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author
Oleg Tselebrovskiy
committed
Refactor some old code, add some comments, update included headers
Co-authored by: Sergey Shinderuk and Oleg Tselebrovskiy
1 parent 4826caa commit 117ac9a

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‎README.md

+3-3
Original file line numberDiff line numberDiff line change
@@ -51,7 +51,7 @@ PostgreSQL installation. It is available from
5151
[github](https://github.com/postgrespro/pg_wait_sampling)
5252
under the same license as
5353
[PostgreSQL](http://www.postgresql.org/about/licence/)
54-
and supports PostgreSQL 12+.
54+
and supports PostgreSQL 13+.
5555

5656
Installation
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------------
@@ -62,10 +62,10 @@ repository: https://download.postgresql.org/pub/repos/
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Manual build
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------------
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65-
`pg_wait_sampling` is PostgreSQL extension which requires PostgreSQL 12 or
65+
`pg_wait_sampling` is PostgreSQL extension which requires PostgreSQL 13 or
6666
higher. Before build and install you should ensure following:
6767

68-
* PostgreSQL version is 12 or higher.
68+
* PostgreSQL version is 13 or higher.
6969
* You have development package of PostgreSQL installed or you built
7070
PostgreSQL from source.
7171
* Your PATH variable is configured so that `pg_config` command available, or

‎collector.c

+63-107
Original file line numberDiff line numberDiff line change
@@ -2,37 +2,65 @@
22
* collector.c
33
* Collector of wait event history and profile.
44
*
5-
* Copyright (c) 2015-2016, Postgres Professional
5+
* Copyright (c) 2015-2025, Postgres Professional
66
*
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* IDENTIFICATION
88
* contrib/pg_wait_sampling/pg_wait_sampling.c
99
*/
1010
#include "postgres.h"
1111

12-
#include "catalog/pg_type.h"
13-
#if PG_VERSION_NUM >= 130000
14-
#include "common/hashfn.h"
15-
#endif
16-
#include "funcapi.h"
1712
#include "miscadmin.h"
13+
#include "pg_wait_sampling.h"
1814
#include "postmaster/bgworker.h"
1915
#include "postmaster/interrupt.h"
20-
#include "storage/ipc.h"
21-
#include "storage/procarray.h"
16+
#include "storage/latch.h"
17+
#include "storage/lock.h"
18+
#include "storage/lwlock.h"
19+
#include "storage/proc.h"
2220
#include "storage/procsignal.h"
2321
#include "storage/shm_mq.h"
24-
#include "storage/shm_toc.h"
25-
#include "storage/spin.h"
26-
#include "utils/memutils.h"
27-
#include "utils/resowner.h"
22+
#include "utils/guc.h"
23+
#include "utils/hsearch.h"
24+
#include "utils/timestamp.h"
25+
#if PG_VERSION_NUM < 140000
2826
#include "pgstat.h"
27+
#else
28+
#include "utils/wait_event.h"
29+
#endif
2930

30-
#include "compat.h"
31-
#include "pg_wait_sampling.h"
31+
static inline shm_mq_result
32+
shm_mq_send_compat(shm_mq_handle *mqh, Size nbytes, const void *data,
33+
bool nowait, bool force_flush)
34+
{
35+
#if PG_VERSION_NUM >= 150000
36+
return shm_mq_send(mqh, nbytes, data, nowait, force_flush);
37+
#else
38+
return shm_mq_send(mqh, nbytes, data, nowait);
39+
#endif
40+
}
3241

33-
static volatile sig_atomic_t shutdown_requested = false;
42+
#if PG_VERSION_NUM < 170000
43+
#define INIT_PG_LOAD_SESSION_LIBS 0x0001
44+
#define INIT_PG_OVERRIDE_ALLOW_CONNS 0x0002
45+
#endif
3446

35-
static void handle_sigterm(SIGNAL_ARGS);
47+
static inline void
48+
InitPostgresCompat(const char *in_dbname, Oid dboid,
49+
const char *username, Oid useroid,
50+
bits32 flags,
51+
char *out_dbname)
52+
{
53+
#if PG_VERSION_NUM >= 170000
54+
InitPostgres(in_dbname, dboid, username, useroid, flags, out_dbname);
55+
#elif PG_VERSION_NUM >= 150000
56+
InitPostgres(in_dbname, dboid, username, useroid,
57+
flags & INIT_PG_LOAD_SESSION_LIBS,
58+
flags & INIT_PG_OVERRIDE_ALLOW_CONNS, out_dbname);
59+
#else
60+
InitPostgres(in_dbname, dboid, username, useroid, out_dbname,
61+
flags & INIT_PG_OVERRIDE_ALLOW_CONNS);
62+
#endif
63+
}
3664

