PostgreSQL Source Code  git master
parallel.c File Reference
#include "postgres_fe.h"
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include "fe_utils/string_utils.h"
#include "parallel.h"
#include "pg_backup_utils.h"
#include "port/pg_bswap.h"
Include dependency graph for parallel.c:

Go to the source code of this file.

Data Structures

struct  ParallelSlot
 
struct  ShutdownInformation
 
struct  DumpSignalInformation
 

Macros

#define PIPE_READ   0
 
#define PIPE_WRITE   1
 
#define NO_SLOT   (-1) /* Failure result for GetIdleWorker() */
 
#define WORKER_IS_RUNNING(workerStatus)    ((workerStatus) == WRKR_IDLE || (workerStatus) == WRKR_WORKING)
 
#define pgpipe(a)   pipe(a)
 
#define piperead(a, b, c)   read(a,b,c)
 
#define pipewrite(a, b, c)   write(a,b,c)
 
#define write_stderr(str)
 
#define messageStartsWith(msg, prefix)    (strncmp(msg, prefix, strlen(prefix)) == 0)
 

Typedefs

typedef struct ShutdownInformation ShutdownInformation
 
typedef struct DumpSignalInformation DumpSignalInformation
 

Enumerations

enum  T_WorkerStatus { WRKR_NOT_STARTED = 0 , WRKR_IDLE , WRKR_WORKING , WRKR_TERMINATED }
 

Functions

static ParallelSlotGetMyPSlot (ParallelState *pstate)
 
static void archive_close_connection (int code, void *arg)
 
static void ShutdownWorkersHard (ParallelState *pstate)
 
static void WaitForTerminatingWorkers (ParallelState *pstate)
 
static void setup_cancel_handler (void)
 
static void set_cancel_pstate (ParallelState *pstate)
 
static void set_cancel_slot_archive (ParallelSlot *slot, ArchiveHandle *AH)
 
static void RunWorker (ArchiveHandle *AH, ParallelSlot *slot)
 
static int GetIdleWorker (ParallelState *pstate)
 
static bool HasEveryWorkerTerminated (ParallelState *pstate)
 
static void lockTableForWorker (ArchiveHandle *AH, TocEntry *te)
 
static void WaitForCommands (ArchiveHandle *AH, int pipefd[2])
 
static bool ListenToWorkers (ArchiveHandle *AH, ParallelState *pstate, bool do_wait)
 
static char * getMessageFromLeader (int pipefd[2])
 
static void sendMessageToLeader (int pipefd[2], const char *str)
 
static int select_loop (int maxFd, fd_set *workerset)
 
static char * getMessageFromWorker (ParallelState *pstate, bool do_wait, int *worker)
 
static void sendMessageToWorker (ParallelState *pstate, int worker, const char *str)
 
static char * readMessageFromPipe (int fd)
 
void init_parallel_dump_utils (void)
 
void on_exit_close_archive (Archive *AHX)
 
static void sigTermHandler (SIGNAL_ARGS)
 
void set_archive_cancel_info (ArchiveHandle *AH, PGconn *conn)
 
ParallelStateParallelBackupStart (ArchiveHandle *AH)
 
void ParallelBackupEnd (ArchiveHandle *AH, ParallelState *pstate)
 
static void buildWorkerCommand (ArchiveHandle *AH, TocEntry *te, T_Action act, char *buf, int buflen)
 
static void parseWorkerCommand (ArchiveHandle *AH, TocEntry **te, T_Action *act, const char *msg)
 
static void buildWorkerResponse (ArchiveHandle *AH, TocEntry *te, T_Action act, int status, char *buf, int buflen)
 
static int parseWorkerResponse (ArchiveHandle *AH, TocEntry *te, const char *msg)
 
void DispatchJobForTocEntry (ArchiveHandle *AH, ParallelState *pstate, TocEntry *te, T_Action act, ParallelCompletionPtr callback, void *callback_data)
 
bool IsEveryWorkerIdle (ParallelState *pstate)
 
void WaitForWorkers (ArchiveHandle *AH, ParallelState *pstate, WFW_WaitOption mode)
 

Variables

static ShutdownInformation shutdown_info
 
static volatile DumpSignalInformation signal_info
 

Macro Definition Documentation

◆ messageStartsWith

#define messageStartsWith (   msg,
  prefix 
)     (strncmp(msg, prefix, strlen(prefix)) == 0)

Definition at line 228 of file parallel.c.

◆ NO_SLOT

#define NO_SLOT   (-1) /* Failure result for GetIdleWorker() */

Definition at line 74 of file parallel.c.

◆ pgpipe

#define pgpipe (   a)    pipe(a)

Definition at line 139 of file parallel.c.

◆ PIPE_READ

#define PIPE_READ   0

Definition at line 71 of file parallel.c.

◆ PIPE_WRITE

#define PIPE_WRITE   1

Definition at line 72 of file parallel.c.

◆ piperead

#define piperead (   a,
  b,
  c 
)    read(a,b,c)

Definition at line 140 of file parallel.c.

◆ pipewrite

#define pipewrite (   a,
  b,
  c 
)    write(a,b,c)

Definition at line 141 of file parallel.c.

◆ WORKER_IS_RUNNING

#define WORKER_IS_RUNNING (   workerStatus)     ((workerStatus) == WRKR_IDLE || (workerStatus) == WRKR_WORKING)

Definition at line 85 of file parallel.c.

◆ write_stderr

#define write_stderr (   str)
Value:
do { \
const char *str_ = (str); \
int rc_; \
rc_ = write(fileno(stderr), str_, strlen(str_)); \
(void) rc_; \
} while (0)
#define write(a, b, c)
Definition: win32.h:14

Definition at line 186 of file parallel.c.

Typedef Documentation

◆ DumpSignalInformation

◆ ShutdownInformation

Enumeration Type Documentation

◆ T_WorkerStatus

Enumerator
WRKR_NOT_STARTED 
WRKR_IDLE 
WRKR_WORKING 
WRKR_TERMINATED 

Definition at line 77 of file parallel.c.

78 {
79  WRKR_NOT_STARTED = 0,
80  WRKR_IDLE,
T_WorkerStatus
Definition: parallel.c:78
@ WRKR_WORKING
Definition: parallel.c:81
@ WRKR_IDLE
Definition: parallel.c:80
@ WRKR_TERMINATED
Definition: parallel.c:82
@ WRKR_NOT_STARTED
Definition: parallel.c:79

Function Documentation

◆ archive_close_connection()

static void archive_close_connection ( int  code,
void *  arg 
)
static

Definition at line 341 of file parallel.c.

