Example #1
0
/* ----------------------------------
 *	Startup Process main entry point
 * ----------------------------------
 */
void
StartupProcessMain(void)
{
	/*
	 * If possible, make this process a group leader, so that the postmaster
	 * can signal any child processes too.
	 */
#ifdef HAVE_SETSID
	if (setsid() < 0)
		elog(FATAL, "setsid() failed: %m");
#endif

	/*
	 * Properly accept or ignore signals the postmaster might send us.
	 */
	pqsignal(SIGHUP, StartupProcSigHupHandler); /* reload config file */
	pqsignal(SIGINT, SIG_IGN);	/* ignore query cancel */
	pqsignal(SIGTERM, StartupProcShutdownHandler);		/* request shutdown */
	pqsignal(SIGQUIT, startupproc_quickdie);	/* hard crash time */
	InitializeTimeouts();		/* establishes SIGALRM handler */
	pqsignal(SIGPIPE, SIG_IGN);
	pqsignal(SIGUSR1, StartupProcSigUsr1Handler);
	pqsignal(SIGUSR2, StartupProcTriggerHandler);

	/*
	 * Reset some signals that are accepted by postmaster but not here
	 */
	pqsignal(SIGCHLD, SIG_DFL);
	pqsignal(SIGTTIN, SIG_DFL);
	pqsignal(SIGTTOU, SIG_DFL);
	pqsignal(SIGCONT, SIG_DFL);
	pqsignal(SIGWINCH, SIG_DFL);

	/*
	 * Register timeouts needed for standby mode
	 */
	RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
	RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);

	/*
	 * Unblock signals (they were blocked when the postmaster forked us)
	 */
	PG_SETMASK(&UnBlockSig);

	/*
	 * Do what we came for.
	 */
	StartupXLOG();

	/*
	 * Exit normally. Exit code 0 tells postmaster that we completed recovery
	 * successfully.
	 */
	proc_exit(0);
}
Example #2
0
/*
 * proc_exit callback to tear down the JVM
 */
static void _destroyJavaVM(int status, Datum dummy)
{
	if(s_javaVM != 0)
	{
		Invocation ctx;
#ifdef USE_PLJAVA_SIGHANDLERS

#if PG_VERSION_NUM >= 90300
		TimeoutId tid;
#else
		pqsigfunc saveSigAlrm;
#endif

		Invocation_pushInvocation(&ctx, false);
		if(sigsetjmp(recoverBuf, 1) != 0)
		{
			elog(DEBUG2,
				"needed to forcibly shut down the Java virtual machine");
			s_javaVM = 0;
			return;
		}

#if PG_VERSION_NUM >= 90300
		InitializeTimeouts();           /* establishes SIGALRM handler */
		tid = RegisterTimeout(USER_TIMEOUT, terminationTimeoutHandler);
#else
		saveSigAlrm = pqsignal(SIGALRM, terminationTimeoutHandler);
		enable_sig_alarm(5000, false);
#endif

		elog(DEBUG2, "shutting down the Java virtual machine");
		JNI_destroyVM(s_javaVM);

#if PG_VERSION_NUM >= 90300
		disable_timeout(tid, false);
#else
		disable_sig_alarm(false);
		pqsignal(SIGALRM, saveSigAlrm);
#endif

