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parallel.c
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1 /*-------------------------------------------------------------------------
2  *
3  * parallel.c
4  * Infrastructure for launching parallel workers
5  *
6  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  * IDENTIFICATION
10  * src/backend/access/transam/parallel.c
11  *
12  *-------------------------------------------------------------------------
13  */
14 
15 #include "postgres.h"
16 
17 #include "access/parallel.h"
18 #include "access/xact.h"
19 #include "access/xlog.h"
20 #include "catalog/namespace.h"
21 #include "commands/async.h"
22 #include "executor/execParallel.h"
23 #include "libpq/libpq.h"
24 #include "libpq/pqformat.h"
25 #include "libpq/pqmq.h"
26 #include "miscadmin.h"
27 #include "optimizer/planmain.h"
28 #include "pgstat.h"
29 #include "storage/ipc.h"
30 #include "storage/sinval.h"
31 #include "storage/spin.h"
32 #include "tcop/tcopprot.h"
33 #include "utils/combocid.h"
34 #include "utils/guc.h"
35 #include "utils/inval.h"
36 #include "utils/memutils.h"
37 #include "utils/resowner.h"
38 #include "utils/snapmgr.h"
39 
40 
41 /*
42  * We don't want to waste a lot of memory on an error queue which, most of
43  * the time, will process only a handful of small messages. However, it is
44  * desirable to make it large enough that a typical ErrorResponse can be sent
45  * without blocking. That way, a worker that errors out can write the whole
46  * message into the queue and terminate without waiting for the user backend.
47  */
48 #define PARALLEL_ERROR_QUEUE_SIZE 16384
49 
50 /* Magic number for parallel context TOC. */
51 #define PARALLEL_MAGIC 0x50477c7c
52 
53 /*
54  * Magic numbers for parallel state sharing. Higher-level code should use
55  * smaller values, leaving these very large ones for use by this module.
56  */
57 #define PARALLEL_KEY_FIXED UINT64CONST(0xFFFFFFFFFFFF0001)
58 #define PARALLEL_KEY_ERROR_QUEUE UINT64CONST(0xFFFFFFFFFFFF0002)
59 #define PARALLEL_KEY_LIBRARY UINT64CONST(0xFFFFFFFFFFFF0003)
60 #define PARALLEL_KEY_GUC UINT64CONST(0xFFFFFFFFFFFF0004)
61 #define PARALLEL_KEY_COMBO_CID UINT64CONST(0xFFFFFFFFFFFF0005)
62 #define PARALLEL_KEY_TRANSACTION_SNAPSHOT UINT64CONST(0xFFFFFFFFFFFF0006)
63 #define PARALLEL_KEY_ACTIVE_SNAPSHOT UINT64CONST(0xFFFFFFFFFFFF0007)
64 #define PARALLEL_KEY_TRANSACTION_STATE UINT64CONST(0xFFFFFFFFFFFF0008)
65 #define PARALLEL_KEY_ENTRYPOINT UINT64CONST(0xFFFFFFFFFFFF0009)
66 
67 /* Fixed-size parallel state. */
68 typedef struct FixedParallelState
69 {
70  /* Fixed-size state that workers must restore. */
80 
81  /* Mutex protects remaining fields. */
83 
84  /* Maximum XactLastRecEnd of any worker. */
87 
88 /*
89  * Our parallel worker number. We initialize this to -1, meaning that we are
90  * not a parallel worker. In parallel workers, it will be set to a value >= 0
91  * and < the number of workers before any user code is invoked; each parallel
92  * worker will get a different parallel worker number.
93  */
95 
96 /* Is there a parallel message pending which we need to receive? */
97 volatile bool ParallelMessagePending = false;
98 
99 /* Are we initializing a parallel worker? */
101 
102 /* Pointer to our fixed parallel state. */
104 
105 /* List of active parallel contexts. */
107 
108 /*
109  * List of internal parallel worker entry points. We need this for
110  * reasons explained in LookupParallelWorkerFunction(), below.
111  */
112 static const struct
113 {
114  const char *fn_name;
117 
118 {
119  {
120  "ParallelQueryMain", ParallelQueryMain
121  }
122 };
123 
124 /* Private functions. */
125 static void HandleParallelMessage(ParallelContext *pcxt, int i, StringInfo msg);
127 static parallel_worker_main_type LookupParallelWorkerFunction(const char *libraryname, const char *funcname);
128 
129 
130 /*
131  * Establish a new parallel context. This should be done after entering
132  * parallel mode, and (unless there is an error) the context should be
133  * destroyed before exiting the current subtransaction.
134  */
136 CreateParallelContext(const char *library_name, const char *function_name,
137  int nworkers)
138 {
139  MemoryContext oldcontext;
140  ParallelContext *pcxt;
141 
142  /* It is unsafe to create a parallel context if not in parallel mode. */
144 
145  /* Number of workers should be non-negative. */
146  Assert(nworkers >= 0);
147 
148  /*
149  * If dynamic shared memory is not available, we won't be able to use
150  * background workers.
151  */
153  nworkers = 0;
154 
155  /*
156  * If we are running under serializable isolation, we can't use parallel
157  * workers, at least not until somebody enhances that mechanism to be
158  * parallel-aware.
159  */
161  nworkers = 0;
162 
163  /* We might be running in a short-lived memory context. */
165 
166  /* Initialize a new ParallelContext. */
167  pcxt = palloc0(sizeof(ParallelContext));
169  pcxt->nworkers = nworkers;
170  pcxt->library_name = pstrdup(library_name);
171  pcxt->function_name = pstrdup(function_name);
174  dlist_push_head(&pcxt_list, &pcxt->node);
175 
176  /* Restore previous memory context. */
177  MemoryContextSwitchTo(oldcontext);
178 
179  return pcxt;
180 }
181 
182 /*
183  * Establish the dynamic shared memory segment for a parallel context and
184  * copy state and other bookkeeping information that will be needed by
185  * parallel workers into it.
186  */
187 void
189 {
190  MemoryContext oldcontext;
191  Size library_len = 0;
192  Size guc_len = 0;
193  Size combocidlen = 0;
194  Size tsnaplen = 0;
195  Size asnaplen = 0;
196  Size tstatelen = 0;
197  Size segsize = 0;
198  int i;
199  FixedParallelState *fps;
200  Snapshot transaction_snapshot = GetTransactionSnapshot();
201  Snapshot active_snapshot = GetActiveSnapshot();
202 
203  /* We might be running in a very short-lived memory context. */
205 
206  /* Allow space to store the fixed-size parallel state. */
208  shm_toc_estimate_keys(&pcxt->estimator, 1);
209 
210  /*
211  * Normally, the user will have requested at least one worker process, but
212  * if by chance they have not, we can skip a bunch of things here.
