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localbuf.c
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1 /*-------------------------------------------------------------------------
2  *
3  * localbuf.c
4  * local buffer manager. Fast buffer manager for temporary tables,
5  * which never need to be WAL-logged or checkpointed, etc.
6  *
7  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994-5, Regents of the University of California
9  *
10  *
11  * IDENTIFICATION
12  * src/backend/storage/buffer/localbuf.c
13  *
14  *-------------------------------------------------------------------------
15  */
16 #include "postgres.h"
17 
18 #include "access/parallel.h"
19 #include "executor/instrument.h"
20 #include "pgstat.h"
21 #include "storage/buf_internals.h"
22 #include "storage/bufmgr.h"
23 #include "storage/fd.h"
24 #include "utils/guc_hooks.h"
25 #include "utils/memutils.h"
26 #include "utils/resowner.h"
27 
28 
29 /*#define LBDEBUG*/
30 
31 /* entry for buffer lookup hashtable */
32 typedef struct
33 {
34  BufferTag key; /* Tag of a disk page */
35  int id; /* Associated local buffer's index */
37 
38 /* Note: this macro only works on local buffers, not shared ones! */
39 #define LocalBufHdrGetBlock(bufHdr) \
40  LocalBufferBlockPointers[-((bufHdr)->buf_id + 2)]
41 
42 int NLocBuffer = 0; /* until buffers are initialized */
43 
47 
48 static int nextFreeLocalBufId = 0;
49 
50 static HTAB *LocalBufHash = NULL;
51 
52 /* number of local buffers pinned at least once */
53 static int NLocalPinnedBuffers = 0;
54 
55 
56 static void InitLocalBuffers(void);
57 static Block GetLocalBufferStorage(void);
58 static Buffer GetLocalVictimBuffer(void);
59 
60 
61 /*
62  * PrefetchLocalBuffer -
63  * initiate asynchronous read of a block of a relation
64  *
65  * Do PrefetchBuffer's work for temporary relations.
66  * No-op if prefetching isn't compiled in.
67  */
70  BlockNumber blockNum)
71 {
72  PrefetchBufferResult result = {InvalidBuffer, false};
73  BufferTag newTag; /* identity of requested block */
74  LocalBufferLookupEnt *hresult;
75 
76  InitBufferTag(&newTag, &smgr->smgr_rlocator.locator, forkNum, blockNum);
77 
78  /* Initialize local buffers if first request in this session */
79  if (LocalBufHash == NULL)
81 
82  /* See if the desired buffer already exists */
83  hresult = (LocalBufferLookupEnt *)
84  hash_search(LocalBufHash, &newTag, HASH_FIND, NULL);
85 
86  if (hresult)
87  {
88  /* Yes, so nothing to do */
89  result.recent_buffer = -hresult->id - 1;
90  }
91  else
92  {
93 #ifdef USE_PREFETCH
94  /* Not in buffers, so initiate prefetch */
95  if ((io_direct_flags & IO_DIRECT_DATA) == 0 &&
96  smgrprefetch(smgr, forkNum, blockNum, 1))
97  {
98  result.initiated_io = true;
99  }
100 #endif /* USE_PREFETCH */
101  }
102 
103  return result;
104 }
105 
106 
107 /*
108  * LocalBufferAlloc -
109  * Find or create a local buffer for the given page of the given relation.
110  *
111  * API is similar to bufmgr.c's BufferAlloc, except that we do not need to do
112  * any locking since this is all local. We support only default access
113  * strategy (hence, usage_count is always advanced).
114  */
115 BufferDesc *
117  bool *foundPtr)
118 {
119  BufferTag newTag; /* identity of requested block */
120  LocalBufferLookupEnt *hresult;
121  BufferDesc *bufHdr;
122  Buffer victim_buffer;
123  int bufid;
124  bool found;
125 
126  InitBufferTag(&newTag, &smgr->smgr_rlocator.locator, forkNum, blockNum);
127 
128  /* Initialize local buffers if first request in this session */
129  if (LocalBufHash == NULL)
131 
133 
134  /* See if the desired buffer already exists */
135  hresult = (LocalBufferLookupEnt *)
136  hash_search(LocalBufHash, &newTag, HASH_FIND, NULL);
137 
138  if (hresult)
139  {
140  bufid = hresult->id;
141  bufHdr = GetLocalBufferDescriptor(bufid);
142  Assert(BufferTagsEqual(&bufHdr->tag, &newTag));
143 
144  *foundPtr = PinLocalBuffer(bufHdr, true);
145  }
146  else
147  {
148  uint32 buf_state;
149 
150  victim_buffer = GetLocalVictimBuffer();
151  bufid = -victim_buffer - 1;
152  bufHdr = GetLocalBufferDescriptor(bufid);
153 
154  hresult = (LocalBufferLookupEnt *)
155  hash_search(LocalBufHash, &newTag, HASH_ENTER, &found);
156  if (found) /* shouldn't happen */
157  elog(ERROR, "local buffer hash table corrupted");
158  hresult->id = bufid;
159 
160  /*
161  * it's all ours now.
