#include "postgres.h"
#include "access/heapam.h"
#include "access/htup.h"
#include "access/htup_details.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/pg_subscription.h"
#include "catalog/pg_subscription_rel.h"
#include "funcapi.h"
#include "lib/dshash.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/bgworker.h"
#include "postmaster/fork_process.h"
#include "postmaster/interrupt.h"
#include "postmaster/postmaster.h"
#include "replication/logicallauncher.h"
#include "replication/logicalworker.h"
#include "replication/slot.h"
#include "replication/walreceiver.h"
#include "replication/worker_internal.h"
#include "storage/ipc.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "storage/procsignal.h"
#include "tcop/tcopprot.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "utils/pg_lsn.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
#include "utils/timeout.h"

Include dependency graph for launcher.c:

Data Structures
struct	LogicalRepCtxStruct

struct	LauncherLastStartTimesEntry

Macros
#define	DEFAULT_NAPTIME_PER_CYCLE 180000L

#define	PG_STAT_GET_SUBSCRIPTION_COLS 10

Typedefs
typedef struct LogicalRepCtxStruct	LogicalRepCtxStruct

typedef struct LauncherLastStartTimesEntry	LauncherLastStartTimesEntry

Functions
static void	ApplyLauncherWakeup (void)

static void	logicalrep_launcher_onexit (int code, Datum arg)

static void	logicalrep_worker_onexit (int code, Datum arg)

static void	logicalrep_worker_detach (void)

static void	logicalrep_worker_cleanup (LogicalRepWorker *worker)

static int	logicalrep_pa_worker_count (Oid subid)

static void	logicalrep_launcher_attach_dshmem (void)

static void	ApplyLauncherSetWorkerStartTime (Oid subid, TimestampTz start_time)

static TimestampTz	ApplyLauncherGetWorkerStartTime (Oid subid)

static List *	get_subscription_list (void)

static bool	WaitForReplicationWorkerAttach (LogicalRepWorker worker, uint16 generation, BackgroundWorkerHandle handle)

LogicalRepWorker *	logicalrep_worker_find (Oid subid, Oid relid, bool only_running)

List *	logicalrep_workers_find (Oid subid, bool only_running)

bool	logicalrep_worker_launch (LogicalRepWorkerType wtype, Oid dbid, Oid subid, const char *subname, Oid userid, Oid relid, dsm_handle subworker_dsm)

static void	logicalrep_worker_stop_internal (LogicalRepWorker *worker, int signo)

void	logicalrep_worker_stop (Oid subid, Oid relid)

void	logicalrep_pa_worker_stop (ParallelApplyWorkerInfo *winfo)

void	logicalrep_worker_wakeup (Oid subid, Oid relid)

void	logicalrep_worker_wakeup_ptr (LogicalRepWorker *worker)

void	logicalrep_worker_attach (int slot)

int	logicalrep_sync_worker_count (Oid subid)

Size	ApplyLauncherShmemSize (void)

void	ApplyLauncherRegister (void)

void	ApplyLauncherShmemInit (void)

void	ApplyLauncherForgetWorkerStartTime (Oid subid)

void	AtEOXact_ApplyLauncher (bool isCommit)

void	ApplyLauncherWakeupAtCommit (void)

void	ApplyLauncherMain (Datum main_arg)

bool	IsLogicalLauncher (void)

pid_t	GetLeaderApplyWorkerPid (pid_t pid)

Datum	pg_stat_get_subscription (PG_FUNCTION_ARGS)

Variables
int	max_logical_replication_workers = 4

int	max_sync_workers_per_subscription = 2

int	max_parallel_apply_workers_per_subscription = 2

LogicalRepWorker *	MyLogicalRepWorker = NULL

static LogicalRepCtxStruct *	LogicalRepCtx

static const dshash_parameters	dsh_params

static dsa_area *	last_start_times_dsa = NULL

static dshash_table *	last_start_times = NULL

static bool	on_commit_launcher_wakeup = false

Macro Definition Documentation

◆ DEFAULT_NAPTIME_PER_CYCLE

#define DEFAULT_NAPTIME_PER_CYCLE 180000L

Definition at line 54 of file launcher.c.

◆ PG_STAT_GET_SUBSCRIPTION_COLS

#define PG_STAT_GET_SUBSCRIPTION_COLS 10

Typedef Documentation

◆ LauncherLastStartTimesEntry

typedef struct LauncherLastStartTimesEntry LauncherLastStartTimesEntry

◆ LogicalRepCtxStruct

typedef struct LogicalRepCtxStruct LogicalRepCtxStruct

Function Documentation

◆ ApplyLauncherForgetWorkerStartTime()

void ApplyLauncherForgetWorkerStartTime ( Oid subid )

Definition at line 1074 of file launcher.c.

 {
     logicalrep_launcher_attach_dshmem();
  
     (void) dshash_delete_key(last_start_times, &subid);
 }

References dshash_delete_key(), last_start_times, and logicalrep_launcher_attach_dshmem().

Referenced by apply_worker_exit(), DisableSubscriptionAndExit(), DropSubscription(), InitializeLogRepWorker(), maybe_reread_subscription(), and process_syncing_tables_for_apply().

◆ ApplyLauncherGetWorkerStartTime()

static TimestampTz ApplyLauncherGetWorkerStartTime ( Oid subid )

static

Definition at line 1048 of file launcher.c.

 {
     LauncherLastStartTimesEntry *entry;
     TimestampTz ret;
  
     logicalrep_launcher_attach_dshmem();
  
     entry = dshash_find(last_start_times, &subid, false);
     if (entry == NULL)
         return 0;
  
     ret = entry->last_start_time;
     dshash_release_lock(last_start_times, entry);
  
     return ret;
 }

References dshash_find(), dshash_release_lock(), LauncherLastStartTimesEntry::last_start_time, last_start_times, and logicalrep_launcher_attach_dshmem().

Referenced by ApplyLauncherMain().

◆ ApplyLauncherMain()

void ApplyLauncherMain ( Datum main_arg )

Definition at line 1121 of file launcher.c.

 {
     ereport(DEBUG1,
             (errmsg_internal("logical replication launcher started")));
  
     before_shmem_exit(logicalrep_launcher_onexit, (Datum) 0);
  
     Assert(LogicalRepCtx->launcher_pid == 0);
     LogicalRepCtx->launcher_pid = MyProcPid;
  
     /* Establish signal handlers. */
     pqsignal(SIGHUP, SignalHandlerForConfigReload);
     pqsignal(SIGTERM, die);
     BackgroundWorkerUnblockSignals();
  
     /*
      * Establish connection to nailed catalogs (we only ever access
      * pg_subscription).
      */
     BackgroundWorkerInitializeConnection(NULL, NULL, 0);
  
     /* Enter main loop */
     for (;;)
     {
         int         rc;
         List       *sublist;
         ListCell   *lc;
         MemoryContext subctx;
         MemoryContext oldctx;
         long        wait_time = DEFAULT_NAPTIME_PER_CYCLE;
  
         CHECK_FOR_INTERRUPTS();
  
         /* Use temporary context to avoid leaking memory across cycles. */
         subctx = AllocSetContextCreate(TopMemoryContext,
                                        "Logical Replication Launcher sublist",
                                        ALLOCSET_DEFAULT_SIZES);
         oldctx = MemoryContextSwitchTo(subctx);
  
