PostgreSQL Source Code  git master
parallel.c File Reference
#include "postgres.h"
#include "access/parallel.h"
#include "access/session.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "catalog/namespace.h"
#include "commands/async.h"
#include "executor/execParallel.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "libpq/pqmq.h"
#include "miscadmin.h"
#include "optimizer/planmain.h"
#include "pgstat.h"
#include "storage/ipc.h"
#include "storage/sinval.h"
#include "storage/spin.h"
#include "tcop/tcopprot.h"
#include "utils/combocid.h"
#include "utils/guc.h"
#include "utils/inval.h"
#include "utils/memutils.h"
#include "utils/resowner.h"
#include "utils/snapmgr.h"
#include "utils/typcache.h"
Include dependency graph for parallel.c:

Go to the source code of this file.

Data Structures

struct  FixedParallelState
 

Macros

#define PARALLEL_ERROR_QUEUE_SIZE   16384
 
#define PARALLEL_MAGIC   0x50477c7c
 
#define PARALLEL_KEY_FIXED   UINT64CONST(0xFFFFFFFFFFFF0001)
 
#define PARALLEL_KEY_ERROR_QUEUE   UINT64CONST(0xFFFFFFFFFFFF0002)
 
#define PARALLEL_KEY_LIBRARY   UINT64CONST(0xFFFFFFFFFFFF0003)
 
#define PARALLEL_KEY_GUC   UINT64CONST(0xFFFFFFFFFFFF0004)
 
#define PARALLEL_KEY_COMBO_CID   UINT64CONST(0xFFFFFFFFFFFF0005)
 
#define PARALLEL_KEY_TRANSACTION_SNAPSHOT   UINT64CONST(0xFFFFFFFFFFFF0006)
 
#define PARALLEL_KEY_ACTIVE_SNAPSHOT   UINT64CONST(0xFFFFFFFFFFFF0007)
 
#define PARALLEL_KEY_TRANSACTION_STATE   UINT64CONST(0xFFFFFFFFFFFF0008)
 
#define PARALLEL_KEY_ENTRYPOINT   UINT64CONST(0xFFFFFFFFFFFF0009)
 
#define PARALLEL_KEY_SESSION_DSM   UINT64CONST(0xFFFFFFFFFFFF000A)
 

Typedefs

typedef struct FixedParallelState FixedParallelState
 

Functions

static void HandleParallelMessage (ParallelContext *pcxt, int i, StringInfo msg)
 
static void WaitForParallelWorkersToExit (ParallelContext *pcxt)
 
static parallel_worker_main_type LookupParallelWorkerFunction (const char *libraryname, const char *funcname)
 
ParallelContextCreateParallelContext (const char *library_name, const char *function_name, int nworkers)
 
void InitializeParallelDSM (ParallelContext *pcxt)
 
void ReinitializeParallelDSM (ParallelContext *pcxt)
 
void LaunchParallelWorkers (ParallelContext *pcxt)
 
void WaitForParallelWorkersToFinish (ParallelContext *pcxt)
 
void DestroyParallelContext (ParallelContext *pcxt)
 
bool ParallelContextActive (void)
 
void HandleParallelMessageInterrupt (void)
 
void HandleParallelMessages (void)
 
void AtEOSubXact_Parallel (bool isCommit, SubTransactionId mySubId)
 
void AtEOXact_Parallel (bool isCommit)
 
void ParallelWorkerMain (Datum main_arg)
 
void ParallelWorkerReportLastRecEnd (XLogRecPtr last_xlog_end)
 

Variables

int ParallelWorkerNumber = -1
 
volatile bool ParallelMessagePending = false
 
bool InitializingParallelWorker = false
 
static FixedParallelStateMyFixedParallelState
 
static dlist_head pcxt_list = DLIST_STATIC_INIT(pcxt_list)
 
struct {
   const char *   fn_name
 
   parallel_worker_main_type   fn_addr
 
InternalParallelWorkers []
 

Macro Definition Documentation

◆ PARALLEL_ERROR_QUEUE_SIZE

#define PARALLEL_ERROR_QUEUE_SIZE   16384

Definition at line 50 of file parallel.c.

Referenced by InitializeParallelDSM(), ParallelWorkerMain(), and ReinitializeParallelDSM().

◆ PARALLEL_KEY_ACTIVE_SNAPSHOT

#define PARALLEL_KEY_ACTIVE_SNAPSHOT   UINT64CONST(0xFFFFFFFFFFFF0007)

Definition at line 66 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_COMBO_CID

#define PARALLEL_KEY_COMBO_CID   UINT64CONST(0xFFFFFFFFFFFF0005)

Definition at line 64 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_ENTRYPOINT

#define PARALLEL_KEY_ENTRYPOINT   UINT64CONST(0xFFFFFFFFFFFF0009)

Definition at line 68 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_ERROR_QUEUE

#define PARALLEL_KEY_ERROR_QUEUE   UINT64CONST(0xFFFFFFFFFFFF0002)

Definition at line 61 of file parallel.c.

Referenced by InitializeParallelDSM(), ParallelWorkerMain(), and ReinitializeParallelDSM().

◆ PARALLEL_KEY_FIXED

#define PARALLEL_KEY_FIXED   UINT64CONST(0xFFFFFFFFFFFF0001)

◆ PARALLEL_KEY_GUC

#define PARALLEL_KEY_GUC   UINT64CONST(0xFFFFFFFFFFFF0004)

Definition at line 63 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_LIBRARY

#define PARALLEL_KEY_LIBRARY   UINT64CONST(0xFFFFFFFFFFFF0003)

Definition at line 62 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_SESSION_DSM

#define PARALLEL_KEY_SESSION_DSM   UINT64CONST(0xFFFFFFFFFFFF000A)

Definition at line 69 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_TRANSACTION_SNAPSHOT

#define PARALLEL_KEY_TRANSACTION_SNAPSHOT   UINT64CONST(0xFFFFFFFFFFFF0006)

Definition at line 65 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_KEY_TRANSACTION_STATE

#define PARALLEL_KEY_TRANSACTION_STATE   UINT64CONST(0xFFFFFFFFFFFF0008)

Definition at line 67 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

◆ PARALLEL_MAGIC

#define PARALLEL_MAGIC   0x50477c7c

Definition at line 53 of file parallel.c.

Referenced by InitializeParallelDSM(), and ParallelWorkerMain().

Typedef Documentation

◆ FixedParallelState

Function Documentation

◆ AtEOSubXact_Parallel()

void AtEOSubXact_Parallel ( bool  isCommit,
SubTransactionId  mySubId 
)

Definition at line 920 of file parallel.c.

References DestroyParallelContext(), dlist_head_element, dlist_is_empty(), elog, ParallelContext::subid, and WARNING.

Referenced by AbortSubTransaction(), and CommitSubTransaction().

921 {
922  while (!dlist_is_empty(&pcxt_list))
923  {
924  ParallelContext *pcxt;
925 
927  if (pcxt->subid != mySubId)
928  break;
929  if (isCommit)
930  elog(WARNING, "leaked parallel context");
932  }
933 }
SubTransactionId subid
Definition: parallel.h:35
void DestroyParallelContext(ParallelContext *pcxt)
Definition: parallel.c:628
#define WARNING
Definition: elog.h:40
#define dlist_head_element(type, membername, lhead)
Definition: ilist.h:487
static bool dlist_is_empty(dlist_head *head)
Definition: ilist.h:289
static dlist_head pcxt_list
Definition: parallel.c:112
#define elog
Definition: elog.h:219

◆ AtEOXact_Parallel()

void AtEOXact_Parallel ( bool  isCommit)

Definition at line 939 of file parallel.c.

References DestroyParallelContext(), dlist_head_element, dlist_is_empty(), elog, and WARNING.

Referenced by AbortTransaction(), and CommitTransaction().

940 {
941  while (!dlist_is_empty(&pcxt_list))
942  {
943  ParallelContext *pcxt;
944 
946  if (isCommit)
947  elog(WARNING, "leaked parallel context");
949  }
950 }
void DestroyParallelContext(ParallelContext *pcxt)
Definition: parallel.c:628
#define WARNING
Definition: elog.h:40
#define dlist_head_element(type, membername, lhead)
Definition: ilist.h:487
static bool dlist_is_empty(dlist_head *head)
Definition: ilist.h:289
static dlist_head pcxt_list
Definition: parallel.c:112
#define elog
Definition: elog.h:219

◆ CreateParallelContext()

ParallelContext* CreateParallelContext ( const char *  library_name,
const char *  function_name,
int  nworkers 
)

Definition at line 142 of file parallel.c.

References Assert, dlist_push_head(), DSM_IMPL_NONE, dynamic_shared_memory_type, ParallelContext::error_context_stack, error_context_stack, ParallelContext::estimator, ParallelContext::function_name, GetCurrentSubTransactionId(), IsInParallelMode(), IsolationIsSerializable, ParallelContext::library_name, MemoryContextSwitchTo(), ParallelContext::node, ParallelContext::nworkers, palloc0(), pstrdup(), shm_toc_initialize_estimator, ParallelContext::subid, and TopTransactionContext.

Referenced by ExecInitParallelPlan().