342 {
344 
345  if (si->pstate)
346  {
347  /* In parallel mode, must figure out who we are */
348  ParallelSlot *slot = GetMyPSlot(si->pstate);
349 
350  if (!slot)
351  {
352  /*
353  * We're the leader. Forcibly shut down workers, then close our
354  * own database connection, if any.
355  */
357 
358  if (si->AHX)
359  DisconnectDatabase(si->AHX);
360  }
361  else
362  {
363  /*
364  * We're a worker. Shut down our own DB connection if any. On
365  * Windows, we also have to close our communication sockets, to
366  * emulate what will happen on Unix when the worker process exits.
367  * (Without this, if this is a premature exit, the leader would
368  * fail to detect it because there would be no EOF condition on
369  * the other end of the pipe.)
370  */
371  if (slot->AH)
372  DisconnectDatabase(&(slot->AH->public));
373 
374 #ifdef WIN32
375  closesocket(slot->pipeRevRead);
376  closesocket(slot->pipeRevWrite);
377 #endif
378  }
379  }
380  else
381  {
382  /* Non-parallel operation: just kill the leader DB connection */
383  if (si->AHX)
384  DisconnectDatabase(si->AHX);
385  }
386 }
static ParallelSlot * GetMyPSlot(ParallelState *pstate)
Definition: parallel.c:266
static void ShutdownWorkersHard(ParallelState *pstate)
Definition: parallel.c:397
void DisconnectDatabase(Archive *AHX)
Definition: pg_backup_db.c:226
void * arg
#define closesocket
Definition: port.h:342
ArchiveHandle * AH
Definition: parallel.c:103
int pipeRevRead
Definition: parallel.c:107
int pipeRevWrite
Definition: parallel.c:108
ParallelState * pstate
Definition: parallel.c:150

References ParallelSlot::AH, ShutdownInformation::AHX, arg, closesocket, DisconnectDatabase(), GetMyPSlot(), ParallelSlot::pipeRevRead, ParallelSlot::pipeRevWrite, ShutdownInformation::pstate, _archiveHandle::public, and ShutdownWorkersHard().

Referenced by on_exit_close_archive().

◆ buildWorkerCommand()

static void buildWorkerCommand ( ArchiveHandle AH,
TocEntry te,
T_Action  act,
char *  buf,
int  buflen 
)
static

Definition at line 1110 of file parallel.c.

1112 {
1113  if (act == ACT_DUMP)
1114  snprintf(buf, buflen, "DUMP %d", te->dumpId);
1115  else if (act == ACT_RESTORE)
1116  snprintf(buf, buflen, "RESTORE %d", te->dumpId);
1117  else
1118  Assert(false);
1119 }
Assert(fmt[strlen(fmt) - 1] !='\n')
@ ACT_RESTORE
@ ACT_DUMP
static char * buf
Definition: pg_test_fsync.c:67
#define snprintf
Definition: port.h:225

References ACT_DUMP, ACT_RESTORE, Assert(), buf, _tocEntry::dumpId, and snprintf.

Referenced by DispatchJobForTocEntry().

◆ buildWorkerResponse()

static void buildWorkerResponse ( ArchiveHandle AH,
TocEntry te,
T_Action  act,
int  status,
char *  buf,
int  buflen 
)
static

Definition at line 1158 of file parallel.c.

1160 {
1161  snprintf(buf, buflen, "OK %d %d %d",
1162  te->dumpId,
1163  status,
1165 }
#define WORKER_IGNORED_ERRORS
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:229
int n_errors
Definition: pg_backup.h:233

References buf, _tocEntry::dumpId, Archive::n_errors, _archiveHandle::public, snprintf, status(), and WORKER_IGNORED_ERRORS.

Referenced by WaitForCommands().

◆ DispatchJobForTocEntry()

void DispatchJobForTocEntry ( ArchiveHandle AH,
ParallelState pstate,
TocEntry te,
T_Action  act,
ParallelCompletionPtr  callback,
void *  callback_data 
)

Definition at line 1207 of file parallel.c.

1213 {
1214  int worker;
1215  char buf[256];
1216 
1217  /* Get a worker, waiting if none are idle */
1218  while ((worker = GetIdleWorker(pstate)) == NO_SLOT)
1219  WaitForWorkers(AH, pstate, WFW_ONE_IDLE);
1220 
1221  /* Construct and send command string */
1222  buildWorkerCommand(AH, te, act, buf, sizeof(buf));
1223 
1224  sendMessageToWorker(pstate, worker, buf);
1225 
1226  /* Remember worker is busy, and which TocEntry it's working on */
1227  pstate->parallelSlot[worker].workerStatus = WRKR_WORKING;
1228  pstate->parallelSlot[worker].callback = callback;
1229  pstate->parallelSlot[worker].callback_data = callback_data;
1230  pstate->te[worker] = te;
1231 }
void WaitForWorkers(ArchiveHandle *AH, ParallelState *pstate, WFW_WaitOption mode)
Definition: parallel.c:1453
static int GetIdleWorker(ParallelState *pstate)
Definition: parallel.c:1238
static void buildWorkerCommand(ArchiveHandle *AH, TocEntry *te, T_Action act, char *buf, int buflen)
Definition: parallel.c:1110
#define NO_SLOT
Definition: parallel.c:74
static void sendMessageToWorker(ParallelState *pstate, int worker, const char *str)
Definition: parallel.c:1646
@ WFW_ONE_IDLE
Definition: parallel.h:34
ParallelCompletionPtr callback
Definition: parallel.c:100
void * callback_data
Definition: parallel.c:101
T_WorkerStatus workerStatus
Definition: parallel.c:97
TocEntry ** te
Definition: parallel.h:59
ParallelSlot * parallelSlot
Definition: parallel.h:60
static void callback(struct sockaddr *addr, struct sockaddr *mask, void *unused)
Definition: test_ifaddrs.c:48

References buf, buildWorkerCommand(), ParallelSlot::callback, callback(), ParallelSlot::callback_data, GetIdleWorker(), NO_SLOT, ParallelState::parallelSlot, sendMessageToWorker(), ParallelState::te, WaitForWorkers(), WFW_ONE_IDLE, ParallelSlot::workerStatus, and WRKR_WORKING.

Referenced by restore_toc_entries_parallel(), and WriteDataChunks().

◆ GetIdleWorker()

static int GetIdleWorker ( ParallelState pstate)
static

Definition at line 1238 of file parallel.c.

1239 {
1240  int i;
1241 
1242  for (i = 0; i < pstate->numWorkers; i++)
1243  {
1244  if (pstate->parallelSlot[i].workerStatus == WRKR_IDLE)
1245  return i;
1246  }
1247  return NO_SLOT;
1248 }
int i
Definition: isn.c:73
int numWorkers
Definition: parallel.h:57

References i, NO_SLOT, ParallelState::numWorkers, ParallelState::parallelSlot, ParallelSlot::workerStatus, and WRKR_IDLE.

Referenced by DispatchJobForTocEntry(), and WaitForWorkers().

◆ getMessageFromLeader()

static char * getMessageFromLeader ( int  pipefd[2])
static

Definition at line 1518 of file parallel.c.

1519 {
1520  return readMessageFromPipe(pipefd[PIPE_READ]);
1521 }
#define PIPE_READ
Definition: parallel.c:71
static char * readMessageFromPipe(int fd)
Definition: parallel.c:1664

References PIPE_READ, and readMessageFromPipe().

Referenced by WaitForCommands().

◆ getMessageFromWorker()

static char * getMessageFromWorker ( ParallelState pstate,
bool  do_wait,
int *  worker 
)
static

Definition at line 1581 of file parallel.c.