162  */
163  bufHdr->tag = newTag;
164 
165  buf_state = pg_atomic_read_u32(&bufHdr->state);
166  buf_state &= ~(BUF_FLAG_MASK | BUF_USAGECOUNT_MASK);
167  buf_state |= BM_TAG_VALID | BUF_USAGECOUNT_ONE;
168  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
169 
170  *foundPtr = false;
171  }
172 
173  return bufHdr;
174 }
175 
176 static Buffer
178 {
179  int victim_bufid;
180  int trycounter;
181  uint32 buf_state;
182  BufferDesc *bufHdr;
183 
185 
186  /*
187  * Need to get a new buffer. We use a clock sweep algorithm (essentially
188  * the same as what freelist.c does now...)
189  */
190  trycounter = NLocBuffer;
191  for (;;)
192  {
193  victim_bufid = nextFreeLocalBufId;
194 
196  nextFreeLocalBufId = 0;
197 
198  bufHdr = GetLocalBufferDescriptor(victim_bufid);
199 
200  if (LocalRefCount[victim_bufid] == 0)
201  {
202  buf_state = pg_atomic_read_u32(&bufHdr->state);
203 
204  if (BUF_STATE_GET_USAGECOUNT(buf_state) > 0)
205  {
206  buf_state -= BUF_USAGECOUNT_ONE;
207  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
208  trycounter = NLocBuffer;
209  }
210  else
211  {
212  /* Found a usable buffer */
213  PinLocalBuffer(bufHdr, false);
214  break;
215  }
216  }
217  else if (--trycounter == 0)
218  ereport(ERROR,
219  (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
220  errmsg("no empty local buffer available")));
221  }
222 
223  /*
224  * lazy memory allocation: allocate space on first use of a buffer.
225  */
226  if (LocalBufHdrGetBlock(bufHdr) == NULL)
227  {
228  /* Set pointer for use by BufferGetBlock() macro */
230  }
231 
232  /*
233  * this buffer is not referenced but it might still be dirty. if that's
234  * the case, write it out before reusing it!
235  */
236  if (buf_state & BM_DIRTY)
237  {
238  instr_time io_start;
239  SMgrRelation oreln;
240  Page localpage = (char *) LocalBufHdrGetBlock(bufHdr);
241 
242  /* Find smgr relation for buffer */
243  oreln = smgropen(BufTagGetRelFileLocator(&bufHdr->tag), MyProcNumber);
244 
245  PageSetChecksumInplace(localpage, bufHdr->tag.blockNum);
246 
248 
249  /* And write... */
250  smgrwrite(oreln,
251  BufTagGetForkNum(&bufHdr->tag),
252  bufHdr->tag.blockNum,
253  localpage,
254  false);
255 
256  /* Temporary table I/O does not use Buffer Access Strategies */
258  IOOP_WRITE, io_start, 1);
259 
260  /* Mark not-dirty now in case we error out below */
261  buf_state &= ~BM_DIRTY;
262  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
263 
265  }
266 
267  /*
268  * Remove the victim buffer from the hashtable and mark as invalid.
269  */
270  if (buf_state & BM_TAG_VALID)
271  {
272  LocalBufferLookupEnt *hresult;
273 
274  hresult = (LocalBufferLookupEnt *)
275  hash_search(LocalBufHash, &bufHdr->tag, HASH_REMOVE, NULL);
276  if (!hresult) /* shouldn't happen */
277  elog(ERROR, "local buffer hash table corrupted");
278  /* mark buffer invalid just in case hash insert fails */
279  ClearBufferTag(&bufHdr->tag);
280  buf_state &= ~(BUF_FLAG_MASK | BUF_USAGECOUNT_MASK);
281  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
283  }
284 
285  return BufferDescriptorGetBuffer(bufHdr);
286 }
287 
288 /* see LimitAdditionalPins() */
289 void
291 {
292  uint32 max_pins;
293 
294  if (*additional_pins <= 1)
295  return;
296 
297  /*
298  * In contrast to LimitAdditionalPins() other backends don't play a role
299  * here. We can allow up to NLocBuffer pins in total, but it might not be
300  * initialized yet so read num_temp_buffers.