144 {
145  MemoryContext oldcontext;
146  ParallelContext *pcxt;
147 
148  /* It is unsafe to create a parallel context if not in parallel mode. */
150 
151  /* Number of workers should be non-negative. */
152  Assert(nworkers >= 0);
153 
154  /*
155  * If dynamic shared memory is not available, we won't be able to use
156  * background workers.
157  */
159  nworkers = 0;
160 
161  /*
162  * If we are running under serializable isolation, we can't use parallel
163  * workers, at least not until somebody enhances that mechanism to be
164  * parallel-aware.
165  */
167  nworkers = 0;
168 
169  /* We might be running in a short-lived memory context. */
171 
172  /* Initialize a new ParallelContext. */
173  pcxt = palloc0(sizeof(ParallelContext));
175  pcxt->nworkers = nworkers;
176  pcxt->library_name = pstrdup(library_name);
177  pcxt->function_name = pstrdup(function_name);
180  dlist_push_head(&pcxt_list, &pcxt->node);
181 
182  /* Restore previous memory context. */
183  MemoryContextSwitchTo(oldcontext);
184 
185  return pcxt;
186 }
MemoryContext TopTransactionContext
Definition: mcxt.c:48
static void dlist_push_head(dlist_head *head, dlist_node *node)
Definition: ilist.h:300
char * pstrdup(const char *in)
Definition: mcxt.c:1076
shm_toc_estimator estimator
Definition: parallel.h:41
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
SubTransactionId subid
Definition: parallel.h:35
ErrorContextCallback * error_context_stack
Definition: elog.c:88
bool IsInParallelMode(void)
Definition: xact.c:906
char * function_name
Definition: parallel.h:39
int dynamic_shared_memory_type
Definition: dsm_impl.c:113
#define shm_toc_initialize_estimator(e)
Definition: shm_toc.h:49
void * palloc0(Size size)
Definition: mcxt.c:877
char * library_name
Definition: parallel.h:38
#define Assert(condition)
Definition: c.h:670
SubTransactionId GetCurrentSubTransactionId(void)
Definition: xact.c:642
#define DSM_IMPL_NONE
Definition: dsm_impl.h:17
dlist_node node
Definition: parallel.h:34
ErrorContextCallback * error_context_stack
Definition: parallel.h:40
#define IsolationIsSerializable()
Definition: xact.h:44
static dlist_head pcxt_list
Definition: parallel.c:112

◆ DestroyParallelContext()

void DestroyParallelContext ( ParallelContext pcxt)

Definition at line 628 of file parallel.c.

References ParallelWorkerInfo::bgwhandle, dlist_delete(), dsm_detach(), ParallelWorkerInfo::error_mqh, ParallelContext::function_name, HOLD_INTERRUPTS, i, ParallelContext::library_name, ParallelContext::node, ParallelContext::nworkers_launched, pfree(), ParallelContext::private_memory, RESUME_INTERRUPTS, ParallelContext::seg, shm_mq_detach(), TerminateBackgroundWorker(), WaitForParallelWorkersToExit(), and ParallelContext::worker.

Referenced by AtEOSubXact_Parallel(), AtEOXact_Parallel(), and ExecParallelCleanup().

629 {
630  int i;
631 
632  /*
633  * Be careful about order of operations here! We remove the parallel
634  * context from the list before we do anything else; otherwise, if an
635  * error occurs during a subsequent step, we might try to nuke it again
636  * from AtEOXact_Parallel or AtEOSubXact_Parallel.
637  */
638  dlist_delete(&pcxt->node);
639 
640  /* Kill each worker in turn, and forget their error queues. */
641  if (pcxt->worker != NULL)
642  {
643  for (i = 0; i < pcxt->nworkers_launched; ++i)
644  {
645  if (pcxt->worker[i].error_mqh != NULL)
646  {
648 
649  shm_mq_detach(pcxt->worker[i].error_mqh);
650  pcxt->worker[i].error_mqh = NULL;
651  }
652  }
653  }
654 
655  /*
656  * If we have allocated a shared memory segment, detach it. This will
657  * implicitly detach the error queues, and any other shared memory queues,
658  * stored there.
659  */
660  if (pcxt->seg != NULL)
661  {
662  dsm_detach(pcxt->seg);
663  pcxt->seg = NULL;
664  }
665 
666  /*
667  * If this parallel context is actually in backend-private memory rather
668  * than shared memory, free that memory instead.
669  */
670  if (pcxt->private_memory != NULL)
671  {
672  pfree(pcxt->private_memory);
673  pcxt->private_memory = NULL;
674  }
675 
676  /*
677  * We can't finish transaction commit or abort until all of the workers
678  * have exited. This means, in particular, that we can't respond to
679  * interrupts at this stage.
680  */
681  HOLD_INTERRUPTS();
684 
685  /* Free the worker array itself. */
686  if (pcxt->worker != NULL)
687  {
688  pfree(pcxt->worker);
689  pcxt->worker = NULL;
690  }
691 
692  /* Free memory. */
693  pfree(pcxt->library_name);
694  pfree(pcxt->function_name);
695  pfree(pcxt);
696 }
void shm_mq_detach(shm_mq_handle *mqh)
Definition: shm_mq.c:775
dsm_segment * seg
Definition: parallel.h:42
static void WaitForParallelWorkersToExit(ParallelContext *pcxt)
Definition: parallel.c:588
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:117
ParallelWorkerInfo * worker
Definition: parallel.h:45
void pfree(void *pointer)
Definition: mcxt.c:949
char * function_name
Definition: parallel.h:39
shm_mq_handle * error_mqh
Definition: parallel.h:28
BackgroundWorkerHandle * bgwhandle
Definition: parallel.h:27
static void dlist_delete(dlist_node *node)
Definition: ilist.h:358
int nworkers_launched
Definition: parallel.h:37
void TerminateBackgroundWorker(BackgroundWorkerHandle *handle)
Definition: bgworker.c:1177
char * library_name
Definition: parallel.h:38
dlist_node node
Definition: parallel.h:34
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:726
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:115
int i
void * private_memory
Definition: parallel.h:43

◆ HandleParallelMessage()

static void HandleParallelMessage ( ParallelContext pcxt,
int  i,
StringInfo  msg 
)
static

Definition at line 815 of file parallel.c.

References _, ErrorData::context, ErrorData::elevel, elog, ERROR, ParallelContext::error_context_stack, error_context_stack, ParallelWorkerInfo::error_mqh, force_parallel_mode, FORCE_PARALLEL_REGRESS, i, StringInfoData::len, Min, NotifyMyFrontEnd(), ParallelWorkerInfo::pid, pq_endmessage(), pq_getmsgbyte(), pq_getmsgend(), pq_getmsgint(), pq_getmsgrawstring(), pq_parse_errornotice(), psprintf(), pstrdup(), shm_mq_detach(), ThrowErrorData(), and ParallelContext::worker.

Referenced by HandleParallelMessages().

816 {
817  char msgtype;
818 
819  msgtype = pq_getmsgbyte(msg);
820 
821  switch (msgtype)
822  {
823  case 'K': /* BackendKeyData */
824  {
825  int32 pid = pq_getmsgint(msg, 4);
826 
827  (void) pq_getmsgint(msg, 4); /* discard cancel key */
828  (void) pq_getmsgend(msg);
829  pcxt->worker[i].pid = pid;
830  break;
831  }
832 
833  case 'E': /* ErrorResponse */
834  case 'N': /* NoticeResponse */
835  {
836  ErrorData edata;
837  ErrorContextCallback *save_error_context_stack;
838 
839  /* Parse ErrorResponse or NoticeResponse. */
840  pq_parse_errornotice(msg, &edata);
841 
842  /* Death of a worker isn't enough justification for suicide. */
843  edata.elevel = Min(edata.elevel, ERROR);
844 
845  /*
846  * If desired, add a context line to show that this is a
847  * message propagated from a parallel worker. Otherwise, it
848  * can sometimes be confusing to understand what actually
849  * happened. (We don't do this in FORCE_PARALLEL_REGRESS mode
850  * because it causes test-result instability depending on
851  * whether a parallel worker is actually used or not.)
852  */
854  {
855  if (edata.context)
856  edata.context = psprintf("%s\n%s", edata.context,
857  _("parallel worker"));
858  else
859  edata.context = pstrdup(_("parallel worker"));
860  }
861 
862  /*
863  * Context beyond that should use the error context callbacks
864  * that were in effect when the ParallelContext was created,
865  * not the current ones.
866  */
867  save_error_context_stack = error_context_stack;
869 
870  /* Rethrow error or print notice. */
871  ThrowErrorData(&edata);
872 
873  /* Not an error, so restore previous context stack. */
874  error_context_stack = save_error_context_stack;
875 
876  break;
877  }
878 
879  case 'A': /* NotifyResponse */
880  {
881  /* Propagate NotifyResponse. */
882  int32 pid;
883  const char *channel;
884  const char *payload;
885 
886  pid = pq_getmsgint(msg, 4);
887  channel = pq_getmsgrawstring(msg);
888  payload = pq_getmsgrawstring(msg);
889  pq_endmessage(msg);
890 
891  NotifyMyFrontEnd(channel, payload, pid);
892 
893  break;
894  }
895 
896  case 'X': /* Terminate, indicating clean exit */
897  {
899  pcxt->worker[i].error_mqh = NULL;
900  break;
901  }
902 
903  default:
904  {
905  elog(ERROR, "unrecognized message type received from parallel worker: %c (message length %d bytes)",
906  msgtype, msg->len);
907  }
908  }
909 }
void shm_mq_detach(shm_mq_handle *mqh)
Definition: shm_mq.c:775
char * pstrdup(const char *in)
Definition: mcxt.c:1076
char * psprintf(const char *fmt,...)
Definition: psprintf.c:46
#define Min(x, y)
Definition: c.h:802
const char * pq_getmsgrawstring(StringInfo msg)
Definition: pqformat.c:610
signed int int32
Definition: c.h:284
ErrorContextCallback * error_context_stack
Definition: elog.c:88
ParallelWorkerInfo * worker
Definition: parallel.h:45
#define ERROR
Definition: elog.h:43
void pq_parse_errornotice(StringInfo msg, ErrorData *edata)
Definition: pqmq.c:215
shm_mq_handle * error_mqh
Definition: parallel.h:28
void ThrowErrorData(ErrorData *edata)
Definition: elog.c:1612
int elevel
Definition: elog.h:331
int pq_getmsgbyte(StringInfo msg)
Definition: pqformat.c:401
int force_parallel_mode
Definition: planner.c:63
char * context
Definition: elog.h:347
ErrorContextCallback * error_context_stack
Definition: parallel.h:40
void pq_endmessage(StringInfo buf)
Definition: pqformat.c:298
int i
unsigned int pq_getmsgint(StringInfo msg, int b)
Definition: pqformat.c:417
#define elog
Definition: elog.h:219
void pq_getmsgend(StringInfo msg)
Definition: pqformat.c:637
#define _(x)
Definition: elog.c:84
void NotifyMyFrontEnd(const char *channel, const char *payload, int32 srcPid)
Definition: async.c:2096

◆ HandleParallelMessageInterrupt()

void HandleParallelMessageInterrupt ( void  )

Definition at line 715 of file parallel.c.

