#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 "miscadmin.h"
#include "pgstat.h"
#include "postmaster/bgworker.h"
#include "postmaster/interrupt.h"
#include "replication/logicallauncher.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 "tcop/tcopprot.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "utils/pg_lsn.h"
#include "utils/snapmgr.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 acquire_lock)

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 47 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 1072 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 1046 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 1119 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 915 of file launcher.c.

{
    BackgroundWorker bgw;
 
    /*
     * The logical replication launcher is disabled during binary upgrades, to
     * prevent logical replication workers from running on the source cluster.
     * That could cause replication origins to move forward after having been
     * copied to the target cluster, potentially creating conflicts with the
     * copied data files.
     */
    if (max_logical_replication_workers == 0 || IsBinaryUpgrade)
        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);
}

Referenced by PostmasterMain().

◆ ApplyLauncherSetWorkerStartTime()

static void ApplyLauncherSetWorkerStartTime	(	Oid	subid,
		TimestampTz	start_time
	)

static

Definition at line 1030 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 951 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 CreateOrAttachShmemStructs().

◆ ApplyLauncherShmemSize()

Size ApplyLauncherShmemSize ( void )

Definition at line 896 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, mul_size(), and size.

Referenced by ApplyLauncherShmemInit(), and CalculateShmemSize().

◆ ApplyLauncherWakeup()

static void ApplyLauncherWakeup ( void )

static

Definition at line 1109 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 1102 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 1083 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 112 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_subscription.
     */
    StartTransactionCommand();
 
    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(), 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 1250 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 1240 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 986 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, NULL);
 
        /* 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 804 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 869 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 630 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 845 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 704 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 783 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 741 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, false);
        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 234 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 297 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 815 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 606 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 524 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 673 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 693 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,
		bool	acquire_lock
	)

Definition at line 266 of file launcher.c.

{
    int         i;
    List       *res = NIL;
 
    if (acquire_lock)
        LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
 
    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);
    }
 
    if (acquire_lock)
        LWLockRelease(LogicalRepWorkerLock);
 
    return res;
}

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

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

◆ pg_stat_get_subscription()

Datum pg_stat_get_subscription ( PG_FUNCTION_ARGS )

Definition at line 1277 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;
}

References CStringGetTextDatum, elog, ERROR, i, InitMaterializedSRF(), Int32GetDatum(), InvalidOid, IsBackendPid(), isParallelApplyWorker, isTablesyncWorker, LogicalRepWorker::last_lsn, LogicalRepWorker::last_recv_time, LogicalRepWorker::last_send_time, LogicalRepWorker::leader_pid, LogicalRepCtx, LSNGetDatum(), LW_SHARED, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, ObjectIdGetDatum(), OidIsValid, PG_ARGISNULL, PG_GETARG_OID, PG_STAT_GET_SUBSCRIPTION_COLS, PGPROC::pid, LogicalRepWorker::proc, LogicalRepWorker::relid, LogicalRepWorker::reply_lsn, LogicalRepWorker::reply_time, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, LogicalRepWorker::subid, TimestampTzGetDatum(), tuplestore_putvalues(), LogicalRepWorker::type, values, LogicalRepCtxStruct::workers, WORKERTYPE_APPLY, WORKERTYPE_PARALLEL_APPLY, WORKERTYPE_TABLESYNC, WORKERTYPE_UNKNOWN, and XLogRecPtrIsInvalid.

◆ WaitForReplicationWorkerAttach()

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

static

Definition at line 174 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,
    dshash_memcpy,
    LWTRANCHE_LAUNCHER_HASH
}

Definition at line 79 of file launcher.c.

Referenced by logicalrep_launcher_attach_dshmem().

◆ last_start_times

dshash_table* last_start_times = NULL

static

Definition at line 89 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 88 of file launcher.c.

Referenced by logicalrep_launcher_attach_dshmem().

◆ LogicalRepCtx

LogicalRepCtxStruct* LogicalRepCtx

static

Definition at line 69 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 50 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 52 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 51 of file launcher.c.

Referenced by logicalrep_worker_launch(), and process_syncing_tables_for_apply().

◆ MyLogicalRepWorker

LogicalRepWorker* MyLogicalRepWorker = NULL

Definition at line 54 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 91 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