1582 {
1583  int i;
1584  fd_set workerset;
1585  int maxFd = -1;
1586  struct timeval nowait = {0, 0};
1587 
1588  /* construct bitmap of socket descriptors for select() */
1589  FD_ZERO(&workerset);
1590  for (i = 0; i < pstate->numWorkers; i++)
1591  {
1593  continue;
1594  FD_SET(pstate->parallelSlot[i].pipeRead, &workerset);
1595  if (pstate->parallelSlot[i].pipeRead > maxFd)
1596  maxFd = pstate->parallelSlot[i].pipeRead;
1597  }
1598 
1599  if (do_wait)
1600  {
1601  i = select_loop(maxFd, &workerset);
1602  Assert(i != 0);
1603  }
1604  else
1605  {
1606  if ((i = select(maxFd + 1, &workerset, NULL, NULL, &nowait)) == 0)
1607  return NULL;
1608  }
1609 
1610  if (i < 0)
1611  pg_fatal("%s() failed: %m", "select");
1612 
1613  for (i = 0; i < pstate->numWorkers; i++)
1614  {
1615  char *msg;
1616 
1618  continue;
1619  if (!FD_ISSET(pstate->parallelSlot[i].pipeRead, &workerset))
1620  continue;
1621 
1622  /*
1623  * Read the message if any. If the socket is ready because of EOF,
1624  * we'll return NULL instead (and the socket will stay ready, so the
1625  * condition will persist).
1626  *
1627  * Note: because this is a blocking read, we'll wait if only part of
1628  * the message is available. Waiting a long time would be bad, but
1629  * since worker status messages are short and are always sent in one
1630  * operation, it shouldn't be a problem in practice.
1631  */
1632  msg = readMessageFromPipe(pstate->parallelSlot[i].pipeRead);
1633  *worker = i;
1634  return msg;
1635  }
1636  Assert(false);
1637  return NULL;
1638 }
static int select_loop(int maxFd, fd_set *workerset)
Definition: parallel.c:1542
#define WORKER_IS_RUNNING(workerStatus)
Definition: parallel.c:85
#define pg_fatal(...)
static bool do_wait
Definition: pg_ctl.c:79
int pipeRead
Definition: parallel.c:105
#define select(n, r, w, e, timeout)
Definition: win32_port.h:474

References Assert(), do_wait, i, ParallelState::numWorkers, ParallelState::parallelSlot, pg_fatal, ParallelSlot::pipeRead, readMessageFromPipe(), select, select_loop(), WORKER_IS_RUNNING, and ParallelSlot::workerStatus.

Referenced by ListenToWorkers().

◆ GetMyPSlot()

static ParallelSlot * GetMyPSlot ( ParallelState pstate)
static

Definition at line 266 of file parallel.c.

267 {
268  int i;
269 
270  for (i = 0; i < pstate->numWorkers; i++)
271  {
272 #ifdef WIN32
273  if (pstate->parallelSlot[i].threadId == GetCurrentThreadId())
274 #else
275  if (pstate->parallelSlot[i].pid == getpid())
276 #endif
277  return &(pstate->parallelSlot[i]);
278  }
279 
280  return NULL;
281 }
pid_t pid
Definition: parallel.c:115

References i, ParallelState::numWorkers, ParallelState::parallelSlot, and ParallelSlot::pid.

Referenced by archive_close_connection().

◆ HasEveryWorkerTerminated()

static bool HasEveryWorkerTerminated ( ParallelState pstate)
static

Definition at line 1254 of file parallel.c.

1255 {
1256  int i;
1257 
1258  for (i = 0; i < pstate->numWorkers; i++)
1259  {
1261  return false;
1262  }
1263  return true;
1264 }

References i, ParallelState::numWorkers, ParallelState::parallelSlot, WORKER_IS_RUNNING, and ParallelSlot::workerStatus.

Referenced by WaitForTerminatingWorkers().

◆ init_parallel_dump_utils()

void init_parallel_dump_utils ( void  )

Definition at line 238 of file parallel.c.

239 {
240 #ifdef WIN32
241  if (!parallel_init_done)
242  {
243  WSADATA wsaData;
244  int err;
245 
246  /* Prepare for threaded operation */
247  tls_index = TlsAlloc();
248  mainThreadId = GetCurrentThreadId();
249 
250  /* Initialize socket access */
251  err = WSAStartup(MAKEWORD(2, 2), &wsaData);
252  if (err != 0)
253  pg_fatal("%s() failed: error code %d", "WSAStartup", err);
254 
255  parallel_init_done = true;
256  }
257 #endif
258 }

References pg_fatal.

Referenced by main().

◆ IsEveryWorkerIdle()

bool IsEveryWorkerIdle ( ParallelState pstate)

Definition at line 1270 of file parallel.c.

1271 {
1272  int i;
1273 
1274  for (i = 0; i < pstate->numWorkers; i++)
1275  {
1276  if (pstate->parallelSlot[i].workerStatus != WRKR_IDLE)
1277  return false;
1278  }
1279  return true;
1280 }

References i, ParallelState::numWorkers, ParallelState::parallelSlot, ParallelSlot::workerStatus, and WRKR_IDLE.

Referenced by ParallelBackupEnd(), restore_toc_entries_parallel(), and WaitForWorkers().

◆ ListenToWorkers()

static bool ListenToWorkers ( ArchiveHandle AH,
ParallelState pstate,
bool  do_wait 
)
static

Definition at line 1400 of file parallel.c.

1401 {
1402  int worker;
1403  char *msg;
1404 
1405  /* Try to collect a status message */
1406  msg = getMessageFromWorker(pstate, do_wait, &worker);
1407 
1408  if (!msg)
1409  {
1410  /* If do_wait is true, we must have detected EOF on some socket */
1411  if (do_wait)
1412  pg_fatal("a worker process died unexpectedly");
1413  return false;
1414  }
1415 
1416  /* Process it and update our idea of the worker's status */
1417  if (messageStartsWith(msg, "OK "))
1418  {
1419  ParallelSlot *slot = &pstate->parallelSlot[worker];
1420  TocEntry *te = pstate->te[worker];
1421  int status;
1422 
1423  status = parseWorkerResponse(AH, te, msg);
1424  slot->callback(AH, te, status, slot->callback_data);
1425  slot->workerStatus = WRKR_IDLE;
1426  pstate->te[worker] = NULL;
1427  }
1428  else
1429  pg_fatal("invalid message received from worker: \"%s\"",
1430  msg);
1431 
1432  /* Free the string returned from getMessageFromWorker */
1433  free(msg);
1434 
1435  return true;
1436 }
static int parseWorkerResponse(ArchiveHandle *AH, TocEntry *te, const char *msg)
Definition: parallel.c:1173
static char * getMessageFromWorker(ParallelState *pstate, bool do_wait, int *worker)
Definition: parallel.c:1581
#define messageStartsWith(msg, prefix)
Definition: parallel.c:228
#define free(a)
Definition: header.h:65

References ParallelSlot::callback, ParallelSlot::callback_data, do_wait, free, getMessageFromWorker(), messageStartsWith, ParallelState::parallelSlot, parseWorkerResponse(), pg_fatal, status(), ParallelState::te, ParallelSlot::workerStatus, and WRKR_IDLE.

Referenced by WaitForWorkers().

◆ lockTableForWorker()

static void lockTableForWorker ( ArchiveHandle AH,
TocEntry te 
)
static

Definition at line 1303 of file parallel.c.

