/*
 * Inserts or updates an entry in the Local MDVSN component.
 * Entry is inserted if not already existing, or updated otherwise.
 *
 * 	local_mdvsn: Which MDVSN to insert/update into. For subtransactions, we have
 * 	  a separate Local MDVSN compoment for each level.
 * 	entry: The mdver_entry to be inserted or updated. A copy of it will be inserted
 * 	  in the hashtable
 * 	local: true if the message was generated locally, and it's coming from CVQ.
 * 	  false if message is coming from the global queue SVQ
 */
void
mdver_local_mdvsn_add(mdver_local_mdvsn *local_mdvsn, mdver_entry *entry, bool local)
{
	Assert(NULL != local_mdvsn);
	Assert(NULL != local_mdvsn->htable);
	Assert(NULL != entry);

	bool found_ptr = false;
	mdver_entry *inserted_entry = (mdver_entry *) hash_search(local_mdvsn->htable,
			&entry->key, HASH_ENTER, &found_ptr);
	Assert(NULL != inserted_entry);

#ifdef MD_VERSIONING_INSTRUMENTATION
	if (found_ptr)
	{
		ereport(gp_mdversioning_loglevel,
				(errmsg("local_mdvsn_add: updating entry Oid=%d [" UINT64_FORMAT ", " UINT64_FORMAT "] --> [" UINT64_FORMAT ", " UINT64_FORMAT "]",
						inserted_entry->key, inserted_entry->ddl_version, inserted_entry->dml_version,
						entry->ddl_version, entry->dml_version),
						errprintstack(false)));
	}
	else
	{
		ereport(gp_mdversioning_loglevel,
				(errmsg("local_mdvsn_add: inserting entry Oid=%d [" UINT64_FORMAT ", " UINT64_FORMAT "]",
						inserted_entry->key,
						entry->ddl_version, entry->dml_version),
						errprintstack(false)));
	}
#endif

		memcpy(inserted_entry, entry, sizeof(mdver_entry));

}
Exemple #2
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/**
 * If this function is changed then update varattrib_untoast_len as well
 */
void varattrib_untoast_ptr_len(Datum d, char **datastart, int *len, void **tofree)
{
	if (DatumGetPointer(d) == NULL)
	{
		ereport(ERROR,
				(errcode(ERRCODE_INTERNAL_ERROR),
				 errmsg(" Unable to detoast datum "),
				 errprintstack(true)));
	}

	struct varlena *va = (struct varlena *) DatumGetPointer(d);
	varattrib *attr = (varattrib *) va;

	*len = -1;
	*tofree = NULL;

	if(VARATT_IS_EXTENDED(attr))
	{
		if(VARATT_IS_EXTERNAL(attr))
		{
			attr = (varattrib *)toast_fetch_datum((struct varlena *)attr);
			/* toast_fetch_datum will palloc, so set it up for free */
			*tofree = attr;
		}

		if(VARATT_IS_COMPRESSED(attr))
		{
			PGLZ_Header *tmp = (PGLZ_Header *) attr;
			attr = (varattrib *) palloc(PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
			SET_VARSIZE(attr, PGLZ_RAW_SIZE(tmp) + VARHDRSZ);
			pglz_decompress(tmp, VARDATA(attr));

			/* If tofree is set, that is, we get it from toast_fetch_datum.  
			 * We need to free it here 
			 */
			if(*tofree)
				pfree(*tofree);
			*tofree = attr;
		}
		else if(VARATT_IS_SHORT(attr))
		{
		    /* Warning! Return unaligned pointer! */
			*len = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
			*datastart = VARDATA_SHORT(attr);
			attr = NULL;
		}
	}

	if(*len == -1)
	{
		*datastart = VARDATA(attr);
		*len = VARSIZE(attr) - VARHDRSZ;
	}

	Assert(*len >= 0);
}
Exemple #3
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/**
 * If this function is changed then update varattrib_untoast_ptr_len as well
 */
int varattrib_untoast_len(Datum d)
{
	if (DatumGetPointer(d) == NULL)
	{
		ereport(ERROR,
				(errcode(ERRCODE_INTERNAL_ERROR),
				 errmsg(" Unable to detoast datum "),
				 errprintstack(true)));
	}

	struct varlena *va = (struct varlena *) DatumGetPointer(d);
	varattrib *attr = (varattrib *) va;

	int len = -1;
	void *toFree = NULL;