References InterruptPending, MyLatch, ParallelMessagePending, and SetLatch().

Referenced by procsignal_sigusr1_handler().

716 {
717  InterruptPending = true;
718  ParallelMessagePending = true;
719  SetLatch(MyLatch);
720 }
volatile bool ParallelMessagePending
Definition: parallel.c:103
volatile bool InterruptPending
Definition: globals.c:29
void SetLatch(volatile Latch *latch)
Definition: latch.c:414
struct Latch * MyLatch
Definition: globals.c:52

◆ HandleParallelMessages()

void HandleParallelMessages ( void  )

Definition at line 726 of file parallel.c.

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate(), appendBinaryStringInfo(), dlist_iter::cur, StringInfoData::data, dlist_container, dlist_foreach, ereport, errcode(), errmsg(), ERROR, ParallelWorkerInfo::error_mqh, HandleParallelMessage(), HOLD_INTERRUPTS, i, initStringInfo(), MemoryContextReset(), MemoryContextSwitchTo(), ParallelContext::nworkers_launched, ParallelMessagePending, pfree(), RESUME_INTERRUPTS, shm_mq_receive(), SHM_MQ_SUCCESS, SHM_MQ_WOULD_BLOCK, TopMemoryContext, and ParallelContext::worker.

Referenced by ProcessInterrupts().

727 {
728  dlist_iter iter;
729  MemoryContext oldcontext;
730 
731  static MemoryContext hpm_context = NULL;
732 
733  /*
734  * This is invoked from ProcessInterrupts(), and since some of the
735  * functions it calls contain CHECK_FOR_INTERRUPTS(), there is a potential
736  * for recursive calls if more signals are received while this runs. It's
737  * unclear that recursive entry would be safe, and it doesn't seem useful
738  * even if it is safe, so let's block interrupts until done.
739  */
740  HOLD_INTERRUPTS();
741 
742  /*
743  * Moreover, CurrentMemoryContext might be pointing almost anywhere. We
744  * don't want to risk leaking data into long-lived contexts, so let's do
745  * our work here in a private context that we can reset on each use.
746  */
747  if (hpm_context == NULL) /* first time through? */
749  "HandleParallelMessages",
751  else
752  MemoryContextReset(hpm_context);
753 
754  oldcontext = MemoryContextSwitchTo(hpm_context);
755 
756  /* OK to process messages. Reset the flag saying there are more to do. */
757  ParallelMessagePending = false;
758 
759  dlist_foreach(iter, &pcxt_list)
760  {
761  ParallelContext *pcxt;
762  int i;
763 
764  pcxt = dlist_container(ParallelContext, node, iter.cur);
765  if (pcxt->worker == NULL)
766  continue;
767 
768  for (i = 0; i < pcxt->nworkers_launched; ++i)
769  {
770  /*
771  * Read as many messages as we can from each worker, but stop when
772  * either (1) the worker's error queue goes away, which can happen
773  * if we receive a Terminate message from the worker; or (2) no
774  * more messages can be read from the worker without blocking.
775  */
776  while (pcxt->worker[i].error_mqh != NULL)
777  {
778  shm_mq_result res;
779  Size nbytes;
780  void *data;
781 
782  res = shm_mq_receive(pcxt->worker[i].error_mqh, &nbytes,
783  &data, true);
784  if (res == SHM_MQ_WOULD_BLOCK)
785  break;
786  else if (res == SHM_MQ_SUCCESS)
787  {
788  StringInfoData msg;
789 
790  initStringInfo(&msg);
791  appendBinaryStringInfo(&msg, data, nbytes);
792  HandleParallelMessage(pcxt, i, &msg);
793  pfree(msg.data);
794  }
795  else
796  ereport(ERROR,
797  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
798  errmsg("lost connection to parallel worker")));
799  }
800  }
801  }
802 
803  MemoryContextSwitchTo(oldcontext);
804 
805  /* Might as well clear the context on our way out */
806  MemoryContextReset(hpm_context);
807 
809 }
#define dlist_foreach(iter, lhead)
Definition: ilist.h:507
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
int errcode(int sqlerrcode)
Definition: elog.c:575
void MemoryContextReset(MemoryContext context)
Definition: mcxt.c:135
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:117
volatile bool ParallelMessagePending
Definition: parallel.c:103
#define dlist_container(type, membername, ptr)
Definition: ilist.h:477
ParallelWorkerInfo * worker
Definition: parallel.h:45
void pfree(void *pointer)
Definition: mcxt.c:949
#define ERROR
Definition: elog.h:43
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:165
static void HandleParallelMessage(ParallelContext *pcxt, int i, StringInfo msg)
Definition: parallel.c:815
shm_mq_handle * error_mqh
Definition: parallel.h:28
int nworkers_launched
Definition: parallel.h:37
#define ereport(elevel, rest)
Definition: elog.h:122
MemoryContext TopMemoryContext
Definition: mcxt.c:43
void initStringInfo(StringInfo str)
Definition: stringinfo.c:46
MemoryContext AllocSetContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: aset.c:322
dlist_node * cur
Definition: ilist.h:161
shm_mq_result
Definition: shm_mq.h:36
size_t Size
Definition: c.h:404
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:115
int i
static dlist_head pcxt_list
Definition: parallel.c:112
shm_mq_result shm_mq_receive(shm_mq_handle *mqh, Size *nbytesp, void **datap, bool nowait)
Definition: shm_mq.c:522
void appendBinaryStringInfo(StringInfo str, const char *data, int datalen)
Definition: stringinfo.c:208

◆ InitializeParallelDSM()

void InitializeParallelDSM ( ParallelContext pcxt)

Definition at line 194 of file parallel.c.

References FixedParallelState::authenticated_user_id, BUFFERALIGN, FixedParallelState::current_user_id, FixedParallelState::database_id, dsm_create(), DSM_CREATE_NULL_IF_MAXSEGMENTS, DSM_HANDLE_INVALID, dsm_segment_address(), ParallelWorkerInfo::error_mqh, EstimateComboCIDStateSpace(), EstimateGUCStateSpace(), EstimateLibraryStateSpace(), EstimateSnapshotSpace(), EstimateTransactionStateSpace(), ParallelContext::estimator, ParallelContext::function_name, GetActiveSnapshot(), GetAuthenticatedUserId(), GetCurrentRoleId(), GetSessionDsmHandle(), GetTempNamespaceState(), GetTransactionSnapshot(), GetUserIdAndSecContext(), i, FixedParallelState::is_superuser, FixedParallelState::last_xlog_end, ParallelContext::library_name, MemoryContextAlloc(), MemoryContextSwitchTo(), mul_size(), FixedParallelState::mutex, MyBackendId, MyDatabaseId, MyProc, MyProcPid, ParallelContext::nworkers, FixedParallelState::outer_user_id, palloc0(), PARALLEL_ERROR_QUEUE_SIZE, PARALLEL_KEY_ACTIVE_SNAPSHOT, PARALLEL_KEY_COMBO_CID, PARALLEL_KEY_ENTRYPOINT, PARALLEL_KEY_ERROR_QUEUE, PARALLEL_KEY_FIXED, PARALLEL_KEY_GUC, PARALLEL_KEY_LIBRARY, PARALLEL_KEY_SESSION_DSM, PARALLEL_KEY_TRANSACTION_SNAPSHOT, PARALLEL_KEY_TRANSACTION_STATE, PARALLEL_MAGIC, FixedParallelState::parallel_master_backend_id, FixedParallelState::parallel_master_pgproc, FixedParallelState::parallel_master_pid, ParallelContext::private_memory, FixedParallelState::sec_context, ParallelContext::seg, SerializeComboCIDState(), SerializeGUCState(), SerializeLibraryState(), SerializeSnapshot(), SerializeTransactionState(), session_auth_is_superuser, shm_mq_attach(), shm_mq_create(), shm_mq_set_receiver(), shm_toc_allocate(), shm_toc_create(), shm_toc_estimate(), shm_toc_estimate_chunk, shm_toc_estimate_keys, shm_toc_insert(), SpinLockInit, StaticAssertStmt, FixedParallelState::temp_namespace_id, FixedParallelState::temp_toast_namespace_id, ParallelContext::toc, TopMemoryContext, TopTransactionContext, and ParallelContext::worker.

