/include/utils/wait_event.h b/src/include/utils/wait_event.h index 3eebdfad38..009b03a520 100644 --- a/src/include/utils/wait_event.h +++ b/src/include/utils/wait_event.h @@ -63,6 +63,7 @@ extern void WaitEventExtensionShmemInit(void); extern Size WaitEventExtensionShmemSize(void); extern uint32 WaitEventExtensionNew(const char *wait_event_name); +extern char **GetWaitEventExtensionNames(int *nwaitevents); /* ---------- * pgstat_report_wait_start() - diff --git a/src/test/modules/worker_spi/t/001_worker_spi.pl b/src/test/modules/worker_spi/t/001_worker_spi.pl index 26b8a49bec..2965acd789 100644 --- a/src/test/modules/worker_spi/t/001_worker_spi.pl +++ b/src/test/modules/worker_spi/t/001_worker_spi.pl @@ -47,6 +47,12 @@ $result = $node->poll_query_until( is($result, 1, 'dynamic bgworker has reported "worker_spi_main" as wait event'); +# Check the wait event used by the dynamic bgworker appears in pg_wait_events +$result = $node->safe_psql('postgres', + q[SELECT count(*) > 0 from pg_wait_events where type = 'Extension' and name = 'worker_spi_main';] +); +is($result, 't', '"worker_spi_main" is reported in pg_wait_events'); + note "testing bgworkers loaded with shared_preload_libraries"; # Create the database first so as the workers can connect to it when diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index e07afcd4aa..55447d8090 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -2631,6 +2631,10 @@ pg_views| SELECT n.nspname AS schemaname, FROM (pg_class c LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (c.relkind = 'v'::"char"); +pg_wait_events| SELECT type, + name, + description + FROM pg_get_wait_events() we(type, name, description); SELECT tablename, rulename, definition FROM pg_rules WHERE schemaname = 'pg_catalog' ORDER BY tablename, rulename; diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out index 001c6e7eb9..aae5d51e1c 100644 --- a/src/test/regress/expected/sysviews.out +++ b/src/test/regress/expected/sysviews.out @@ -134,6 +134,22 @@ select name, setting from pg_settings where name like 'enable%'; enable_tidscan | on (21 rows) +-- There are always wait event descriptions for various types. +select type, count(*) > 0 as ok FROM pg_wait_events + group by type order by type COLLATE "C"; + type | ok +-----------+---- + Activity | t + BufferPin | t + Client | t + Extension | t + IO | t + IPC | t + LWLock | t + Lock | t + Timeout | t +(9 rows) + -- Test that the pg_timezone_names and pg_timezone_abbrevs views are -- more-or-less working. We can't test their contents in any great detail -- without the outputs changing anytime IANA updates the underlying data, diff --git a/src/test/regress/sql/sysviews.sql b/src/test/regress/sql/sysviews.sql index 351e469c77..6b4e24601d 100644 --- a/src/test/regress/sql/sysviews.sql +++ b/src/test/regress/sql/sysviews.sql @@ -55,6 +55,10 @@ select count(*) = 0 as ok from pg_stat_wal_receiver; -- a regression test run. select name, setting from pg_settings where name like 'enable%'; +-- There are always wait event descriptions for various types. +select type, count(*) > 0 as ok FROM pg_wait_events + group by type order by type COLLATE "C"; + -- Test that the pg_timezone_names and pg_timezone_abbrevs views are -- more-or-less working. We can't test their contents in any great detail -- without the outputs changing anytime IANA updates the underlying data, diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm index c98a1e9f9a..a50f730260 100644 --- a/src/tools/msvc/Solution.pm +++ b/src/tools/msvc/Solution.pm @@ -588,7 +588,8 @@ sub GenerateFiles 'src/include/utils/wait_event_types.h', 'src/backend/utils/activity/wait_event_names.txt')) { - print "Generating pgstat_wait_event.c and wait_event_types.h...\n"; + print + "Generating pgstat_wait_event.c, wait_event_types.h and wait_event_funcs_data.c...\n"; my $activ = 'src/backend/utils/activity'; system( "perl $activ/generate-wait_event_types.pl --outdir $activ --code $activ/wait_event_names.txt" diff --git a/src/tools/msvc/clean.bat b/src/tools/msvc/clean.bat index 7cb23ea894..ac8da581e4 100755 --- a/src/tools/msvc/clean.bat +++ b/src/tools/msvc/clean.bat @@ -55,6 +55,7 @@ if exist src\include\catalog\header-stamp del /q src\include\catalog\header-stam if exist doc\src\sgml\version.sgml del /q doc\src\sgml\version.sgml if %DIST%==1 if exist src\backend\utils\activity\pgstat_wait_event.c del /q src\backend\utils\activity\pgstat_wait_event.c +if %DIST%==1 if exist src\backend\utils\activity\wait_event_funcs_data.c del /q src\backend\utils\activity\wait_event_funcs_data.c if %DIST%==1 if exist src\backend\utils\activity\wait_event_types.h del /q src\backend\utils\activity\wait_event_types.h if %DIST%==1 if exist src\backend\utils\fmgroids.h del /q src\backend\utils\fmgroids.h if %DIST%==1 if exist src\backend\utils\fmgrprotos.h del /q src\backend\utils\fmgrprotos.h -- 2.34.1