213  */
214  if (pcxt->nworkers > 0)
215  {
216  /* Estimate space for various kinds of state sharing. */
217  library_len = EstimateLibraryStateSpace();
218  shm_toc_estimate_chunk(&pcxt->estimator, library_len);
219  guc_len = EstimateGUCStateSpace();
220  shm_toc_estimate_chunk(&pcxt->estimator, guc_len);
221  combocidlen = EstimateComboCIDStateSpace();
222  shm_toc_estimate_chunk(&pcxt->estimator, combocidlen);
223  tsnaplen = EstimateSnapshotSpace(transaction_snapshot);
224  shm_toc_estimate_chunk(&pcxt->estimator, tsnaplen);
225  asnaplen = EstimateSnapshotSpace(active_snapshot);
226  shm_toc_estimate_chunk(&pcxt->estimator, asnaplen);
227  tstatelen = EstimateTransactionStateSpace();
228  shm_toc_estimate_chunk(&pcxt->estimator, tstatelen);
229  /* If you add more chunks here, you probably need to add keys. */
230  shm_toc_estimate_keys(&pcxt->estimator, 6);
231 
232  /* Estimate space need for error queues. */
235  "parallel error queue size not buffer-aligned");
238  pcxt->nworkers));
239  shm_toc_estimate_keys(&pcxt->estimator, 1);
240 
241  /* Estimate how much we'll need for the entrypoint info. */
242  shm_toc_estimate_chunk(&pcxt->estimator, strlen(pcxt->library_name) +
243  strlen(pcxt->function_name) + 2);
244  shm_toc_estimate_keys(&pcxt->estimator, 1);
245  }
246 
247  /*
248  * Create DSM and initialize with new table of contents. But if the user
249  * didn't request any workers, then don't bother creating a dynamic shared
250  * memory segment; instead, just use backend-private memory.
251  *
252  * Also, if we can't create a dynamic shared memory segment because the
253  * maximum number of segments have already been created, then fall back to
254  * backend-private memory, and plan not to use any workers. We hope this
255  * won't happen very often, but it's better to abandon the use of
256  * parallelism than to fail outright.
257  */
258  segsize = shm_toc_estimate(&pcxt->estimator);
259  if (pcxt->nworkers > 0)
261  if (pcxt->seg != NULL)
263  dsm_segment_address(pcxt->seg),
264  segsize);
265  else
266  {
267  pcxt->nworkers = 0;
270  segsize);
271  }
272 
273  /* Initialize fixed-size state in shared memory. */
274  fps = (FixedParallelState *)
275  shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
276  fps->database_id = MyDatabaseId;
284  SpinLockInit(&fps->mutex);
285  fps->last_xlog_end = 0;
287 
288  /* We can skip the rest of this if we're not budgeting for any workers. */
289  if (pcxt->nworkers > 0)
290  {
291  char *libraryspace;
292  char *gucspace;
293  char *combocidspace;
294  char *tsnapspace;
295  char *asnapspace;
296  char *tstatespace;
297  char *error_queue_space;
298  char *entrypointstate;
299  Size lnamelen;
300 
301  /* Serialize shared libraries we have loaded. */
302  libraryspace = shm_toc_allocate(pcxt->toc, library_len);
303  SerializeLibraryState(library_len, libraryspace);
304  shm_toc_insert(pcxt->toc, PARALLEL_KEY_LIBRARY, libraryspace);
305 
306  /* Serialize GUC settings. */
307  gucspace = shm_toc_allocate(pcxt->toc, guc_len);
308  SerializeGUCState(guc_len, gucspace);
309  shm_toc_insert(pcxt->toc, PARALLEL_KEY_GUC, gucspace);
310 
311  /* Serialize combo CID state. */
312  combocidspace = shm_toc_allocate(pcxt->toc, combocidlen);
313  SerializeComboCIDState(combocidlen, combocidspace);
314  shm_toc_insert(pcxt->toc, PARALLEL_KEY_COMBO_CID, combocidspace);
315 
316  /* Serialize transaction snapshot and active snapshot. */
317  tsnapspace = shm_toc_allocate(pcxt->toc, tsnaplen);
318  SerializeSnapshot(transaction_snapshot, tsnapspace);
320  tsnapspace);
321  asnapspace = shm_toc_allocate(pcxt->toc, asnaplen);
322  SerializeSnapshot(active_snapshot, asnapspace);
323  shm_toc_insert(pcxt->toc, PARALLEL_KEY_ACTIVE_SNAPSHOT, asnapspace);
324 
325  /* Serialize transaction state. */
326  tstatespace = shm_toc_allocate(pcxt->toc, tstatelen);
327  SerializeTransactionState(tstatelen, tstatespace);
329 
330  /* Allocate space for worker information. */
331  pcxt->worker = palloc0(sizeof(ParallelWorkerInfo) * pcxt->nworkers);
332 
333  /*
334  * Establish error queues in dynamic shared memory.
335  *
336  * These queues should be used only for transmitting ErrorResponse,
337  * NoticeResponse, and NotifyResponse protocol messages. Tuple data
338  * should be transmitted via separate (possibly larger?) queues.
339  */
340  error_queue_space =
341  shm_toc_allocate(pcxt->toc,
343  pcxt->nworkers));
344  for (i = 0; i < pcxt->nworkers; ++i)
345  {
346  char *start;
347  shm_mq *mq;
348 
349  start = error_queue_space + i * PARALLEL_ERROR_QUEUE_SIZE;
350  mq = shm_mq_create(start, PARALLEL_ERROR_QUEUE_SIZE);
352  pcxt->worker[i].error_mqh = shm_mq_attach(mq, pcxt->seg, NULL);
353  }
354  shm_toc_insert(pcxt->toc, PARALLEL_KEY_ERROR_QUEUE, error_queue_space);
355 
356  /*
357  * Serialize entrypoint information. It's unsafe to pass function
358  * pointers across processes, as the function pointer may be different
359  * in each process in EXEC_BACKEND builds, so we always pass library
360  * and function name. (We use library name "postgres" for functions
361  * in the core backend.)