1304 {
1305  const char *qualId;
1306  PQExpBuffer query;
1307  PGresult *res;
1308 
1309  /* Nothing to do for BLOBS */
1310  if (strcmp(te->desc, "BLOBS") == 0)
1311  return;
1312 
1313  query = createPQExpBuffer();
1314 
1315  qualId = fmtQualifiedId(te->namespace, te->tag);
1316 
1317  appendPQExpBuffer(query, "LOCK TABLE %s IN ACCESS SHARE MODE NOWAIT",
1318  qualId);
1319 
1320  res = PQexec(AH->connection, query->data);
1321 
1322  if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
1323  pg_fatal("could not obtain lock on relation \"%s\"\n"
1324  "This usually means that someone requested an ACCESS EXCLUSIVE lock "
1325  "on the table after the pg_dump parent process had gotten the "
1326  "initial ACCESS SHARE lock on the table.", qualId);
1327 
1328  PQclear(res);
1329  destroyPQExpBuffer(query);
1330 }
ExecStatusType PQresultStatus(const PGresult *res)
Definition: fe-exec.c:3270
void PQclear(PGresult *res)
Definition: fe-exec.c:718
PGresult * PQexec(PGconn *conn, const char *query)
Definition: fe-exec.c:2273
@ PGRES_COMMAND_OK
Definition: libpq-fe.h:97
PQExpBuffer createPQExpBuffer(void)
Definition: pqexpbuffer.c:74
void appendPQExpBuffer(PQExpBuffer str, const char *fmt,...)
Definition: pqexpbuffer.c:267
void destroyPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:116
const char * fmtQualifiedId(const char *schema, const char *id)
Definition: string_utils.c:145

References appendPQExpBuffer(), _archiveHandle::connection, createPQExpBuffer(), PQExpBufferData::data, _tocEntry::desc, destroyPQExpBuffer(), fmtQualifiedId(), pg_fatal, PGRES_COMMAND_OK, PQclear(), PQexec(), PQresultStatus(), res, and _tocEntry::tag.

Referenced by WaitForCommands().

◆ on_exit_close_archive()

void on_exit_close_archive ( Archive AHX)

Definition at line 330 of file parallel.c.

331 {
332  shutdown_info.AHX = AHX;
334 }
static void archive_close_connection(int code, void *arg)
Definition: parallel.c:341
static ShutdownInformation shutdown_info
Definition: parallel.c:154
void on_exit_nicely(on_exit_nicely_callback function, void *arg)

References ShutdownInformation::AHX, archive_close_connection(), on_exit_nicely(), and shutdown_info.

Referenced by main().

◆ ParallelBackupEnd()

void ParallelBackupEnd ( ArchiveHandle AH,
ParallelState pstate 
)

Definition at line 1061 of file parallel.c.

1062 {
1063  int i;
1064 
1065  /* No work if non-parallel */
1066  if (pstate->numWorkers == 1)
1067  return;
1068 
1069  /* There should not be any unfinished jobs */
1070  Assert(IsEveryWorkerIdle(pstate));
1071 
1072  /* Close the sockets so that the workers know they can exit */
1073  for (i = 0; i < pstate->numWorkers; i++)
1074  {
1075  closesocket(pstate->parallelSlot[i].pipeRead);
1076  closesocket(pstate->parallelSlot[i].pipeWrite);
1077  }
1078 
1079  /* Wait for them to exit */
1080  WaitForTerminatingWorkers(pstate);
1081 
1082  /*
1083  * Unlink pstate from shutdown_info, so the exit handler will not try to
1084  * use it; and likewise unlink from signal_info.
1085  */
1086  shutdown_info.pstate = NULL;
1087  set_cancel_pstate(NULL);
1088 
1089  /* Release state (mere neatnik-ism, since we're about to terminate) */
1090  free(pstate->te);
1091  free(pstate->parallelSlot);
1092  free(pstate);
1093 }
static void set_cancel_pstate(ParallelState *pstate)
Definition: parallel.c:791
bool IsEveryWorkerIdle(ParallelState *pstate)
Definition: parallel.c:1270
static void WaitForTerminatingWorkers(ParallelState *pstate)
Definition: parallel.c:448
int pipeWrite
Definition: parallel.c:106

References Assert(), closesocket, free, i, IsEveryWorkerIdle(), ParallelState::numWorkers, ParallelState::parallelSlot, ParallelSlot::pipeRead, ParallelSlot::pipeWrite, ShutdownInformation::pstate, set_cancel_pstate(), shutdown_info, ParallelState::te, and WaitForTerminatingWorkers().

Referenced by _CloseArchive(), and RestoreArchive().

◆ ParallelBackupStart()

ParallelState* ParallelBackupStart ( ArchiveHandle AH)

Definition at line 899 of file parallel.c.

900 {
901  ParallelState *pstate;
902  int i;
903 
904  Assert(AH->public.numWorkers > 0);
905 
906  pstate = (ParallelState *) pg_malloc(sizeof(ParallelState));
907 
908  pstate->numWorkers = AH->public.numWorkers;
909  pstate->te = NULL;
910  pstate->parallelSlot = NULL;
911 
912  if (AH->public.numWorkers == 1)
913  return pstate;
914 
915  /* Create status arrays, being sure to initialize all fields to 0 */
916  pstate->te = (TocEntry **)
917  pg_malloc0(pstate->numWorkers * sizeof(TocEntry *));
918  pstate->parallelSlot = (ParallelSlot *)
919  pg_malloc0(pstate->numWorkers * sizeof(ParallelSlot));
920 
921 #ifdef WIN32
922  /* Make fmtId() and fmtQualifiedId() use thread-local storage */
923  getLocalPQExpBuffer = getThreadLocalPQExpBuffer;
924 #endif
925 
926  /*
927  * Set the pstate in shutdown_info, to tell the exit handler that it must
928  * clean up workers as well as the main database connection. But we don't
929  * set this in signal_info yet, because we don't want child processes to
930  * inherit non-NULL signal_info.pstate.
931  */
932  shutdown_info.pstate = pstate;
933 
934  /*
935  * Temporarily disable query cancellation on the leader connection. This
936  * ensures that child processes won't inherit valid AH->connCancel
937  * settings and thus won't try to issue cancels against the leader's
938  * connection. No harm is done if we fail while it's disabled, because
939  * the leader connection is idle at this point anyway.
940  */
941  set_archive_cancel_info(AH, NULL);
942 
943  /* Ensure stdio state is quiesced before forking */
944  fflush(NULL);
945 
946  /* Create desired number of workers */
947  for (i = 0; i < pstate->numWorkers; i++)
948  {
949 #ifdef WIN32
950  WorkerInfo *wi;
951  uintptr_t handle;
952 #else
953  pid_t pid;
954 #endif
955  ParallelSlot *slot = &(pstate->parallelSlot[i]);
956  int pipeMW[2],
957  pipeWM[2];
958 
959  /* Create communication pipes for this worker */
960  if (pgpipe(pipeMW) < 0 || pgpipe(pipeWM) < 0)
961  pg_fatal("could not create communication channels: %m");
962 
963  /* leader's ends of the pipes */
964  slot->pipeRead = pipeWM[PIPE_READ];
965  slot->pipeWrite = pipeMW[PIPE_WRITE];
966  /* child's ends of the pipes */
967  slot->pipeRevRead = pipeMW[PIPE_READ];
968  slot->pipeRevWrite = pipeWM[PIPE_WRITE];
969 
970 #ifdef WIN32
971  /* Create transient structure to pass args to worker function */
972  wi = (WorkerInfo *) pg_malloc(sizeof(WorkerInfo));
973 
974  wi->AH = AH;
975  wi->slot = slot;
976 
977  handle = _beginthreadex(NULL, 0, (void *) &init_spawned_worker_win32,
978  wi, 0, &(slot->threadId));
979  slot->hThread = handle;
980  slot->workerStatus = WRKR_IDLE;
981 #else /* !WIN32 */
982  pid = fork();
983  if (pid == 0)
984  {
985  /* we are the worker */
986  int j;
987 
988  /* this is needed for GetMyPSlot() */
989  slot->pid = getpid();
990 
991  /* instruct signal handler that we're in a worker now */
992  signal_info.am_worker = true;
993 
994  /* close read end of Worker -> Leader */
995  closesocket(pipeWM[PIPE_READ]);
996  /* close write end of Leader -> Worker */
997  closesocket(pipeMW[PIPE_WRITE]);
998 
999  /*
1000  * Close all inherited fds for communication of the leader with
1001  * previously-forked workers.
1002  */
1003  for (j = 0; j < i; j++)
1004  {
1005  closesocket(pstate->parallelSlot[j].pipeRead);
1006  closesocket(pstate->parallelSlot[j].pipeWrite);
1007  }
1008 
1009  /* Run the worker ... */
1010  RunWorker(AH, slot);
1011 
1012  /* We can just exit(0) when done */
1013  exit(0);
1014  }
1015  else if (pid < 0)
1016  {
1017  /* fork failed */
1018  pg_fatal("could not create worker process: %m");
1019  }
1020 
1021  /* In Leader after successful fork */
1022  slot->pid = pid;
1023  slot->workerStatus = WRKR_IDLE;
1024 
1025  /* close read end of Leader -> Worker */
1026  closesocket(pipeMW[PIPE_READ]);
1027  /* close write end of Worker -> Leader */
1028  closesocket(pipeWM[PIPE_WRITE]);
1029 #endif /* WIN32 */
1030  }
1031 
1032  /*
1033  * Having forked off the workers, disable SIGPIPE so that leader isn't
1034  * killed if it tries to send a command to a dead worker. We don't want
1035  * the workers to inherit this setting, though.
1036  */
1037 #ifndef WIN32
1039 #endif
1040 
1041  /*
1042  * Re-establish query cancellation on the leader connection.
1043  */
1045 
1046  /*
1047  * Tell the cancel signal handler to forward signals to worker processes,
1048  * too. (As with query cancel, we did not need this earlier because the
1049  * workers have not yet been given anything to do; if we die before this
1050  * point, any already-started workers will see EOF and quit promptly.)
1051  */
1052  set_cancel_pstate(pstate);
1053 
1054  return pstate;
1055 }
#define pgpipe(a)
Definition: parallel.c:139
static void RunWorker(ArchiveHandle *AH, ParallelSlot *slot)
Definition: parallel.c:831
#define PIPE_WRITE
Definition: parallel.c:72
static volatile DumpSignalInformation signal_info
Definition: parallel.c:175
void set_archive_cancel_info(ArchiveHandle *AH, PGconn *conn)
Definition: parallel.c:732
void * pg_malloc0(size_t size)
Definition: fe_memutils.c:53
void * pg_malloc(size_t size)
Definition: fe_memutils.c:47
int j
Definition: isn.c:74
static void const char fflush(stdout)
exit(1)
pqsigfunc pqsignal(int signum, pqsigfunc handler)
Definition: signal.c:180
PQExpBuffer(* getLocalPQExpBuffer)(void)
Definition: string_utils.c:27
int numWorkers
Definition: pg_backup.h:220
#define SIGPIPE
Definition: win32_port.h:172
#define SIG_IGN
Definition: win32_port.h:164