	if(VARATT_IS_EXTENDED(attr))
	{
		if(VARATT_IS_EXTERNAL(attr))
		{
			attr = (varattrib *)toast_fetch_datum((struct varlena *)attr);
			/* toast_fetch_datum will palloc, so set it up for free */
			toFree = attr;
		}

		if(VARATT_IS_COMPRESSED(attr))
		{
			PGLZ_Header *tmp = (PGLZ_Header *) attr;
			len = PGLZ_RAW_SIZE(tmp);
		}
		else if(VARATT_IS_SHORT(attr))
		{
			len = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
		}
	}

	if(len == -1)
	{
		len = VARSIZE(attr) - VARHDRSZ;
	}

	if ( toFree)
		pfree(toFree);

	Assert(len >= 0);
	return len;
}
/*
 * Starts a runaway cleanup by triggering an ERROR if the VMEM tracker is active
 * and a commit is not already in progress. Otherwise, it marks the process as clean
 */
void
RunawayCleaner_StartCleanup()
{
	/*
	 * Cleanup can be attempted from multiple places, such as before deactivating
	 * a process (if a pending runaway event) or periodically from CHECK_FOR_INTERRUPTS
	 * (indirectly via RedZoneHandler_DetectRunaway). We don't carry multiple cleanup
	 * for a single runaway event. Every time we *start* a cleanup process, we set the
	 * beginCleanupRunawayVersion to the runaway version for which we started cleaning
	 * up. Later on, if we reenter this method (e.g., another CHECK_FOR_INTERRUPTS()
	 * during cleanup), we can observe that the cleanup already started from this runaway
	 * event, and therefore we skip duplicate cleanup
	 */
	if (RunawayCleaner_ShouldStartRunawayCleanup())
	{
		Assert(beginCleanupRunawayVersion < *latestRunawayVersion);
		Assert(endCleanupRunawayVersion < *latestRunawayVersion);
		/* We don't want to cleanup multiple times for same runaway event */
		beginCleanupRunawayVersion = *latestRunawayVersion;

		if (CritSectionCount == 0 && InterruptHoldoffCount == 0 && vmemTrackerInited &&
			gp_command_count > 0 /* Cleaning up QEs that are not executing a valid command
			may cause the QD to get stuck [MPP-24950] */ &&
			/* Super user is terminated only when it's the primary runaway consumer (i.e., the top consumer) */
			(!superuser() || MySessionState->runawayStatus == RunawayStatus_PrimaryRunawaySession))
		{
#ifdef FAULT_INJECTOR
	FaultInjector_InjectFaultIfSet(
			RunawayCleanup,
			DDLNotSpecified,
			"",  // databaseName
			""); // tableName
#endif

			ereport(ERROR, (errmsg("Canceling query because of high VMEM usage. Used: %dMB, available %dMB, red zone: %dMB",
					VmemTracker_ConvertVmemChunksToMB(MySessionState->sessionVmem), VmemTracker_GetAvailableVmemMB(),
					RedZoneHandler_GetRedZoneLimitMB()), errprintstack(true)));
		}

		/*
		 * If we cannot error out because of a critical section or because we are a super user
		 * or for some other reason (such as the QE is not running any valid command, i.e.,
		 * gp_command_count is not positive) simply declare this process as clean
		 */
		RunawayCleaner_RunawayCleanupDoneForProcess(true /* ignoredCleanup */);
	}
}
Exemple #5
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/*
 * increment_command_count
 *	  Increment gp_command_count. If the new command count is 0 or a negative number, reset it to 1.
 */
void
increment_command_count()
{
	if (gp_cancel_query_print_log)
	{
		ereport(LOG,
				(errmsg("Incrementing command count from %d to %d",
						gp_command_count, gp_command_count + 1),
				 errprintstack(true)));
	}

	gp_command_count++;
	if (gp_command_count <= 0)
	{
		gp_command_count = 1;
	}
}
/*
 * When a backend is requesting the more recent version of an object,
 * if the Local MDVSN cache doesn't have the version, and if a NUKE event
 * has been encountered in the current transaction, a new version is
 * generated and returned for the object. A new versioning event is also
 * produced.
 *
 *   key: The key of the looked-up object
 *   ddl_version: used to return the ddl version for the object
 *   dml_version: used to return the dml version for the object
 *
 */
static void
mdver_request_after_nuke(Oid key, uint64 *ddl_version, uint64 *dml_version)
{
	Assert(NULL != ddl_version);
	Assert(NULL != dml_version);