#else
		Invocation_pushInvocation(&ctx, false);
		elog(DEBUG2, "shutting down the Java virtual machine");
		JNI_destroyVM(s_javaVM);
#endif
		elog(DEBUG2, "done shutting down the Java virtual machine");
		s_javaVM = 0;
		currentInvocation = 0;
	}
}
Example #3
0
/* --------------------------------
 * InitPostgres
 *		Initialize POSTGRES.
 *
 * The database can be specified by name, using the in_dbname parameter, or by
 * OID, using the dboid parameter.  In the latter case, the actual database
 * name can be returned to the caller in out_dbname.  If out_dbname isn't
 * NULL, it must point to a buffer of size NAMEDATALEN.
 *
 * In bootstrap mode no parameters are used.  The autovacuum launcher process
 * doesn't use any parameters either, because it only goes far enough to be
 * able to read pg_database; it doesn't connect to any particular database.
 * In walsender mode only username is used.
 *
 * As of PostgreSQL 8.2, we expect InitProcess() was already called, so we
 * already have a PGPROC struct ... but it's not completely filled in yet.
 *
 * Note:
 *		Be very careful with the order of calls in the InitPostgres function.
 * --------------------------------
 */
void
InitPostgres(const char *in_dbname, Oid dboid, const char *username,
             char *out_dbname)
{
    bool		bootstrap = IsBootstrapProcessingMode();
    bool		am_superuser;
    char	   *fullpath;
    char		dbname[NAMEDATALEN];

    elog(DEBUG3, "InitPostgres");

    /*
     * Add my PGPROC struct to the ProcArray.
     *
     * Once I have done this, I am visible to other backends!
     */
    InitProcessPhase2();

    /*
     * Initialize my entry in the shared-invalidation manager's array of
     * per-backend data.
     *
     * Sets up MyBackendId, a unique backend identifier.
     */
    MyBackendId = InvalidBackendId;

    SharedInvalBackendInit(false);

    if (MyBackendId > MaxBackends || MyBackendId <= 0)
        elog(FATAL, "bad backend ID: %d", MyBackendId);

    /* Now that we have a BackendId, we can participate in ProcSignal */
    ProcSignalInit(MyBackendId);

    /*
     * Also set up timeout handlers needed for backend operation.  We need
     * these in every case except bootstrap.
     */
    if (!bootstrap)
    {
        RegisterTimeout(DEADLOCK_TIMEOUT, CheckDeadLock);
        RegisterTimeout(STATEMENT_TIMEOUT, StatementTimeoutHandler);
        RegisterTimeout(LOCK_TIMEOUT, LockTimeoutHandler);
    }

    /*
     * bufmgr needs another initialization call too
     */
    InitBufferPoolBackend();

    /*
     * Initialize local process's access to XLOG.
     */
    if (IsUnderPostmaster)
    {
        /*
         * The postmaster already started the XLOG machinery, but we need to
         * call InitXLOGAccess(), if the system isn't in hot-standby mode.
         * This is handled by calling RecoveryInProgress and ignoring the
         * result.
         */
        (void) RecoveryInProgress();
    }
    else
    {
        /*
         * We are either a bootstrap process or a standalone backend. Either
         * way, start up the XLOG machinery, and register to have it closed
         * down at exit.
         */
        StartupXLOG();
        on_shmem_exit(ShutdownXLOG, 0);
    }

    /*
     * Initialize the relation cache and the system catalog caches.  Note that
     * no catalog access happens here; we only set up the hashtable structure.
     * We must do this before starting a transaction because transaction abort
     * would try to touch these hashtables.
     */
    RelationCacheInitialize();
    InitCatalogCache();
    InitPlanCache();

    /* Initialize portal manager */
    EnablePortalManager();

    /* Initialize stats collection --- must happen before first xact */
    if (!bootstrap)
        pgstat_initialize();

    /*
     * Load relcache entries for the shared system catalogs.  This must create
     * at least entries for pg_database and catalogs used for authentication.
     */
    RelationCacheInitializePhase2();

    /*
     * Set up process-exit callback to do pre-shutdown cleanup.  This is the
     * first before_shmem_exit callback we register; thus, this will be the
     * last thing we do before low-level modules like the buffer manager begin
     * to close down.  We need to have this in place before we begin our first
     * transaction --- if we fail during the initialization transaction, as is
     * entirely possible, we need the AbortTransaction call to clean up.
     */
    before_shmem_exit(ShutdownPostgres, 0);

    /* The autovacuum launcher is done here */
    if (IsAutoVacuumLauncherProcess())
        return;

