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bgworker.h File Reference
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Data Structures

struct  BackgroundWorker
 

Macros

#define BGWORKER_SHMEM_ACCESS   0x0001
 
#define BGWORKER_BACKEND_DATABASE_CONNECTION   0x0002
 
#define BGWORKER_CLASS_PARALLEL   0x0010
 
#define BGW_DEFAULT_RESTART_INTERVAL   60
 
#define BGW_NEVER_RESTART   -1
 
#define BGW_MAXLEN   96
 
#define BGW_EXTRALEN   128
 
#define BGWORKER_BYPASS_ALLOWCONN   0x0001
 
#define BGWORKER_BYPASS_ROLELOGINCHECK   0x0002
 

Typedefs

typedef void(* bgworker_main_type) (Datum main_arg)
 
typedef struct BackgroundWorker BackgroundWorker
 
typedef enum BgwHandleStatus BgwHandleStatus
 
typedef struct BackgroundWorkerHandle BackgroundWorkerHandle
 

Enumerations

enum  BgWorkerStartTime { BgWorkerStart_PostmasterStart , BgWorkerStart_ConsistentState , BgWorkerStart_RecoveryFinished }
 
enum  BgwHandleStatus { BGWH_STARTED , BGWH_NOT_YET_STARTED , BGWH_STOPPED , BGWH_POSTMASTER_DIED }
 

Functions

void RegisterBackgroundWorker (BackgroundWorker *worker)
 
bool RegisterDynamicBackgroundWorker (BackgroundWorker *worker, BackgroundWorkerHandle **handle)
 
BgwHandleStatus GetBackgroundWorkerPid (BackgroundWorkerHandle *handle, pid_t *pidp)
 
BgwHandleStatus WaitForBackgroundWorkerStartup (BackgroundWorkerHandle *handle, pid_t *pidp)
 
BgwHandleStatus WaitForBackgroundWorkerShutdown (BackgroundWorkerHandle *)
 
const char * GetBackgroundWorkerTypeByPid (pid_t pid)
 
void TerminateBackgroundWorker (BackgroundWorkerHandle *handle)
 
void BackgroundWorkerInitializeConnection (const char *dbname, const char *username, uint32 flags)
 
void BackgroundWorkerInitializeConnectionByOid (Oid dboid, Oid useroid, uint32 flags)
 
void BackgroundWorkerBlockSignals (void)
 
void BackgroundWorkerUnblockSignals (void)
 

Variables

PGDLLIMPORT BackgroundWorkerMyBgworkerEntry
 

Macro Definition Documentation

◆ BGW_DEFAULT_RESTART_INTERVAL

#define BGW_DEFAULT_RESTART_INTERVAL   60

Definition at line 84 of file bgworker.h.

◆ BGW_EXTRALEN

#define BGW_EXTRALEN   128

Definition at line 87 of file bgworker.h.

◆ BGW_MAXLEN

#define BGW_MAXLEN   96

Definition at line 86 of file bgworker.h.

◆ BGW_NEVER_RESTART

#define BGW_NEVER_RESTART   -1

Definition at line 85 of file bgworker.h.

◆ BGWORKER_BACKEND_DATABASE_CONNECTION

#define BGWORKER_BACKEND_DATABASE_CONNECTION   0x0002

Definition at line 60 of file bgworker.h.

◆ BGWORKER_BYPASS_ALLOWCONN

#define BGWORKER_BYPASS_ALLOWCONN   0x0001

Definition at line 156 of file bgworker.h.

◆ BGWORKER_BYPASS_ROLELOGINCHECK

#define BGWORKER_BYPASS_ROLELOGINCHECK   0x0002

Definition at line 157 of file bgworker.h.

◆ BGWORKER_CLASS_PARALLEL

#define BGWORKER_CLASS_PARALLEL   0x0010

Definition at line 68 of file bgworker.h.

◆ BGWORKER_SHMEM_ACCESS

#define BGWORKER_SHMEM_ACCESS   0x0001

Definition at line 53 of file bgworker.h.

Typedef Documentation

◆ BackgroundWorker

◆ BackgroundWorkerHandle

Definition at line 112 of file bgworker.h.