301  */
302  max_pins = (num_temp_buffers - NLocalPinnedBuffers);
303 
304  if (*additional_pins >= max_pins)
305  *additional_pins = max_pins;
306 }
307 
308 /*
309  * Implementation of ExtendBufferedRelBy() and ExtendBufferedRelTo() for
310  * temporary buffers.
311  */
314  ForkNumber fork,
315  uint32 flags,
316  uint32 extend_by,
317  BlockNumber extend_upto,
318  Buffer *buffers,
319  uint32 *extended_by)
320 {
321  BlockNumber first_block;
322  instr_time io_start;
323 
324  /* Initialize local buffers if first request in this session */
325  if (LocalBufHash == NULL)
327 
328  LimitAdditionalLocalPins(&extend_by);
329 
330  for (uint32 i = 0; i < extend_by; i++)
331  {
332  BufferDesc *buf_hdr;
333  Block buf_block;
334 
335  buffers[i] = GetLocalVictimBuffer();
336  buf_hdr = GetLocalBufferDescriptor(-buffers[i] - 1);
337  buf_block = LocalBufHdrGetBlock(buf_hdr);
338 
339  /* new buffers are zero-filled */
340  MemSet((char *) buf_block, 0, BLCKSZ);
341  }
342 
343  first_block = smgrnblocks(bmr.smgr, fork);
344 
345  if (extend_upto != InvalidBlockNumber)
346  {
347  /*
348  * In contrast to shared relations, nothing could change the relation
349  * size concurrently. Thus we shouldn't end up finding that we don't
350  * need to do anything.
351  */
352  Assert(first_block <= extend_upto);
353 
354  Assert((uint64) first_block + extend_by <= extend_upto);
355  }
356 
357  /* Fail if relation is already at maximum possible length */
358  if ((uint64) first_block + extend_by >= MaxBlockNumber)
359  ereport(ERROR,
360  (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
361  errmsg("cannot extend relation %s beyond %u blocks",
362  relpath(bmr.smgr->smgr_rlocator, fork),
363  MaxBlockNumber)));
364 
365  for (uint32 i = 0; i < extend_by; i++)
366  {
367  int victim_buf_id;
368  BufferDesc *victim_buf_hdr;
369  BufferTag tag;
370  LocalBufferLookupEnt *hresult;
371  bool found;
372 
373  victim_buf_id = -buffers[i] - 1;
374  victim_buf_hdr = GetLocalBufferDescriptor(victim_buf_id);
375 
376  /* in case we need to pin an existing buffer below */
378 
379  InitBufferTag(&tag, &bmr.smgr->smgr_rlocator.locator, fork, first_block + i);
380 
381  hresult = (LocalBufferLookupEnt *)
382  hash_search(LocalBufHash, (void *) &tag, HASH_ENTER, &found);
383  if (found)
384  {
385  BufferDesc *existing_hdr;
386  uint32 buf_state;
387 
389 
390  existing_hdr = GetLocalBufferDescriptor(hresult->id);
391  PinLocalBuffer(existing_hdr, false);
392  buffers[i] = BufferDescriptorGetBuffer(existing_hdr);
393 
394  buf_state = pg_atomic_read_u32(&existing_hdr->state);
395  Assert(buf_state & BM_TAG_VALID);
396  Assert(!(buf_state & BM_DIRTY));
397  buf_state &= ~BM_VALID;
398  pg_atomic_unlocked_write_u32(&existing_hdr->state, buf_state);
399  }
400  else
401  {
402  uint32 buf_state = pg_atomic_read_u32(&victim_buf_hdr->state);
403 
404  Assert(!(buf_state & (BM_VALID | BM_TAG_VALID | BM_DIRTY | BM_JUST_DIRTIED)));
405 
406  victim_buf_hdr->tag = tag;
407 
408  buf_state |= BM_TAG_VALID | BUF_USAGECOUNT_ONE;
409 
410  pg_atomic_unlocked_write_u32(&victim_buf_hdr->state, buf_state);