    /*
     * Start a new transaction here before first access to db, 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.)
     */
    if (!bootstrap)
    {
        /* statement_timestamp must be set for timeouts to work correctly */
        SetCurrentStatementStartTimestamp();
        StartTransactionCommand();

        /*
         * transaction_isolation will have been set to the default by the
         * above.  If the default is "serializable", and we are in hot
         * standby, we will fail if we don't change it to something lower.
         * Fortunately, "read committed" is plenty good enough.
         */
        XactIsoLevel = XACT_READ_COMMITTED;

        (void) GetTransactionSnapshot();
    }

    /*
     * Perform client authentication if necessary, then figure out our
     * postgres user ID, and see if we are a superuser.
     *
     * In standalone mode and in autovacuum worker processes, we use a fixed
     * ID, otherwise we figure it out from the authenticated user name.
     */
    if (bootstrap || IsAutoVacuumWorkerProcess())
    {
        InitializeSessionUserIdStandalone();
        am_superuser = true;
    }
    else if (!IsUnderPostmaster)
    {
        InitializeSessionUserIdStandalone();
        am_superuser = true;
        if (!ThereIsAtLeastOneRole())
            ereport(WARNING,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("no roles are defined in this database system"),
                     errhint("You should immediately run CREATE USER \"%s\" SUPERUSER;.",
                             username)));
    }
    else if (IsBackgroundWorker)
    {
        if (username == NULL)
        {
            InitializeSessionUserIdStandalone();
            am_superuser = true;
        }
        else
        {
            InitializeSessionUserId(username);
            am_superuser = superuser();
        }
    }
    else
    {
        /* normal multiuser case */
        Assert(MyProcPort != NULL);
        PerformAuthentication(MyProcPort);
        InitializeSessionUserId(username);
        am_superuser = superuser();
    }

    /*
     * If we're trying to shut down, only superusers can connect, and new
     * replication connections are not allowed.
     */
    if ((!am_superuser || am_walsender) &&
            MyProcPort != NULL &&
            MyProcPort->canAcceptConnections == CAC_WAITBACKUP)
    {
        if (am_walsender)
            ereport(FATAL,
                    (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                     errmsg("new replication connections are not allowed during database shutdown")));
        else
            ereport(FATAL,
                    (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                     errmsg("must be superuser to connect during database shutdown")));
    }

    /*
     * Binary upgrades only allowed super-user connections
     */
    if (IsBinaryUpgrade && !am_superuser)
    {
        ereport(FATAL,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to connect in binary upgrade mode")));
    }

    /*
     * The last few connections slots are reserved for superusers. Although
     * replication connections currently require superuser privileges, we
     * don't allow them to consume the reserved slots, which are intended for
     * interactive use.
     */
    if ((!am_superuser || am_walsender) &&
            ReservedBackends > 0 &&
            !HaveNFreeProcs(ReservedBackends))
        ereport(FATAL,
                (errcode(ERRCODE_TOO_MANY_CONNECTIONS),
                 errmsg("remaining connection slots are reserved for non-replication superuser connections")));

    /* Check replication permissions needed for walsender processes. */
    if (am_walsender)
    {
        Assert(!bootstrap);

        if (!superuser() && !has_rolreplication(GetUserId()))
            ereport(FATAL,
                    (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                     errmsg("must be superuser or replication role to start walsender")));
    }

    /*
     * If this is a plain walsender only supporting physical replication, we
     * don't want to connect to any particular database. Just finish the
     * backend startup by processing any options from the startup packet, and
     * we're done.
     */
    if (am_walsender && !am_db_walsender)
    {
        /* process any options passed in the startup packet */
        if (MyProcPort != NULL)
            process_startup_options(MyProcPort, am_superuser);

        /* Apply PostAuthDelay as soon as we've read all options */
        if (PostAuthDelay > 0)
            pg_usleep(PostAuthDelay * 1000000L);

        /* initialize client encoding */
        InitializeClientEncoding();

        /* report this backend in the PgBackendStatus array */
        pgstat_bestart();