References DumpSignalInformation::am_worker, Assert(), closesocket, _archiveHandle::connection, exit(), fflush(), getLocalPQExpBuffer, i, j, ParallelState::numWorkers, Archive::numWorkers, ParallelState::parallelSlot, pg_fatal, pg_malloc(), pg_malloc0(), pgpipe, ParallelSlot::pid, PIPE_READ, PIPE_WRITE, ParallelSlot::pipeRead, ParallelSlot::pipeRevRead, ParallelSlot::pipeRevWrite, ParallelSlot::pipeWrite, pqsignal(), ShutdownInformation::pstate, _archiveHandle::public, RunWorker(), set_archive_cancel_info(), set_cancel_pstate(), shutdown_info, SIG_IGN, signal_info, SIGPIPE, ParallelState::te, ParallelSlot::workerStatus, and WRKR_IDLE.

Referenced by _CloseArchive(), and RestoreArchive().

◆ parseWorkerCommand()

static void parseWorkerCommand ( ArchiveHandle AH,
TocEntry **  te,
T_Action act,
const char *  msg 
)
static

Definition at line 1125 of file parallel.c.

1127 {
1128  DumpId dumpId;
1129  int nBytes;
1130 
1131  if (messageStartsWith(msg, "DUMP "))
1132  {
1133  *act = ACT_DUMP;
1134  sscanf(msg, "DUMP %d%n", &dumpId, &nBytes);
1135  Assert(nBytes == strlen(msg));
1136  *te = getTocEntryByDumpId(AH, dumpId);
1137  Assert(*te != NULL);
1138  }
1139  else if (messageStartsWith(msg, "RESTORE "))
1140  {
1141  *act = ACT_RESTORE;
1142  sscanf(msg, "RESTORE %d%n", &dumpId, &nBytes);
1143  Assert(nBytes == strlen(msg));
1144  *te = getTocEntryByDumpId(AH, dumpId);
1145  Assert(*te != NULL);
1146  }
1147  else
1148  pg_fatal("unrecognized command received from leader: \"%s\"",
1149  msg);
1150 }
int DumpId
Definition: pg_backup.h:265
TocEntry * getTocEntryByDumpId(ArchiveHandle *AH, DumpId id)

References ACT_DUMP, ACT_RESTORE, Assert(), getTocEntryByDumpId(), messageStartsWith, and pg_fatal.

Referenced by WaitForCommands().

◆ parseWorkerResponse()

static int parseWorkerResponse ( ArchiveHandle AH,
TocEntry te,
const char *  msg 
)
static

Definition at line 1173 of file parallel.c.

1175 {
1176  DumpId dumpId;
1177  int nBytes,
1178  n_errors;
1179  int status = 0;
1180 
1181  if (messageStartsWith(msg, "OK "))
1182  {
1183  sscanf(msg, "OK %d %d %d%n", &dumpId, &status, &n_errors, &nBytes);
1184 
1185  Assert(dumpId == te->dumpId);
1186  Assert(nBytes == strlen(msg));
1187 
1188  AH->public.n_errors += n_errors;
1189  }
1190  else
1191  pg_fatal("invalid message received from worker: \"%s\"",
1192  msg);
1193 
1194  return status;
1195 }

References Assert(), _tocEntry::dumpId, messageStartsWith, Archive::n_errors, pg_fatal, _archiveHandle::public, and status().

Referenced by ListenToWorkers().

◆ readMessageFromPipe()

static char * readMessageFromPipe ( int  fd)
static

Definition at line 1664 of file parallel.c.