◆ BgwHandleStatus

◆ bgworker_main_type

typedef void(* bgworker_main_type) (Datum main_arg)

Definition at line 72 of file bgworker.h.

Enumeration Type Documentation

◆ BgwHandleStatus

Enumerator
BGWH_STARTED 
BGWH_NOT_YET_STARTED 
BGWH_STOPPED 
BGWH_POSTMASTER_DIED 

Definition at line 103 of file bgworker.h.

104{
105 BGWH_STARTED, /* worker is running */
106 BGWH_NOT_YET_STARTED, /* worker hasn't been started yet */
107 BGWH_STOPPED, /* worker has exited */
108 BGWH_POSTMASTER_DIED, /* postmaster died; worker status unclear */
BgwHandleStatus
Definition: bgworker.h:104
@ BGWH_POSTMASTER_DIED
Definition: bgworker.h:108
@ BGWH_STARTED
Definition: bgworker.h:105
@ BGWH_NOT_YET_STARTED
Definition: bgworker.h:106
@ BGWH_STOPPED
Definition: bgworker.h:107

◆ BgWorkerStartTime

Enumerator
BgWorkerStart_PostmasterStart 
BgWorkerStart_ConsistentState 
BgWorkerStart_RecoveryFinished 

Definition at line 77 of file bgworker.h.

78{
BgWorkerStartTime
Definition: bgworker.h:78
@ BgWorkerStart_RecoveryFinished
Definition: bgworker.h:81
@ BgWorkerStart_ConsistentState
Definition: bgworker.h:80
@ BgWorkerStart_PostmasterStart
Definition: bgworker.h:79

Function Documentation

◆ BackgroundWorkerBlockSignals()

void BackgroundWorkerBlockSignals ( void  )

Definition at line 920 of file bgworker.c.

921{
922 sigprocmask(SIG_SETMASK, &BlockSig, NULL);
923}
sigset_t BlockSig
Definition: pqsignal.c:23

References BlockSig.

◆ BackgroundWorkerInitializeConnection()

void BackgroundWorkerInitializeConnection ( const char *  dbname,
const char *  username,
uint32  flags 
)

Definition at line 852 of file bgworker.c.

853{
855 bits32 init_flags = 0; /* never honor session_preload_libraries */
856
857 /* ignore datallowconn and ACL_CONNECT? */
858 if (flags & BGWORKER_BYPASS_ALLOWCONN)
859 init_flags |= INIT_PG_OVERRIDE_ALLOW_CONNS;
860 /* ignore rolcanlogin? */
862 init_flags |= INIT_PG_OVERRIDE_ROLE_LOGIN;
863
864 /* XXX is this the right errcode? */
867 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
868 errmsg("database connection requirement not indicated during registration")));
869
870 InitPostgres(dbname, InvalidOid, /* database to connect to */
871 username, InvalidOid, /* role to connect as */
872 init_flags,
873 NULL); /* no out_dbname */
874
875 /* it had better not gotten out of "init" mode yet */
878 (errmsg("invalid processing mode in background worker")));
880}
#define BGWORKER_BYPASS_ROLELOGINCHECK
Definition: bgworker.h:157
#define BGWORKER_BACKEND_DATABASE_CONNECTION
Definition: bgworker.h:60
#define BGWORKER_BYPASS_ALLOWCONN
Definition: bgworker.h:156
uint32 bits32
Definition: c.h:511
int errcode(int sqlerrcode)
Definition: elog.c:854
int errmsg(const char *fmt,...)
Definition: elog.c:1071
#define FATAL
Definition: elog.h:41
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:149
static char * username
Definition: initdb.c:153
@ NormalProcessing
Definition: miscadmin.h:472
#define IsInitProcessingMode()
Definition: miscadmin.h:478
#define SetProcessingMode(mode)
Definition: miscadmin.h:483
#define INIT_PG_OVERRIDE_ROLE_LOGIN
Definition: miscadmin.h:501
#define INIT_PG_OVERRIDE_ALLOW_CONNS
Definition: miscadmin.h:500
#define InvalidOid
Definition: postgres_ext.h:35
void InitPostgres(const char *in_dbname, Oid dboid, const char *username, Oid useroid, bits32 flags, char *out_dbname)
Definition: postinit.c:723
BackgroundWorker * MyBgworkerEntry
Definition: postmaster.c:200
char * dbname
Definition: streamutil.c:49