3765
/*
3866
* Register background worker for collecting waits history.
@@ -111,16 +139,6 @@ realloc_history(History *observations, int count)
111139
observations->wraparound = false;
112140
}
113141

114-
static void
115-
handle_sigterm(SIGNAL_ARGS)
116-
{
117-
int save_errno = errno;
118-
shutdown_requested = true;
119-
if (MyProc)
120-
SetLatch(&MyProc->procLatch);
121-
errno = save_errno;
122-
}
123-
124142
/*
125143
* Get next item of history with rotation.
126144
*/
@@ -129,6 +147,7 @@ get_next_observation(History *observations)
129147
{
130148
HistoryItem *result;
131149

150+
/* Check for wraparound */
132151
if (observations->index >= observations->count)
133152
{
134153
observations->index = 0;
@@ -215,6 +234,7 @@ send_history(History *observations, shm_mq_handle *mqh)
215234
else
216235
count = observations->index;
217236

237+
/* Send array size first since receive_array expects this */
218238
mq_result = shm_mq_send_compat(mqh, sizeof(count), &count, false, true);
219239
if (mq_result == SHM_MQ_DETACHED)
220240
{
@@ -251,6 +271,7 @@ send_profile(HTAB *profile_hash, shm_mq_handle *mqh)
251271
Size count = hash_get_num_entries(profile_hash);
252272
shm_mq_result mq_result;
253273

274+
/* Send array size first since receive_array expects this */
254275
mq_result = shm_mq_send_compat(mqh, sizeof(count), &count, false, true);
255276
if (mq_result == SHM_MQ_DETACHED)
256277
{
@@ -283,32 +304,11 @@ make_profile_hash()
283304
{
284305
HASHCTL hash_ctl;
285306

286-
hash_ctl.hash = tag_hash;
287-
hash_ctl.hcxt = TopMemoryContext;
288-
289-
if (pgws_profileQueries)
290-
hash_ctl.keysize = offsetof(ProfileItem, count);
291-
else
292-
hash_ctl.keysize = offsetof(ProfileItem, queryId);
293-
307+
/* We always include queryId in hash key */
308+
hash_ctl.keysize = offsetof(ProfileItem, count);
294309
hash_ctl.entrysize = sizeof(ProfileItem);
295310
return hash_create("Waits profile hash", 1024, &hash_ctl,
296-
HASH_FUNCTION | HASH_ELEM);
297-
}
298-
299-
/*
300-
* Delta between two timestamps in milliseconds.
301-
*/
302-
static int64
303-
millisecs_diff(TimestampTz tz1, TimestampTz tz2)
304-
{
305-
long secs;
306-
int microsecs;
307-
308-
TimestampDifference(tz1, tz2, &secs, &microsecs);
309-
310-
return secs * 1000 + microsecs / 1000;
311-
311+
HASH_ELEM | HASH_BLOBS);
312312
}
313313

314314
/*
@@ -319,77 +319,49 @@ pgws_collector_main(Datum main_arg)
319319
{
320320
HTAB *profile_hash = NULL;
321321
History observations;
322-
MemoryContext old_context,
323-
collector_context;
324322
TimestampTz current_ts,
325323
history_ts,
326324
profile_ts;
327325

328-
/*
329-
* Establish signal handlers.
330-
*
331-
* We want CHECK_FOR_INTERRUPTS() to kill off this worker process just as
332-
* it would a normal user backend. To make that happen, we establish a
333-
* signal handler that is a stripped-down version of die(). We don't have
334-
* any equivalent of the backend's command-read loop, where interrupts can
335-
* be processed immediately, so make sure ImmediateInterruptOK is turned
336-
* off.
337-
*
338-
* We also want to respond to the ProcSignal notifications. This is done
339-
* in the upstream provided procsignal_sigusr1_handler, which is
340-
* automatically used if a bgworker connects to a database. But since our
341-
* worker doesn't connect to any database even though it calls
342-
* InitPostgres, which will still initializze a new backend and thus
343-
* partitipate to the ProcSignal infrastructure.
344-
*/
345-
pqsignal(SIGTERM, handle_sigterm);
326+
/* Establish signal handlers */
346327
pqsignal(SIGHUP, SignalHandlerForConfigReload);
347328
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
348329
BackgroundWorkerUnblockSignals();
349330
InitPostgresCompat(NULL, InvalidOid, NULL, InvalidOid, 0, NULL);
350331
SetProcessingMode(NormalProcessing);
351332