411 
412  hresult->id = victim_buf_id;
413  }
414  }
415 
417 
418  /* actually extend relation */
419  smgrzeroextend(bmr.smgr, fork, first_block, extend_by, false);
420 
422  io_start, extend_by);
423 
424  for (uint32 i = 0; i < extend_by; i++)
425  {
426  Buffer buf = buffers[i];
427  BufferDesc *buf_hdr;
428  uint32 buf_state;
429 
430  buf_hdr = GetLocalBufferDescriptor(-buf - 1);
431 
432  buf_state = pg_atomic_read_u32(&buf_hdr->state);
433  buf_state |= BM_VALID;
434  pg_atomic_unlocked_write_u32(&buf_hdr->state, buf_state);
435  }
436 
437  *extended_by = extend_by;
438 
439  pgBufferUsage.local_blks_written += extend_by;
440 
441  return first_block;
442 }
443 
444 /*
445  * MarkLocalBufferDirty -
446  * mark a local buffer dirty
447  */
448 void
450 {
451  int bufid;
452  BufferDesc *bufHdr;
453  uint32 buf_state;
454 
455  Assert(BufferIsLocal(buffer));
456 
457 #ifdef LBDEBUG
458  fprintf(stderr, "LB DIRTY %d\n", buffer);
459 #endif
460 
461  bufid = -buffer - 1;
462 
463  Assert(LocalRefCount[bufid] > 0);
464 
465  bufHdr = GetLocalBufferDescriptor(bufid);
466 
467  buf_state = pg_atomic_read_u32(&bufHdr->state);
468 
469  if (!(buf_state & BM_DIRTY))
471 
472  buf_state |= BM_DIRTY;
473 
474  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
475 }
476 
477 /*
478  * DropRelationLocalBuffers
479  * This function removes from the buffer pool all the pages of the
480  * specified relation that have block numbers >= firstDelBlock.
481  * (In particular, with firstDelBlock = 0, all pages are removed.)
482  * Dirty pages are simply dropped, without bothering to write them
483  * out first. Therefore, this is NOT rollback-able, and so should be
484  * used only with extreme caution!
485  *
486  * See DropRelationBuffers in bufmgr.c for more notes.
487  */
488 void
490  BlockNumber firstDelBlock)
491 {
492  int i;
493 
494  for (i = 0; i < NLocBuffer; i++)
495  {
497  LocalBufferLookupEnt *hresult;
498  uint32 buf_state;
499 
500  buf_state = pg_atomic_read_u32(&bufHdr->state);
501 
502  if ((buf_state & BM_TAG_VALID) &&
503  BufTagMatchesRelFileLocator(&bufHdr->tag, &rlocator) &&
504  BufTagGetForkNum(&bufHdr->tag) == forkNum &&
505  bufHdr->tag.blockNum >= firstDelBlock)
506  {
507  if (LocalRefCount[i] != 0)
508  elog(ERROR, "block %u of %s is still referenced (local %u)",
509  bufHdr->tag.blockNum,
511  MyProcNumber,
512  BufTagGetForkNum(&bufHdr->tag)),
513  LocalRefCount[i]);
514 
515  /* Remove entry from hashtable */
516  hresult = (LocalBufferLookupEnt *)
517  hash_search(LocalBufHash, &bufHdr->tag, HASH_REMOVE, NULL);
518  if (!hresult) /* shouldn't happen */
519  elog(ERROR, "local buffer hash table corrupted");
520  /* Mark buffer invalid */
521  ClearBufferTag(&bufHdr->tag);
522  buf_state &= ~BUF_FLAG_MASK;
523  buf_state &= ~BUF_USAGECOUNT_MASK;
524  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
525  }
526  }
527 }
528 
529 /*
530  * DropRelationAllLocalBuffers
531  * This function removes from the buffer pool all pages of all forks
532  * of the specified relation.
533  *
534  * See DropRelationsAllBuffers in bufmgr.c for more notes.