         /* Start any missing workers for enabled subscriptions. */
         sublist = get_subscription_list();
         foreach(lc, sublist)
         {
             Subscription *sub = (Subscription *) lfirst(lc);
             LogicalRepWorker *w;
             TimestampTz last_start;
             TimestampTz now;
             long        elapsed;
  
             if (!sub->enabled)
                 continue;
  
             LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
             w = logicalrep_worker_find(sub->oid, InvalidOid, false);
             LWLockRelease(LogicalRepWorkerLock);
  
             if (w != NULL)
                 continue;       /* worker is running already */
  
             /*
              * If the worker is eligible to start now, launch it.  Otherwise,
              * adjust wait_time so that we'll wake up as soon as it can be
              * started.
              *
              * Each subscription's apply worker can only be restarted once per
              * wal_retrieve_retry_interval, so that errors do not cause us to
              * repeatedly restart the worker as fast as possible.  In cases
              * where a restart is expected (e.g., subscription parameter
              * changes), another process should remove the last-start entry
              * for the subscription so that the worker can be restarted
              * without waiting for wal_retrieve_retry_interval to elapse.
              */
             last_start = ApplyLauncherGetWorkerStartTime(sub->oid);
             now = GetCurrentTimestamp();
             if (last_start == 0 ||
                 (elapsed = TimestampDifferenceMilliseconds(last_start, now)) >= wal_retrieve_retry_interval)
             {
                 ApplyLauncherSetWorkerStartTime(sub->oid, now);
                 logicalrep_worker_launch(WORKERTYPE_APPLY,
                                          sub->dbid, sub->oid, sub->name,
                                          sub->owner, InvalidOid,
                                          DSM_HANDLE_INVALID);
             }
             else
             {
                 wait_time = Min(wait_time,
                                 wal_retrieve_retry_interval - elapsed);
             }
         }
  
         /* Switch back to original memory context. */
         MemoryContextSwitchTo(oldctx);
         /* Clean the temporary memory. */
         MemoryContextDelete(subctx);
  
         /* Wait for more work. */
         rc = WaitLatch(MyLatch,
                        WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
                        wait_time,
                        WAIT_EVENT_LOGICAL_LAUNCHER_MAIN);
  
         if (rc & WL_LATCH_SET)
         {
             ResetLatch(MyLatch);
             CHECK_FOR_INTERRUPTS();
         }
  
         if (ConfigReloadPending)
         {
             ConfigReloadPending = false;
             ProcessConfigFile(PGC_SIGHUP);
         }
     }
  
     /* Not reachable */
 }

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, ApplyLauncherGetWorkerStartTime(), ApplyLauncherSetWorkerStartTime(), Assert(), BackgroundWorkerInitializeConnection(), BackgroundWorkerUnblockSignals(), before_shmem_exit(), CHECK_FOR_INTERRUPTS, ConfigReloadPending, Subscription::dbid, DEBUG1, DEFAULT_NAPTIME_PER_CYCLE, die, DSM_HANDLE_INVALID, Subscription::enabled, ereport, errmsg_internal(), get_subscription_list(), GetCurrentTimestamp(), InvalidOid, LogicalRepCtxStruct::launcher_pid, lfirst, logicalrep_launcher_onexit(), logicalrep_worker_find(), logicalrep_worker_launch(), LogicalRepCtx, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemoryContextDelete(), MemoryContextSwitchTo(), Min, MyLatch, MyProcPid, Subscription::name, now(), Subscription::oid, Subscription::owner, PGC_SIGHUP, pqsignal(), ProcessConfigFile(), ResetLatch(), SIGHUP, SignalHandlerForConfigReload(), TimestampDifferenceMilliseconds(), TopMemoryContext, WaitLatch(), wal_retrieve_retry_interval, WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, WL_TIMEOUT, and WORKERTYPE_APPLY.

◆ ApplyLauncherRegister()

void ApplyLauncherRegister ( void )

Definition at line 924 of file launcher.c.

 {
     BackgroundWorker bgw;
  
     if (max_logical_replication_workers == 0)
         return;
  
     memset(&bgw, 0, sizeof(bgw));
     bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
         BGWORKER_BACKEND_DATABASE_CONNECTION;
     bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
     snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
     snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ApplyLauncherMain");
     snprintf(bgw.bgw_name, BGW_MAXLEN,
              "logical replication launcher");
     snprintf(bgw.bgw_type, BGW_MAXLEN,
              "logical replication launcher");
     bgw.bgw_restart_time = 5;
     bgw.bgw_notify_pid = 0;
     bgw.bgw_main_arg = (Datum) 0;
  
     RegisterBackgroundWorker(&bgw);
 }

References BackgroundWorker::bgw_flags, BackgroundWorker::bgw_function_name, BackgroundWorker::bgw_library_name, BackgroundWorker::bgw_main_arg, BGW_MAXLEN, BackgroundWorker::bgw_name, BackgroundWorker::bgw_notify_pid, BackgroundWorker::bgw_restart_time, BackgroundWorker::bgw_start_time, BackgroundWorker::bgw_type, BGWORKER_BACKEND_DATABASE_CONNECTION, BGWORKER_SHMEM_ACCESS, BgWorkerStart_RecoveryFinished, max_logical_replication_workers, MAXPGPATH, RegisterBackgroundWorker(), and snprintf.

Referenced by PostmasterMain().

◆ ApplyLauncherSetWorkerStartTime()

static void ApplyLauncherSetWorkerStartTime	(	Oid	subid,
		TimestampTz	start_time
	)

static

Definition at line 1032 of file launcher.c.

 {
     LauncherLastStartTimesEntry *entry;
     bool        found;
  
     logicalrep_launcher_attach_dshmem();
  
     entry = dshash_find_or_insert(last_start_times, &subid, &found);
     entry->last_start_time = start_time;
     dshash_release_lock(last_start_times, entry);
 }

References dshash_find_or_insert(), dshash_release_lock(), LauncherLastStartTimesEntry::last_start_time, last_start_times, logicalrep_launcher_attach_dshmem(), and start_time.

Referenced by ApplyLauncherMain().

◆ ApplyLauncherShmemInit()

void ApplyLauncherShmemInit ( void )

Definition at line 953 of file launcher.c.

 {
     bool        found;
  
     LogicalRepCtx = (LogicalRepCtxStruct *)
         ShmemInitStruct("Logical Replication Launcher Data",
                         ApplyLauncherShmemSize(),
                         &found);
  
     if (!found)
     {
         int         slot;
  
         memset(LogicalRepCtx, 0, ApplyLauncherShmemSize());
  
         LogicalRepCtx->last_start_dsa = DSA_HANDLE_INVALID;
         LogicalRepCtx->last_start_dsh = DSHASH_HANDLE_INVALID;
  
         /* Initialize memory and spin locks for each worker slot. */
         for (slot = 0; slot < max_logical_replication_workers; slot++)
         {
             LogicalRepWorker *worker = &LogicalRepCtx->workers[slot];
  
             memset(worker, 0, sizeof(LogicalRepWorker));
             SpinLockInit(&worker->relmutex);
         }
     }
 }

References ApplyLauncherShmemSize(), DSA_HANDLE_INVALID, DSHASH_HANDLE_INVALID, LogicalRepCtxStruct::last_start_dsa, LogicalRepCtxStruct::last_start_dsh, LogicalRepCtx, max_logical_replication_workers, LogicalRepWorker::relmutex, ShmemInitStruct(), SpinLockInit, and LogicalRepCtxStruct::workers.