	/* Generate new version */
	*ddl_version = mdver_next_global_version();
	*dml_version = mdver_next_global_version();

	mdver_event *new_event = (mdver_event *) palloc0(sizeof(mdver_event));
	new_event->key = key;
	new_event->new_ddl_version = *ddl_version;
	new_event->new_dml_version = *dml_version;
	new_event->old_ddl_version = INVALID_MD_VERSION;
	new_event->old_dml_version = INVALID_MD_VERSION;

#ifdef MD_VERSIONING_INSTRUMENTATION
	/* Add my current process id as the originating backend pid */
	new_event->backend_pid = MyProcPid;
#endif

	/* Annotate Versioning Event with the current version from Global MDVSN if exists */
	mdver_entry *crt_entry = mdver_glob_mdvsn_find(key);
	if (NULL != crt_entry)
	{
		new_event->old_ddl_version = crt_entry->ddl_version;
		new_event->old_dml_version = crt_entry->dml_version;
	}

	CacheAddVersioningEvent(new_event);

#ifdef MD_VERSIONING_INSTRUMENTATION
	char *mdev_str = mdver_event_str(new_event);
	ereport(gp_mdversioning_loglevel,
			(errmsg("mdver_consume_after_nuke: generated new VE %s",
					mdev_str),
					errprintstack(false)));
	pfree(mdev_str);
#endif

	/* A copy of the event is added to the queue above. We can pfree our local copy */
	pfree(new_event);
}
/*
 * Look up an entry in the specified Local MDVSN component. This function
 *  doesn't traverse to the parent Local MDVSN.
 *
 * 	 Returns the entry if found, NULL otherwise.
 *
 * 	 local_mdvsn: Which MDVSN to look into. For subtransactions, we have
 * 	   a separate Local MDVSN component for each level
 * 	 key: The key of the object to look for
 */
mdver_entry *
mdver_local_mdvsn_find(mdver_local_mdvsn *local_mdvsn, Oid key)
{
	Assert(NULL != local_mdvsn);
	Assert(InvalidOid != key);

	mdver_entry *entry = (mdver_entry *) hash_search(local_mdvsn->htable, &key,
			HASH_FIND, NULL /* foundPtr */);

	ereport(gp_mdversioning_loglevel,
			(errmsg("LocalMDVSN find for key=%d. Found=%s, nukeHappened=%s",
			key,
			(NULL!=entry)?"yes":"no",
			local_mdvsn->nuke_happened?"yes":"no"),
			errprintstack(true)));


	return entry;
}
Exemple #8
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/*
 * Workfile-manager specific function to clean up before releasing a
 * workfile set from the cache.
 *
 */
static void
workfile_mgr_cleanup_set(const void *resource)
{
	workfile_set *work_set = (workfile_set *) resource;

	ereport(gp_workfile_caching_loglevel,
			(errmsg("workfile mgr cleanup deleting set: key=0x%0xd, size=" INT64_FORMAT
					" in_progress_size=" INT64_FORMAT " path=%s",
					work_set->key,
					work_set->size,
					work_set->in_progress_size,
					work_set->path),
					errprintstack(true)));

	workfile_mgr_delete_set_directory(work_set->path);

	/*
	 * The most accurate size of a workset is recorded in work_set->in_progress_size.
	 * work_set->size is only updated when we close a file, so it lags behind
	 */

	Assert(work_set->in_progress_size >= work_set->size);
	int64 size_to_delete = work_set->in_progress_size;

	elog(gp_workfile_caching_loglevel, "Subtracting " INT64_FORMAT " from workfile diskspace", size_to_delete);

	/*
	 * When subtracting the size of this workset from our accounting,
	 * only update the per-query counter if we created the workset.
	 * In that case, the state is ACQUIRED, otherwise is CACHED or DELETED
	 */
	CacheEntry *cacheEntry = CACHE_ENTRY_HEADER(resource);
	bool update_query_space = (cacheEntry->state == CACHE_ENTRY_ACQUIRED);

	WorkfileDiskspace_Commit(0, size_to_delete, update_query_space);
}
/*
 * Workfile-manager specific function to clean up before releasing a
 * workfile set from the cache.
 *
 */
static void
workfile_mgr_cleanup_set(const void *resource)
{
	workfile_set *work_set = (workfile_set *) resource;