References BackgroundWorker::bgw_flags, BGWORKER_BACKEND_DATABASE_CONNECTION, BGWORKER_BYPASS_ALLOWCONN, BGWORKER_BYPASS_ROLELOGINCHECK, dbname, ereport, errcode(), errmsg(), ERROR, FATAL, INIT_PG_OVERRIDE_ALLOW_CONNS, INIT_PG_OVERRIDE_ROLE_LOGIN, InitPostgres(), InvalidOid, IsInitProcessingMode, MyBgworkerEntry, NormalProcessing, SetProcessingMode, and username.

Referenced by ApplyLauncherMain(), and worker_spi_main().

◆ BackgroundWorkerInitializeConnectionByOid()

void BackgroundWorkerInitializeConnectionByOid ( Oid  dboid,
Oid  useroid,
uint32  flags 
)

Definition at line 886 of file bgworker.c.

887{
889 bits32 init_flags = 0; /* never honor session_preload_libraries */
890
891 /* ignore datallowconn and ACL_CONNECT? */
892 if (flags & BGWORKER_BYPASS_ALLOWCONN)
893 init_flags |= INIT_PG_OVERRIDE_ALLOW_CONNS;
894 /* ignore rolcanlogin? */
896 init_flags |= INIT_PG_OVERRIDE_ROLE_LOGIN;
897
898 /* XXX is this the right errcode? */
901 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
902 errmsg("database connection requirement not indicated during registration")));
903
904 InitPostgres(NULL, dboid, /* database to connect to */
905 NULL, useroid, /* role to connect as */
906 init_flags,
907 NULL); /* no out_dbname */
908
909 /* it had better not gotten out of "init" mode yet */
912 (errmsg("invalid processing mode in background worker")));
914}

References BackgroundWorker::bgw_flags, BGWORKER_BACKEND_DATABASE_CONNECTION, BGWORKER_BYPASS_ALLOWCONN, BGWORKER_BYPASS_ROLELOGINCHECK, ereport, errcode(), errmsg(), ERROR, FATAL, INIT_PG_OVERRIDE_ALLOW_CONNS, INIT_PG_OVERRIDE_ROLE_LOGIN, InitPostgres(), IsInitProcessingMode, MyBgworkerEntry, NormalProcessing, and SetProcessingMode.

Referenced by autoprewarm_database_main(), InitializeLogRepWorker(), ParallelWorkerMain(), and worker_spi_main().

◆ BackgroundWorkerUnblockSignals()

void BackgroundWorkerUnblockSignals ( void  )

◆ GetBackgroundWorkerPid()

BgwHandleStatus GetBackgroundWorkerPid ( BackgroundWorkerHandle handle,
pid_t *  pidp 
)

Definition at line 1157 of file bgworker.c.

1158{
1160 pid_t pid;
1161
1162 Assert(handle->slot < max_worker_processes);
1163 slot = &BackgroundWorkerData->slot[handle->slot];
1164
1165 /*
1166 * We could probably arrange to synchronize access to data using memory
1167 * barriers only, but for now, let's just keep it simple and grab the
1168 * lock. It seems unlikely that there will be enough traffic here to
1169 * result in meaningful contention.
1170 */
1171 LWLockAcquire(BackgroundWorkerLock, LW_SHARED);
1172
1173 /*
1174 * The generation number can't be concurrently changed while we hold the
1175 * lock. The pid, which is updated by the postmaster, can change at any
1176 * time, but we assume such changes are atomic. So the value we read
1177 * won't be garbage, but it might be out of date by the time the caller
1178 * examines it (but that's unavoidable anyway).
1179 *
1180 * The in_use flag could be in the process of changing from true to false,
1181 * but if it is already false then it can't change further.
1182 */
1183 if (handle->generation != slot->generation || !slot->in_use)
1184 pid = 0;
1185 else
1186 pid = slot->pid;
1187
1188 /* All done. */
1189 LWLockRelease(BackgroundWorkerLock);
1190
1191 if (pid == 0)
1192 return BGWH_STOPPED;
1193 else if (pid == InvalidPid)
1194 return BGWH_NOT_YET_STARTED;
1195 *pidp = pid;
1196 return BGWH_STARTED;
1197}
static BackgroundWorkerArray * BackgroundWorkerData
Definition: bgworker.c:108
int max_worker_processes
Definition: globals.c:145
Assert(PointerIsAligned(start, uint64))
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1182
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1902
@ LW_SHARED
Definition: lwlock.h:115
#define InvalidPid
Definition: miscadmin.h:32
BackgroundWorkerSlot slot[FLEXIBLE_ARRAY_MEMBER]
Definition: bgworker.c:99