Referenced by ExecInitParallelPlan().

195 {
196  MemoryContext oldcontext;
197  Size library_len = 0;
198  Size guc_len = 0;
199  Size combocidlen = 0;
200  Size tsnaplen = 0;
201  Size asnaplen = 0;
202  Size tstatelen = 0;
203  Size segsize = 0;
204  int i;
205  FixedParallelState *fps;
206  dsm_handle session_dsm_handle = DSM_HANDLE_INVALID;
207  Snapshot transaction_snapshot = GetTransactionSnapshot();
208  Snapshot active_snapshot = GetActiveSnapshot();
209 
210  /* We might be running in a very short-lived memory context. */
212 
213  /* Allow space to store the fixed-size parallel state. */
215  shm_toc_estimate_keys(&pcxt->estimator, 1);
216 
217  /*
218  * Normally, the user will have requested at least one worker process, but
219  * if by chance they have not, we can skip a bunch of things here.
220  */
221  if (pcxt->nworkers > 0)
222  {
223  /* Get (or create) the per-session DSM segment's handle. */
224  session_dsm_handle = GetSessionDsmHandle();
225 
226  /*
227  * If we weren't able to create a per-session DSM segment, then we can
228  * continue but we can't safely launch any workers because their
229  * record typmods would be incompatible so they couldn't exchange
230  * tuples.
231  */
232  if (session_dsm_handle == DSM_HANDLE_INVALID)
233  pcxt->nworkers = 0;
234  }
235 
236  if (pcxt->nworkers > 0)
237  {
238  /* Estimate space for various kinds of state sharing. */
239  library_len = EstimateLibraryStateSpace();
240  shm_toc_estimate_chunk(&pcxt->estimator, library_len);
241  guc_len = EstimateGUCStateSpace();
242  shm_toc_estimate_chunk(&pcxt->estimator, guc_len);
243  combocidlen = EstimateComboCIDStateSpace();
244  shm_toc_estimate_chunk(&pcxt->estimator, combocidlen);
245  tsnaplen = EstimateSnapshotSpace(transaction_snapshot);
246  shm_toc_estimate_chunk(&pcxt->estimator, tsnaplen);
247  asnaplen = EstimateSnapshotSpace(active_snapshot);
248  shm_toc_estimate_chunk(&pcxt->estimator, asnaplen);
249  tstatelen = EstimateTransactionStateSpace();
250  shm_toc_estimate_chunk(&pcxt->estimator, tstatelen);
252  /* If you add more chunks here, you probably need to add keys. */
253  shm_toc_estimate_keys(&pcxt->estimator, 7);
254 
255  /* Estimate space need for error queues. */
258  "parallel error queue size not buffer-aligned");
261  pcxt->nworkers));
262  shm_toc_estimate_keys(&pcxt->estimator, 1);
263 
264  /* Estimate how much we'll need for the entrypoint info. */
265  shm_toc_estimate_chunk(&pcxt->estimator, strlen(pcxt->library_name) +
266  strlen(pcxt->function_name) + 2);
267  shm_toc_estimate_keys(&pcxt->estimator, 1);
268  }
269 
270  /*
271  * Create DSM and initialize with new table of contents. But if the user
272  * didn't request any workers, then don't bother creating a dynamic shared
273  * memory segment; instead, just use backend-private memory.
274  *
275  * Also, if we can't create a dynamic shared memory segment because the
276  * maximum number of segments have already been created, then fall back to
277  * backend-private memory, and plan not to use any workers. We hope this
278  * won't happen very often, but it's better to abandon the use of
279  * parallelism than to fail outright.
280  */
281  segsize = shm_toc_estimate(&pcxt->estimator);
282  if (pcxt->nworkers > 0)
284  if (pcxt->seg != NULL)
286  dsm_segment_address(pcxt->seg),
287  segsize);
288  else
289  {
290  pcxt->nworkers = 0;
293  segsize);
294  }
295 
296  /* Initialize fixed-size state in shared memory. */
297  fps = (FixedParallelState *)
298  shm_toc_allocate(pcxt->toc, sizeof(FixedParallelState));
299  fps->database_id = MyDatabaseId;
309  SpinLockInit(&fps->mutex);
310  fps->last_xlog_end = 0;
312 
313  /* We can skip the rest of this if we're not budgeting for any workers. */
314  if (pcxt->nworkers > 0)
315  {
316  char *libraryspace;
317  char *gucspace;
318  char *combocidspace;
319  char *tsnapspace;
320  char *asnapspace;
321  char *tstatespace;
322  char *error_queue_space;
323  char *session_dsm_handle_space;
324  char *entrypointstate;
325  Size lnamelen;
326 
327  /* Serialize shared libraries we have loaded. */
328  libraryspace = shm_toc_allocate(pcxt->toc, library_len);
329  SerializeLibraryState(library_len, libraryspace);
330  shm_toc_insert(pcxt->toc, PARALLEL_KEY_LIBRARY, libraryspace);
331 
332  /* Serialize GUC settings. */
333  gucspace = shm_toc_allocate(pcxt->toc, guc_len);
334  SerializeGUCState(guc_len, gucspace);
335  shm_toc_insert(pcxt->toc, PARALLEL_KEY_GUC, gucspace);
336 
337  /* Serialize combo CID state. */
338  combocidspace = shm_toc_allocate(pcxt->toc, combocidlen);
339  SerializeComboCIDState(combocidlen, combocidspace);
340  shm_toc_insert(pcxt->toc, PARALLEL_KEY_COMBO_CID, combocidspace);
341 
342  /* Serialize transaction snapshot and active snapshot. */
343  tsnapspace = shm_toc_allocate(pcxt->toc, tsnaplen);
344  SerializeSnapshot(transaction_snapshot, tsnapspace);
346  tsnapspace);
347  asnapspace = shm_toc_allocate(pcxt->toc, asnaplen);
348  SerializeSnapshot(active_snapshot, asnapspace);
349  shm_toc_insert(pcxt->toc, PARALLEL_KEY_ACTIVE_SNAPSHOT, asnapspace);
350 
351  /* Provide the handle for per-session segment. */
352  session_dsm_handle_space = shm_toc_allocate(pcxt->toc,
353  sizeof(dsm_handle));
354  *(dsm_handle *) session_dsm_handle_space = session_dsm_handle;
356  session_dsm_handle_space);
357 
358  /* Serialize transaction state. */
359  tstatespace = shm_toc_allocate(pcxt->toc, tstatelen);
360  SerializeTransactionState(tstatelen, tstatespace);
362 
363  /* Allocate space for worker information. */
364  pcxt->worker = palloc0(sizeof(ParallelWorkerInfo) * pcxt->nworkers);
365 
366  /*
367  * Establish error queues in dynamic shared memory.
368  *
369  * These queues should be used only for transmitting ErrorResponse,
370  * NoticeResponse, and NotifyResponse protocol messages. Tuple data
371  * should be transmitted via separate (possibly larger?) queues.
372  */
373  error_queue_space =
374  shm_toc_allocate(pcxt->toc,
376  pcxt->nworkers));
377  for (i = 0; i < pcxt->nworkers; ++i)
378  {
379  char *start;
380  shm_mq *mq;
381 
382  start = error_queue_space + i * PARALLEL_ERROR_QUEUE_SIZE;
383  mq = shm_mq_create(start, PARALLEL_ERROR_QUEUE_SIZE);
385  pcxt->worker[i].error_mqh = shm_mq_attach(mq, pcxt->seg, NULL);
386  }
387  shm_toc_insert(pcxt->toc, PARALLEL_KEY_ERROR_QUEUE, error_queue_space);
388 
389  /*
390  * Serialize entrypoint information. It's unsafe to pass function
391  * pointers across processes, as the function pointer may be different
392  * in each process in EXEC_BACKEND builds, so we always pass library
393  * and function name. (We use library name "postgres" for functions
394  * in the core backend.)
395  */
396  lnamelen = strlen(pcxt->library_name);
397  entrypointstate = shm_toc_allocate(pcxt->toc, lnamelen +
398  strlen(pcxt->function_name) + 2);
399  strcpy(entrypointstate, pcxt->library_name);
400  strcpy(entrypointstate + lnamelen + 1, pcxt->function_name);
401  shm_toc_insert(pcxt->toc, PARALLEL_KEY_ENTRYPOINT, entrypointstate);
402  }
403 
404  /* Restore previous memory context. */
405  MemoryContextSwitchTo(oldcontext);
406 }
#define PARALLEL_ERROR_QUEUE_SIZE
Definition: parallel.c:50
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
MemoryContext TopTransactionContext
Definition: mcxt.c:48
uint32 dsm_handle
Definition: dsm_impl.h:55
PGPROC * MyProc
Definition: proc.c:67
dsm_segment * seg
Definition: parallel.h:42
shm_toc_estimator estimator
Definition: parallel.h:41
#define SpinLockInit(lock)
Definition: spin.h:60
void GetTempNamespaceState(Oid *tempNamespaceId, Oid *tempToastNamespaceId)
Definition: namespace.c:3234
Oid authenticated_user_id
Definition: parallel.c:76
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Snapshot GetActiveSnapshot(void)
Definition: snapmgr.c:839
PGPROC * parallel_master_pgproc
Definition: parallel.c:83
Oid temp_toast_namespace_id
Definition: parallel.c:80
Size shm_toc_estimate(shm_toc_estimator *e)
Definition: shm_toc.c:263
void SerializeTransactionState(Size maxsize, char *start_address)
Definition: xact.c:4993
#define shm_toc_estimate_chunk(e, sz)
Definition: shm_toc.h:51
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:304
Oid GetCurrentRoleId(void)
Definition: miscinit.c:636
#define DSM_HANDLE_INVALID
Definition: dsm.h:23
#define StaticAssertStmt(condition, errmessage)
Definition: c.h:753
ParallelWorkerInfo * worker
Definition: parallel.h:45
void SerializeLibraryState(Size maxsize, char *start_address)
Definition: dfmgr.c:728
Oid GetAuthenticatedUserId(void)
Definition: miscinit.c:343
#define PARALLEL_KEY_TRANSACTION_SNAPSHOT
Definition: parallel.c:65
char * function_name
Definition: parallel.h:39
void SerializeSnapshot(Snapshot snapshot, char *start_address)
Definition: snapmgr.c:2070
shm_mq * shm_mq_create(void *address, Size size)
Definition: shm_mq.c:170
#define PARALLEL_KEY_FIXED
Definition: parallel.c:60
#define PARALLEL_KEY_ERROR_QUEUE
Definition: parallel.c:61
#define DSM_CREATE_NULL_IF_MAXSEGMENTS
Definition: dsm.h:20
void GetUserIdAndSecContext(Oid *userid, int *sec_context)
Definition: miscinit.c:389
shm_mq_handle * error_mqh
Definition: parallel.h:28
#define PARALLEL_KEY_GUC
Definition: parallel.c:63
Size EstimateGUCStateSpace(void)
Definition: guc.c:9118
Size EstimateComboCIDStateSpace(void)
Definition: combocid.c:299
XLogRecPtr last_xlog_end
Definition: parallel.c:91
MemoryContext TopMemoryContext
Definition: mcxt.c:43
Size EstimateSnapshotSpace(Snapshot snap)
Definition: snapmgr.c:2046
Size mul_size(Size s1, Size s2)
Definition: shmem.c:492
void * palloc0(Size size)
Definition: mcxt.c:877
dsm_segment * dsm_create(Size size, int flags)
Definition: dsm.c:465
Oid MyDatabaseId
Definition: globals.c:77
pid_t parallel_master_pid
Definition: parallel.c:84
Size EstimateLibraryStateSpace(void)
Definition: dfmgr.c:711
#define PARALLEL_MAGIC
Definition: parallel.c:53
char * library_name
Definition: parallel.h:38
BackendId parallel_master_backend_id
Definition: parallel.c:85
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:1000
Size EstimateTransactionStateSpace(void)
Definition: xact.c:4960
size_t Size
Definition: c.h:404
#define shm_toc_estimate_keys(e, cnt)
Definition: shm_toc.h:53
void * shm_toc_allocate(shm_toc *toc, Size nbytes)
Definition: shm_toc.c:88
shm_mq_handle * shm_mq_attach(shm_mq *mq, dsm_segment *seg, BackgroundWorkerHandle *handle)
Definition: shm_mq.c:287
#define PARALLEL_KEY_TRANSACTION_STATE
Definition: parallel.c:67
void shm_toc_insert(shm_toc *toc, uint64 key, void *address)
Definition: shm_toc.c:171
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:706
int i
Definition: shm_mq.c:69
#define PARALLEL_KEY_SESSION_DSM
Definition: parallel.c:69
#define BUFFERALIGN(LEN)
Definition: c.h:625
void shm_mq_set_receiver(shm_mq *mq, PGPROC *proc)
Definition: shm_mq.c:199
dsm_handle GetSessionDsmHandle(void)
Definition: session.c:70
bool session_auth_is_superuser
Definition: guc.c:449
#define PARALLEL_KEY_ENTRYPOINT
Definition: parallel.c:68
#define PARALLEL_KEY_COMBO_CID
Definition: parallel.c:64
void SerializeGUCState(Size maxsize, char *start_address)
Definition: guc.c:9265
#define PARALLEL_KEY_ACTIVE_SNAPSHOT
Definition: parallel.c:66
void SerializeComboCIDState(Size maxsize, char *start_address)
Definition: combocid.c:318
#define PARALLEL_KEY_LIBRARY
Definition: parallel.c:62
shm_toc * toc
Definition: parallel.h:44
void * private_memory
Definition: parallel.h:43