535  */
536 void
538 {
539  int i;
540 
541  for (i = 0; i < NLocBuffer; i++)
542  {
544  LocalBufferLookupEnt *hresult;
545  uint32 buf_state;
546 
547  buf_state = pg_atomic_read_u32(&bufHdr->state);
548 
549  if ((buf_state & BM_TAG_VALID) &&
550  BufTagMatchesRelFileLocator(&bufHdr->tag, &rlocator))
551  {
552  if (LocalRefCount[i] != 0)
553  elog(ERROR, "block %u of %s is still referenced (local %u)",
554  bufHdr->tag.blockNum,
556  MyProcNumber,
557  BufTagGetForkNum(&bufHdr->tag)),
558  LocalRefCount[i]);
559  /* Remove entry from hashtable */
560  hresult = (LocalBufferLookupEnt *)
561  hash_search(LocalBufHash, &bufHdr->tag, HASH_REMOVE, NULL);
562  if (!hresult) /* shouldn't happen */
563  elog(ERROR, "local buffer hash table corrupted");
564  /* Mark buffer invalid */
565  ClearBufferTag(&bufHdr->tag);
566  buf_state &= ~BUF_FLAG_MASK;
567  buf_state &= ~BUF_USAGECOUNT_MASK;
568  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
569  }
570  }
571 }
572 
573 /*
574  * InitLocalBuffers -
575  * init the local buffer cache. Since most queries (esp. multi-user ones)
576  * don't involve local buffers, we delay allocating actual memory for the
577  * buffers until we need them; just make the buffer headers here.
578  */
579 static void
581 {
582  int nbufs = num_temp_buffers;
583  HASHCTL info;
584  int i;
585 
586  /*
587  * Parallel workers can't access data in temporary tables, because they
588  * have no visibility into the local buffers of their leader. This is a
589  * convenient, low-cost place to provide a backstop check for that. Note
590  * that we don't wish to prevent a parallel worker from accessing catalog
591  * metadata about a temp table, so checks at higher levels would be
592  * inappropriate.
593  */
594  if (IsParallelWorker())
595  ereport(ERROR,
596  (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
597  errmsg("cannot access temporary tables during a parallel operation")));
598 
599  /* Allocate and zero buffer headers and auxiliary arrays */
600  LocalBufferDescriptors = (BufferDesc *) calloc(nbufs, sizeof(BufferDesc));
601  LocalBufferBlockPointers = (Block *) calloc(nbufs, sizeof(Block));
602  LocalRefCount = (int32 *) calloc(nbufs, sizeof(int32));
604  ereport(FATAL,
605  (errcode(ERRCODE_OUT_OF_MEMORY),
606  errmsg("out of memory")));
607 
608  nextFreeLocalBufId = 0;
609 
610  /* initialize fields that need to start off nonzero */
611  for (i = 0; i < nbufs; i++)
612  {
614 
615  /*
616  * negative to indicate local buffer. This is tricky: shared buffers
617  * start with 0. We have to start with -2. (Note that the routine
618  * BufferDescriptorGetBuffer adds 1 to buf_id so our first buffer id
619  * is -1.)
620  */
621  buf->buf_id = -i - 2;
622 
623  /*
624  * Intentionally do not initialize the buffer's atomic variable
625  * (besides zeroing the underlying memory above). That way we get
626  * errors on platforms without atomics, if somebody (re-)introduces
627  * atomic operations for local buffers.
628  */
629  }
630 
631  /* Create the lookup hash table */
632  info.keysize = sizeof(BufferTag);
633  info.entrysize = sizeof(LocalBufferLookupEnt);
634 
635  LocalBufHash = hash_create("Local Buffer Lookup Table",
636  nbufs,
637  &info,
639 
640  if (!LocalBufHash)
641  elog(ERROR, "could not initialize local buffer hash table");
642 
643  /* Initialization done, mark buffers allocated */
644  NLocBuffer = nbufs;
645 }
646 
647 /*
648  * XXX: We could have a slightly more efficient version of PinLocalBuffer()
649  * that does not support adjusting the usagecount - but so far it does not
650  * seem worth the trouble.
651  *
652  * Note that ResourceOwnerEnlarge() must have been done already.
653  */
654 bool
655 PinLocalBuffer(BufferDesc *buf_hdr, bool adjust_usagecount)
656 {
657  uint32 buf_state;
658  Buffer buffer = BufferDescriptorGetBuffer(buf_hdr);
659  int bufid = -buffer - 1;
660 
661  buf_state = pg_atomic_read_u32(&buf_hdr->state);
662 
663  if (LocalRefCount[bufid] == 0)
664  {
666  if (adjust_usagecount &&
668  {
669  buf_state += BUF_USAGECOUNT_ONE;
670  pg_atomic_unlocked_write_u32(&buf_hdr->state, buf_state);
671  }
672  }
673  LocalRefCount[bufid]++;
675  BufferDescriptorGetBuffer(buf_hdr));
676 
677  return buf_state & BM_VALID;
678 }
679 
680 void
682 {
683  UnpinLocalBufferNoOwner(buffer);
685 }
686 
687 void
689 {
690  int buffid = -buffer - 1;
691 
692  Assert(BufferIsLocal(buffer));
693  Assert(LocalRefCount[buffid] > 0);
695 
696  if (--LocalRefCount[buffid] == 0)
698 }
699 
700 /*
701  * GUC check_hook for temp_buffers
702  */
703 bool
705 {
706  /*
707  * Once local buffers have been initialized, it's too late to change this.