        /* close the transaction we started above */
        CommitTransactionCommand();

        return;
    }

    /*
     * Set up the global variables holding database id and default tablespace.
     * But note we won't actually try to touch the database just yet.
     *
     * We take a shortcut in the bootstrap case, otherwise we have to look up
     * the db's entry in pg_database.
     */
    if (bootstrap)
    {
        MyDatabaseId = TemplateDbOid;
        MyDatabaseTableSpace = DEFAULTTABLESPACE_OID;
    }
    else if (in_dbname != NULL)
    {
        HeapTuple	tuple;
        Form_pg_database dbform;

        tuple = GetDatabaseTuple(in_dbname);
        if (!HeapTupleIsValid(tuple))
            ereport(FATAL,
                    (errcode(ERRCODE_UNDEFINED_DATABASE),
                     errmsg("database \"%s\" does not exist", in_dbname)));
        dbform = (Form_pg_database) GETSTRUCT(tuple);
        MyDatabaseId = HeapTupleGetOid(tuple);
        MyDatabaseTableSpace = dbform->dattablespace;
        /* take database name from the caller, just for paranoia */
        strlcpy(dbname, in_dbname, sizeof(dbname));
    }
    else if (OidIsValid(dboid))
    {
        /* caller specified database by OID */
        HeapTuple	tuple;
        Form_pg_database dbform;

        tuple = GetDatabaseTupleByOid(dboid);
        if (!HeapTupleIsValid(tuple))
            ereport(FATAL,
                    (errcode(ERRCODE_UNDEFINED_DATABASE),
                     errmsg("database %u does not exist", dboid)));
        dbform = (Form_pg_database) GETSTRUCT(tuple);
        MyDatabaseId = HeapTupleGetOid(tuple);
        MyDatabaseTableSpace = dbform->dattablespace;
        Assert(MyDatabaseId == dboid);
        strlcpy(dbname, NameStr(dbform->datname), sizeof(dbname));
        /* pass the database name back to the caller */
        if (out_dbname)
            strcpy(out_dbname, dbname);
    }
    else
    {
        /*
         * If this is a background worker not bound to any particular
         * database, we're done now.  Everything that follows only makes
         * sense if we are bound to a specific database.  We do need to
         * close the transaction we started before returning.
         */
        if (!bootstrap)
            CommitTransactionCommand();
        return;
    }

    /*
     * Now, take a writer's lock on the database we are trying to connect to.
     * If there is a concurrently running DROP DATABASE on that database, this
     * will block us until it finishes (and has committed its update of
     * pg_database).
     *
     * Note that the lock is not held long, only until the end of this startup
     * transaction.  This is OK since we will advertise our use of the
     * database in the ProcArray before dropping the lock (in fact, that's the
     * next thing to do).  Anyone trying a DROP DATABASE after this point will
     * see us in the array once they have the lock.  Ordering is important for
     * this because we don't want to advertise ourselves as being in this
     * database until we have the lock; otherwise we create what amounts to a
     * deadlock with CountOtherDBBackends().
     *
     * Note: use of RowExclusiveLock here is reasonable because we envision
     * our session as being a concurrent writer of the database.  If we had a
     * way of declaring a session as being guaranteed-read-only, we could use
     * AccessShareLock for such sessions and thereby not conflict against
     * CREATE DATABASE.
     */
    if (!bootstrap)
        LockSharedObject(DatabaseRelationId, MyDatabaseId, 0,
                         RowExclusiveLock);

    /*
     * Now we can mark our PGPROC entry with the database ID.
     *
     * We assume this is an atomic store so no lock is needed; though actually
     * things would work fine even if it weren't atomic.  Anyone searching the
     * ProcArray for this database's ID should hold the database lock, so they
     * would not be executing concurrently with this store.  A process looking
     * for another database's ID could in theory see a chance match if it read
     * a partially-updated databaseId value; but as long as all such searches
     * wait and retry, as in CountOtherDBBackends(), they will certainly see
     * the correct value on their next try.
     */
    MyProc->databaseId = MyDatabaseId;