References Assert(), BackgroundWorkerData, BGWH_NOT_YET_STARTED, BGWH_STARTED, BGWH_STOPPED, BackgroundWorkerSlot::generation, BackgroundWorkerHandle::generation, BackgroundWorkerSlot::in_use, InvalidPid, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_worker_processes, BackgroundWorkerSlot::pid, BackgroundWorkerArray::slot, and BackgroundWorkerHandle::slot.

Referenced by check_worker_status(), shm_mq_counterparty_gone(), shm_mq_wait_internal(), WaitForBackgroundWorkerShutdown(), WaitForBackgroundWorkerStartup(), WaitForParallelWorkersToAttach(), WaitForParallelWorkersToFinish(), and WaitForReplicationWorkerAttach().

◆ GetBackgroundWorkerTypeByPid()

const char * GetBackgroundWorkerTypeByPid ( pid_t  pid)

Definition at line 1371 of file bgworker.c.

1372{
1373 int slotno;
1374 bool found = false;
1375 static char result[BGW_MAXLEN];
1376
1377 LWLockAcquire(BackgroundWorkerLock, LW_SHARED);
1378
1379 for (slotno = 0; slotno < BackgroundWorkerData->total_slots; slotno++)
1380 {
1382
1383 if (slot->pid > 0 && slot->pid == pid)
1384 {
1385 strcpy(result, slot->worker.bgw_type);
1386 found = true;
1387 break;
1388 }
1389 }
1390
1391 LWLockRelease(BackgroundWorkerLock);
1392
1393 if (!found)
1394 return NULL;
1395
1396 return result;
1397}
#define BGW_MAXLEN
Definition: bgworker.h:86
BackgroundWorker worker
Definition: bgworker.c:80
char bgw_type[BGW_MAXLEN]
Definition: bgworker.h:92

References BackgroundWorkerData, BGW_MAXLEN, BackgroundWorker::bgw_type, LW_SHARED, LWLockAcquire(), LWLockRelease(), BackgroundWorkerSlot::pid, BackgroundWorkerArray::slot, BackgroundWorkerArray::total_slots, and BackgroundWorkerSlot::worker.

Referenced by pg_stat_get_activity().

◆ RegisterBackgroundWorker()

void RegisterBackgroundWorker ( BackgroundWorker worker)

Definition at line 939 of file bgworker.c.