708  * However, if this is only a test call, allow it.
709  */
710  if (source != PGC_S_TEST && NLocBuffer && NLocBuffer != *newval)
711  {
712  GUC_check_errdetail("\"temp_buffers\" cannot be changed after any temporary tables have been accessed in the session.");
713  return false;
714  }
715  return true;
716 }
717 
718 /*
719  * GetLocalBufferStorage - allocate memory for a local buffer
720  *
721  * The idea of this function is to aggregate our requests for storage
722  * so that the memory manager doesn't see a whole lot of relatively small
723  * requests. Since we'll never give back a local buffer once it's created
724  * within a particular process, no point in burdening memmgr with separately
725  * managed chunks.
726  */
727 static Block
729 {
730  static char *cur_block = NULL;
731  static int next_buf_in_block = 0;
732  static int num_bufs_in_block = 0;
733  static int total_bufs_allocated = 0;
734  static MemoryContext LocalBufferContext = NULL;
735 
736  char *this_buf;
737 
738  Assert(total_bufs_allocated < NLocBuffer);
739 
740  if (next_buf_in_block >= num_bufs_in_block)
741  {
742  /* Need to make a new request to memmgr */
743  int num_bufs;
744 
745  /*
746  * We allocate local buffers in a context of their own, so that the
747  * space eaten for them is easily recognizable in MemoryContextStats
748  * output. Create the context on first use.
749  */
750  if (LocalBufferContext == NULL)
751  LocalBufferContext =
753  "LocalBufferContext",
755 
756  /* Start with a 16-buffer request; subsequent ones double each time */
757  num_bufs = Max(num_bufs_in_block * 2, 16);
758  /* But not more than what we need for all remaining local bufs */
759  num_bufs = Min(num_bufs, NLocBuffer - total_bufs_allocated);
760  /* And don't overflow MaxAllocSize, either */
761  num_bufs = Min(num_bufs, MaxAllocSize / BLCKSZ);
762 
763  /* Buffers should be I/O aligned. */
764  cur_block = (char *)
766  MemoryContextAlloc(LocalBufferContext,
767  num_bufs * BLCKSZ + PG_IO_ALIGN_SIZE));
768  next_buf_in_block = 0;
769  num_bufs_in_block = num_bufs;
770  }
771 
772  /* Allocate next buffer in current memory block */
773  this_buf = cur_block + next_buf_in_block * BLCKSZ;
774  next_buf_in_block++;
775  total_bufs_allocated++;
776 
777  return (Block) this_buf;
778 }
779 
780 /*
781  * CheckForLocalBufferLeaks - ensure this backend holds no local buffer pins
782  *
783  * This is just like CheckForBufferLeaks(), but for local buffers.
784  */
785 static void
787 {
788 #ifdef USE_ASSERT_CHECKING
789  if (LocalRefCount)
790  {
791  int RefCountErrors = 0;
792  int i;
793 
794  for (i = 0; i < NLocBuffer; i++)
795  {
796  if (LocalRefCount[i] != 0)
797  {
798  Buffer b = -i - 1;
799  char *s;
800 
802  elog(WARNING, "local buffer refcount leak: %s", s);
803  pfree(s);
804 
805  RefCountErrors++;
806  }
807  }
808  Assert(RefCountErrors == 0);
809  }
810 #endif
811 }
812 
813 /*
814  * AtEOXact_LocalBuffers - clean up at end of transaction.
815  *
816  * This is just like AtEOXact_Buffers, but for local buffers.
817  */
818 void
819 AtEOXact_LocalBuffers(bool isCommit)
820 {
822 }
823 
824 /*
825  * AtProcExit_LocalBuffers - ensure we have dropped pins during backend exit.
826  *
827  * This is just like AtProcExit_Buffers, but for local buffers.
828  */
829 void
831 {
832  /*
833  * We shouldn't be holding any remaining pins; if we are, and assertions
834  * aren't enabled, we'll fail later in DropRelationBuffers while trying to
835  * drop the temp rels.