◆ LaunchParallelWorkers()

void LaunchParallelWorkers ( ParallelContext pcxt)

Definition at line 450 of file parallel.c.

References Assert, BecomeLockGroupLeader(), BackgroundWorker::bgw_extra, BackgroundWorker::bgw_flags, BackgroundWorker::bgw_function_name, BackgroundWorker::bgw_library_name, BackgroundWorker::bgw_main_arg, BGW_MAXLEN, BackgroundWorker::bgw_name, BGW_NEVER_RESTART, BackgroundWorker::bgw_notify_pid, BackgroundWorker::bgw_restart_time, BackgroundWorker::bgw_start_time, BackgroundWorker::bgw_type, ParallelWorkerInfo::bgwhandle, BGWORKER_BACKEND_DATABASE_CONNECTION, BGWORKER_CLASS_PARALLEL, BGWORKER_SHMEM_ACCESS, BgWorkerStart_ConsistentState, dsm_segment_handle(), ParallelWorkerInfo::error_mqh, i, MemoryContextSwitchTo(), MyProcPid, ParallelContext::nworkers, ParallelContext::nworkers_launched, RegisterDynamicBackgroundWorker(), ParallelContext::seg, shm_mq_detach(), shm_mq_set_handle(), snprintf(), TopTransactionContext, UInt32GetDatum, and ParallelContext::worker.

Referenced by ExecGather(), and ExecGatherMerge().

451 {
452  MemoryContext oldcontext;
453  BackgroundWorker worker;
454  int i;
455  bool any_registrations_failed = false;
456 
457  /* Skip this if we have no workers. */
458  if (pcxt->nworkers == 0)
459  return;
460 
461  /* We need to be a lock group leader. */
463 
464  /* If we do have workers, we'd better have a DSM segment. */
465  Assert(pcxt->seg != NULL);
466 
467  /* We might be running in a short-lived memory context. */
469 
470  /* Configure a worker. */
471  memset(&worker, 0, sizeof(worker));
472  snprintf(worker.bgw_name, BGW_MAXLEN, "parallel worker for PID %d",
473  MyProcPid);
474  snprintf(worker.bgw_type, BGW_MAXLEN, "parallel worker");
475  worker.bgw_flags =
480  sprintf(worker.bgw_library_name, "postgres");
481  sprintf(worker.bgw_function_name, "ParallelWorkerMain");
483  worker.bgw_notify_pid = MyProcPid;
484 
485  /*
486  * Start workers.
487  *
488  * The caller must be able to tolerate ending up with fewer workers than
489  * expected, so there is no need to throw an error here if registration
490  * fails. It wouldn't help much anyway, because registering the worker in
491  * no way guarantees that it will start up and initialize successfully.
492  */
493  for (i = 0; i < pcxt->nworkers; ++i)
494  {
495  memcpy(worker.bgw_extra, &i, sizeof(int));
496  if (!any_registrations_failed &&
498  &pcxt->worker[i].bgwhandle))
499  {
501  pcxt->worker[i].bgwhandle);
502  pcxt->nworkers_launched++;
503  }
504  else
505  {
506  /*
507  * If we weren't able to register the worker, then we've bumped up
508  * against the max_worker_processes limit, and future
509  * registrations will probably fail too, so arrange to skip them.
510  * But we still have to execute this code for the remaining slots
511  * to make sure that we forget about the error queues we budgeted
512  * for those workers. Otherwise, we'll wait for them to start,
513  * but they never will.
514  */
515  any_registrations_failed = true;
516  pcxt->worker[i].bgwhandle = NULL;
517  shm_mq_detach(pcxt->worker[i].error_mqh);
518  pcxt->worker[i].error_mqh = NULL;
519  }
520  }
521 
522  /* Restore previous memory context. */
523  MemoryContextSwitchTo(oldcontext);
524 }
char bgw_extra[BGW_EXTRALEN]
Definition: bgworker.h:98
int MyProcPid
Definition: globals.c:39
MemoryContext TopTransactionContext
Definition: mcxt.c:48
void shm_mq_detach(shm_mq_handle *mqh)
Definition: shm_mq.c:775
dsm_segment * seg
Definition: parallel.h:42
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
dsm_handle dsm_segment_handle(dsm_segment *seg)
Definition: dsm.c:1028
int bgw_restart_time
Definition: bgworker.h:94
#define BGWORKER_CLASS_PARALLEL
Definition: bgworker.h:67
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
#define BGWORKER_SHMEM_ACCESS
Definition: bgworker.h:52
char bgw_function_name[BGW_MAXLEN]
Definition: bgworker.h:96
ParallelWorkerInfo * worker
Definition: parallel.h:45
Datum bgw_main_arg
Definition: bgworker.h:97
shm_mq_handle * error_mqh
Definition: parallel.h:28
BackgroundWorkerHandle * bgwhandle
Definition: parallel.h:27
#define BGW_NEVER_RESTART
Definition: bgworker.h:84
#define UInt32GetDatum(X)
Definition: postgres.h:499
int nworkers_launched
Definition: parallel.h:37
void BecomeLockGroupLeader(void)
Definition: proc.c:1824
void shm_mq_set_handle(shm_mq_handle *mqh, BackgroundWorkerHandle *handle)
Definition: shm_mq.c:315
char bgw_name[BGW_MAXLEN]
Definition: bgworker.h:90
#define Assert(condition)
Definition: c.h:670
#define BGWORKER_BACKEND_DATABASE_CONNECTION
Definition: bgworker.h:59
#define BGW_MAXLEN
Definition: bgworker.h:85
BgWorkerStartTime bgw_start_time
Definition: bgworker.h:93
bool RegisterDynamicBackgroundWorker(BackgroundWorker *worker, BackgroundWorkerHandle **handle)
Definition: bgworker.c:939
char bgw_type[BGW_MAXLEN]
Definition: bgworker.h:91
pid_t bgw_notify_pid
Definition: bgworker.h:99
int i
char bgw_library_name[BGW_MAXLEN]
Definition: bgworker.h:95

◆ LookupParallelWorkerFunction()

static parallel_worker_main_type LookupParallelWorkerFunction ( const char *  libraryname,
const char *  funcname 
)
static

Definition at line 1202 of file parallel.c.