1665 {
1666  char *msg;
1667  int msgsize,
1668  bufsize;
1669  int ret;
1670 
1671  /*
1672  * In theory, if we let piperead() read multiple bytes, it might give us
1673  * back fragments of multiple messages. (That can't actually occur, since
1674  * neither leader nor workers send more than one message without waiting
1675  * for a reply, but we don't wish to assume that here.) For simplicity,
1676  * read a byte at a time until we get the terminating '\0'. This method
1677  * is a bit inefficient, but since this is only used for relatively short
1678  * command and status strings, it shouldn't matter.
1679  */
1680  bufsize = 64; /* could be any number */
1681  msg = (char *) pg_malloc(bufsize);
1682  msgsize = 0;
1683  for (;;)
1684  {
1685  Assert(msgsize < bufsize);
1686  ret = piperead(fd, msg + msgsize, 1);
1687  if (ret <= 0)
1688  break; /* error or connection closure */
1689 
1690  Assert(ret == 1);
1691 
1692  if (msg[msgsize] == '\0')
1693  return msg; /* collected whole message */
1694 
1695  msgsize++;
1696  if (msgsize == bufsize) /* enlarge buffer if needed */
1697  {
1698  bufsize += 16; /* could be any number */
1699  msg = (char *) pg_realloc(msg, bufsize);
1700  }
1701  }
1702 
1703  /* Other end has closed the connection */
1704  pg_free(msg);
1705  return NULL;
1706 }
#define piperead(a, b, c)
Definition: parallel.c:140
void * pg_realloc(void *ptr, size_t size)
Definition: fe_memutils.c:65
void pg_free(void *ptr)
Definition: fe_memutils.c:105
static int fd(const char *x, int i)
Definition: preproc-init.c:105

References Assert(), fd(), pg_free(), pg_malloc(), pg_realloc(), and piperead.

Referenced by getMessageFromLeader(), and getMessageFromWorker().

◆ RunWorker()

static void RunWorker ( ArchiveHandle AH,
ParallelSlot slot 
)
static

Definition at line 831 of file parallel.c.

832 {
833  int pipefd[2];
834 
835  /* fetch child ends of pipes */
836  pipefd[PIPE_READ] = slot->pipeRevRead;
837  pipefd[PIPE_WRITE] = slot->pipeRevWrite;
838 
839  /*
840  * Clone the archive so that we have our own state to work with, and in
841  * particular our own database connection.
842  *
843  * We clone on Unix as well as Windows, even though technically we don't
844  * need to because fork() gives us a copy in our own address space
845  * already. But CloneArchive resets the state information and also clones
846  * the database connection which both seem kinda helpful.
847  */
848  AH = CloneArchive(AH);
849 
850  /* Remember cloned archive where signal handler can find it */
851  set_cancel_slot_archive(slot, AH);
852 
853  /*
854  * Call the setup worker function that's defined in the ArchiveHandle.
855  */
856  (AH->SetupWorkerPtr) ((Archive *) AH);
857 
858  /*
859  * Execute commands until done.
860  */
861  WaitForCommands(AH, pipefd);
862 
863  /*
864  * Disconnect from database and clean up.
865  */
866  set_cancel_slot_archive(slot, NULL);
867  DisconnectDatabase(&(AH->public));
868  DeCloneArchive(AH);
869 }
static void WaitForCommands(ArchiveHandle *AH, int pipefd[2])
Definition: parallel.c:1338
static void set_cancel_slot_archive(ParallelSlot *slot, ArchiveHandle *AH)
Definition: parallel.c:811
void DeCloneArchive(ArchiveHandle *AH)
ArchiveHandle * CloneArchive(ArchiveHandle *AH)
SetupWorkerPtrType SetupWorkerPtr

References CloneArchive(), DeCloneArchive(), DisconnectDatabase(), PIPE_READ, PIPE_WRITE, ParallelSlot::pipeRevRead, ParallelSlot::pipeRevWrite, _archiveHandle::public, set_cancel_slot_archive(), _archiveHandle::SetupWorkerPtr, and WaitForCommands().

Referenced by ParallelBackupStart().

◆ select_loop()

static int select_loop ( int  maxFd,
fd_set *  workerset 
)
static

Definition at line 1542 of file parallel.c.

1543 {
1544  int i;
1545  fd_set saveSet = *workerset;
1546 
1547  for (;;)
1548  {
1549  *workerset = saveSet;
1550  i = select(maxFd + 1, workerset, NULL, NULL, NULL);
1551 
1552 #ifndef WIN32
1553  if (i < 0 && errno == EINTR)
1554  continue;
1555 #else
1556  if (i == SOCKET_ERROR && WSAGetLastError() == WSAEINTR)
1557  continue;
1558 #endif
1559  break;
1560  }
1561 
1562  return i;
1563 }
#define EINTR
Definition: win32_port.h:351

References EINTR, i, and select.

Referenced by getMessageFromWorker().

◆ sendMessageToLeader()

static void sendMessageToLeader ( int  pipefd[2],
const char *  str 
)
static

Definition at line 1529 of file parallel.c.

1530 {
1531  int len = strlen(str) + 1;
1532 
1533  if (pipewrite(pipefd[PIPE_WRITE], str, len) != len)
1534  pg_fatal("could not write to the communication channel: %m");
1535 }
#define pipewrite(a, b, c)
Definition: parallel.c:141
const void size_t len

References len, pg_fatal, PIPE_WRITE, pipewrite, and generate_unaccent_rules::str.

Referenced by WaitForCommands().

◆ sendMessageToWorker()

static void sendMessageToWorker ( ParallelState pstate,
int  worker,
const char *  str 
)
static

Definition at line 1646 of file parallel.c.

1647 {
1648  int len = strlen(str) + 1;
1649 
1650  if (pipewrite(pstate->parallelSlot[worker].pipeWrite, str, len) != len)
1651  {
1652  pg_fatal("could not write to the communication channel: %m");
1653  }
1654 }

References len, ParallelState::parallelSlot, pg_fatal, ParallelSlot::pipeWrite, pipewrite, and generate_unaccent_rules::str.

Referenced by DispatchJobForTocEntry().

◆ set_archive_cancel_info()

void set_archive_cancel_info ( ArchiveHandle AH,
PGconn conn 
)

Definition at line 732 of file parallel.c.

733 {
734  PGcancel *oldConnCancel;
735 
736  /*
737  * Activate the interrupt handler if we didn't yet in this process. On
738  * Windows, this also initializes signal_info_lock; therefore it's
739  * important that this happen at least once before we fork off any
740  * threads.
741  */
743 
744  /*
745  * On Unix, we assume that storing a pointer value is atomic with respect
746  * to any possible signal interrupt. On Windows, use a critical section.
747  */
748 
749 #ifdef WIN32
750  EnterCriticalSection(&signal_info_lock);
751 #endif
752 
753  /* Free the old one if we have one */
754  oldConnCancel = AH->connCancel;
755  /* be sure interrupt handler doesn't use pointer while freeing */
756  AH->connCancel = NULL;
757 
758  if (oldConnCancel != NULL)
759  PQfreeCancel(oldConnCancel);
760 
761  /* Set the new one if specified */
762  if (conn)
763  AH->connCancel = PQgetCancel(conn);
764 
765  /*
766  * On Unix, there's only ever one active ArchiveHandle per process, so we
767  * can just set signal_info.myAH unconditionally. On Windows, do that
768  * only in the main thread; worker threads have to make sure their
769  * ArchiveHandle appears in the pstate data, which is dealt with in
770  * RunWorker().
771  */
772 #ifndef WIN32
773  signal_info.myAH = AH;
774 #else
775  if (mainThreadId == GetCurrentThreadId())
776  signal_info.myAH = AH;
777 #endif
778 
779 #ifdef WIN32
780  LeaveCriticalSection(&signal_info_lock);
781 #endif
782 }
static void setup_cancel_handler(void)
Definition: parallel.c:610
PGcancel * PQgetCancel(PGconn *conn)
Definition: fe-connect.c:4366
void PQfreeCancel(PGcancel *cancel)
Definition: fe-connect.c:4434
PGconn * conn
Definition: streamutil.c:54
ArchiveHandle * myAH
Definition: parallel.c:167
PGcancel *volatile connCancel

References conn, _archiveHandle::connCancel, DumpSignalInformation::myAH, PQfreeCancel(), PQgetCancel(), setup_cancel_handler(), and signal_info.