Referenced by CreateSharedMemoryAndSemaphores().

◆ ApplyLauncherShmemSize()

Size ApplyLauncherShmemSize ( void )

Definition at line 905 of file launcher.c.

 {
     Size        size;
  
     /*
      * Need the fixed struct and the array of LogicalRepWorker.
      */
     size = sizeof(LogicalRepCtxStruct);
     size = MAXALIGN(size);
     size = add_size(size, mul_size(max_logical_replication_workers,
                                    sizeof(LogicalRepWorker)));
     return size;
 }

References add_size(), max_logical_replication_workers, MAXALIGN, and mul_size().

Referenced by ApplyLauncherShmemInit(), and CalculateShmemSize().

◆ ApplyLauncherWakeup()

static void ApplyLauncherWakeup ( void )

static

Definition at line 1111 of file launcher.c.

 {
     if (LogicalRepCtx->launcher_pid != 0)
         kill(LogicalRepCtx->launcher_pid, SIGUSR1);
 }

References kill, LogicalRepCtxStruct::launcher_pid, LogicalRepCtx, and SIGUSR1.

Referenced by AtEOXact_ApplyLauncher(), and logicalrep_worker_onexit().

◆ ApplyLauncherWakeupAtCommit()

void ApplyLauncherWakeupAtCommit ( void )

Definition at line 1104 of file launcher.c.

 {
     if (!on_commit_launcher_wakeup)
         on_commit_launcher_wakeup = true;
 }

References on_commit_launcher_wakeup.

Referenced by AlterSubscription(), AlterSubscriptionOwner_internal(), and CreateSubscription().

◆ AtEOXact_ApplyLauncher()

void AtEOXact_ApplyLauncher ( bool isCommit )

Definition at line 1085 of file launcher.c.

 {
     if (isCommit)
     {
         if (on_commit_launcher_wakeup)
             ApplyLauncherWakeup();
     }
  
     on_commit_launcher_wakeup = false;
 }

References ApplyLauncherWakeup(), and on_commit_launcher_wakeup.

Referenced by AbortTransaction(), CommitTransaction(), and PrepareTransaction().

◆ get_subscription_list()

static List* get_subscription_list ( void )

static

Definition at line 118 of file launcher.c.

 {
     List       *res = NIL;
     Relation    rel;
     TableScanDesc scan;
     HeapTuple   tup;
     MemoryContext resultcxt;
  
     /* This is the context that we will allocate our output data in */
     resultcxt = CurrentMemoryContext;
  
     /*
      * Start a transaction so we can access pg_database, and get a snapshot.
      * We don't have a use for the snapshot itself, but we're interested in
      * the secondary effect that it sets RecentGlobalXmin.  (This is critical
      * for anything that reads heap pages, because HOT may decide to prune
      * them even if the process doesn't attempt to modify any tuples.)
      *
      * FIXME: This comment is inaccurate / the code buggy. A snapshot that is
      * not pushed/active does not reliably prevent HOT pruning (->xmin could
      * e.g. be cleared when cache invalidations are processed).
      */
     StartTransactionCommand();
     (void) GetTransactionSnapshot();
  
     rel = table_open(SubscriptionRelationId, AccessShareLock);
     scan = table_beginscan_catalog(rel, 0, NULL);
  
     while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
     {
         Form_pg_subscription subform = (Form_pg_subscription) GETSTRUCT(tup);
         Subscription *sub;
         MemoryContext oldcxt;
  
         /*
          * Allocate our results in the caller's context, not the
          * transaction's. We do this inside the loop, and restore the original
          * context at the end, so that leaky things like heap_getnext() are
          * not called in a potentially long-lived context.
          */
         oldcxt = MemoryContextSwitchTo(resultcxt);
  
         sub = (Subscription *) palloc0(sizeof(Subscription));
         sub->oid = subform->oid;
         sub->dbid = subform->subdbid;
         sub->owner = subform->subowner;
         sub->enabled = subform->subenabled;
         sub->name = pstrdup(NameStr(subform->subname));
         /* We don't fill fields we are not interested in. */
  
         res = lappend(res, sub);
         MemoryContextSwitchTo(oldcxt);
     }
  
     table_endscan(scan);
     table_close(rel, AccessShareLock);
  
     CommitTransactionCommand();
  
     return res;
 }

References AccessShareLock, CommitTransactionCommand(), CurrentMemoryContext, Subscription::dbid, Subscription::enabled, ForwardScanDirection, GETSTRUCT, GetTransactionSnapshot(), heap_getnext(), HeapTupleIsValid, lappend(), MemoryContextSwitchTo(), Subscription::name, NameStr, NIL, Subscription::oid, Subscription::owner, palloc0(), pstrdup(), res, StartTransactionCommand(), table_beginscan_catalog(), table_close(), table_endscan(), and table_open().

Referenced by ApplyLauncherMain().

◆ GetLeaderApplyWorkerPid()

pid_t GetLeaderApplyWorkerPid ( pid_t pid )

Definition at line 1252 of file launcher.c.

 {
     int         leader_pid = InvalidPid;
     int         i;
  
     LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
         if (isParallelApplyWorker(w) && w->proc && pid == w->proc->pid)
         {
             leader_pid = w->leader_pid;
             break;
         }
     }
  
     LWLockRelease(LogicalRepWorkerLock);
  
     return leader_pid;
 }

References i, InvalidPid, isParallelApplyWorker, LogicalRepWorker::leader_pid, LogicalRepCtx, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, PGPROC::pid, LogicalRepWorker::proc, and LogicalRepCtxStruct::workers.

Referenced by pg_stat_get_activity().

◆ IsLogicalLauncher()

bool IsLogicalLauncher ( void )

Definition at line 1242 of file launcher.c.

 {
     return LogicalRepCtx->launcher_pid == MyProcPid;
 }

References LogicalRepCtxStruct::launcher_pid, LogicalRepCtx, and MyProcPid.

Referenced by ProcessInterrupts().

◆ logicalrep_launcher_attach_dshmem()

static void logicalrep_launcher_attach_dshmem ( void )

static

Definition at line 988 of file launcher.c.