362  */
363  lnamelen = strlen(pcxt->library_name);
364  entrypointstate = shm_toc_allocate(pcxt->toc, lnamelen +
365  strlen(pcxt->function_name) + 2);
366  strcpy(entrypointstate, pcxt->library_name);
367  strcpy(entrypointstate + lnamelen + 1, pcxt->function_name);
368  shm_toc_insert(pcxt->toc, PARALLEL_KEY_ENTRYPOINT, entrypointstate);
369  }
370 
371  /* Restore previous memory context. */
372  MemoryContextSwitchTo(oldcontext);
373 }
374 
375 /*
376  * Reinitialize the dynamic shared memory segment for a parallel context such
377  * that we could launch workers for it again.
378  */
379 void
381 {
382  FixedParallelState *fps;
383  char *error_queue_space;
384  int i;
385 
386  /* Wait for any old workers to exit. */
387  if (pcxt->nworkers_launched > 0)
388  {
391  pcxt->nworkers_launched = 0;
392  }
393 
394  /* Reset a few bits of fixed parallel state to a clean state. */
395  fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
396  fps->last_xlog_end = 0;
397 
398  /* Recreate error queues. */
399  error_queue_space =
401  for (i = 0; i < pcxt->nworkers; ++i)
402  {
403  char *start;
404  shm_mq *mq;
405 
406  start = error_queue_space + i * PARALLEL_ERROR_QUEUE_SIZE;
407  mq = shm_mq_create(start, PARALLEL_ERROR_QUEUE_SIZE);
409  pcxt->worker[i].error_mqh = shm_mq_attach(mq, pcxt->seg, NULL);
410  }
411 }
412 
413 /*
414  * Launch parallel workers.
415  */
416 void
418 {
419  MemoryContext oldcontext;
420  BackgroundWorker worker;
421  int i;
422  bool any_registrations_failed = false;
423 
424  /* Skip this if we have no workers. */
425  if (pcxt->nworkers == 0)
426  return;
427 
428  /* We need to be a lock group leader. */
430 
431  /* If we do have workers, we'd better have a DSM segment. */
432  Assert(pcxt->seg != NULL);
433 
434  /* We might be running in a short-lived memory context. */
436 
437  /* Configure a worker. */
438  memset(&worker, 0, sizeof(worker));
439  snprintf(worker.bgw_name, BGW_MAXLEN, "parallel worker for PID %d",
440  MyProcPid);
441  worker.bgw_flags =
446  sprintf(worker.bgw_library_name, "postgres");
447  sprintf(worker.bgw_function_name, "ParallelWorkerMain");
449  worker.bgw_notify_pid = MyProcPid;
450 
451  /*
452  * Start workers.
453  *
454  * The caller must be able to tolerate ending up with fewer workers than
455  * expected, so there is no need to throw an error here if registration
456  * fails. It wouldn't help much anyway, because registering the worker in
457  * no way guarantees that it will start up and initialize successfully.
458  */
459  for (i = 0; i < pcxt->nworkers; ++i)
460  {
461  memcpy(worker.bgw_extra, &i, sizeof(int));
462  if (!any_registrations_failed &&
464  &pcxt->worker[i].bgwhandle))
465  {
467  pcxt->worker[i].bgwhandle);
468  pcxt->nworkers_launched++;
469  }
470  else
471  {
472  /*
473  * If we weren't able to register the worker, then we've bumped up
474  * against the max_worker_processes limit, and future
475  * registrations will probably fail too, so arrange to skip them.
476  * But we still have to execute this code for the remaining slots
477  * to make sure that we forget about the error queues we budgeted
478  * for those workers. Otherwise, we'll wait for them to start,
479  * but they never will.
480  */
481  any_registrations_failed = true;
482  pcxt->worker[i].bgwhandle = NULL;
483  pfree(pcxt->worker[i].error_mqh);
484  pcxt->worker[i].error_mqh = NULL;
485  }
486  }
487 
488  /* Restore previous memory context. */
489  MemoryContextSwitchTo(oldcontext);
490 }
491 
492 /*
493  * Wait for all workers to finish computing.
494  *
495  * Even if the parallel operation seems to have completed successfully, it's
496  * important to call this function afterwards. We must not miss any errors
497  * the workers may have thrown during the parallel operation, or any that they
498  * may yet throw while shutting down.
499  *
500  * Also, we want to update our notion of XactLastRecEnd based on worker
501  * feedback.
502  */
503 void
505 {
506  for (;;)
507  {
508  bool anyone_alive = false;
509  int i;
510 
511  /*
512  * This will process any parallel messages that are pending, which may
513  * change the outcome of the loop that follows. It may also throw an
514  * error propagated from a worker.
515  */
517 
518  for (i = 0; i < pcxt->nworkers_launched; ++i)
519  {
520  if (pcxt->worker[i].error_mqh != NULL)
521  {
522  anyone_alive = true;
523  break;
524  }
525  }
526 
527  if (!anyone_alive)
528  break;
529 
533  }
534 
535  if (pcxt->toc != NULL)
536  {
537  FixedParallelState *fps;
538 
539  fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
540  if (fps->last_xlog_end > XactLastRecEnd)
542  }
543 }
544 
545 /*
546  * Wait for all workers to exit.
547  *
548  * This function ensures that workers have been completely shutdown. The
549  * difference between WaitForParallelWorkersToFinish and this function is
550  * that former just ensures that last message sent by worker backend is
551  * received by master backend whereas this ensures the complete shutdown.
552  */
553 static void
555 {
556  int i;
557 
558  /* Wait until the workers actually die. */
559  for (i = 0; i < pcxt->nworkers_launched; ++i)
560  {
562 
563  if (pcxt->worker == NULL || pcxt->worker[i].bgwhandle == NULL)
564  continue;
565 
567 
568  /*
569  * If the postmaster kicked the bucket, we have no chance of cleaning
570  * up safely -- we won't be able to tell when our workers are actually
571  * dead. This doesn't necessitate a PANIC since they will all abort
572  * eventually, but we can't safely continue this session.
573  */
574  if (status == BGWH_POSTMASTER_DIED)
575  ereport(FATAL,
576  (errcode(ERRCODE_ADMIN_SHUTDOWN),
577  errmsg("postmaster exited during a parallel transaction")));
578 
579  /* Release memory. */
580  pfree(pcxt->worker[i].bgwhandle);
581  pcxt->worker[i].bgwhandle = NULL;
582  }
583 }
584 
585 /*
586  * Destroy a parallel context.
587  *
588  * If expecting a clean exit, you should use WaitForParallelWorkersToFinish()
589  * first, before calling this function. When this function is invoked, any
590  * remaining workers are forcibly killed; the dynamic shared memory segment
591  * is unmapped; and we then wait (uninterruptibly) for the workers to exit.
