database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-22 12:22:45 +03:00
Code Activity

Add system view pg_wait_events

Browse Source 
This new view, wrapped around a SRF, shows some information known about
wait events, as of:
- Name.
- Type (Activity, I/O, Extension, etc.).
- Description.

All the information retrieved comes from wait_event_names.txt, and the
description is the same as the documentation with filters applied to
remove any XML markups.  This view is useful when joined with
pg_stat_activity to get the description of a wait event reported.

Custom wait events for extensions are included in the view.

Original idea by Yves Colin.

Author: Bertrand Drouvot
Reviewed-by: Kyotaro Horiguchi, Masahiro Ikeda, Tom Lane, Michael
Paquier
Discussion: https://postgr.es/m/0e2ae164-dc89-03c3-cf7f-de86378053ac@gmail.com
This commit is contained in:
Michael Paquier
2023-08-20 15:35:02 +09:00
parent a2a6249cf1
commit 1e68e43d3f
19 changed files with 317 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

93
src/backend/utils/activity/wait_event_funcs.c Normal file
View File

@@ -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 information about 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);
}
/* Handle custom wait events for extensions */
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);
appendStringInfo(&buf,
"Waiting for custom wait event \"%s\" defined by extension module",
waiteventnames[idx]);
values[2] = CStringGetTextDatum(buf.data);
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
}
return (Datum) 0;
}