 {
     MemoryContext oldcontext;
  
     /* Quick exit if we already did this. */
     if (LogicalRepCtx->last_start_dsh != DSHASH_HANDLE_INVALID &&
         last_start_times != NULL)
         return;
  
     /* Otherwise, use a lock to ensure only one process creates the table. */
     LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
  
     /* Be sure any local memory allocated by DSA routines is persistent. */
     oldcontext = MemoryContextSwitchTo(TopMemoryContext);
  
     if (LogicalRepCtx->last_start_dsh == DSHASH_HANDLE_INVALID)
     {
         /* Initialize dynamic shared hash table for last-start times. */
         last_start_times_dsa = dsa_create(LWTRANCHE_LAUNCHER_DSA);
         dsa_pin(last_start_times_dsa);
         dsa_pin_mapping(last_start_times_dsa);
         last_start_times = dshash_create(last_start_times_dsa, &dsh_params, 0);
  
         /* Store handles in shared memory for other backends to use. */
         LogicalRepCtx->last_start_dsa = dsa_get_handle(last_start_times_dsa);
         LogicalRepCtx->last_start_dsh = dshash_get_hash_table_handle(last_start_times);
     }
     else if (!last_start_times)
     {
         /* Attach to existing dynamic shared hash table. */
         last_start_times_dsa = dsa_attach(LogicalRepCtx->last_start_dsa);
         dsa_pin_mapping(last_start_times_dsa);
         last_start_times = dshash_attach(last_start_times_dsa, &dsh_params,
                                          LogicalRepCtx->last_start_dsh, 0);
     }
  
     MemoryContextSwitchTo(oldcontext);
     LWLockRelease(LogicalRepWorkerLock);
 }

References dsa_attach(), dsa_create(), dsa_get_handle(), dsa_pin(), dsa_pin_mapping(), dsh_params, dshash_attach(), dshash_create(), dshash_get_hash_table_handle(), DSHASH_HANDLE_INVALID, LogicalRepCtxStruct::last_start_dsa, LogicalRepCtxStruct::last_start_dsh, last_start_times, last_start_times_dsa, LogicalRepCtx, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), LWTRANCHE_LAUNCHER_DSA, MemoryContextSwitchTo(), and TopMemoryContext.

Referenced by ApplyLauncherForgetWorkerStartTime(), ApplyLauncherGetWorkerStartTime(), and ApplyLauncherSetWorkerStartTime().

◆ logicalrep_launcher_onexit()

static void logicalrep_launcher_onexit	(	int	code,
		Datum	arg
	)

static

Definition at line 813 of file launcher.c.

 {
     LogicalRepCtx->launcher_pid = 0;
 }

References LogicalRepCtxStruct::launcher_pid, and LogicalRepCtx.

Referenced by ApplyLauncherMain().

◆ logicalrep_pa_worker_count()

static int logicalrep_pa_worker_count ( Oid subid )

static

Definition at line 878 of file launcher.c.

 {
     int         i;
     int         res = 0;
  
     Assert(LWLockHeldByMe(LogicalRepWorkerLock));
  
     /*
      * Scan all attached parallel apply workers, only counting those which
      * have the given subscription id.
      */
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
         if (isParallelApplyWorker(w) && w->subid == subid)
             res++;
     }
  
     return res;
 }

References Assert(), i, isParallelApplyWorker, LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by logicalrep_worker_launch().

◆ logicalrep_pa_worker_stop()

void logicalrep_pa_worker_stop ( ParallelApplyWorkerInfo * winfo )

Definition at line 639 of file launcher.c.

 {
     int         slot_no;
     uint16      generation;
     LogicalRepWorker *worker;
  
     SpinLockAcquire(&winfo->shared->mutex);
     generation = winfo->shared->logicalrep_worker_generation;
     slot_no = winfo->shared->logicalrep_worker_slot_no;
     SpinLockRelease(&winfo->shared->mutex);
  
     Assert(slot_no >= 0 && slot_no < max_logical_replication_workers);
  
     /*
      * Detach from the error_mq_handle for the parallel apply worker before
      * stopping it. This prevents the leader apply worker from trying to
      * receive the message from the error queue that might already be detached
      * by the parallel apply worker.
      */
     if (winfo->error_mq_handle)
     {
         shm_mq_detach(winfo->error_mq_handle);
         winfo->error_mq_handle = NULL;
     }
  
     LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
     worker = &LogicalRepCtx->workers[slot_no];
     Assert(isParallelApplyWorker(worker));
  
     /*
      * Only stop the worker if the generation matches and the worker is alive.
      */
     if (worker->generation == generation && worker->proc)
         logicalrep_worker_stop_internal(worker, SIGINT);
  
     LWLockRelease(LogicalRepWorkerLock);
 }

References Assert(), ParallelApplyWorkerInfo::error_mq_handle, LogicalRepWorker::generation, isParallelApplyWorker, ParallelApplyWorkerShared::logicalrep_worker_generation, ParallelApplyWorkerShared::logicalrep_worker_slot_no, logicalrep_worker_stop_internal(), LogicalRepCtx, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, ParallelApplyWorkerShared::mutex, LogicalRepWorker::proc, ParallelApplyWorkerInfo::shared, shm_mq_detach(), SpinLockAcquire, SpinLockRelease, and LogicalRepCtxStruct::workers.

Referenced by pa_free_worker().

◆ logicalrep_sync_worker_count()

int logicalrep_sync_worker_count ( Oid subid )

Definition at line 854 of file launcher.c.

 {
     int         i;
     int         res = 0;
  
     Assert(LWLockHeldByMe(LogicalRepWorkerLock));
  
     /* Search for attached worker for a given subscription id. */
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
         if (isTablesyncWorker(w) && w->subid == subid)
             res++;
     }
  
     return res;
 }

References Assert(), i, isTablesyncWorker, LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by logicalrep_worker_launch(), and process_syncing_tables_for_apply().

◆ logicalrep_worker_attach()

void logicalrep_worker_attach ( int slot )

Definition at line 713 of file launcher.c.

 {
     /* Block concurrent access. */
     LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
  
     Assert(slot >= 0 && slot < max_logical_replication_workers);
     MyLogicalRepWorker = &LogicalRepCtx->workers[slot];
  
     if (!MyLogicalRepWorker->in_use)
     {
         LWLockRelease(LogicalRepWorkerLock);
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("logical replication worker slot %d is empty, cannot attach",
                         slot)));
     }
  
     if (MyLogicalRepWorker->proc)
     {
         LWLockRelease(LogicalRepWorkerLock);
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("logical replication worker slot %d is already used by "
                         "another worker, cannot attach", slot)));
     }
  
     MyLogicalRepWorker->proc = MyProc;
     before_shmem_exit(logicalrep_worker_onexit, (Datum) 0);
  
     LWLockRelease(LogicalRepWorkerLock);
 }

References Assert(), before_shmem_exit(), ereport, errcode(), errmsg(), ERROR, LogicalRepWorker::in_use, logicalrep_worker_onexit(), LogicalRepCtx, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, MyLogicalRepWorker, MyProc, LogicalRepWorker::proc, and LogicalRepCtxStruct::workers.

Referenced by ParallelApplyWorkerMain(), and SetupApplyOrSyncWorker().

◆ logicalrep_worker_cleanup()

static void logicalrep_worker_cleanup ( LogicalRepWorker * worker )

static

Definition at line 792 of file launcher.c.

 {
     Assert(LWLockHeldByMeInMode(LogicalRepWorkerLock, LW_EXCLUSIVE));
  
     worker->type = WORKERTYPE_UNKNOWN;
     worker->in_use = false;
     worker->proc = NULL;
     worker->dbid = InvalidOid;
     worker->userid = InvalidOid;
     worker->subid = InvalidOid;
     worker->relid = InvalidOid;
     worker->leader_pid = InvalidPid;
     worker->parallel_apply = false;
 }

References Assert(), LogicalRepWorker::dbid, LogicalRepWorker::in_use, InvalidOid, InvalidPid, LogicalRepWorker::leader_pid, LW_EXCLUSIVE, LWLockHeldByMeInMode(), LogicalRepWorker::parallel_apply, LogicalRepWorker::proc, LogicalRepWorker::relid, LogicalRepWorker::subid, LogicalRepWorker::type, LogicalRepWorker::userid, and WORKERTYPE_UNKNOWN.