592  */
593 void
595 {
596  int i;
597 
598  /*
599  * Be careful about order of operations here! We remove the parallel
600  * context from the list before we do anything else; otherwise, if an
601  * error occurs during a subsequent step, we might try to nuke it again
602  * from AtEOXact_Parallel or AtEOSubXact_Parallel.
603  */
604  dlist_delete(&pcxt->node);
605 
606  /* Kill each worker in turn, and forget their error queues. */
607  if (pcxt->worker != NULL)
608  {
609  for (i = 0; i < pcxt->nworkers_launched; ++i)
610  {
611  if (pcxt->worker[i].error_mqh != NULL)
612  {
614 
615  pfree(pcxt->worker[i].error_mqh);
616  pcxt->worker[i].error_mqh = NULL;
617  }
618  }
619  }
620 
621  /*
622  * If we have allocated a shared memory segment, detach it. This will
623  * implicitly detach the error queues, and any other shared memory queues,
624  * stored there.
625  */
626  if (pcxt->seg != NULL)
627  {
628  dsm_detach(pcxt->seg);
629  pcxt->seg = NULL;
630  }
631 
632  /*
633  * If this parallel context is actually in backend-private memory rather
634  * than shared memory, free that memory instead.
635  */
636  if (pcxt->private_memory != NULL)
637  {
638  pfree(pcxt->private_memory);
639  pcxt->private_memory = NULL;
640  }
641 
642  /*
643  * We can't finish transaction commit or abort until all of the workers
644  * have exited. This means, in particular, that we can't respond to
645  * interrupts at this stage.
646  */
647  HOLD_INTERRUPTS();
650 
651  /* Free the worker array itself. */
652  if (pcxt->worker != NULL)
653  {
654  pfree(pcxt->worker);
655  pcxt->worker = NULL;
656  }
657 
658  /* Free memory. */
659  pfree(pcxt->library_name);
660  pfree(pcxt->function_name);
661  pfree(pcxt);
662 }
663 
664 /*
665  * Are there any parallel contexts currently active?
666  */
667 bool
669 {
670  return !dlist_is_empty(&pcxt_list);
671 }
672 
673 /*
674  * Handle receipt of an interrupt indicating a parallel worker message.
675  *
676  * Note: this is called within a signal handler! All we can do is set
677  * a flag that will cause the next CHECK_FOR_INTERRUPTS() to invoke
678  * HandleParallelMessages().
679  */
680 void
682 {
683  InterruptPending = true;
684  ParallelMessagePending = true;
685  SetLatch(MyLatch);
686 }
687 
688 /*
689  * Handle any queued protocol messages received from parallel workers.
690  */
691 void
693 {
694  dlist_iter iter;
695  MemoryContext oldcontext;
696 
697  static MemoryContext hpm_context = NULL;
698 
699  /*
700  * This is invoked from ProcessInterrupts(), and since some of the
701  * functions it calls contain CHECK_FOR_INTERRUPTS(), there is a potential
702  * for recursive calls if more signals are received while this runs. It's
703  * unclear that recursive entry would be safe, and it doesn't seem useful
704  * even if it is safe, so let's block interrupts until done.
705  */
706  HOLD_INTERRUPTS();
707 
708  /*
709  * Moreover, CurrentMemoryContext might be pointing almost anywhere. We
710  * don't want to risk leaking data into long-lived contexts, so let's do
711  * our work here in a private context that we can reset on each use.
712  */
713  if (hpm_context == NULL) /* first time through? */
715  "HandleParallelMessages",
717  else
718  MemoryContextReset(hpm_context);
719 
720  oldcontext = MemoryContextSwitchTo(hpm_context);
721 
722  /* OK to process messages. Reset the flag saying there are more to do. */
723  ParallelMessagePending = false;
724 
725  dlist_foreach(iter, &pcxt_list)
726  {
727  ParallelContext *pcxt;
728  int i;
729 
730  pcxt = dlist_container(ParallelContext, node, iter.cur);
731  if (pcxt->worker == NULL)
732  continue;
733 
734  for (i = 0; i < pcxt->nworkers_launched; ++i)
735  {
736  /*
737  * Read as many messages as we can from each worker, but stop when
738  * either (1) the worker's error queue goes away, which can happen
739  * if we receive a Terminate message from the worker; or (2) no
740  * more messages can be read from the worker without blocking.
741  */
742  while (pcxt->worker[i].error_mqh != NULL)
743  {
744  shm_mq_result res;
745  Size nbytes;
746  void *data;
747 
748  res = shm_mq_receive(pcxt->worker[i].error_mqh, &nbytes,
749  &data, true);
750  if (res == SHM_MQ_WOULD_BLOCK)
751  break;
752  else if (res == SHM_MQ_SUCCESS)
753  {
754  StringInfoData msg;
755 
756  initStringInfo(&msg);
757  appendBinaryStringInfo(&msg, data, nbytes);
758  HandleParallelMessage(pcxt, i, &msg);
759  pfree(msg.data);
760  }
761  else
762  ereport(ERROR,
763  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
764  errmsg("lost connection to parallel worker")));
765  }
766  }
767  }
768 
769  MemoryContextSwitchTo(oldcontext);
770 
771  /* Might as well clear the context on our way out */
772  MemoryContextReset(hpm_context);
773 
775 }
776 
777 /*
778  * Handle a single protocol message received from a single parallel worker.
779  */
780 static void
782 {
783  char msgtype;
784 
785  msgtype = pq_getmsgbyte(msg);
786 
787  switch (msgtype)
788  {
789  case 'K': /* BackendKeyData */
790  {
791  int32 pid = pq_getmsgint(msg, 4);
792 
793  (void) pq_getmsgint(msg, 4); /* discard cancel key */
794  (void) pq_getmsgend(msg);
795  pcxt->worker[i].pid = pid;
796  break;
797  }
798 
799  case 'E': /* ErrorResponse */
800  case 'N': /* NoticeResponse */
801  {
802  ErrorData edata;
803  ErrorContextCallback *save_error_context_stack;
804 
805  /* Parse ErrorResponse or NoticeResponse. */
806  pq_parse_errornotice(msg, &edata);
807 
808  /* Death of a worker isn't enough justification for suicide. */
809  edata.elevel = Min(edata.elevel, ERROR);
810 
811  /*
812  * If desired, add a context line to show that this is a
813  * message propagated from a parallel worker. Otherwise, it
814  * can sometimes be confusing to understand what actually
815  * happened. (We don't do this in FORCE_PARALLEL_REGRESS mode
816  * because it causes test-result instability depending on
817  * whether a parallel worker is actually used or not.)