940{
942 static int numworkers = 0;
943
944 /*
945 * Static background workers can only be registered in the postmaster
946 * process.
947 */
949 {
950 /*
951 * In EXEC_BACKEND or single-user mode, we process
952 * shared_preload_libraries in backend processes too. We cannot
953 * register static background workers at that stage, but many
954 * libraries' _PG_init() functions don't distinguish whether they're
955 * being loaded in the postmaster or in a backend, they just check
956 * process_shared_preload_libraries_in_progress. It's a bit sloppy,
957 * but for historical reasons we tolerate it. In EXEC_BACKEND mode,
958 * the background workers should already have been registered when the
959 * library was loaded in postmaster.
960 */
962 return;
963 ereport(LOG,
964 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
965 errmsg("background worker \"%s\": must be registered in \"shared_preload_libraries\"",
966 worker->bgw_name)));
967 return;
968 }
969
970 /*
971 * Cannot register static background workers after calling
972 * BackgroundWorkerShmemInit().
973 */
974 if (BackgroundWorkerData != NULL)
975 elog(ERROR, "cannot register background worker \"%s\" after shmem init",
976 worker->bgw_name);
977
979 (errmsg_internal("registering background worker \"%s\"", worker->bgw_name)));
980
981 if (!SanityCheckBackgroundWorker(worker, LOG))
982 return;
983
984 if (worker->bgw_notify_pid != 0)
985 {
986 ereport(LOG,
987 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
988 errmsg("background worker \"%s\": only dynamic background workers can request notification",
989 worker->bgw_name)));
990 return;
991 }
992
993 /*
994 * Enforce maximum number of workers. Note this is overly restrictive: we
995 * could allow more non-shmem-connected workers, because these don't count
996 * towards the MAX_BACKENDS limit elsewhere. For now, it doesn't seem
997 * important to relax this restriction.
998 */
999 if (++numworkers > max_worker_processes)
1000 {
1001 ereport(LOG,
1002 (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
1003 errmsg("too many background workers"),
1004 errdetail_plural("Up to %d background worker can be registered with the current settings.",
1005 "Up to %d background workers can be registered with the current settings.",
1008 errhint("Consider increasing the configuration parameter \"%s\".", "max_worker_processes")));
1009 return;
1010 }
1011
1012 /*
1013 * Copy the registration data into the registered workers list.
1014 */
1016 sizeof(RegisteredBgWorker),
1018 if (rw == NULL)
1019 {
1020 ereport(LOG,
1021 (errcode(ERRCODE_OUT_OF_MEMORY),
1022 errmsg("out of memory")));
1023 return;
1024 }
1025
1026 rw->rw_worker = *worker;
1027 rw->rw_pid = 0;
1028 rw->rw_crashed_at = 0;
1029 rw->rw_terminate = false;
1030
1032}
static bool SanityCheckBackgroundWorker(BackgroundWorker *worker, int elevel)
Definition: bgworker.c:631
dlist_head BackgroundWorkerList
Definition: bgworker.c:40
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1158
int errdetail_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:1296
int errhint(const char *fmt,...)
Definition: elog.c:1318
#define LOG
Definition: elog.h:31
#define DEBUG1
Definition: elog.h:30
#define elog(elevel,...)
Definition: elog.h:225
#define MCXT_ALLOC_NO_OOM
Definition: fe_memutils.h:29
bool IsUnderPostmaster
Definition: globals.c:121
bool IsPostmasterEnvironment
Definition: globals.c:120
static void dlist_push_head(dlist_head *head, dlist_node *node)
Definition: ilist.h:347
void * MemoryContextAllocExtended(MemoryContext context, Size size, int flags)
Definition: mcxt.c:1317
MemoryContext PostmasterContext
Definition: mcxt.c:167
bool process_shared_preload_libraries_in_progress
Definition: miscinit.c:1837
char bgw_name[BGW_MAXLEN]
Definition: bgworker.h:91
pid_t bgw_notify_pid
Definition: bgworker.h:100
BackgroundWorker rw_worker

References BackgroundWorkerData, BackgroundWorkerList, BackgroundWorker::bgw_name, BackgroundWorker::bgw_notify_pid, DEBUG1, dlist_push_head(), elog, ereport, errcode(), errdetail_plural(), errhint(), errmsg(), errmsg_internal(), ERROR, IsPostmasterEnvironment, IsUnderPostmaster, LOG, max_worker_processes, MCXT_ALLOC_NO_OOM, MemoryContextAllocExtended(), PostmasterContext, process_shared_preload_libraries_in_progress, RegisteredBgWorker::rw_crashed_at, RegisteredBgWorker::rw_lnode, RegisteredBgWorker::rw_pid, RegisteredBgWorker::rw_terminate, RegisteredBgWorker::rw_worker, and SanityCheckBackgroundWorker().

Referenced by _PG_init(), ApplyLauncherRegister(), and apw_start_leader_worker().

◆ RegisterDynamicBackgroundWorker()

bool RegisterDynamicBackgroundWorker ( BackgroundWorker worker,
BackgroundWorkerHandle **  handle 
)

Definition at line 1045 of file bgworker.c.

