logicalworker.h File Reference

#include <signal.h>

Include dependency graph for logicalworker.h:

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Functions
void	ApplyWorkerMain (Datum main_arg)
void	ParallelApplyWorkerMain (Datum main_arg)
void	TableSyncWorkerMain (Datum main_arg)
void	SequenceSyncWorkerMain (Datum main_arg)
bool	IsLogicalWorker (void)
bool	IsLogicalParallelApplyWorker (void)
void	HandleParallelApplyMessageInterrupt (void)
void	ProcessParallelApplyMessages (void)
void	LogicalRepWorkersWakeupAtCommit (Oid subid)
void	AtEOXact_LogicalRepWorkers (bool isCommit)

Variables
PGDLLIMPORT volatile sig_atomic_t	ParallelApplyMessagePending

Function Documentation

ApplyWorkerMain()

void ApplyWorkerMain ( Datum  main_arg )

extern

Definition at line 5987 of file worker.c.

{
    int         worker_slot = DatumGetInt32(main_arg);
 
    InitializingApplyWorker = true;
 
    SetupApplyOrSyncWorker(worker_slot);
 
    InitializingApplyWorker = false;
 
    run_apply_worker();
 
    proc_exit(0);
}

References DatumGetInt32(), fb(), InitializingApplyWorker, proc_exit(), run_apply_worker(), and SetupApplyOrSyncWorker().

AtEOXact_LogicalRepWorkers()

void AtEOXact_LogicalRepWorkers ( bool  isCommit )

extern

Definition at line 6332 of file worker.c.

{
    if (isCommit && on_commit_wakeup_workers_subids != NIL)
    {
        ListCell   *lc;
 
        LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
        foreach(lc, on_commit_wakeup_workers_subids)
        {
            Oid         subid = lfirst_oid(lc);
            List       *workers;
            ListCell   *lc2;
 
            workers = logicalrep_workers_find(subid, true, false);
            foreach(lc2, workers)
            {
                LogicalRepWorker *worker = (LogicalRepWorker *) lfirst(lc2);
 
                logicalrep_worker_wakeup_ptr(worker);
            }
        }
        LWLockRelease(LogicalRepWorkerLock);
    }
 
    /* The List storage will be reclaimed automatically in xact cleanup. */
    on_commit_wakeup_workers_subids = NIL;
}

References fb(), lfirst, lfirst_oid, logicalrep_worker_wakeup_ptr(), logicalrep_workers_find(), LW_SHARED, LWLockAcquire(), LWLockRelease(), NIL, and on_commit_wakeup_workers_subids.

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

HandleParallelApplyMessageInterrupt()

void HandleParallelApplyMessageInterrupt ( void  )

extern

Definition at line 999 of file applyparallelworker.c.

{
    InterruptPending = true;
    ParallelApplyMessagePending = true;
    /* latch will be set by procsignal_sigusr1_handler */
}

References InterruptPending, and ParallelApplyMessagePending.

Referenced by procsignal_sigusr1_handler().

IsLogicalParallelApplyWorker()

bool IsLogicalParallelApplyWorker ( void  )

extern

Definition at line 6074 of file worker.c.

{
    return IsLogicalWorker() && am_parallel_apply_worker();
}

References am_parallel_apply_worker(), and IsLogicalWorker().

Referenced by mq_putmessage().

IsLogicalWorker()

bool IsLogicalWorker ( void  )

extern

Definition at line 6065 of file worker.c.

{
    return MyLogicalRepWorker != NULL;
}

References fb(), and MyLogicalRepWorker.

Referenced by IsLogicalParallelApplyWorker(), and ProcessInterrupts().

LogicalRepWorkersWakeupAtCommit()

void LogicalRepWorkersWakeupAtCommit ( Oid  subid )

extern

Definition at line 6318 of file worker.c.