    /*
     * We established a catalog snapshot while reading pg_authid and/or
     * pg_database; but until we have set up MyDatabaseId, we won't react to
     * incoming sinval messages for unshared catalogs, so we won't realize it
     * if the snapshot has been invalidated.  Assume it's no good anymore.
     */
    InvalidateCatalogSnapshot();

    /*
     * Recheck pg_database to make sure the target database hasn't gone away.
     * If there was a concurrent DROP DATABASE, this ensures we will die
     * cleanly without creating a mess.
     */
    if (!bootstrap)
    {
        HeapTuple	tuple;

        tuple = GetDatabaseTuple(dbname);
        if (!HeapTupleIsValid(tuple) ||
                MyDatabaseId != HeapTupleGetOid(tuple) ||
                MyDatabaseTableSpace != ((Form_pg_database) GETSTRUCT(tuple))->dattablespace)
            ereport(FATAL,
                    (errcode(ERRCODE_UNDEFINED_DATABASE),
                     errmsg("database \"%s\" does not exist", dbname),
                     errdetail("It seems to have just been dropped or renamed.")));
    }

    /*
     * Now we should be able to access the database directory safely. Verify
     * it's there and looks reasonable.
     */
    fullpath = GetDatabasePath(MyDatabaseId, MyDatabaseTableSpace);

    if (!bootstrap)
    {
        if (access(fullpath, F_OK) == -1)
        {
            if (errno == ENOENT)
                ereport(FATAL,
                        (errcode(ERRCODE_UNDEFINED_DATABASE),
                         errmsg("database \"%s\" does not exist",
                                dbname),
                         errdetail("The database subdirectory \"%s\" is missing.",
                                   fullpath)));
            else
                ereport(FATAL,
                        (errcode_for_file_access(),
                         errmsg("could not access directory \"%s\": %m",
                                fullpath)));
        }

        ValidatePgVersion(fullpath);
    }

    SetDatabasePath(fullpath);

    /*
     * It's now possible to do real access to the system catalogs.
     *
     * Load relcache entries for the system catalogs.  This must create at
     * least the minimum set of "nailed-in" cache entries.
     */
    RelationCacheInitializePhase3();

    /* set up ACL framework (so CheckMyDatabase can check permissions) */
    initialize_acl();

    /*
     * Re-read the pg_database row for our database, check permissions and set
     * up database-specific GUC settings.  We can't do this until all the
     * database-access infrastructure is up.  (Also, it wants to know if the
     * user is a superuser, so the above stuff has to happen first.)
     */
    if (!bootstrap)
        CheckMyDatabase(dbname, am_superuser);

    /*
     * Now process any command-line switches and any additional GUC variable
     * settings passed in the startup packet.   We couldn't do this before
     * because we didn't know if client is a superuser.
     */
    if (MyProcPort != NULL)
        process_startup_options(MyProcPort, am_superuser);

    /* Process pg_db_role_setting options */
    process_settings(MyDatabaseId, GetSessionUserId());

    /* Apply PostAuthDelay as soon as we've read all options */
    if (PostAuthDelay > 0)
        pg_usleep(PostAuthDelay * 1000000L);

    /*
     * Initialize various default states that can't be set up until we've
     * selected the active user and gotten the right GUC settings.
     */

    /* set default namespace search path */
    InitializeSearchPath();

    /* initialize client encoding */
    InitializeClientEncoding();

    /* report this backend in the PgBackendStatus array */
    if (!bootstrap)
        pgstat_bestart();

    /* close the transaction we started above */
    if (!bootstrap)
        CommitTransactionCommand();
}
Example #4
0
Scheduler::ID Scheduler::Heartbeat(Handler&& handler, std::time_t millisecond) {
  return RegisterTimeout(std::move(handler), millisecond, true);
}
Example #5
0
Scheduler::ID Scheduler::Timeout(Handler&& handler, std::time_t millisecond) {
  return RegisterTimeout(std::move(handler), millisecond, false);
}