Referenced by logicalrep_worker_detach(), logicalrep_worker_launch(), and WaitForReplicationWorkerAttach().

◆ logicalrep_worker_detach()

static void logicalrep_worker_detach ( void )

static

Definition at line 750 of file launcher.c.

 {
     /* Stop the parallel apply workers. */
     if (am_leader_apply_worker())
     {
         List       *workers;
         ListCell   *lc;
  
         /*
          * Detach from the error_mq_handle for all parallel apply workers
          * before terminating them. This prevents the leader apply worker from
          * receiving the worker termination message and sending it to logs
          * when the same is already done by the parallel worker.
          */
         pa_detach_all_error_mq();
  
         LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
         workers = logicalrep_workers_find(MyLogicalRepWorker->subid, true);
         foreach(lc, workers)
         {
             LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
  
             if (isParallelApplyWorker(w))
                 logicalrep_worker_stop_internal(w, SIGTERM);
         }
  
         LWLockRelease(LogicalRepWorkerLock);
     }
  
     /* Block concurrent access. */
     LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
  
     logicalrep_worker_cleanup(MyLogicalRepWorker);
  
     LWLockRelease(LogicalRepWorkerLock);
 }

References am_leader_apply_worker(), isParallelApplyWorker, lfirst, logicalrep_worker_cleanup(), logicalrep_worker_stop_internal(), logicalrep_workers_find(), LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MyLogicalRepWorker, pa_detach_all_error_mq(), and LogicalRepWorker::subid.

Referenced by logicalrep_worker_onexit().

◆ logicalrep_worker_find()

LogicalRepWorker* logicalrep_worker_find	(	Oid	subid,
		Oid	relid,
		bool	only_running
	)

Definition at line 249 of file launcher.c.

 {
     int         i;
     LogicalRepWorker *res = NULL;
  
     Assert(LWLockHeldByMe(LogicalRepWorkerLock));
  
     /* Search for attached worker for a given subscription id. */
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
         /* Skip parallel apply workers. */
         if (isParallelApplyWorker(w))
             continue;
  
         if (w->in_use && w->subid == subid && w->relid == relid &&
             (!only_running || w->proc))
         {
             res = w;
             break;
         }
     }
  
     return res;
 }

References Assert(), i, LogicalRepWorker::in_use, isParallelApplyWorker, LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, LogicalRepWorker::proc, LogicalRepWorker::relid, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by ApplyLauncherMain(), logicalrep_worker_stop(), logicalrep_worker_wakeup(), process_syncing_tables_for_apply(), wait_for_relation_state_change(), and wait_for_worker_state_change().

◆ logicalrep_worker_launch()

bool logicalrep_worker_launch	(	LogicalRepWorkerType	wtype,
		Oid	dbid,
		Oid	subid,
		const char *	subname,
		Oid	userid,
		Oid	relid,
		dsm_handle	subworker_dsm
	)

Definition at line 306 of file launcher.c.

 {
     BackgroundWorker bgw;
     BackgroundWorkerHandle *bgw_handle;
     uint16      generation;
     int         i;
     int         slot = 0;
     LogicalRepWorker *worker = NULL;
     int         nsyncworkers;
     int         nparallelapplyworkers;
     TimestampTz now;
     bool        is_tablesync_worker = (wtype == WORKERTYPE_TABLESYNC);
     bool        is_parallel_apply_worker = (wtype == WORKERTYPE_PARALLEL_APPLY);
  
     /*----------
      * Sanity checks:
      * - must be valid worker type
      * - tablesync workers are only ones to have relid
      * - parallel apply worker is the only kind of subworker
      */
     Assert(wtype != WORKERTYPE_UNKNOWN);
     Assert(is_tablesync_worker == OidIsValid(relid));
     Assert(is_parallel_apply_worker == (subworker_dsm != DSM_HANDLE_INVALID));
  
     ereport(DEBUG1,
             (errmsg_internal("starting logical replication worker for subscription \"%s\"",
                              subname)));
  
     /* Report this after the initial starting message for consistency. */
     if (max_replication_slots == 0)
         ereport(ERROR,
                 (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
                  errmsg("cannot start logical replication workers when max_replication_slots = 0")));
  
     /*
      * We need to do the modification of the shared memory under lock so that
      * we have consistent view.
      */
     LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
  
 retry:
     /* Find unused worker slot. */
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
         if (!w->in_use)
         {
             worker = w;
             slot = i;
             break;
         }
     }
  
     nsyncworkers = logicalrep_sync_worker_count(subid);
  
     now = GetCurrentTimestamp();
  
     /*
      * If we didn't find a free slot, try to do garbage collection.  The
      * reason we do this is because if some worker failed to start up and its
      * parent has crashed while waiting, the in_use state was never cleared.
      */
     if (worker == NULL || nsyncworkers >= max_sync_workers_per_subscription)
     {
         bool        did_cleanup = false;
  
         for (i = 0; i < max_logical_replication_workers; i++)
         {
             LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
             /*
              * If the worker was marked in use but didn't manage to attach in
              * time, clean it up.
              */
             if (w->in_use && !w->proc &&
                 TimestampDifferenceExceeds(w->launch_time, now,
                                            wal_receiver_timeout))
             {
                 elog(WARNING,
                      "logical replication worker for subscription %u took too long to start; canceled",
                      w->subid);
  
                 logicalrep_worker_cleanup(w);
                 did_cleanup = true;
             }
         }
  
         if (did_cleanup)
             goto retry;
     }
  
     /*
      * We don't allow to invoke more sync workers once we have reached the
      * sync worker limit per subscription. So, just return silently as we
      * might get here because of an otherwise harmless race condition.
      */
     if (is_tablesync_worker && nsyncworkers >= max_sync_workers_per_subscription)
     {
         LWLockRelease(LogicalRepWorkerLock);
         return false;
     }
  
     nparallelapplyworkers = logicalrep_pa_worker_count(subid);
  
     /*
      * Return false if the number of parallel apply workers reached the limit
      * per subscription.
      */
     if (is_parallel_apply_worker &&
         nparallelapplyworkers >= max_parallel_apply_workers_per_subscription)
     {
         LWLockRelease(LogicalRepWorkerLock);
         return false;
     }
  
     /*
      * However if there are no more free worker slots, inform user about it
      * before exiting.
      */
     if (worker == NULL)
     {
         LWLockRelease(LogicalRepWorkerLock);
         ereport(WARNING,
                 (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
                  errmsg("out of logical replication worker slots"),
                  errhint("You might need to increase %s.", "max_logical_replication_workers")));
         return false;
     }
  