{
    MemoryContext oldcxt;
 
    oldcxt = MemoryContextSwitchTo(TopTransactionContext);
    on_commit_wakeup_workers_subids =
        list_append_unique_oid(on_commit_wakeup_workers_subids, subid);
    MemoryContextSwitchTo(oldcxt);
}

References fb(), list_append_unique_oid(), MemoryContextSwitchTo(), on_commit_wakeup_workers_subids, and TopTransactionContext.

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

ParallelApplyWorkerMain()

void ParallelApplyWorkerMain ( Datum  main_arg )

extern

Definition at line 861 of file applyparallelworker.c.

{
    ParallelApplyWorkerShared *shared;
    dsm_handle  handle;
    dsm_segment *seg;
    shm_toc    *toc;
    shm_mq     *mq;
    shm_mq_handle *mqh;
    shm_mq_handle *error_mqh;
    ReplOriginId originid;
    int         worker_slot = DatumGetInt32(main_arg);
    char        originname[NAMEDATALEN];
 
    InitializingApplyWorker = true;
 
    /*
     * Setup signal handling.
     *
     * Note: We intentionally used SIGUSR2 to trigger a graceful shutdown
     * initiated by the leader apply worker. This helps to differentiate it
     * from the case where we abort the current transaction and exit on
     * receiving SIGTERM.
     */
    pqsignal(SIGHUP, SignalHandlerForConfigReload);
    pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
    BackgroundWorkerUnblockSignals();
 
    /*
     * Attach to the dynamic shared memory segment for the parallel apply, and
     * find its table of contents.
     *
     * Like parallel query, we don't need resource owner by this time. See
     * ParallelWorkerMain.
     */
    memcpy(&handle, MyBgworkerEntry->bgw_extra, sizeof(dsm_handle));
    seg = dsm_attach(handle);
    if (!seg)
        ereport(ERROR,
                (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                 errmsg("could not map dynamic shared memory segment")));
 
    toc = shm_toc_attach(PG_LOGICAL_APPLY_SHM_MAGIC, dsm_segment_address(seg));
    if (!toc)
        ereport(ERROR,
                (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                 errmsg("invalid magic number in dynamic shared memory segment")));
 
    /* Look up the shared information. */
    shared = shm_toc_lookup(toc, PARALLEL_APPLY_KEY_SHARED, false);
    MyParallelShared = shared;
 
    /*
     * Attach to the message queue.
     */
    mq = shm_toc_lookup(toc, PARALLEL_APPLY_KEY_MQ, false);
    shm_mq_set_receiver(mq, MyProc);
    mqh = shm_mq_attach(mq, seg, NULL);
 
    /*
     * Primary initialization is complete. Now, we can attach to our slot.
     * This is to ensure that the leader apply worker does not write data to
     * the uninitialized memory queue.
     */
    logicalrep_worker_attach(worker_slot);
 
    /*
     * Register the shutdown callback after we are attached to the worker
     * slot. This is to ensure that MyLogicalRepWorker remains valid when this
     * callback is invoked.
     */
    before_shmem_exit(pa_shutdown, PointerGetDatum(seg));
 
    SpinLockAcquire(&MyParallelShared->mutex);
    MyParallelShared->logicalrep_worker_generation = MyLogicalRepWorker->generation;
    MyParallelShared->logicalrep_worker_slot_no = worker_slot;
    SpinLockRelease(&MyParallelShared->mutex);
 
    /*
     * Attach to the error queue.
     */
    mq = shm_toc_lookup(toc, PARALLEL_APPLY_KEY_ERROR_QUEUE, false);
    shm_mq_set_sender(mq, MyProc);
    error_mqh = shm_mq_attach(mq, seg, NULL);
 
    pq_redirect_to_shm_mq(seg, error_mqh);
    pq_set_parallel_leader(MyLogicalRepWorker->leader_pid,
                           INVALID_PROC_NUMBER);
 
    MyLogicalRepWorker->last_send_time = MyLogicalRepWorker->last_recv_time =
        MyLogicalRepWorker->reply_time = 0;
 