1047{
1048 int slotno;
1049 bool success = false;
1050 bool parallel;
1051 uint64 generation = 0;
1052
1053 /*
1054 * We can't register dynamic background workers from the postmaster. If
1055 * this is a standalone backend, we're the only process and can't start
1056 * any more. In a multi-process environment, it might be theoretically
1057 * possible, but we don't currently support it due to locking
1058 * considerations; see comments on the BackgroundWorkerSlot data
1059 * structure.
1060 */
1061 if (!IsUnderPostmaster)
1062 return false;
1063
1064 if (!SanityCheckBackgroundWorker(worker, ERROR))
1065 return false;
1066
1067 parallel = (worker->bgw_flags & BGWORKER_CLASS_PARALLEL) != 0;
1068
1069 LWLockAcquire(BackgroundWorkerLock, LW_EXCLUSIVE);
1070
1071 /*
1072 * If this is a parallel worker, check whether there are already too many
1073 * parallel workers; if so, don't register another one. Our view of
1074 * parallel_terminate_count may be slightly stale, but that doesn't really
1075 * matter: we would have gotten the same result if we'd arrived here
1076 * slightly earlier anyway. There's no help for it, either, since the
1077 * postmaster must not take locks; a memory barrier wouldn't guarantee
1078 * anything useful.
1079 */
1083 {
1087 LWLockRelease(BackgroundWorkerLock);
1088 return false;
1089 }
1090
1091 /*
1092 * Look for an unused slot. If we find one, grab it.
1093 */
1094 for (slotno = 0; slotno < BackgroundWorkerData->total_slots; ++slotno)
1095 {
1097
1098 if (!slot->in_use)
1099 {
1100 memcpy(&slot->worker, worker, sizeof(BackgroundWorker));
1101 slot->pid = InvalidPid; /* indicates not started yet */
1102 slot->generation++;
1103 slot->terminate = false;
1104 generation = slot->generation;
1105 if (parallel)
1107
1108 /*
1109 * Make sure postmaster doesn't see the slot as in use before it
1110 * sees the new contents.
1111 */
1113
1114 slot->in_use = true;
1115 success = true;
1116 break;
1117 }
1118 }
1119
1120 LWLockRelease(BackgroundWorkerLock);
1121
1122 /* If we found a slot, tell the postmaster to notice the change. */
1123 if (success)
1125
1126 /*
1127 * If we found a slot and the user has provided a handle, initialize it.
1128 */
1129 if (success && handle)
1130 {
1131 *handle = palloc(sizeof(BackgroundWorkerHandle));
1132 (*handle)->slot = slotno;
1133 (*handle)->generation = generation;
1134 }
1135
1136 return success;
1137}
#define pg_write_barrier()
Definition: atomics.h:157
#define BGWORKER_CLASS_PARALLEL
Definition: bgworker.h:68
#define MAX_PARALLEL_WORKER_LIMIT
uint64_t uint64
Definition: c.h:503
int max_parallel_workers
Definition: globals.c:146
static bool success
Definition: initdb.c:187
@ LW_EXCLUSIVE
Definition: lwlock.h:114
void * palloc(Size size)
Definition: mcxt.c:1943
void SendPostmasterSignal(PMSignalReason reason)
Definition: pmsignal.c:165
@ PMSIGNAL_BACKGROUND_WORKER_CHANGE
Definition: pmsignal.h:41
uint32 parallel_terminate_count
Definition: bgworker.c:98
uint32 parallel_register_count
Definition: bgworker.c:97

References Assert(), BackgroundWorkerData, BackgroundWorker::bgw_flags, BGWORKER_CLASS_PARALLEL, ERROR, BackgroundWorkerSlot::generation, BackgroundWorkerSlot::in_use, InvalidPid, IsUnderPostmaster, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAX_PARALLEL_WORKER_LIMIT, max_parallel_workers, palloc(), BackgroundWorkerArray::parallel_register_count, BackgroundWorkerArray::parallel_terminate_count, pg_write_barrier, BackgroundWorkerSlot::pid, PMSIGNAL_BACKGROUND_WORKER_CHANGE, SanityCheckBackgroundWorker(), SendPostmasterSignal(), BackgroundWorkerArray::slot, success, BackgroundWorkerSlot::terminate, BackgroundWorkerArray::total_slots, and BackgroundWorkerSlot::worker.

Referenced by apw_start_database_worker(), apw_start_leader_worker(), LaunchParallelWorkers(), logicalrep_worker_launch(), setup_background_workers(), and worker_spi_launch().

◆ TerminateBackgroundWorker()

void TerminateBackgroundWorker ( BackgroundWorkerHandle handle)

Definition at line 1296 of file bgworker.c.