References elog, ERROR, fn_addr, fn_name, i, InternalParallelWorkers, lengthof, and load_external_function().

Referenced by ParallelWorkerMain().

1203 {
1204  /*
1205  * If the function is to be loaded from postgres itself, search the
1206  * InternalParallelWorkers array.
1207  */
1208  if (strcmp(libraryname, "postgres") == 0)
1209  {
1210  int i;
1211 
1212  for (i = 0; i < lengthof(InternalParallelWorkers); i++)
1213  {
1214  if (strcmp(InternalParallelWorkers[i].fn_name, funcname) == 0)
1215  return InternalParallelWorkers[i].fn_addr;
1216  }
1217 
1218  /* We can only reach this by programming error. */
1219  elog(ERROR, "internal function \"%s\" not found", funcname);
1220  }
1221 
1222  /* Otherwise load from external library. */
1223  return (parallel_worker_main_type)
1224  load_external_function(libraryname, funcname, true, NULL);
1225 }
static const struct @21 InternalParallelWorkers[]
#define lengthof(array)
Definition: c.h:600
parallel_worker_main_type fn_addr
Definition: parallel.c:121
#define ERROR
Definition: elog.h:43
PGFunction load_external_function(const char *filename, const char *funcname, bool signalNotFound, void **filehandle)
Definition: dfmgr.c:94
const char * fn_name
Definition: parallel.c:120
void(* parallel_worker_main_type)(dsm_segment *seg, shm_toc *toc)
Definition: parallel.h:23
int i
#define elog
Definition: elog.h:219

◆ ParallelContextActive()

bool ParallelContextActive ( void  )

Definition at line 702 of file parallel.c.

References dlist_is_empty().

Referenced by ExitParallelMode().

703 {
704  return !dlist_is_empty(&pcxt_list);
705 }
static bool dlist_is_empty(dlist_head *head)
Definition: ilist.h:289
static dlist_head pcxt_list
Definition: parallel.c:112

◆ ParallelWorkerMain()

void ParallelWorkerMain ( Datum  main_arg)

Definition at line 956 of file parallel.c.

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate(), Assert, AttachSession(), FixedParallelState::authenticated_user_id, BackgroundWorkerInitializeConnectionByOid(), BackgroundWorkerUnblockSignals(), BecomeLockGroupMember(), BackgroundWorker::bgw_extra, CommitTransactionCommand(), FixedParallelState::current_user_id, CurrentMemoryContext, CurrentResourceOwner, FixedParallelState::database_id, DatumGetUInt32, DetachSession(), die(), dsm_attach(), dsm_segment_address(), EndParallelWorkerTransaction(), EnterParallelMode(), ereport, errcode(), errmsg(), ERROR, ExitParallelMode(), GetDatabaseEncoding(), InitializingParallelWorker, InvalidateSystemCaches(), FixedParallelState::is_superuser, LookupParallelWorkerFunction(), MyBgworkerEntry, MyCancelKey, MyProc, MyProcPid, FixedParallelState::outer_user_id, PARALLEL_ERROR_QUEUE_SIZE, PARALLEL_KEY_ACTIVE_SNAPSHOT, PARALLEL_KEY_COMBO_CID, PARALLEL_KEY_ENTRYPOINT, PARALLEL_KEY_ERROR_QUEUE, PARALLEL_KEY_FIXED, PARALLEL_KEY_GUC, PARALLEL_KEY_LIBRARY, PARALLEL_KEY_SESSION_DSM, PARALLEL_KEY_TRANSACTION_SNAPSHOT, PARALLEL_KEY_TRANSACTION_STATE, PARALLEL_MAGIC, FixedParallelState::parallel_master_backend_id, FixedParallelState::parallel_master_pgproc, FixedParallelState::parallel_master_pid, ParallelMasterBackendId, ParallelWorkerNumber, PopActiveSnapshot(), pq_beginmessage(), pq_endmessage(), pq_putmessage, pq_redirect_to_shm_mq(), pq_sendint32(), pq_set_parallel_master(), pqsignal(), PushActiveSnapshot(), ResourceOwnerCreate(), RestoreComboCIDState(), RestoreGUCState(), RestoreLibraryState(), RestoreSnapshot(), RestoreTransactionSnapshot(), FixedParallelState::sec_context, SetClientEncoding(), SetCurrentRoleId(), SetTempNamespaceState(), SetUserIdAndSecContext(), shm_mq_attach(), shm_mq_set_sender(), shm_toc_attach(), shm_toc_lookup(), StartParallelWorkerTransaction(), StartTransactionCommand(), FixedParallelState::temp_namespace_id, FixedParallelState::temp_toast_namespace_id, and TopMemoryContext.