     /* Prepare the worker slot. */
     worker->type = wtype;
     worker->launch_time = now;
     worker->in_use = true;
     worker->generation++;
     worker->proc = NULL;
     worker->dbid = dbid;
     worker->userid = userid;
     worker->subid = subid;
     worker->relid = relid;
     worker->relstate = SUBREL_STATE_UNKNOWN;
     worker->relstate_lsn = InvalidXLogRecPtr;
     worker->stream_fileset = NULL;
     worker->leader_pid = is_parallel_apply_worker ? MyProcPid : InvalidPid;
     worker->parallel_apply = is_parallel_apply_worker;
     worker->last_lsn = InvalidXLogRecPtr;
     TIMESTAMP_NOBEGIN(worker->last_send_time);
     TIMESTAMP_NOBEGIN(worker->last_recv_time);
     worker->reply_lsn = InvalidXLogRecPtr;
     TIMESTAMP_NOBEGIN(worker->reply_time);
  
     /* Before releasing lock, remember generation for future identification. */
     generation = worker->generation;
  
     LWLockRelease(LogicalRepWorkerLock);
  
     /* Register the new dynamic worker. */
     memset(&bgw, 0, sizeof(bgw));
     bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
         BGWORKER_BACKEND_DATABASE_CONNECTION;
     bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
     snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
  
     switch (worker->type)
     {
         case WORKERTYPE_APPLY:
             snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ApplyWorkerMain");
             snprintf(bgw.bgw_name, BGW_MAXLEN,
                      "logical replication apply worker for subscription %u",
                      subid);
             snprintf(bgw.bgw_type, BGW_MAXLEN, "logical replication apply worker");
             break;
  
         case WORKERTYPE_PARALLEL_APPLY:
             snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ParallelApplyWorkerMain");
             snprintf(bgw.bgw_name, BGW_MAXLEN,
                      "logical replication parallel apply worker for subscription %u",
                      subid);
             snprintf(bgw.bgw_type, BGW_MAXLEN, "logical replication parallel worker");
  
             memcpy(bgw.bgw_extra, &subworker_dsm, sizeof(dsm_handle));
             break;
  
         case WORKERTYPE_TABLESYNC:
             snprintf(bgw.bgw_function_name, BGW_MAXLEN, "TablesyncWorkerMain");
             snprintf(bgw.bgw_name, BGW_MAXLEN,
                      "logical replication tablesync worker for subscription %u sync %u",
                      subid,
                      relid);
             snprintf(bgw.bgw_type, BGW_MAXLEN, "logical replication tablesync worker");
             break;
  
         case WORKERTYPE_UNKNOWN:
             /* Should never happen. */
             elog(ERROR, "unknown worker type");
     }
  
     bgw.bgw_restart_time = BGW_NEVER_RESTART;
     bgw.bgw_notify_pid = MyProcPid;
     bgw.bgw_main_arg = Int32GetDatum(slot);
  
     if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle))
     {
         /* Failed to start worker, so clean up the worker slot. */
         LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
         Assert(generation == worker->generation);
         logicalrep_worker_cleanup(worker);
         LWLockRelease(LogicalRepWorkerLock);
  
         ereport(WARNING,
                 (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
                  errmsg("out of background worker slots"),
                  errhint("You might need to increase %s.", "max_worker_processes")));
         return false;
     }
  
     /* Now wait until it attaches. */
     return WaitForReplicationWorkerAttach(worker, generation, bgw_handle);
 }

Referenced by ApplyLauncherMain(), pa_launch_parallel_worker(), and process_syncing_tables_for_apply().

◆ logicalrep_worker_onexit()

static void logicalrep_worker_onexit	(	int	code,
		Datum	arg
	)

static

Definition at line 824 of file launcher.c.

 {
     /* Disconnect gracefully from the remote side. */
     if (LogRepWorkerWalRcvConn)
         walrcv_disconnect(LogRepWorkerWalRcvConn);
  
     logicalrep_worker_detach();
  
     /* Cleanup fileset used for streaming transactions. */
     if (MyLogicalRepWorker->stream_fileset != NULL)
         FileSetDeleteAll(MyLogicalRepWorker->stream_fileset);
  
     /*
      * Session level locks may be acquired outside of a transaction in
      * parallel apply mode and will not be released when the worker
      * terminates, so manually release all locks before the worker exits.
      *
      * The locks will be acquired once the worker is initialized.
      */
     if (!InitializingApplyWorker)
         LockReleaseAll(DEFAULT_LOCKMETHOD, true);
  
     ApplyLauncherWakeup();
 }

References ApplyLauncherWakeup(), DEFAULT_LOCKMETHOD, FileSetDeleteAll(), InitializingApplyWorker, LockReleaseAll(), logicalrep_worker_detach(), LogRepWorkerWalRcvConn, MyLogicalRepWorker, LogicalRepWorker::stream_fileset, and walrcv_disconnect.

Referenced by logicalrep_worker_attach().

◆ logicalrep_worker_stop()

void logicalrep_worker_stop	(	Oid	subid,
		Oid	relid
	)

Definition at line 615 of file launcher.c.

 {
     LogicalRepWorker *worker;
  
     LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
     worker = logicalrep_worker_find(subid, relid, false);
  
     if (worker)
     {
         Assert(!isParallelApplyWorker(worker));
         logicalrep_worker_stop_internal(worker, SIGTERM);
     }
  
     LWLockRelease(LogicalRepWorkerLock);
 }

References Assert(), isParallelApplyWorker, logicalrep_worker_find(), logicalrep_worker_stop_internal(), LW_SHARED, LWLockAcquire(), and LWLockRelease().

Referenced by AlterSubscription_refresh(), and DropSubscription().

◆ logicalrep_worker_stop_internal()

static void logicalrep_worker_stop_internal	(	LogicalRepWorker *	worker,
		int	signo
	)

static

Definition at line 533 of file launcher.c.

 {
     uint16      generation;
  
     Assert(LWLockHeldByMeInMode(LogicalRepWorkerLock, LW_SHARED));
  
     /*
      * Remember which generation was our worker so we can check if what we see
      * is still the same one.
      */
     generation = worker->generation;
  
     /*
      * If we found a worker but it does not have proc set then it is still
      * starting up; wait for it to finish starting and then kill it.
      */
     while (worker->in_use && !worker->proc)
     {
         int         rc;
  
         LWLockRelease(LogicalRepWorkerLock);
  
         /* Wait a bit --- we don't expect to have to wait long. */
         rc = WaitLatch(MyLatch,
                        WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
                        10L, WAIT_EVENT_BGWORKER_STARTUP);
  
         if (rc & WL_LATCH_SET)
         {
             ResetLatch(MyLatch);
             CHECK_FOR_INTERRUPTS();
         }
  
         /* Recheck worker status. */
         LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
         /*
          * Check whether the worker slot is no longer used, which would mean
          * that the worker has exited, or whether the worker generation is
          * different, meaning that a different worker has taken the slot.
          */
         if (!worker->in_use || worker->generation != generation)
             return;
  
         /* Worker has assigned proc, so it has started. */
         if (worker->proc)
             break;
     }
  
     /* Now terminate the worker ... */
     kill(worker->proc->pid, signo);
  
     /* ... and wait for it to die. */
     for (;;)
     {
         int         rc;
  
         /* is it gone? */
         if (!worker->proc || worker->generation != generation)
             break;
  
         LWLockRelease(LogicalRepWorkerLock);
  
         /* Wait a bit --- we don't expect to have to wait long. */
         rc = WaitLatch(MyLatch,
                        WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
                        10L, WAIT_EVENT_BGWORKER_SHUTDOWN);
  
         if (rc & WL_LATCH_SET)
         {
             ResetLatch(MyLatch);
             CHECK_FOR_INTERRUPTS();
         }
  
         LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
     }
 }

References Assert(), CHECK_FOR_INTERRUPTS, LogicalRepWorker::generation, LogicalRepWorker::in_use, kill, LW_SHARED, LWLockAcquire(), LWLockHeldByMeInMode(), LWLockRelease(), MyLatch, PGPROC::pid, LogicalRepWorker::proc, ResetLatch(), WaitLatch(), WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, and WL_TIMEOUT.