    InitializeLogRepWorker();
 
    InitializingApplyWorker = false;
 
    /* Setup replication origin tracking. */
    StartTransactionCommand();
    ReplicationOriginNameForLogicalRep(MySubscription->oid, InvalidOid,
                                       originname, sizeof(originname));
    originid = replorigin_by_name(originname, false);
 
    /*
     * The parallel apply worker doesn't need to monopolize this replication
     * origin which was already acquired by its leader process.
     */
    replorigin_session_setup(originid, MyLogicalRepWorker->leader_pid);
    replorigin_xact_state.origin = originid;
    CommitTransactionCommand();
 
    /*
     * Setup callback for syscache so that we know when something changes in
     * the subscription relation state.
     */
    CacheRegisterSyscacheCallback(SUBSCRIPTIONRELMAP,
                                  InvalidateSyncingRelStates,
                                  (Datum) 0);
 
    set_apply_error_context_origin(originname);
 
    LogicalParallelApplyLoop(mqh);
 
    /*
     * The parallel apply worker must not get here because the parallel apply
     * worker will only stop when it receives a SIGTERM or SIGUSR2 from the
     * leader, or SIGINT from itself, or when there is an error. None of these
     * cases will allow the code to reach here.
     */
    Assert(false);
}

References Assert, BackgroundWorkerUnblockSignals(), before_shmem_exit(), BackgroundWorker::bgw_extra, CacheRegisterSyscacheCallback(), CommitTransactionCommand(), DatumGetInt32(), dsm_attach(), dsm_segment_address(), ereport, errcode(), errmsg, ERROR, fb(), LogicalRepWorker::generation, InitializeLogRepWorker(), InitializingApplyWorker, INVALID_PROC_NUMBER, InvalidateSyncingRelStates(), InvalidOid, LogicalRepWorker::last_recv_time, LogicalRepWorker::last_send_time, LogicalRepWorker::leader_pid, LogicalParallelApplyLoop(), logicalrep_worker_attach(), ParallelApplyWorkerShared::logicalrep_worker_generation, ParallelApplyWorkerShared::logicalrep_worker_slot_no, ParallelApplyWorkerShared::mutex, MyBgworkerEntry, MyLogicalRepWorker, MyParallelShared, MyProc, MySubscription, NAMEDATALEN, Subscription::oid, ReplOriginXactState::origin, pa_shutdown(), PARALLEL_APPLY_KEY_ERROR_QUEUE, PARALLEL_APPLY_KEY_MQ, PARALLEL_APPLY_KEY_SHARED, PG_LOGICAL_APPLY_SHM_MAGIC, PointerGetDatum(), pq_redirect_to_shm_mq(), pq_set_parallel_leader(), pqsignal, ReplicationOriginNameForLogicalRep(), replorigin_by_name(), replorigin_session_setup(), replorigin_xact_state, LogicalRepWorker::reply_time, set_apply_error_context_origin(), shm_mq_attach(), shm_mq_set_receiver(), shm_mq_set_sender(), shm_toc_attach(), shm_toc_lookup(), SIGHUP, SignalHandlerForConfigReload(), SignalHandlerForShutdownRequest(), SIGUSR2, SpinLockAcquire(), SpinLockRelease(), and StartTransactionCommand().

ProcessParallelApplyMessages()

void ProcessParallelApplyMessages ( void  )

extern

Definition at line 1073 of file applyparallelworker.c.