957 {
958  dsm_segment *seg;
959  shm_toc *toc;
960  FixedParallelState *fps;
961  char *error_queue_space;
962  shm_mq *mq;
963  shm_mq_handle *mqh;
964  char *libraryspace;
965  char *entrypointstate;
966  char *library_name;
967  char *function_name;
969  char *gucspace;
970  char *combocidspace;
971  char *tsnapspace;
972  char *asnapspace;
973  char *tstatespace;
974  StringInfoData msgbuf;
975  char *session_dsm_handle_space;
976 
977  /* Set flag to indicate that we're initializing a parallel worker. */
979 
980  /* Establish signal handlers. */
981  pqsignal(SIGTERM, die);
983 
984  /* Determine and set our parallel worker number. */
986  memcpy(&ParallelWorkerNumber, MyBgworkerEntry->bgw_extra, sizeof(int));
987 
988  /* Set up a memory context and resource owner. */
989  Assert(CurrentResourceOwner == NULL);
990  CurrentResourceOwner = ResourceOwnerCreate(NULL, "parallel toplevel");
992  "Parallel worker",
994 
995  /*
996  * Now that we have a resource owner, we can attach to the dynamic shared
997  * memory segment and read the table of contents.
998  */
999  seg = dsm_attach(DatumGetUInt32(main_arg));
1000  if (seg == NULL)
1001  ereport(ERROR,
1002  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1003  errmsg("could not map dynamic shared memory segment")));
1005  if (toc == NULL)
1006  ereport(ERROR,
1007  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1008  errmsg("invalid magic number in dynamic shared memory segment")));
1009 
1010  /* Look up fixed parallel state. */
1011  fps = shm_toc_lookup(toc, PARALLEL_KEY_FIXED, false);
1012  MyFixedParallelState = fps;
1013 
1014  /*
1015  * Now that we have a worker number, we can find and attach to the error
1016  * queue provided for us. That's good, because until we do that, any
1017  * errors that happen here will not be reported back to the process that
1018  * requested that this worker be launched.
1019  */
1020  error_queue_space = shm_toc_lookup(toc, PARALLEL_KEY_ERROR_QUEUE, false);
1021  mq = (shm_mq *) (error_queue_space +
1024  mqh = shm_mq_attach(mq, seg, NULL);
1025  pq_redirect_to_shm_mq(seg, mqh);
1028 
1029  /*
1030  * Send a BackendKeyData message to the process that initiated parallelism
1031  * so that it has access to our PID before it receives any other messages
1032  * from us. Our cancel key is sent, too, since that's the way the
1033  * protocol message is defined, but it won't actually be used for anything
1034  * in this case.
1035  */
1036  pq_beginmessage(&msgbuf, 'K');
1037  pq_sendint32(&msgbuf, (int32) MyProcPid);
1038  pq_sendint32(&msgbuf, (int32) MyCancelKey);
1039  pq_endmessage(&msgbuf);
1040 
1041  /*
1042  * Hooray! Primary initialization is complete. Now, we need to set up our
1043  * backend-local state to match the original backend.
1044  */
1045 
1046  /*
1047  * Join locking group. We must do this before anything that could try to
1048  * acquire a heavyweight lock, because any heavyweight locks acquired to
1049  * this point could block either directly against the parallel group
1050  * leader or against some process which in turn waits for a lock that
1051  * conflicts with the parallel group leader, causing an undetected
1052  * deadlock. (If we can't join the lock group, the leader has gone away,
1053  * so just exit quietly.)
1054  */
1056  fps->parallel_master_pid))
1057  return;
1058 
1059  /*
1060  * Load libraries that were loaded by original backend. We want to do
1061  * this before restoring GUCs, because the libraries might define custom
1062  * variables.
1063  */
1064  libraryspace = shm_toc_lookup(toc, PARALLEL_KEY_LIBRARY, false);
1065  RestoreLibraryState(libraryspace);
1066 
1067  /*
1068  * Identify the entry point to be called. In theory this could result in
1069  * loading an additional library, though most likely the entry point is in
1070  * the core backend or in a library we just loaded.
1071  */
1072  entrypointstate = shm_toc_lookup(toc, PARALLEL_KEY_ENTRYPOINT, false);
1073  library_name = entrypointstate;
1074  function_name = entrypointstate + strlen(library_name) + 1;
1075 
1076  entrypt = LookupParallelWorkerFunction(library_name, function_name);
1077 
1078  /* Restore database connection. */
1080  fps->authenticated_user_id);
1081 
1082  /*
1083  * Set the client encoding to the database encoding, since that is what
1084  * the leader will expect.
1085  */
1087 
1088  /* Restore GUC values from launching backend. */
1089  gucspace = shm_toc_lookup(toc, PARALLEL_KEY_GUC, false);
1091  RestoreGUCState(gucspace);
1093 
1094  /* Crank up a transaction state appropriate to a parallel worker. */
1095  tstatespace = shm_toc_lookup(toc, PARALLEL_KEY_TRANSACTION_STATE, false);
1096  StartParallelWorkerTransaction(tstatespace);
1097 
1098  /* Restore combo CID state. */
1099  combocidspace = shm_toc_lookup(toc, PARALLEL_KEY_COMBO_CID, false);
1100  RestoreComboCIDState(combocidspace);
1101 
1102  /* Attach to the per-session DSM segment and contained objects. */
1103  session_dsm_handle_space =
1105  AttachSession(*(dsm_handle *) session_dsm_handle_space);
1106 
1107  /* Restore transaction snapshot. */
1108  tsnapspace = shm_toc_lookup(toc, PARALLEL_KEY_TRANSACTION_SNAPSHOT, false);
1110  fps->parallel_master_pgproc);
1111 
1112  /* Restore active snapshot. */
1113  asnapspace = shm_toc_lookup(toc, PARALLEL_KEY_ACTIVE_SNAPSHOT, false);
1114  PushActiveSnapshot(RestoreSnapshot(asnapspace));
1115 
1116  /*
1117  * We've changed which tuples we can see, and must therefore invalidate
1118  * system caches.
1119  */
1121 
1122  /*
1123  * Restore current role id. Skip verifying whether session user is
1124  * allowed to become this role and blindly restore the leader's state for
1125  * current role.
1126  */
1128 
1129  /* Restore user ID and security context. */
1131 
1132  /* Restore temp-namespace state to ensure search path matches leader's. */
1135 
1136  /* Set ParallelMasterBackendId so we know how to address temp relations. */
1138 
1139  /*
1140  * We've initialized all of our state now; nothing should change
1141  * hereafter.
1142  */
1145 
1146  /*
1147  * Time to do the real work: invoke the caller-supplied code.
1148  */
1149  entrypt(seg, toc);
1150 
1151  /* Must exit parallel mode to pop active snapshot. */
1152  ExitParallelMode();
1153 
1154  /* Must pop active snapshot so resowner.c doesn't complain. */
1156 
1157  /* Shut down the parallel-worker transaction. */
1159 
1160  /* Detach from the per-session DSM segment. */
1161  DetachSession();
1162 
1163  /* Report success. */
1164  pq_putmessage('X', NULL, 0);
1165 }
char bgw_extra[BGW_EXTRALEN]
Definition: bgworker.h:98
#define DatumGetUInt32(X)
Definition: postgres.h:492
#define PARALLEL_ERROR_QUEUE_SIZE
Definition: parallel.c:50
int MyProcPid
Definition: globals.c:39
Snapshot RestoreSnapshot(char *start_address)
Definition: snapmgr.c:2129
uint32 dsm_handle
Definition: dsm_impl.h:55
void SetUserIdAndSecContext(Oid userid, int sec_context)
Definition: miscinit.c:396
PGPROC * MyProc
Definition: proc.c:67
static void pq_sendint32(StringInfo buf, int32 i)
Definition: pqformat.h:148
ResourceOwner CurrentResourceOwner
Definition: resowner.c:138
void CommitTransactionCommand(void)
Definition: xact.c:2744
void EndParallelWorkerTransaction(void)
Definition: xact.c:5084
void RestoreTransactionSnapshot(Snapshot snapshot, void *master_pgproc)
Definition: snapmgr.c:2193
dsm_segment * dsm_attach(dsm_handle h)
Definition: dsm.c:561
Oid authenticated_user_id
Definition: parallel.c:76
int errcode(int sqlerrcode)
Definition: elog.c:575
PGPROC * parallel_master_pgproc
Definition: parallel.c:83
Oid temp_toast_namespace_id
Definition: parallel.c:80
void DetachSession(void)
Definition: session.c:201
BackgroundWorker * MyBgworkerEntry
Definition: postmaster.c:189
bool BecomeLockGroupMember(PGPROC *leader, int pid)
Definition: proc.c:1854
void PopActiveSnapshot(void)
Definition: snapmgr.c:812
void InvalidateSystemCaches(void)
Definition: inval.c:641
void pq_beginmessage(StringInfo buf, char msgtype)
Definition: pqformat.c:87
void RestoreComboCIDState(char *comboCIDstate)
Definition: combocid.c:344
signed int int32
Definition: c.h:284
#define ERROR
Definition: elog.h:43
#define PARALLEL_KEY_TRANSACTION_SNAPSHOT
Definition: parallel.c:65
int32 MyCancelKey
Definition: globals.c:42
void ExitParallelMode(void)
Definition: xact.c:886
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:165
#define PARALLEL_KEY_FIXED
Definition: parallel.c:60
#define PARALLEL_KEY_ERROR_QUEUE
Definition: parallel.c:61
void SetTempNamespaceState(Oid tempNamespaceId, Oid tempToastNamespaceId)
Definition: namespace.c:3250
void PushActiveSnapshot(Snapshot snap)
Definition: snapmgr.c:733
#define PARALLEL_KEY_GUC
Definition: parallel.c:63
int SetClientEncoding(int encoding)
Definition: mbutils.c:201
int ParallelWorkerNumber
Definition: parallel.c:100
void AttachSession(dsm_handle handle)
Definition: session.c:155
MemoryContext CurrentMemoryContext
Definition: mcxt.c:37
void BackgroundWorkerInitializeConnectionByOid(Oid dboid, Oid useroid)
Definition: postmaster.c:5563
void shm_mq_set_sender(shm_mq *mq, PGPROC *proc)
Definition: shm_mq.c:218
#define ereport(elevel, rest)
Definition: elog.h:122
MemoryContext TopMemoryContext
Definition: mcxt.c:43
MemoryContext AllocSetContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: aset.c:322
static parallel_worker_main_type LookupParallelWorkerFunction(const char *libraryname, const char *funcname)
Definition: parallel.c:1202
void RestoreLibraryState(char *start_address)
Definition: dfmgr.c:750
shm_toc * shm_toc_attach(uint64 magic, void *address)
Definition: shm_toc.c:64
int GetDatabaseEncoding(void)
Definition: mbutils.c:1004
pid_t parallel_master_pid
Definition: parallel.c:84
#define PARALLEL_MAGIC
Definition: parallel.c:53
void pq_redirect_to_shm_mq(dsm_segment *seg, shm_mq_handle *mqh)
Definition: pqmq.c:55
pqsigfunc pqsignal(int signum, pqsigfunc handler)
Definition: signal.c:168
BackendId parallel_master_backend_id
Definition: parallel.c:85
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:1000
#define Assert(condition)
Definition: c.h:670
BackendId ParallelMasterBackendId
Definition: globals.c:75
void StartParallelWorkerTransaction(char *tstatespace)
Definition: xact.c:5061
void StartTransactionCommand(void)
Definition: xact.c:2673
void EnterParallelMode(void)
Definition: xact.c:873
shm_mq_handle * shm_mq_attach(shm_mq *mq, dsm_segment *seg, BackgroundWorkerHandle *handle)
Definition: shm_mq.c:287
void pq_set_parallel_master(pid_t pid, BackendId backend_id)
Definition: pqmq.c:80
#define PARALLEL_KEY_TRANSACTION_STATE
Definition: parallel.c:67
int errmsg(const char *fmt,...)
Definition: elog.c:797
void(* parallel_worker_main_type)(dsm_segment *seg, shm_toc *toc)
Definition: parallel.h:23
void pq_endmessage(StringInfo buf)
Definition: pqformat.c:298
static FixedParallelState * MyFixedParallelState
Definition: parallel.c:109
void die(SIGNAL_ARGS)
Definition: postgres.c:2652
void SetCurrentRoleId(Oid roleid, bool is_superuser)
Definition: miscinit.c:657
bool InitializingParallelWorker
Definition: parallel.c:106
Definition: shm_mq.c:69
#define PARALLEL_KEY_SESSION_DSM
Definition: parallel.c:69
#define pq_putmessage(msgtype, s, len)
Definition: libpq.h:42
#define PARALLEL_KEY_ENTRYPOINT
Definition: parallel.c:68
#define PARALLEL_KEY_COMBO_CID
Definition: parallel.c:64
#define PARALLEL_KEY_ACTIVE_SNAPSHOT
Definition: parallel.c:66
void * shm_toc_lookup(shm_toc *toc, uint64 key, bool noError)
Definition: shm_toc.c:232
#define PARALLEL_KEY_LIBRARY
Definition: parallel.c:62
void RestoreGUCState(void *gucstate)
Definition: guc.c:9330
ResourceOwner ResourceOwnerCreate(ResourceOwner parent, const char *name)
Definition: resowner.c:416
void BackgroundWorkerUnblockSignals(void)
Definition: postmaster.c:5592

◆ ParallelWorkerReportLastRecEnd()

void ParallelWorkerReportLastRecEnd ( XLogRecPtr  last_xlog_end)

Definition at line 1172 of file parallel.c.