Referenced by logicalrep_pa_worker_stop(), logicalrep_worker_detach(), and logicalrep_worker_stop().

◆ logicalrep_worker_wakeup()

void logicalrep_worker_wakeup	(	Oid	subid,
		Oid	relid
	)

Definition at line 682 of file launcher.c.

 {
     LogicalRepWorker *worker;
  
     LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
     worker = logicalrep_worker_find(subid, relid, true);
  
     if (worker)
         logicalrep_worker_wakeup_ptr(worker);
  
     LWLockRelease(LogicalRepWorkerLock);
 }

References logicalrep_worker_find(), logicalrep_worker_wakeup_ptr(), LW_SHARED, LWLockAcquire(), and LWLockRelease().

Referenced by apply_handle_stream_start(), and pg_attribute_noreturn().

◆ logicalrep_worker_wakeup_ptr()

void logicalrep_worker_wakeup_ptr ( LogicalRepWorker * worker )

Definition at line 702 of file launcher.c.

 {
     Assert(LWLockHeldByMe(LogicalRepWorkerLock));
  
     SetLatch(&worker->proc->procLatch);
 }

References Assert(), LWLockHeldByMe(), LogicalRepWorker::proc, PGPROC::procLatch, and SetLatch().

Referenced by AtEOXact_LogicalRepWorkers(), logicalrep_worker_wakeup(), process_syncing_tables_for_apply(), and wait_for_worker_state_change().

◆ logicalrep_workers_find()

List* logicalrep_workers_find	(	Oid	subid,
		bool	only_running
	)

Definition at line 281 of file launcher.c.

 {
     int         i;
     List       *res = NIL;
  
     Assert(LWLockHeldByMe(LogicalRepWorkerLock));
  
     /* Search for attached worker for a given subscription id. */
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         LogicalRepWorker *w = &LogicalRepCtx->workers[i];
  
         if (w->in_use && w->subid == subid && (!only_running || w->proc))
             res = lappend(res, w);
     }
  
     return res;
 }

References Assert(), i, LogicalRepWorker::in_use, lappend(), LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, NIL, LogicalRepWorker::proc, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by AtEOXact_LogicalRepWorkers(), DropSubscription(), and logicalrep_worker_detach().

◆ pg_stat_get_subscription()

Datum pg_stat_get_subscription ( PG_FUNCTION_ARGS )

Definition at line 1279 of file launcher.c.

 {
 #define PG_STAT_GET_SUBSCRIPTION_COLS   10
     Oid         subid = PG_ARGISNULL(0) ? InvalidOid : PG_GETARG_OID(0);
     int         i;
     ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
  
     InitMaterializedSRF(fcinfo, 0);
  
     /* Make sure we get consistent view of the workers. */
     LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
     for (i = 0; i < max_logical_replication_workers; i++)
     {
         /* for each row */
         Datum       values[PG_STAT_GET_SUBSCRIPTION_COLS] = {0};
         bool        nulls[PG_STAT_GET_SUBSCRIPTION_COLS] = {0};
         int         worker_pid;
         LogicalRepWorker worker;
  
         memcpy(&worker, &LogicalRepCtx->workers[i],
                sizeof(LogicalRepWorker));
         if (!worker.proc || !IsBackendPid(worker.proc->pid))
             continue;
  
         if (OidIsValid(subid) && worker.subid != subid)
             continue;
  
         worker_pid = worker.proc->pid;
  
         values[0] = ObjectIdGetDatum(worker.subid);
         if (isTablesyncWorker(&worker))
             values[1] = ObjectIdGetDatum(worker.relid);
         else
             nulls[1] = true;
         values[2] = Int32GetDatum(worker_pid);
  
         if (isParallelApplyWorker(&worker))
             values[3] = Int32GetDatum(worker.leader_pid);
         else
             nulls[3] = true;
  
         if (XLogRecPtrIsInvalid(worker.last_lsn))
             nulls[4] = true;
         else
             values[4] = LSNGetDatum(worker.last_lsn);
         if (worker.last_send_time == 0)
             nulls[5] = true;
         else
             values[5] = TimestampTzGetDatum(worker.last_send_time);
         if (worker.last_recv_time == 0)
             nulls[6] = true;
         else
             values[6] = TimestampTzGetDatum(worker.last_recv_time);
         if (XLogRecPtrIsInvalid(worker.reply_lsn))
             nulls[7] = true;
         else
             values[7] = LSNGetDatum(worker.reply_lsn);
         if (worker.reply_time == 0)
             nulls[8] = true;
         else
             values[8] = TimestampTzGetDatum(worker.reply_time);
  
         switch (worker.type)
         {
             case WORKERTYPE_APPLY:
                 values[9] = CStringGetTextDatum("apply");
                 break;
             case WORKERTYPE_PARALLEL_APPLY:
                 values[9] = CStringGetTextDatum("parallel apply");
                 break;
             case WORKERTYPE_TABLESYNC:
                 values[9] = CStringGetTextDatum("table synchronization");
                 break;
             case WORKERTYPE_UNKNOWN:
                 /* Should never happen. */
                 elog(ERROR, "unknown worker type");
         }
  
         tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
                              values, nulls);
  
         /*
          * If only a single subscription was requested, and we found it,
          * break.
          */
         if (OidIsValid(subid))
             break;
     }
  
     LWLockRelease(LogicalRepWorkerLock);
  
     return (Datum) 0;
 }

◆ WaitForReplicationWorkerAttach()

static bool WaitForReplicationWorkerAttach	(	LogicalRepWorker *	worker,
		uint16	generation,
		BackgroundWorkerHandle *	handle
	)

static

Definition at line 189 of file launcher.c.

 {
     BgwHandleStatus status;
     int         rc;
  
     for (;;)
     {
         pid_t       pid;
  
         CHECK_FOR_INTERRUPTS();
  
         LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
  
         /* Worker either died or has started. Return false if died. */
         if (!worker->in_use || worker->proc)
         {
             LWLockRelease(LogicalRepWorkerLock);
             return worker->in_use;
         }
  
         LWLockRelease(LogicalRepWorkerLock);
  
         /* Check if worker has died before attaching, and clean up after it. */
         status = GetBackgroundWorkerPid(handle, &pid);
  
         if (status == BGWH_STOPPED)
         {
             LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
             /* Ensure that this was indeed the worker we waited for. */
             if (generation == worker->generation)
                 logicalrep_worker_cleanup(worker);
             LWLockRelease(LogicalRepWorkerLock);
             return false;
         }
  
         /*
          * We need timeout because we generally don't get notified via latch
          * about the worker attach.  But we don't expect to have to wait long.
          */
         rc = WaitLatch(MyLatch,
                        WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
                        10L, WAIT_EVENT_BGWORKER_STARTUP);
  
         if (rc & WL_LATCH_SET)
         {
             ResetLatch(MyLatch);
             CHECK_FOR_INTERRUPTS();
         }
     }
 }

References BGWH_STOPPED, CHECK_FOR_INTERRUPTS, LogicalRepWorker::generation, GetBackgroundWorkerPid(), LogicalRepWorker::in_use, logicalrep_worker_cleanup(), LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MyLatch, LogicalRepWorker::proc, ResetLatch(), WaitLatch(), WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, and WL_TIMEOUT.