818  */
820  {
821  if (edata.context)
822  edata.context = psprintf("%s\n%s", edata.context,
823  _("parallel worker"));
824  else
825  edata.context = pstrdup(_("parallel worker"));
826  }
827 
828  /*
829  * Context beyond that should use the error context callbacks
830  * that were in effect when the ParallelContext was created,
831  * not the current ones.
832  */
833  save_error_context_stack = error_context_stack;
835 
836  /* Rethrow error or print notice. */
837  ThrowErrorData(&edata);
838 
839  /* Not an error, so restore previous context stack. */
840  error_context_stack = save_error_context_stack;
841 
842  break;
843  }
844 
845  case 'A': /* NotifyResponse */
846  {
847  /* Propagate NotifyResponse. */
848  int32 pid;
849  const char *channel;
850  const char *payload;
851 
852  pid = pq_getmsgint(msg, 4);
853  channel = pq_getmsgrawstring(msg);
854  payload = pq_getmsgrawstring(msg);
855  pq_endmessage(msg);
856 
857  NotifyMyFrontEnd(channel, payload, pid);
858 
859  break;
860  }
861 
862  case 'X': /* Terminate, indicating clean exit */
863  {
864  pfree(pcxt->worker[i].error_mqh);
865  pcxt->worker[i].error_mqh = NULL;
866  break;
867  }
868 
869  default:
870  {
871  elog(ERROR, "unrecognized message type received from parallel worker: %c (message length %d bytes)",
872  msgtype, msg->len);
873  }
874  }
875 }
876 
877 /*
878  * End-of-subtransaction cleanup for parallel contexts.
879  *
880  * Currently, it's forbidden to enter or leave a subtransaction while
881  * parallel mode is in effect, so we could just blow away everything. But
882  * we may want to relax that restriction in the future, so this code
883  * contemplates that there may be multiple subtransaction IDs in pcxt_list.
884  */
885 void
886 AtEOSubXact_Parallel(bool isCommit, SubTransactionId mySubId)
887 {
888  while (!dlist_is_empty(&pcxt_list))
889  {
890  ParallelContext *pcxt;
891 
892  pcxt = dlist_head_element(ParallelContext, node, &pcxt_list);
893  if (pcxt->subid != mySubId)
894  break;
895  if (isCommit)
896  elog(WARNING, "leaked parallel context");
898  }
899 }
900 
901 /*
902  * End-of-transaction cleanup for parallel contexts.
903  */
904 void
905 AtEOXact_Parallel(bool isCommit)
906 {
907  while (!dlist_is_empty(&pcxt_list))
908  {
909  ParallelContext *pcxt;
910 
911  pcxt = dlist_head_element(ParallelContext, node, &pcxt_list);
912  if (isCommit)
913  elog(WARNING, "leaked parallel context");
915  }
916 }
917 
918 /*
919  * Main entrypoint for parallel workers.
920  */
921 void
923 {
924  dsm_segment *seg;
925  shm_toc *toc;
926  FixedParallelState *fps;
927  char *error_queue_space;
928  shm_mq *mq;
929  shm_mq_handle *mqh;
930  char *libraryspace;
931  char *entrypointstate;
932  char *library_name;
933  char *function_name;
935  char *gucspace;
936  char *combocidspace;
937  char *tsnapspace;
938  char *asnapspace;
939  char *tstatespace;
940  StringInfoData msgbuf;
941 
942  /* Set flag to indicate that we're initializing a parallel worker. */
944 
945  /* Establish signal handlers. */
946  pqsignal(SIGTERM, die);
948 
949  /* Determine and set our parallel worker number. */
951  memcpy(&ParallelWorkerNumber, MyBgworkerEntry->bgw_extra, sizeof(int));
952 
953  /* Set up a memory context and resource owner. */
955  CurrentResourceOwner = ResourceOwnerCreate(NULL, "parallel toplevel");
957  "Parallel worker",
959 
960  /*
961  * Now that we have a resource owner, we can attach to the dynamic shared
962  * memory segment and read the table of contents.
963  */
964  seg = dsm_attach(DatumGetUInt32(main_arg));
965  if (seg == NULL)
966  ereport(ERROR,
967  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
968  errmsg("could not map dynamic shared memory segment")));
970  if (toc == NULL)
971  ereport(ERROR,
972  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
973  errmsg("invalid magic number in dynamic shared memory segment")));
974 
975  /* Look up fixed parallel state. */
976  fps = shm_toc_lookup(toc, PARALLEL_KEY_FIXED, false);
977  MyFixedParallelState = fps;
978 
979  /*
980  * Now that we have a worker number, we can find and attach to the error
981  * queue provided for us. That's good, because until we do that, any
982  * errors that happen here will not be reported back to the process that
983  * requested that this worker be launched.
984  */
985  error_queue_space = shm_toc_lookup(toc, PARALLEL_KEY_ERROR_QUEUE, false);
986  mq = (shm_mq *) (error_queue_space +
989  mqh = shm_mq_attach(mq, seg, NULL);
990  pq_redirect_to_shm_mq(seg, mqh);
993 
994  /*
995  * Send a BackendKeyData message to the process that initiated parallelism
996  * so that it has access to our PID before it receives any other messages
997  * from us. Our cancel key is sent, too, since that's the way the
998  * protocol message is defined, but it won't actually be used for anything
999  * in this case.
1000  */
1001  pq_beginmessage(&msgbuf, 'K');
1002  pq_sendint(&msgbuf, (int32) MyProcPid, sizeof(int32));
1003  pq_sendint(&msgbuf, (int32) MyCancelKey, sizeof(int32));
1004  pq_endmessage(&msgbuf);
1005 
1006  /*
1007  * Hooray! Primary initialization is complete. Now, we need to set up our
1008  * backend-local state to match the original backend.
1009  */
1010 
1011  /*
1012  * Join locking group. We must do this before anything that could try to
1013  * acquire a heavyweight lock, because any heavyweight locks acquired to
1014  * this point could block either directly against the parallel group
1015  * leader or against some process which in turn waits for a lock that
1016  * conflicts with the parallel group leader, causing an undetected
1017  * deadlock. (If we can't join the lock group, the leader has gone away,
1018  * so just exit quietly.)
1019  */
1021  fps->parallel_master_pid))
1022  return;
1023 
1024  /*
1025  * Load libraries that were loaded by original backend. We want to do
1026  * this before restoring GUCs, because the libraries might define custom
1027  * variables.
1028  */
1029  libraryspace = shm_toc_lookup(toc, PARALLEL_KEY_LIBRARY, false);
1030  RestoreLibraryState(libraryspace);
1031 
1032  /*
1033  * Identify the entry point to be called. In theory this could result in
1034  * loading an additional library, though most likely the entry point is in
1035  * the core backend or in a library we just loaded.