836  */
838 }
static void pg_atomic_unlocked_write_u32(volatile pg_atomic_uint32 *ptr, uint32 val)
Definition: atomics.h:290
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:234
uint32 BlockNumber
Definition: block.h:31
#define InvalidBlockNumber
Definition: block.h:33
#define MaxBlockNumber
Definition: block.h:35
int Buffer
Definition: buf.h:23
#define InvalidBuffer
Definition: buf.h:25
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BM_MAX_USAGE_COUNT
Definition: buf_internals.h:78
static void InitBufferTag(BufferTag *tag, const RelFileLocator *rlocator, ForkNumber forkNum, BlockNumber blockNum)
#define BM_TAG_VALID
Definition: buf_internals.h:63
#define BUF_USAGECOUNT_MASK
Definition: buf_internals.h:45
static ForkNumber BufTagGetForkNum(const BufferTag *tag)
static BufferDesc * GetLocalBufferDescriptor(uint32 id)
static bool BufferTagsEqual(const BufferTag *tag1, const BufferTag *tag2)
static bool BufTagMatchesRelFileLocator(const BufferTag *tag, const RelFileLocator *rlocator)
#define BUF_FLAG_MASK
Definition: buf_internals.h:48
#define BM_DIRTY
Definition: buf_internals.h:61
#define BM_JUST_DIRTIED
Definition: buf_internals.h:66
#define BUF_STATE_GET_USAGECOUNT(state)
Definition: buf_internals.h:52
static void ClearBufferTag(BufferTag *tag)
static void ResourceOwnerRememberBuffer(ResourceOwner owner, Buffer buffer)
struct buftag BufferTag
static void ResourceOwnerForgetBuffer(ResourceOwner owner, Buffer buffer)
#define BUF_USAGECOUNT_ONE
Definition: buf_internals.h:46
static RelFileLocator BufTagGetRelFileLocator(const BufferTag *tag)
#define BM_VALID
Definition: buf_internals.h:62
static Buffer BufferDescriptorGetBuffer(const BufferDesc *bdesc)
bool track_io_timing
Definition: bufmgr.c:142
char * DebugPrintBufferRefcount(Buffer buffer)
Definition: bufmgr.c:3654
void * Block
Definition: bufmgr.h:25
void PageSetChecksumInplace(Page page, BlockNumber blkno)
Definition: bufpage.c:1542
Pointer Page
Definition: bufpage.h:78
unsigned int uint32
Definition: c.h:506
#define Min(x, y)
Definition: c.h:1004
#define TYPEALIGN(ALIGNVAL, LEN)
Definition: c.h:804
signed int int32
Definition: c.h:494
#define Max(x, y)
Definition: c.h:998
#define Assert(condition)
Definition: c.h:858
#define MemSet(start, val, len)
Definition: c.h:1020
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:955
HTAB * hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
Definition: dynahash.c:352
int errcode(int sqlerrcode)
Definition: elog.c:857
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define FATAL
Definition: elog.h:41
#define WARNING
Definition: elog.h:36
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:224
#define ereport(elevel,...)
Definition: elog.h:149
int io_direct_flags
Definition: fd.c:168
#define IO_DIRECT_DATA
Definition: fd.h:54
ProcNumber MyProcNumber
Definition: globals.c:87
#define newval
#define GUC_check_errdetail
Definition: guc.h:447
GucSource
Definition: guc.h:108
@ PGC_S_TEST
Definition: guc.h:121
int num_temp_buffers
Definition: guc_tables.c:537
#define calloc(a, b)
Definition: header.h:55
@ HASH_FIND
Definition: hsearch.h:113
@ HASH_REMOVE
Definition: hsearch.h:115
@ HASH_ENTER
Definition: hsearch.h:114
#define HASH_ELEM
Definition: hsearch.h:95
#define HASH_BLOBS
Definition: hsearch.h:97
#define IsParallelWorker()
Definition: parallel.h:60
BufferUsage pgBufferUsage
Definition: instrument.c:20
int b
Definition: isn.c:70
int i
Definition: isn.c:73
int32 * LocalRefCount
Definition: localbuf.c:46
void UnpinLocalBuffer(Buffer buffer)
Definition: localbuf.c:681
BufferDesc * LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum, bool *foundPtr)
Definition: localbuf.c:116
static HTAB * LocalBufHash
Definition: localbuf.c:50
static int NLocalPinnedBuffers
Definition: localbuf.c:53
void AtEOXact_LocalBuffers(bool isCommit)
Definition: localbuf.c:819