Referenced by logicalrep_worker_launch().

Variable Documentation

◆ dsh_params

const dshash_parameters dsh_params

static

Initial value:

= {
    sizeof(Oid),
    sizeof(LauncherLastStartTimesEntry),
    dshash_memcmp,
    dshash_memhash,
    LWTRANCHE_LAUNCHER_HASH
}

Definition at line 86 of file launcher.c.

Referenced by logicalrep_launcher_attach_dshmem().

◆ last_start_times

dshash_table* last_start_times = NULL

static

Definition at line 95 of file launcher.c.

Referenced by ApplyLauncherForgetWorkerStartTime(), ApplyLauncherGetWorkerStartTime(), ApplyLauncherSetWorkerStartTime(), logicalrep_launcher_attach_dshmem(), and process_syncing_tables_for_apply().

◆ last_start_times_dsa

dsa_area* last_start_times_dsa = NULL

static

Definition at line 94 of file launcher.c.

Referenced by logicalrep_launcher_attach_dshmem().

◆ LogicalRepCtx

LogicalRepCtxStruct* LogicalRepCtx

static

Definition at line 76 of file launcher.c.

Referenced by ApplyLauncherMain(), ApplyLauncherShmemInit(), ApplyLauncherWakeup(), GetLeaderApplyWorkerPid(), IsLogicalLauncher(), logicalrep_launcher_attach_dshmem(), logicalrep_launcher_onexit(), logicalrep_pa_worker_count(), logicalrep_pa_worker_stop(), logicalrep_sync_worker_count(), logicalrep_worker_attach(), logicalrep_worker_find(), logicalrep_worker_launch(), logicalrep_workers_find(), and pg_stat_get_subscription().

◆ max_logical_replication_workers

int max_logical_replication_workers = 4

Definition at line 57 of file launcher.c.

Referenced by ApplyLauncherRegister(), ApplyLauncherShmemInit(), ApplyLauncherShmemSize(), GetLeaderApplyWorkerPid(), logicalrep_pa_worker_count(), logicalrep_pa_worker_stop(), logicalrep_sync_worker_count(), logicalrep_worker_attach(), logicalrep_worker_find(), logicalrep_worker_launch(), logicalrep_workers_find(), and pg_stat_get_subscription().

◆ max_parallel_apply_workers_per_subscription

int max_parallel_apply_workers_per_subscription = 2

Definition at line 59 of file launcher.c.

Referenced by logicalrep_worker_launch(), and pa_free_worker().

◆ max_sync_workers_per_subscription

int max_sync_workers_per_subscription = 2

Definition at line 58 of file launcher.c.

Referenced by logicalrep_worker_launch(), and process_syncing_tables_for_apply().

◆ MyLogicalRepWorker

LogicalRepWorker* MyLogicalRepWorker = NULL

Definition at line 61 of file launcher.c.

Referenced by am_leader_apply_worker(), am_parallel_apply_worker(), am_tablesync_worker(), apply_handle_stream_abort(), apply_handle_stream_commit(), apply_handle_stream_prepare(), apply_handle_stream_start(), apply_spooled_messages(), apply_worker_exit(), DisableSubscriptionAndExit(), ensure_last_message(), InitializeLogRepWorker(), IsLogicalWorker(), logicalrep_worker_attach(), logicalrep_worker_detach(), logicalrep_worker_onexit(), LogicalRepSyncTableStart(), maybe_reread_subscription(), pa_can_start(), pa_free_worker_info(), pa_launch_parallel_worker(), pa_lock_stream(), pa_lock_transaction(), pa_set_fileset_state(), pa_shutdown(), pa_unlock_stream(), pa_unlock_transaction(), ParallelApplyWorkerMain(), pg_attribute_noreturn(), process_syncing_tables(), process_syncing_tables_for_apply(), process_syncing_tables_for_sync(), run_tablesync_worker(), set_stream_options(), SetupApplyOrSyncWorker(), should_apply_changes_for_rel(), stream_abort_internal(), stream_cleanup_files(), stream_open_file(), stream_start_internal(), stream_stop_internal(), subxact_info_read(), subxact_info_write(), UpdateWorkerStats(), wait_for_relation_state_change(), and wait_for_worker_state_change().

◆ on_commit_launcher_wakeup

bool on_commit_launcher_wakeup = false

static

Definition at line 97 of file launcher.c.

Referenced by ApplyLauncherWakeupAtCommit(), and AtEOXact_ApplyLauncher().

Data Structures

Macros

Typedefs

Functions

Variables

Macro Definition Documentation

◆ DEFAULT_NAPTIME_PER_CYCLE

◆ PG_STAT_GET_SUBSCRIPTION_COLS

Typedef Documentation

◆ LauncherLastStartTimesEntry

◆ LogicalRepCtxStruct

Function Documentation

◆ ApplyLauncherForgetWorkerStartTime()

◆ ApplyLauncherGetWorkerStartTime()

◆ ApplyLauncherMain()

◆ ApplyLauncherRegister()

◆ ApplyLauncherSetWorkerStartTime()

◆ ApplyLauncherShmemInit()

◆ ApplyLauncherShmemSize()

◆ ApplyLauncherWakeup()

◆ ApplyLauncherWakeupAtCommit()

◆ AtEOXact_ApplyLauncher()

◆ get_subscription_list()

◆ GetLeaderApplyWorkerPid()

◆ IsLogicalLauncher()

◆ logicalrep_launcher_attach_dshmem()

◆ logicalrep_launcher_onexit()

◆ logicalrep_pa_worker_count()

◆ logicalrep_pa_worker_stop()

◆ logicalrep_sync_worker_count()

◆ logicalrep_worker_attach()

◆ logicalrep_worker_cleanup()

◆ logicalrep_worker_detach()

◆ logicalrep_worker_find()

◆ logicalrep_worker_launch()

◆ logicalrep_worker_onexit()

◆ logicalrep_worker_stop()

◆ logicalrep_worker_stop_internal()

◆ logicalrep_worker_wakeup()

◆ logicalrep_worker_wakeup_ptr()

◆ logicalrep_workers_find()

◆ pg_stat_get_subscription()

◆ WaitForReplicationWorkerAttach()

Variable Documentation

◆ dsh_params

◆ last_start_times

◆ last_start_times_dsa

◆ LogicalRepCtx

◆ max_logical_replication_workers

◆ max_parallel_apply_workers_per_subscription

◆ max_sync_workers_per_subscription

◆ MyLogicalRepWorker

◆ on_commit_launcher_wakeup