Referenced by ConnectDatabase(), DisconnectDatabase(), and ParallelBackupStart().

◆ set_cancel_pstate()

static void set_cancel_pstate ( ParallelState pstate)
static

Definition at line 791 of file parallel.c.

792 {
793 #ifdef WIN32
794  EnterCriticalSection(&signal_info_lock);
795 #endif
796 
797  signal_info.pstate = pstate;
798 
799 #ifdef WIN32
800  LeaveCriticalSection(&signal_info_lock);
801 #endif
802 }
ParallelState * pstate
Definition: parallel.c:168

References DumpSignalInformation::pstate, and signal_info.

Referenced by ParallelBackupEnd(), and ParallelBackupStart().

◆ set_cancel_slot_archive()

static void set_cancel_slot_archive ( ParallelSlot slot,
ArchiveHandle AH 
)
static

Definition at line 811 of file parallel.c.

812 {
813 #ifdef WIN32
814  EnterCriticalSection(&signal_info_lock);
815 #endif
816 
817  slot->AH = AH;
818 
819 #ifdef WIN32
820  LeaveCriticalSection(&signal_info_lock);
821 #endif
822 }

References ParallelSlot::AH.

Referenced by RunWorker().

◆ setup_cancel_handler()

static void setup_cancel_handler ( void  )
static

Definition at line 610 of file parallel.c.

611 {
612  /*
613  * When forking, signal_info.handler_set will propagate into the new
614  * process, but that's fine because the signal handler state does too.
615  */
617  {
618  signal_info.handler_set = true;
619 
620  pqsignal(SIGINT, sigTermHandler);
621  pqsignal(SIGTERM, sigTermHandler);
623  }
624 }
static void sigTermHandler(SIGNAL_ARGS)
Definition: parallel.c:547
#define SIGQUIT
Definition: win32_port.h:168

References DumpSignalInformation::handler_set, pqsignal(), signal_info, SIGQUIT, and sigTermHandler().

Referenced by main(), psql_setup_cancel_handler(), runInitSteps(), and set_archive_cancel_info().

◆ ShutdownWorkersHard()

static void ShutdownWorkersHard ( ParallelState pstate)
static

Definition at line 397 of file parallel.c.

398 {
399  int i;
400 
401  /*
402  * Close our write end of the sockets so that any workers waiting for
403  * commands know they can exit. (Note: some of the pipeWrite fields might
404  * still be zero, if we failed to initialize all the workers. Hence, just
405  * ignore errors here.)
406  */
407  for (i = 0; i < pstate->numWorkers; i++)
409 
410  /*
411  * Force early termination of any commands currently in progress.
412  */
413 #ifndef WIN32
414  /* On non-Windows, send SIGTERM to each worker process. */
415  for (i = 0; i < pstate->numWorkers; i++)
416  {
417  pid_t pid = pstate->parallelSlot[i].pid;
418 
419  if (pid != 0)
420  kill(pid, SIGTERM);
421  }
422 #else
423 
424  /*
425  * On Windows, send query cancels directly to the workers' backends. Use
426  * a critical section to ensure worker threads don't change state.
427  */
428  EnterCriticalSection(&signal_info_lock);
429  for (i = 0; i < pstate->numWorkers; i++)
430  {
431  ArchiveHandle *AH = pstate->parallelSlot[i].AH;
432  char errbuf[1];
433 
434  if (AH != NULL && AH->connCancel != NULL)
435  (void) PQcancel(AH->connCancel, errbuf, sizeof(errbuf));
436  }
437  LeaveCriticalSection(&signal_info_lock);
438 #endif
439 
440  /* Now wait for them to terminate. */
442 }
int PQcancel(PGcancel *cancel, char *errbuf, int errbufsize)
Definition: fe-connect.c:4481
#define kill(pid, sig)
Definition: win32_port.h:464

References ParallelSlot::AH, closesocket, _archiveHandle::connCancel, i, kill, ParallelState::numWorkers, ParallelState::parallelSlot, ParallelSlot::pid, ParallelSlot::pipeWrite, PQcancel(), and WaitForTerminatingWorkers().

Referenced by archive_close_connection().

◆ sigTermHandler()

static void sigTermHandler ( SIGNAL_ARGS  )
static

Definition at line 547 of file parallel.c.

548 {
549  int i;
550  char errbuf[1];
551 
552  /*
553  * Some platforms allow delivery of new signals to interrupt an active
554  * signal handler. That could muck up our attempt to send PQcancel, so
555  * disable the signals that setup_cancel_handler enabled.
556  */
557  pqsignal(SIGINT, SIG_IGN);
558  pqsignal(SIGTERM, SIG_IGN);
560 
561  /*
562  * If we're in the leader, forward signal to all workers. (It seems best
563  * to do this before PQcancel; killing the leader transaction will result
564  * in invalid-snapshot errors from active workers, which maybe we can
565  * quiet by killing workers first.) Ignore any errors.
566  */
567  if (signal_info.pstate != NULL)
568  {
569  for (i = 0; i < signal_info.pstate->numWorkers; i++)
570  {
571  pid_t pid = signal_info.pstate->parallelSlot[i].pid;
572 
573  if (pid != 0)
574  kill(pid, SIGTERM);
575  }
576  }
577 
578  /*
579  * Send QueryCancel if we have a connection to send to. Ignore errors,
580  * there's not much we can do about them anyway.
581  */
582  if (signal_info.myAH != NULL && signal_info.myAH->connCancel != NULL)
583  (void) PQcancel(signal_info.myAH->connCancel, errbuf, sizeof(errbuf));
584 
585  /*
586  * Report we're quitting, using nothing more complicated than write(2).
587  * When in parallel operation, only the leader process should do this.
588  */
589  if (!signal_info.am_worker)
590  {
591  if (progname)
592  {
594  write_stderr(": ");
595  }
596  write_stderr("terminated by user\n");
597  }
598 
599  /*
600  * And die, using _exit() not exit() because the latter will invoke atexit
601  * handlers that can fail if we interrupted related code.
602  */
603  _exit(1);
604 }
#define write_stderr(str)
Definition: parallel.c:186
const char * progname
Definition: main.c:50

References DumpSignalInformation::am_worker, _archiveHandle::connCancel, i, kill, DumpSignalInformation::myAH, ParallelState::numWorkers, ParallelState::parallelSlot, ParallelSlot::pid, PQcancel(), pqsignal(), progname, DumpSignalInformation::pstate, SIG_IGN, signal_info, SIGQUIT, and write_stderr.

Referenced by setup_cancel_handler().

◆ WaitForCommands()

static void WaitForCommands ( ArchiveHandle AH,
int  pipefd[2] 
)
static

Definition at line 1338 of file parallel.c.