{
    ListCell   *lc;
    MemoryContext oldcontext;
 
    static MemoryContext hpam_context = NULL;
 
    /*
     * This is invoked from ProcessInterrupts(), and since some of the
     * functions it calls contain CHECK_FOR_INTERRUPTS(), there is a potential
     * for recursive calls if more signals are received while this runs. It's
     * unclear that recursive entry would be safe, and it doesn't seem useful
     * even if it is safe, so let's block interrupts until done.
     */
    HOLD_INTERRUPTS();
 
    /*
     * Moreover, CurrentMemoryContext might be pointing almost anywhere. We
     * don't want to risk leaking data into long-lived contexts, so let's do
     * our work here in a private context that we can reset on each use.
     */
    if (!hpam_context)          /* first time through? */
        hpam_context = AllocSetContextCreate(TopMemoryContext,
                                             "ProcessParallelApplyMessages",
                                             ALLOCSET_DEFAULT_SIZES);
    else
        MemoryContextReset(hpam_context);
 
    oldcontext = MemoryContextSwitchTo(hpam_context);
 
    ParallelApplyMessagePending = false;
 
    foreach(lc, ParallelApplyWorkerPool)
    {
        shm_mq_result res;
        Size        nbytes;
        void       *data;
        ParallelApplyWorkerInfo *winfo = (ParallelApplyWorkerInfo *) lfirst(lc);
 
        /*
         * The leader will detach from the error queue and set it to NULL
         * before preparing to stop all parallel apply workers, so we don't
         * need to handle error messages anymore. See
         * logicalrep_worker_detach.
         */
        if (!winfo->error_mq_handle)
            continue;
 
        res = shm_mq_receive(winfo->error_mq_handle, &nbytes, &data, true);
 
        if (res == SHM_MQ_WOULD_BLOCK)
            continue;
        else if (res == SHM_MQ_SUCCESS)
        {
            StringInfoData msg;
 
            initStringInfo(&msg);
            appendBinaryStringInfo(&msg, data, nbytes);
            ProcessParallelApplyMessage(&msg);
            pfree(msg.data);
        }
        else
            ereport(ERROR,
                    (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                     errmsg("lost connection to the logical replication parallel apply worker")));
    }
 
    MemoryContextSwitchTo(oldcontext);
 
    /* Might as well clear the context on our way out */
    MemoryContextReset(hpam_context);
 
    RESUME_INTERRUPTS();
}

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, appendBinaryStringInfo(), StringInfoData::data, data, ereport, errcode(), errmsg, ERROR, ParallelApplyWorkerInfo::error_mq_handle, fb(), HOLD_INTERRUPTS, initStringInfo(), lfirst, MemoryContextReset(), MemoryContextSwitchTo(), ParallelApplyMessagePending, ParallelApplyWorkerPool, pfree(), ProcessParallelApplyMessage(), RESUME_INTERRUPTS, shm_mq_receive(), SHM_MQ_SUCCESS, SHM_MQ_WOULD_BLOCK, and TopMemoryContext.

Referenced by ProcessInterrupts().

SequenceSyncWorkerMain()

void SequenceSyncWorkerMain ( Datum  main_arg )

extern

Definition at line 764 of file sequencesync.c.

{
    int         worker_slot = DatumGetInt32(main_arg);
 
    SetupApplyOrSyncWorker(worker_slot);
 
    start_sequence_sync();
 
    FinishSyncWorker();
}

References DatumGetInt32(), fb(), FinishSyncWorker(), SetupApplyOrSyncWorker(), and start_sequence_sync().

TableSyncWorkerMain()

void TableSyncWorkerMain ( Datum  main_arg )

extern

Definition at line 1577 of file tablesync.c.

{
    int         worker_slot = DatumGetInt32(main_arg);
 
    SetupApplyOrSyncWorker(worker_slot);
 
    run_tablesync_worker();
 
    FinishSyncWorker();
}

References DatumGetInt32(), fb(), FinishSyncWorker(), run_tablesync_worker(), and SetupApplyOrSyncWorker().

Variable Documentation

ParallelApplyMessagePending

PGDLLIMPORT volatile sig_atomic_t ParallelApplyMessagePending

extern

Definition at line 248 of file applyparallelworker.c.

Referenced by HandleParallelApplyMessageInterrupt(), ProcessInterrupts(), and ProcessParallelApplyMessages().