1036  */
1037  entrypointstate = shm_toc_lookup(toc, PARALLEL_KEY_ENTRYPOINT, false);
1038  library_name = entrypointstate;
1039  function_name = entrypointstate + strlen(library_name) + 1;
1040 
1041  entrypt = LookupParallelWorkerFunction(library_name, function_name);
1042 
1043  /* Restore database connection. */
1045  fps->authenticated_user_id);
1046 
1047  /*
1048  * Set the client encoding to the database encoding, since that is what
1049  * the leader will expect.
1050  */
1052 
1053  /* Restore GUC values from launching backend. */
1054  gucspace = shm_toc_lookup(toc, PARALLEL_KEY_GUC, false);
1056  RestoreGUCState(gucspace);
1058 
1059  /* Crank up a transaction state appropriate to a parallel worker. */
1060  tstatespace = shm_toc_lookup(toc, PARALLEL_KEY_TRANSACTION_STATE, false);
1061  StartParallelWorkerTransaction(tstatespace);
1062 
1063  /* Restore combo CID state. */
1064  combocidspace = shm_toc_lookup(toc, PARALLEL_KEY_COMBO_CID, false);
1065  RestoreComboCIDState(combocidspace);
1066 
1067  /* Restore transaction snapshot. */
1068  tsnapspace = shm_toc_lookup(toc, PARALLEL_KEY_TRANSACTION_SNAPSHOT, false);
1070  fps->parallel_master_pgproc);
1071 
1072  /* Restore active snapshot. */
1073  asnapspace = shm_toc_lookup(toc, PARALLEL_KEY_ACTIVE_SNAPSHOT, false);
1074  PushActiveSnapshot(RestoreSnapshot(asnapspace));
1075 
1076  /*
1077  * We've changed which tuples we can see, and must therefore invalidate
1078  * system caches.
1079  */
1081 
1082  /* Restore user ID and security context. */
1084 
1085  /* Restore temp-namespace state to ensure search path matches leader's. */
1088 
1089  /* Set ParallelMasterBackendId so we know how to address temp relations. */
1091 
1092  /*
1093  * We've initialized all of our state now; nothing should change
1094  * hereafter.
1095  */
1098 
1099  /*
1100  * Time to do the real work: invoke the caller-supplied code.
1101  */
1102  entrypt(seg, toc);
1103 
1104  /* Must exit parallel mode to pop active snapshot. */
1105  ExitParallelMode();
1106 
1107  /* Must pop active snapshot so resowner.c doesn't complain. */
1109 
1110  /* Shut down the parallel-worker transaction. */
1112 
1113  /* Report success. */
1114  pq_putmessage('X', NULL, 0);
1115 }
1116 
1117 /*
1118  * Update shared memory with the ending location of the last WAL record we
1119  * wrote, if it's greater than the value already stored there.
1120  */
1121 void
1123 {
1125 
1126  Assert(fps != NULL);
1127  SpinLockAcquire(&fps->mutex);
1128  if (fps->last_xlog_end < last_xlog_end)
1129  fps->last_xlog_end = last_xlog_end;
1130  SpinLockRelease(&fps->mutex);
1131 }
1132 
1133 /*
1134  * Look up (and possibly load) a parallel worker entry point function.
1135  *
1136  * For functions contained in the core code, we use library name "postgres"
1137  * and consult the InternalParallelWorkers array. External functions are
1138  * looked up, and loaded if necessary, using load_external_function().
1139  *
1140  * The point of this is to pass function names as strings across process
1141  * boundaries. We can't pass actual function addresses because of the
1142  * possibility that the function has been loaded at a different address
1143  * in a different process. This is obviously a hazard for functions in
1144  * loadable libraries, but it can happen even for functions in the core code
1145  * on platforms using EXEC_BACKEND (e.g., Windows).
1146  *
1147  * At some point it might be worthwhile to get rid of InternalParallelWorkers[]
1148  * in favor of applying load_external_function() for core functions too;
1149  * but that raises portability issues that are not worth addressing now.
1150  */
1152 LookupParallelWorkerFunction(const char *libraryname, const char *funcname)
1153 {
1154  /*
1155  * If the function is to be loaded from postgres itself, search the
1156  * InternalParallelWorkers array.
1157  */
1158  if (strcmp(libraryname, "postgres") == 0)
1159  {
1160  int i;
1161 
1162  for (i = 0; i < lengthof(InternalParallelWorkers); i++)
1163  {
1164  if (strcmp(InternalParallelWorkers[i].fn_name, funcname) == 0)
1165  return InternalParallelWorkers[i].fn_addr;
1166  }
1167 
1168  /* We can only reach this by programming error. */
1169  elog(ERROR, "internal function \"%s\" not found", funcname);
1170  }
1171 
1172  /* Otherwise load from external library. */
1173  return (parallel_worker_main_type)
1174  load_external_function(libraryname, funcname, true, NULL);
1175 }
char bgw_extra[BGW_EXTRALEN]
Definition: bgworker.h:97
#define DatumGetUInt32(X)
Definition: postgres.h:492
int slock_t
Definition: s_lock.h:888
#define PARALLEL_ERROR_QUEUE_SIZE
Definition: parallel.c:48
static const struct @21 InternalParallelWorkers[]
shm_toc * shm_toc_create(uint64 magic, void *address, Size nbytes)
Definition: shm_toc.c:40
int MyProcPid
Definition: globals.c:39
BackendId MyBackendId
Definition: globals.c:73
Snapshot RestoreSnapshot(char *start_address)
Definition: snapmgr.c:2121
MemoryContext TopTransactionContext
Definition: mcxt.c:48
ParallelContext * CreateParallelContext(const char *library_name, const char *function_name, int nworkers)
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void SetUserIdAndSecContext(Oid userid, int sec_context)
Definition: miscinit.c:396
static void dlist_push_head(dlist_head *head, dlist_node *node)
Definition: ilist.h:300
XLogRecPtr XactLastRecEnd
Definition: xlog.c:337
PGPROC * MyProc
Definition: proc.c:67
dsm_segment * seg
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static void WaitForParallelWorkersToExit(ParallelContext *pcxt)
Definition: parallel.c:554
#define dlist_foreach(iter, lhead)
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ResourceOwner CurrentResourceOwner
Definition: resowner.c:138
char * pstrdup(const char *in)
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void CommitTransactionCommand(void)
Definition: xact.c:2750
shm_toc_estimator estimator
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char * psprintf(const char *fmt,...)