352-
/* Make pg_wait_sampling recognisable in pg_stat_activity */
353-
pgstat_report_appname("pg_wait_sampling collector");
354333

355-
profile_hash = make_profile_hash();
356334
pgws_collector_hdr->latch = &MyProc->procLatch;
357335

358-
CurrentResourceOwner = ResourceOwnerCreate(NULL, "pg_wait_sampling collector");
359-
collector_context = AllocSetContextCreate(TopMemoryContext,
360-
"pg_wait_sampling context", ALLOCSET_DEFAULT_SIZES);
361-
old_context = MemoryContextSwitchTo(collector_context);
362336
alloc_history(&observations, pgws_historySize);
363-
MemoryContextSwitchTo(old_context);
337+
profile_hash = make_profile_hash();
364338

365-
ereport(LOG, (errmsg("pg_wait_sampling collector started")));
339+
ereport(LOG, errmsg("pg_wait_sampling collector started"));
366340

367341
/* Start counting time for history and profile samples */
368342
profile_ts = history_ts = GetCurrentTimestamp();
369343

370344
while (1)
371345
{
372-
int rc;
373346
shm_mq_handle *mqh;
374347
int64 history_diff,
375348
profile_diff;
376349
bool write_history,
377350
write_profile;
378351

379-
/* We need an explicit call for at least ProcSignal notifications. */
380-
CHECK_FOR_INTERRUPTS();
352+
HandleMainLoopInterrupts();
381353

382354
if (ConfigReloadPending)
383355
{
384356
ConfigReloadPending = false;
385357
ProcessConfigFile(PGC_SIGHUP);
386358
}
387359

388-
/* Wait calculate time to next sample for history or profile */
360+
/* Calculate time to next sample for history or profile */
389361
current_ts = GetCurrentTimestamp();
390362

391-
history_diff = millisecs_diff(history_ts, current_ts);
392-
profile_diff = millisecs_diff(profile_ts, current_ts);
363+
history_diff = TimestampDifferenceMilliseconds(history_ts, current_ts);
364+
profile_diff = TimestampDifferenceMilliseconds(profile_ts, current_ts);
393365

394366
write_history = (history_diff >= (int64)pgws_historyPeriod);
395367
write_profile = (profile_diff >= (int64)pgws_profilePeriod);
@@ -412,20 +384,15 @@ pgws_collector_main(Datum main_arg)
412384
}
413385
}
414386

415-
/* Shutdown if requested */
416-
if (shutdown_requested)
417-
break;
418-
419387
/*
420-
* Wait until next sample time or request to do something through
388+
* Wait for sample time or until request to do something through
421389
* shared memory.
422390
*/
423-
rc = WaitLatch(&MyProc->procLatch, WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
424-
Min(pgws_historyPeriod - (int)history_diff,
425-
pgws_historyPeriod - (int)profile_diff), PG_WAIT_EXTENSION);
426-
427-
if (rc & WL_POSTMASTER_DEATH)
428-
proc_exit(1);
391+
WaitLatch(&MyProc->procLatch,
392+
WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
393+
Min(pgws_historyPeriod - (int)history_diff,
394+
pgws_profilePeriod - (int)profile_diff),
395+
PG_WAIT_EXTENSION);
429396

430397
ResetLatch(&MyProc->procLatch);
431398

@@ -484,15 +451,4 @@ pgws_collector_main(Datum main_arg)
484451
LockRelease(&tag, ExclusiveLock, false);
485452
}
486453
}
487-
488-
MemoryContextReset(collector_context);
489-
490-
/*
491-
* We're done. Explicitly detach the shared memory segment so that we
492-
* don't get a resource leak warning at commit time. This will fire any
493-
* on_dsm_detach callbacks we've registered, as well. Once that's done,
494-
* we can go ahead and exit.
495-
*/
496-
ereport(LOG, (errmsg("pg_wait_sampling collector shutting down")));
497-
proc_exit(0);
498454
}

‎compat.h

-54
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