1339 {
1340  char *command;
1341  TocEntry *te;
1342  T_Action act;
1343  int status = 0;
1344  char buf[256];
1345 
1346  for (;;)
1347  {
1348  if (!(command = getMessageFromLeader(pipefd)))
1349  {
1350  /* EOF, so done */
1351  return;
1352  }
1353 
1354  /* Decode the command */
1355  parseWorkerCommand(AH, &te, &act, command);
1356 
1357  if (act == ACT_DUMP)
1358  {
1359  /* Acquire lock on this table within the worker's session */
1360  lockTableForWorker(AH, te);
1361 
1362  /* Perform the dump command */
1363  status = (AH->WorkerJobDumpPtr) (AH, te);
1364  }
1365  else if (act == ACT_RESTORE)
1366  {
1367  /* Perform the restore command */
1368  status = (AH->WorkerJobRestorePtr) (AH, te);
1369  }
1370  else
1371  Assert(false);
1372 
1373  /* Return status to leader */
1374  buildWorkerResponse(AH, te, act, status, buf, sizeof(buf));
1375 
1376  sendMessageToLeader(pipefd, buf);
1377 
1378  /* command was pg_malloc'd and we are responsible for free()ing it. */
1379  free(command);
1380  }
1381 }
static void sendMessageToLeader(int pipefd[2], const char *str)
Definition: parallel.c:1529
static char * getMessageFromLeader(int pipefd[2])
Definition: parallel.c:1518
static void lockTableForWorker(ArchiveHandle *AH, TocEntry *te)
Definition: parallel.c:1303
static void buildWorkerResponse(ArchiveHandle *AH, TocEntry *te, T_Action act, int status, char *buf, int buflen)
Definition: parallel.c:1158
static void parseWorkerCommand(ArchiveHandle *AH, TocEntry **te, T_Action *act, const char *msg)
Definition: parallel.c:1125
WorkerJobDumpPtrType WorkerJobDumpPtr
WorkerJobRestorePtrType WorkerJobRestorePtr

References ACT_DUMP, ACT_RESTORE, Assert(), buf, buildWorkerResponse(), free, getMessageFromLeader(), lockTableForWorker(), parseWorkerCommand(), sendMessageToLeader(), status(), _archiveHandle::WorkerJobDumpPtr, and _archiveHandle::WorkerJobRestorePtr.

Referenced by RunWorker().

◆ WaitForTerminatingWorkers()

static void WaitForTerminatingWorkers ( ParallelState pstate)
static

Definition at line 448 of file parallel.c.

449 {
450  while (!HasEveryWorkerTerminated(pstate))
451  {
452  ParallelSlot *slot = NULL;
453  int j;
454 
455 #ifndef WIN32
456  /* On non-Windows, use wait() to wait for next worker to end */
457  int status;
458  pid_t pid = wait(&status);
459 
460  /* Find dead worker's slot, and clear the PID field */
461  for (j = 0; j < pstate->numWorkers; j++)
462  {
463  slot = &(pstate->parallelSlot[j]);
464  if (slot->pid == pid)
465  {
466  slot->pid = 0;
467  break;
468  }
469  }
470 #else /* WIN32 */
471  /* On Windows, we must use WaitForMultipleObjects() */
472  HANDLE *lpHandles = pg_malloc(sizeof(HANDLE) * pstate->numWorkers);
473  int nrun = 0;
474  DWORD ret;
475  uintptr_t hThread;
476 
477  for (j = 0; j < pstate->numWorkers; j++)
478  {
480  {
481  lpHandles[nrun] = (HANDLE) pstate->parallelSlot[j].hThread;
482  nrun++;
483  }
484  }
485  ret = WaitForMultipleObjects(nrun, lpHandles, false, INFINITE);
486  Assert(ret != WAIT_FAILED);
487  hThread = (uintptr_t) lpHandles[ret - WAIT_OBJECT_0];
488  free(lpHandles);
489 
490  /* Find dead worker's slot, and clear the hThread field */
491  for (j = 0; j < pstate->numWorkers; j++)
492  {
493  slot = &(pstate->parallelSlot[j]);
494  if (slot->hThread == hThread)
495  {
496  /* For cleanliness, close handles for dead threads */
497  CloseHandle((HANDLE) slot->hThread);
498  slot->hThread = (uintptr_t) INVALID_HANDLE_VALUE;
499  break;
500  }
501  }
502 #endif /* WIN32 */
503 
504  /* On all platforms, update workerStatus and te[] as well */
505  Assert(j < pstate->numWorkers);
507  pstate->te[j] = NULL;
508  }
509 }
static bool HasEveryWorkerTerminated(ParallelState *pstate)
Definition: parallel.c:1254

References Assert(), free, HasEveryWorkerTerminated(), j, ParallelState::numWorkers, ParallelState::parallelSlot, pg_malloc(), ParallelSlot::pid, status(), ParallelState::te, WORKER_IS_RUNNING, ParallelSlot::workerStatus, and WRKR_TERMINATED.

Referenced by ParallelBackupEnd(), and ShutdownWorkersHard().

◆ WaitForWorkers()

void WaitForWorkers ( ArchiveHandle AH,
ParallelState pstate,
WFW_WaitOption  mode 
)

Definition at line 1453 of file parallel.c.

1454 {
1455  bool do_wait = false;
1456 
1457  /*
1458  * In GOT_STATUS mode, always block waiting for a message, since we can't
1459  * return till we get something. In other modes, we don't block the first
1460  * time through the loop.
1461  */
1462  if (mode == WFW_GOT_STATUS)
1463  {
1464  /* Assert that caller knows what it's doing */
1465  Assert(!IsEveryWorkerIdle(pstate));
1466  do_wait = true;
1467  }
1468 
1469  for (;;)
1470  {
1471  /*
1472  * Check for status messages, even if we don't need to block. We do
1473  * not try very hard to reap all available messages, though, since
1474  * there's unlikely to be more than one.
1475  */
1476  if (ListenToWorkers(AH, pstate, do_wait))
1477  {
1478  /*
1479  * If we got a message, we are done by definition for GOT_STATUS
1480  * mode, and we can also be certain that there's at least one idle
1481  * worker. So we're done in all but ALL_IDLE mode.
1482  */
1483  if (mode != WFW_ALL_IDLE)
1484  return;
1485  }
1486 
1487  /* Check whether we must wait for new status messages */
1488  switch (mode)
1489  {
1490  case WFW_NO_WAIT:
1491  return; /* never wait */
1492  case WFW_GOT_STATUS:
1493  Assert(false); /* can't get here, because we waited */
1494  break;
1495  case WFW_ONE_IDLE:
1496  if (GetIdleWorker(pstate) != NO_SLOT)
1497  return;
1498  break;
1499  case WFW_ALL_IDLE:
1500  if (IsEveryWorkerIdle(pstate))
1501  return;
1502  break;
1503  }
1504 
1505  /* Loop back, and this time wait for something to happen */
1506  do_wait = true;
1507  }
1508 }
static bool ListenToWorkers(ArchiveHandle *AH, ParallelState *pstate, bool do_wait)
Definition: parallel.c:1400
@ WFW_ALL_IDLE
Definition: parallel.h:35
@ WFW_GOT_STATUS
Definition: parallel.h:33
@ WFW_NO_WAIT
Definition: parallel.h:32
static PgChecksumMode mode
Definition: pg_checksums.c:65

References Assert(), do_wait, GetIdleWorker(), IsEveryWorkerIdle(), ListenToWorkers(), mode, NO_SLOT, WFW_ALL_IDLE, WFW_GOT_STATUS, WFW_NO_WAIT, and WFW_ONE_IDLE.

Referenced by DispatchJobForTocEntry(), restore_toc_entries_parallel(), and WriteDataChunks().

Variable Documentation

◆ shutdown_info

ShutdownInformation shutdown_info
static

Definition at line 154 of file parallel.c.

Referenced by on_exit_close_archive(), ParallelBackupEnd(), and ParallelBackupStart().

◆ signal_info