Definition: psprintf.c:46
void EndParallelWorkerTransaction(void)
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#define SpinLockInit(lock)
Definition: spin.h:60
void GetTempNamespaceState(Oid *tempNamespaceId, Oid *tempToastNamespaceId)
Definition: namespace.c:3234
void RestoreTransactionSnapshot(Snapshot snapshot, void *master_pgproc)
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dsm_segment * dsm_attach(dsm_handle h)
Definition: dsm.c:561
#define Min(x, y)
Definition: c.h:807
Oid authenticated_user_id
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static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Snapshot GetActiveSnapshot(void)
Definition: snapmgr.c:839
dsm_handle dsm_segment_handle(dsm_segment *seg)
Definition: dsm.c:1028
int bgw_restart_time
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int errcode(int sqlerrcode)
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PGPROC * parallel_master_pgproc
Definition: parallel.c:77
Oid temp_toast_namespace_id
Definition: parallel.c:75
#define BGWORKER_CLASS_PARALLEL
Definition: bgworker.h:67
BackgroundWorker * MyBgworkerEntry
Definition: postmaster.c:190
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
void MemoryContextReset(MemoryContext context)
Definition: mcxt.c:135
bool BecomeLockGroupMember(PGPROC *leader, int pid)
Definition: proc.c:1845
void PopActiveSnapshot(void)
Definition: snapmgr.c:812
uint32 SubTransactionId
Definition: c.h:401
Size shm_toc_estimate(shm_toc_estimator *e)
Definition: shm_toc.c:263
#define lengthof(array)
Definition: c.h:562
void ResetLatch(volatile Latch *latch)
Definition: latch.c:497
void SerializeTransactionState(Size maxsize, char *start_address)
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parallel_worker_main_type fn_addr
Definition: parallel.c:115
const char * pq_getmsgrawstring(StringInfo msg)
Definition: pqformat.c:650
unsigned int Oid
Definition: postgres_ext.h:31
#define shm_toc_estimate_chunk(e, sz)
Definition: shm_toc.h:51
#define BGWORKER_SHMEM_ACCESS
Definition: bgworker.h:52
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:304
void InvalidateSystemCaches(void)
Definition: inval.c:641
char bgw_function_name[BGW_MAXLEN]
Definition: bgworker.h:95
void pq_beginmessage(StringInfo buf, char msgtype)
Definition: pqformat.c:88
void RestoreComboCIDState(char *comboCIDstate)
Definition: combocid.c:344
signed int int32
Definition: c.h:256
SubTransactionId subid
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#define RESUME_INTERRUPTS()
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ErrorContextCallback * error_context_stack
Definition: elog.c:88
volatile bool ParallelMessagePending
Definition: parallel.c:97
#define StaticAssertStmt(condition, errmessage)
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void WaitForParallelWorkersToFinish(ParallelContext *pcxt)
Definition: parallel.c:504
#define SpinLockAcquire(lock)
Definition: spin.h:62
void DestroyParallelContext(ParallelContext *pcxt)
Definition: parallel.c:594
#define dlist_container(type, membername, ptr)
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ParallelWorkerInfo * worker
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Datum bgw_main_arg
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int WaitLatch(volatile Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
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void pfree(void *pointer)
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bool IsInParallelMode(void)
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Definition: dfmgr.c:728
#define ERROR
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BgwHandleStatus WaitForBackgroundWorkerShutdown(BackgroundWorkerHandle *handle)
Definition: bgworker.c:1132
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Definition: execParallel.c:834
Oid GetAuthenticatedUserId(void)
Definition: miscinit.c:343
#define PARALLEL_KEY_TRANSACTION_SNAPSHOT
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char * function_name
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void SerializeSnapshot(Snapshot snapshot, char *start_address)
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int32 MyCancelKey
Definition: globals.c:42
void pq_parse_errornotice(StringInfo msg, ErrorData *edata)
Definition: pqmq.c:219
#define FATAL
Definition: elog.h:52
shm_mq * shm_mq_create(void *address, Size size)
Definition: shm_mq.c:167
void ExitParallelMode(void)
Definition: xact.c:893
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:165
#define PARALLEL_KEY_FIXED
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void HandleParallelMessages(void)
Definition: parallel.c:692
#define PARALLEL_KEY_ERROR_QUEUE
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void SetTempNamespaceState(Oid tempNamespaceId, Oid tempToastNamespaceId)
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static void HandleParallelMessage(ParallelContext *pcxt, int i, StringInfo msg)
Definition: parallel.c:781
#define DSM_CREATE_NULL_IF_MAXSEGMENTS
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void PushActiveSnapshot(Snapshot snap)
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shm_mq_handle * error_mqh
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#define PARALLEL_KEY_GUC
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BackgroundWorkerHandle * bgwhandle
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Size EstimateGUCStateSpace(void)
Definition: guc.c:9102
#define BGW_NEVER_RESTART
Definition: bgworker.h:84
#define shm_toc_initialize_estimator(e)
Definition: shm_toc.h:49
Size EstimateComboCIDStateSpace(void)
Definition: combocid.c:299
#define UInt32GetDatum(X)
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MemoryContext CurrentMemoryContext
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int nworkers_launched
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XLogRecPtr last_xlog_end
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PGFunction load_external_function(const char *filename, const char *funcname, bool signalNotFound, void **filehandle)
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void BecomeLockGroupLeader(void)
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MemoryContext TopMemoryContext
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#define DLIST_STATIC_INIT(name)
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#define WARNING
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int elevel
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bool ParallelContextActive(void)
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#define SpinLockRelease(lock)
Definition: spin.h:64
#define dlist_head_element(type, membername, lhead)