References Assert, FixedParallelState::last_xlog_end, FixedParallelState::mutex, MyFixedParallelState, SpinLockAcquire, and SpinLockRelease.

Referenced by CommitTransaction().

1173 {
1175 
1176  Assert(fps != NULL);
1177  SpinLockAcquire(&fps->mutex);
1178  if (fps->last_xlog_end < last_xlog_end)
1179  fps->last_xlog_end = last_xlog_end;
1180  SpinLockRelease(&fps->mutex);
1181 }
#define SpinLockAcquire(lock)
Definition: spin.h:62
XLogRecPtr last_xlog_end
Definition: parallel.c:91
#define SpinLockRelease(lock)
Definition: spin.h:64
#define Assert(condition)
Definition: c.h:670
static FixedParallelState * MyFixedParallelState
Definition: parallel.c:109

◆ ReinitializeParallelDSM()

void ReinitializeParallelDSM ( ParallelContext pcxt)

Definition at line 413 of file parallel.c.

References ParallelWorkerInfo::error_mqh, i, FixedParallelState::last_xlog_end, MyProc, ParallelContext::nworkers, ParallelContext::nworkers_launched, PARALLEL_ERROR_QUEUE_SIZE, PARALLEL_KEY_ERROR_QUEUE, PARALLEL_KEY_FIXED, ParallelContext::seg, shm_mq_attach(), shm_mq_create(), shm_mq_set_receiver(), shm_toc_lookup(), ParallelContext::toc, WaitForParallelWorkersToExit(), WaitForParallelWorkersToFinish(), and ParallelContext::worker.

Referenced by ExecParallelReinitialize().

414 {
415  FixedParallelState *fps;
416  char *error_queue_space;
417  int i;
418 
419  /* Wait for any old workers to exit. */
420  if (pcxt->nworkers_launched > 0)
421  {
424  pcxt->nworkers_launched = 0;
425  }
426 
427  /* Reset a few bits of fixed parallel state to a clean state. */
428  fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
429  fps->last_xlog_end = 0;
430 
431  /* Recreate error queues. */
432  error_queue_space =
434  for (i = 0; i < pcxt->nworkers; ++i)
435  {
436  char *start;
437  shm_mq *mq;
438 
439  start = error_queue_space + i * PARALLEL_ERROR_QUEUE_SIZE;
440  mq = shm_mq_create(start, PARALLEL_ERROR_QUEUE_SIZE);
442  pcxt->worker[i].error_mqh = shm_mq_attach(mq, pcxt->seg, NULL);
443  }
444 }
#define PARALLEL_ERROR_QUEUE_SIZE
Definition: parallel.c:50
PGPROC * MyProc
Definition: proc.c:67
dsm_segment * seg
Definition: parallel.h:42
static void WaitForParallelWorkersToExit(ParallelContext *pcxt)
Definition: parallel.c:588
void WaitForParallelWorkersToFinish(ParallelContext *pcxt)
Definition: parallel.c:538
ParallelWorkerInfo * worker
Definition: parallel.h:45
shm_mq * shm_mq_create(void *address, Size size)
Definition: shm_mq.c:170
#define PARALLEL_KEY_FIXED
Definition: parallel.c:60
#define PARALLEL_KEY_ERROR_QUEUE
Definition: parallel.c:61
shm_mq_handle * error_mqh
Definition: parallel.h:28
int nworkers_launched
Definition: parallel.h:37
XLogRecPtr last_xlog_end
Definition: parallel.c:91
shm_mq_handle * shm_mq_attach(shm_mq *mq, dsm_segment *seg, BackgroundWorkerHandle *handle)
Definition: shm_mq.c:287
int i
Definition: shm_mq.c:69
void shm_mq_set_receiver(shm_mq *mq, PGPROC *proc)
Definition: shm_mq.c:199
void * shm_toc_lookup(shm_toc *toc, uint64 key, bool noError)
Definition: shm_toc.c:232
shm_toc * toc
Definition: parallel.h:44

◆ WaitForParallelWorkersToExit()

static void WaitForParallelWorkersToExit ( ParallelContext pcxt)
static

Definition at line 588 of file parallel.c.

References BGWH_POSTMASTER_DIED, ParallelWorkerInfo::bgwhandle, ereport, errcode(), errmsg(), FATAL, i, ParallelContext::nworkers_launched, pfree(), status(), WaitForBackgroundWorkerShutdown(), and ParallelContext::worker.

Referenced by DestroyParallelContext(), and ReinitializeParallelDSM().

589 {
590  int i;
591 
592  /* Wait until the workers actually die. */
593  for (i = 0; i < pcxt->nworkers_launched; ++i)
594  {
596 
597  if (pcxt->worker == NULL || pcxt->worker[i].bgwhandle == NULL)
598  continue;
599 
601 
602  /*
603  * If the postmaster kicked the bucket, we have no chance of cleaning
604  * up safely -- we won't be able to tell when our workers are actually
605  * dead. This doesn't necessitate a PANIC since they will all abort
606  * eventually, but we can't safely continue this session.
607  */
608  if (status == BGWH_POSTMASTER_DIED)
609  ereport(FATAL,
610  (errcode(ERRCODE_ADMIN_SHUTDOWN),
611  errmsg("postmaster exited during a parallel transaction")));
612 
613  /* Release memory. */
614  pfree(pcxt->worker[i].bgwhandle);
615  pcxt->worker[i].bgwhandle = NULL;
616  }
617 }
int errcode(int sqlerrcode)
Definition: elog.c:575
ParallelWorkerInfo * worker
Definition: parallel.h:45
void pfree(void *pointer)
Definition: mcxt.c:949
BgwHandleStatus WaitForBackgroundWorkerShutdown(BackgroundWorkerHandle *handle)
Definition: bgworker.c:1138
#define FATAL
Definition: elog.h:52
BackgroundWorkerHandle * bgwhandle
Definition: parallel.h:27
int nworkers_launched
Definition: parallel.h:37
BgwHandleStatus
Definition: bgworker.h:102
#define ereport(elevel, rest)
Definition: elog.h:122
int errmsg(const char *fmt,...)
Definition: elog.c:797
int i
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:225

◆ WaitForParallelWorkersToFinish()

void WaitForParallelWorkersToFinish ( ParallelContext pcxt)

Definition at line 538 of file parallel.c.

References CHECK_FOR_INTERRUPTS, ParallelWorkerInfo::error_mqh, i, FixedParallelState::last_xlog_end, MyLatch, ParallelContext::nworkers_launched, PARALLEL_KEY_FIXED, ResetLatch(), shm_toc_lookup(), ParallelContext::toc, WAIT_EVENT_PARALLEL_FINISH, WaitLatch(), WL_LATCH_SET, ParallelContext::worker, and XactLastRecEnd.

Referenced by ExecParallelFinish(), and ReinitializeParallelDSM().

539 {
540  for (;;)
541  {
542  bool anyone_alive = false;
543  int i;
544 
545  /*
546  * This will process any parallel messages that are pending, which may
547  * change the outcome of the loop that follows. It may also throw an
548  * error propagated from a worker.
549  */
551 
552  for (i = 0; i < pcxt->nworkers_launched; ++i)
553  {
554  if (pcxt->worker[i].error_mqh != NULL)
555  {
556  anyone_alive = true;
557  break;
558  }
559  }
560 
561  if (!anyone_alive)
562  break;
563 
567  }
568 
569  if (pcxt->toc != NULL)
570  {
571  FixedParallelState *fps;
572 
573  fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
574  if (fps->last_xlog_end > XactLastRecEnd)
576  }
577 }
XLogRecPtr XactLastRecEnd
Definition: xlog.c:339
void ResetLatch(volatile Latch *latch)
Definition: latch.c:497
ParallelWorkerInfo * worker
Definition: parallel.h:45
int WaitLatch(volatile Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:336
#define PARALLEL_KEY_FIXED
Definition: parallel.c:60
shm_mq_handle * error_mqh
Definition: parallel.h:28
int nworkers_launched
Definition: parallel.h:37
XLogRecPtr last_xlog_end
Definition: parallel.c:91
int i
struct Latch * MyLatch
Definition: globals.c:52
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:98
#define WL_LATCH_SET
Definition: latch.h:124
void * shm_toc_lookup(shm_toc *toc, uint64 key, bool noError)
Definition: shm_toc.c:232
shm_toc * toc
Definition: parallel.h:44

Variable Documentation

◆ fn_addr

Definition at line 121 of file parallel.c.

Referenced by LookupParallelWorkerFunction().

◆ fn_name

const char* fn_name

Definition at line 120 of file parallel.c.

Referenced by LookupParallelWorkerFunction().

◆ InitializingParallelWorker

bool InitializingParallelWorker = false

◆ InternalParallelWorkers

const { ... } InternalParallelWorkers[]
Initial value:
=
{
{
"ParallelQueryMain", ParallelQueryMain
}
}
void ParallelQueryMain(dsm_segment *seg, shm_toc *toc)

Referenced by LookupParallelWorkerFunction().

◆ MyFixedParallelState

FixedParallelState* MyFixedParallelState
static

Definition at line 109 of file parallel.c.

Referenced by ParallelWorkerReportLastRecEnd().

◆ ParallelMessagePending

volatile bool ParallelMessagePending = false

◆ ParallelWorkerNumber

◆ pcxt_list

dlist_head pcxt_list = DLIST_STATIC_INIT(pcxt_list)
static

Definition at line 112 of file parallel.c.