1297{
1299 bool signal_postmaster = false;
1300
1301 Assert(handle->slot < max_worker_processes);
1302 slot = &BackgroundWorkerData->slot[handle->slot];
1303
1304 /* Set terminate flag in shared memory, unless slot has been reused. */
1305 LWLockAcquire(BackgroundWorkerLock, LW_EXCLUSIVE);
1306 if (handle->generation == slot->generation)
1307 {
1308 slot->terminate = true;
1309 signal_postmaster = true;
1310 }
1311 LWLockRelease(BackgroundWorkerLock);
1312
1313 /* Make sure the postmaster notices the change to shared memory. */
1314 if (signal_postmaster)
1316}

References Assert(), BackgroundWorkerData, BackgroundWorkerSlot::generation, BackgroundWorkerHandle::generation, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), max_worker_processes, PMSIGNAL_BACKGROUND_WORKER_CHANGE, SendPostmasterSignal(), BackgroundWorkerArray::slot, BackgroundWorkerHandle::slot, and BackgroundWorkerSlot::terminate.

Referenced by cleanup_background_workers(), and DestroyParallelContext().

◆ WaitForBackgroundWorkerShutdown()

BgwHandleStatus WaitForBackgroundWorkerShutdown ( BackgroundWorkerHandle handle)

Definition at line 1257 of file bgworker.c.

1258{
1259 BgwHandleStatus status;
1260 int rc;
1261
1262 for (;;)
1263 {
1264 pid_t pid;
1265
1267
1268 status = GetBackgroundWorkerPid(handle, &pid);
1269 if (status == BGWH_STOPPED)
1270 break;
1271
1272 rc = WaitLatch(MyLatch,
1274 WAIT_EVENT_BGWORKER_SHUTDOWN);
1275
1276 if (rc & WL_POSTMASTER_DEATH)
1277 {
1278 status = BGWH_POSTMASTER_DIED;
1279 break;
1280 }
1281
1283 }
1284
1285 return status;
1286}
BgwHandleStatus GetBackgroundWorkerPid(BackgroundWorkerHandle *handle, pid_t *pidp)
Definition: bgworker.c:1157
struct Latch * MyLatch
Definition: globals.c:64
void ResetLatch(Latch *latch)
Definition: latch.c:372
int WaitLatch(Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:172
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:123
#define WL_LATCH_SET
Definition: waiteventset.h:34
#define WL_POSTMASTER_DEATH
Definition: waiteventset.h:38

References BGWH_POSTMASTER_DIED, BGWH_STOPPED, CHECK_FOR_INTERRUPTS, GetBackgroundWorkerPid(), MyLatch, ResetLatch(), WaitLatch(), WL_LATCH_SET, and WL_POSTMASTER_DEATH.

Referenced by apw_start_database_worker(), and WaitForParallelWorkersToExit().

◆ WaitForBackgroundWorkerStartup()

BgwHandleStatus WaitForBackgroundWorkerStartup ( BackgroundWorkerHandle handle,
pid_t *  pidp 
)

Definition at line 1212 of file bgworker.c.

1213{
1214 BgwHandleStatus status;
1215 int rc;
1216
1217 for (;;)
1218 {
1219 pid_t pid;
1220
1222
1223 status = GetBackgroundWorkerPid(handle, &pid);
1224 if (status == BGWH_STARTED)
1225 *pidp = pid;
1226 if (status != BGWH_NOT_YET_STARTED)
1227 break;
1228
1229 rc = WaitLatch(MyLatch,
1231 WAIT_EVENT_BGWORKER_STARTUP);
1232
1233 if (rc & WL_POSTMASTER_DEATH)
1234 {
1235 status = BGWH_POSTMASTER_DIED;
1236 break;
1237 }
1238
1240 }
1241
1242 return status;
1243}

References BGWH_NOT_YET_STARTED, BGWH_POSTMASTER_DIED, BGWH_STARTED, CHECK_FOR_INTERRUPTS, GetBackgroundWorkerPid(), MyLatch, ResetLatch(), WaitLatch(), WL_LATCH_SET, and WL_POSTMASTER_DEATH.

Referenced by apw_start_leader_worker(), and worker_spi_launch().

Variable Documentation

◆ MyBgworkerEntry