#define LocalBufHdrGetBlock(bufHdr)
Definition: localbuf.c:39
static void CheckForLocalBufferLeaks(void)
Definition: localbuf.c:786
void DropRelationLocalBuffers(RelFileLocator rlocator, ForkNumber forkNum, BlockNumber firstDelBlock)
Definition: localbuf.c:489
static Block GetLocalBufferStorage(void)
Definition: localbuf.c:728
static int nextFreeLocalBufId
Definition: localbuf.c:48
bool check_temp_buffers(int *newval, void **extra, GucSource source)
Definition: localbuf.c:704
void AtProcExit_LocalBuffers(void)
Definition: localbuf.c:830
bool PinLocalBuffer(BufferDesc *buf_hdr, bool adjust_usagecount)
Definition: localbuf.c:655
static void InitLocalBuffers(void)
Definition: localbuf.c:580
void LimitAdditionalLocalPins(uint32 *additional_pins)
Definition: localbuf.c:290
static Buffer GetLocalVictimBuffer(void)
Definition: localbuf.c:177
void MarkLocalBufferDirty(Buffer buffer)
Definition: localbuf.c:449
void DropRelationAllLocalBuffers(RelFileLocator rlocator)
Definition: localbuf.c:537
int NLocBuffer
Definition: localbuf.c:42
PrefetchBufferResult PrefetchLocalBuffer(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum)
Definition: localbuf.c:69
BlockNumber ExtendBufferedRelLocal(BufferManagerRelation bmr, ForkNumber fork, uint32 flags, uint32 extend_by, BlockNumber extend_upto, Buffer *buffers, uint32 *extended_by)
Definition: localbuf.c:313
Block * LocalBufferBlockPointers
Definition: localbuf.c:45
void UnpinLocalBufferNoOwner(Buffer buffer)
Definition: localbuf.c:688
BufferDesc * LocalBufferDescriptors
Definition: localbuf.c:44
void pfree(void *pointer)
Definition: mcxt.c:1520
MemoryContext TopMemoryContext
Definition: mcxt.c:149
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:1180
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:160
#define MaxAllocSize
Definition: memutils.h:40
#define PG_IO_ALIGN_SIZE
static rewind_source * source
Definition: pg_rewind.c:89
static char * buf
Definition: pg_test_fsync.c:73
@ IOOBJECT_TEMP_RELATION
Definition: pgstat.h:281
@ IOCONTEXT_NORMAL
Definition: pgstat.h:290
@ IOOP_EXTEND
Definition: pgstat.h:299
@ IOOP_EVICT
Definition: pgstat.h:298
@ IOOP_WRITE
Definition: pgstat.h:304
instr_time pgstat_prepare_io_time(bool track_io_guc)
Definition: pgstat_io.c:100
void pgstat_count_io_op_time(IOObject io_object, IOContext io_context, IOOp io_op, instr_time start_time, uint32 cnt)
Definition: pgstat_io.c:122
void pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op)
Definition: pgstat_io.c:77
#define fprintf
Definition: port.h:242
ForkNumber
Definition: relpath.h:48
#define relpath(rlocator, forknum)
Definition: relpath.h:94
#define relpathbackend(rlocator, backend, forknum)
Definition: relpath.h:85
ResourceOwner CurrentResourceOwner
Definition: resowner.c:165
void ResourceOwnerEnlarge(ResourceOwner owner)
Definition: resowner.c:442
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:655
SMgrRelation smgropen(RelFileLocator rlocator, ProcNumber backend)
Definition: smgr.c:198
void smgrzeroextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, int nblocks, bool skipFsync)
Definition: smgr.c:560
bool smgrprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, int nblocks)
Definition: smgr.c:585
static void smgrwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, const void *buffer, bool skipFsync)
Definition: smgr.h:121
BufferTag tag
pg_atomic_uint32 state
struct SMgrRelationData * smgr
Definition: bufmgr.h:103
int64 local_blks_written
Definition: instrument.h:33
int64 local_blks_dirtied
Definition: instrument.h:32
Size keysize
Definition: hsearch.h:75
Size entrysize
Definition: hsearch.h:76
Definition: dynahash.c:220
Buffer recent_buffer
Definition: bufmgr.h:60
RelFileLocator locator
RelFileLocatorBackend smgr_rlocator
Definition: smgr.h:37
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Definition: buf_internals.h:98