Definition: ilist.h:487
Size EstimateSnapshotSpace(Snapshot snap)
Definition: snapmgr.c:2038
Size mul_size(Size s1, Size s2)
Definition: shmem.c:492
MemoryContext AllocSetContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: aset.c:322
void * palloc0(Size size)
Definition: mcxt.c:878
static parallel_worker_main_type LookupParallelWorkerFunction(const char *libraryname, const char *funcname)
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void RestoreLibraryState(char *start_address)
Definition: dfmgr.c:750
uintptr_t Datum
Definition: postgres.h:372
dsm_segment * dsm_create(Size size, int flags)
Definition: dsm.c:465
shm_toc * shm_toc_attach(uint64 magic, void *address)
Definition: shm_toc.c:64
int GetDatabaseEncoding(void)
Definition: mbutils.c:1015
int BackendId
Definition: backendid.h:21
Oid MyDatabaseId
Definition: globals.c:77
pid_t parallel_master_pid
Definition: parallel.c:78
Size EstimateLibraryStateSpace(void)
Definition: dfmgr.c:711
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Definition: parallel.c:380
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Definition: shm_mq.c:311
dlist_node * cur
Definition: ilist.h:161
#define PARALLEL_MAGIC
Definition: parallel.c:51
void pq_redirect_to_shm_mq(dsm_segment *seg, shm_mq_handle *mqh)
Definition: pqmq.c:56
void ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
Definition: parallel.c:1122
void TerminateBackgroundWorker(BackgroundWorkerHandle *handle)
Definition: bgworker.c:1171
pqsigfunc pqsignal(int signum, pqsigfunc handler)
Definition: signal.c:168
volatile bool InterruptPending
Definition: globals.c:29
int pq_getmsgbyte(StringInfo msg)
Definition: pqformat.c:432
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Definition: shm_mq.h:36
char * library_name
Definition: parallel.h:38
void SetLatch(volatile Latch *latch)
Definition: latch.c:414
BackendId parallel_master_backend_id
Definition: parallel.c:79
#define NULL
Definition: c.h:229
int force_parallel_mode
Definition: planner.c:63
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:1000
uint64 XLogRecPtr
Definition: xlogdefs.h:21
char bgw_name[BGW_MAXLEN]
Definition: bgworker.h:90
#define Assert(condition)
Definition: c.h:676
BackendId ParallelMasterBackendId
Definition: globals.c:75
void StartParallelWorkerTransaction(char *tstatespace)
Definition: xact.c:4941
#define BGWORKER_BACKEND_DATABASE_CONNECTION
Definition: bgworker.h:59
SubTransactionId GetCurrentSubTransactionId(void)
Definition: xact.c:649
Size EstimateTransactionStateSpace(void)
Definition: xact.c:4840
void StartTransactionCommand(void)
Definition: xact.c:2680
const char * fn_name
Definition: parallel.c:114
static bool dlist_is_empty(dlist_head *head)
Definition: ilist.h:289
#define DSM_IMPL_NONE
Definition: dsm_impl.h:17
#define BGW_MAXLEN
Definition: bgworker.h:85
size_t Size
Definition: c.h:356
BgWorkerStartTime bgw_start_time
Definition: bgworker.h:92
dlist_node node
Definition: parallel.h:34
#define shm_toc_estimate_keys(e, cnt)
Definition: shm_toc.h:53
bool RegisterDynamicBackgroundWorker(BackgroundWorker *worker, BackgroundWorkerHandle **handle)
Definition: bgworker.c:933
void EnterParallelMode(void)
Definition: xact.c:880
void * shm_toc_allocate(shm_toc *toc, Size nbytes)
Definition: shm_toc.c:88
char * context
Definition: elog.h:347
shm_mq_handle * shm_mq_attach(shm_mq *mq, dsm_segment *seg, BackgroundWorkerHandle *handle)
Definition: shm_mq.c:284
ErrorContextCallback * error_context_stack
Definition: parallel.h:40
void pq_set_parallel_master(pid_t pid, BackendId backend_id)
Definition: pqmq.c:83
#define PARALLEL_KEY_TRANSACTION_STATE
Definition: parallel.c:64
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:726
void shm_toc_insert(shm_toc *toc, uint64 key, void *address)
Definition: shm_toc.c:171
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define IsolationIsSerializable()
Definition: xact.h:44
void pq_sendint(StringInfo buf, int i, int b)
Definition: pqformat.c:236
void pq_endmessage(StringInfo buf)
Definition: pqformat.c:344
void ParallelWorkerMain(Datum main_arg)
Definition: parallel.c:922
pid_t bgw_notify_pid
Definition: bgworker.h:98
static FixedParallelState * MyFixedParallelState
Definition: parallel.c:103
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:707
void die(SIGNAL_ARGS)
Definition: postgres.c:2617
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:115
bool InitializingParallelWorker
Definition: parallel.c:100
int i
Definition: shm_mq.c:69
#define BUFFERALIGN(LEN)
Definition: c.h:590
struct Latch * MyLatch
Definition: globals.c:52
void HandleParallelMessageInterrupt(void)
Definition: parallel.c:681
unsigned int pq_getmsgint(StringInfo msg, int b)
Definition: pqformat.c:448
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:98
void shm_mq_set_receiver(shm_mq *mq, PGPROC *proc)
Definition: shm_mq.c:196
static dlist_head pcxt_list
Definition: parallel.c:106
#define elog
Definition: elog.h:219
void pq_getmsgend(StringInfo msg)
Definition: pqformat.c:677
#define pq_putmessage(msgtype, s, len)
Definition: libpq.h:42
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:224
struct FixedParallelState FixedParallelState
shm_mq_result shm_mq_receive(shm_mq_handle *mqh, Size *nbytesp, void **datap, bool nowait)
Definition: shm_mq.c:518
char bgw_library_name[BGW_MAXLEN]
Definition: bgworker.h:94
void AtEOXact_Parallel(bool isCommit)
Definition: parallel.c:905
Definition: proc.h:94
#define PARALLEL_KEY_ENTRYPOINT
Definition: parallel.c:65
#define PARALLEL_KEY_COMBO_CID
Definition: parallel.c:61
#define WL_LATCH_SET
Definition: latch.h:124
#define _(x)
Definition: elog.c:84
void AtEOSubXact_Parallel(bool isCommit, SubTransactionId mySubId)
Definition: parallel.c:886
void SerializeGUCState(Size maxsize, char *start_address)
Definition: guc.c:9249
void appendBinaryStringInfo(StringInfo str, const char *data, int datalen)
Definition: stringinfo.c:208
#define PARALLEL_KEY_ACTIVE_SNAPSHOT
Definition: parallel.c:63
void * shm_toc_lookup(shm_toc *toc, uint64 key, bool noError)
Definition: shm_toc.c:232
void SerializeComboCIDState(Size maxsize, char *start_address)
Definition: combocid.c:318
#define PARALLEL_KEY_LIBRARY
Definition: parallel.c:59
void RestoreGUCState(void *gucstate)
Definition: guc.c:9327
shm_toc * toc
Definition: parallel.h:44
void NotifyMyFrontEnd(const char *channel, const char *payload, int32 srcPid)
Definition: async.c:2077
void * private_memory
Definition: parallel.h:43
ResourceOwner ResourceOwnerCreate(ResourceOwner parent, const char *name)
Definition: resowner.c:416
void(* parallel_worker_main_type)(dsm_segment *seg, shm_toc *toc)
Definition: parallel.h:23
void BackgroundWorkerUnblockSignals(void)
Definition: postmaster.c:5579