	/*
	 *  We have to make this callback function return cleanly ALL the
	 *  time. It shouldn't throw an exception.
	 *  We must try to clean up as much as we can in the callback, and
	 *  then never be called again.
	 *  This means holding interrupts, catching and handling all exceptions.
	 */

	if (work_set->on_disk)
	{
		ereport(gp_workfile_caching_loglevel,
				(errmsg("workfile mgr cleanup deleting set: key=0x%0xd, size=" INT64_FORMAT
				" in_progress_size=" INT64_FORMAT " path=%s",
				work_set->key,
				work_set->size,
				work_set->in_progress_size,
				work_set->path),
				errprintstack(true)));

		Assert(NULL == work_set->set_plan);

		PG_TRY();
		{

#ifdef FAULT_INJECTOR
			FaultInjector_InjectFaultIfSet(
				WorkfileCleanupSet,
				DDLNotSpecified,
				"", /* databaseName */
				"" /* tableName */
				);
#endif

			/* Prevent interrupts while cleaning up */
			HOLD_INTERRUPTS();

			workfile_mgr_delete_set_directory(work_set->path);

			/* Now we can allow interrupts again */
			RESUME_INTERRUPTS();

		}
		PG_CATCH();
		{
			elog(LOG, "Cleaning up workfile set directory path=%s failed. Proceeding",
					work_set->path);

			/* We're not re-throwing the error. Otherwise we'll end up having
			 * to clean up again, probably failing again.
			 */
		}
		PG_END_TRY();

		/*
		 * The most accurate size of a workset is recorded in work_set->in_progress_size.
		 * work_set->size is only updated when we close a file, so it lags behind
		 */

		Assert(work_set->in_progress_size >= work_set->size);
		int64 size_to_delete = work_set->in_progress_size;

		elog(gp_workfile_caching_loglevel, "Subtracting " INT64_FORMAT " from workfile diskspace", size_to_delete);

		/*
		 * When subtracting the size of this workset from our accounting,
		 * only update the per-query counter if we created the workset.
		 * In that case, the state is ACQUIRED, otherwise is CACHED or DELETED
		 */
		CacheEntry *cacheEntry = CACHE_ENTRY_HEADER(resource);
		bool update_query_space = (cacheEntry->state == CACHE_ENTRY_ACQUIRED);

		WorkfileDiskspace_Commit(0, size_to_delete, update_query_space);
	}
	else
	{
		/* Non-physical workfile set, we need to free up the plan memory */
		if (NULL != work_set->set_plan->serialized_plan)
		{
			pfree(work_set->set_plan->serialized_plan);
		}

		if (NULL != work_set->set_plan)
		{
			pfree(work_set->set_plan);
		}
	}
}
Exemple #10
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/*
 * Grabs one entry in the sessionStateArray for current session.
 * If the current session already has an entry, it just returns the
 * pointer to the previously grabbed entry.
 */
static SessionState*
SessionState_Acquire(int sessionId)
{
	LWLockAcquire(SessionStateLock, LW_EXCLUSIVE);

	SessionState *cur = AllSessionStateEntries->usedList;

	while (cur != NULL && cur->sessionId != sessionId)
	{
		Assert(INVALID_SESSION_ID != cur->sessionId);
		cur = cur->next;
	}

	if (NULL == cur && NULL == AllSessionStateEntries->freeList)
	{
		LWLockRelease(SessionStateLock);
		ereport(FATAL,
				(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
						errmsg("Too many sessions."),
						errdetail("Could not acquire resources for additional sessions."),
						errhint("Disconnect some sessions and try again.")));
	}

	SessionState *acquired = cur;

	/*
	 * Nothing was acquired for this session from any other processes. Therefore,
	 * acquire a new entry, and reset its properties.
	 */
	if (NULL == acquired)
	{
		acquired = AllSessionStateEntries->freeList;
		Assert(INVALID_SESSION_ID == acquired->sessionId &&
				acquired->runawayStatus == RunawayStatus_NotRunaway &&
				0 == acquired->pinCount &&
				CLEANUP_COUNTDOWN_BEFORE_RUNAWAY == acquired->cleanupCountdown &&
				0 == acquired->activeProcessCount &&
				0 == acquired->sessionVmem &&
				0 == acquired->spinLock &&
				0 == acquired->sessionVmemRunaway &&
				0 == acquired->commandCountRunaway &&
				!acquired->isModifiedSessionId);

		AllSessionStateEntries->freeList = acquired->next;

		acquired->next = AllSessionStateEntries->usedList;
		AllSessionStateEntries->usedList = acquired;
		AllSessionStateEntries->numSession++;
		Assert(AllSessionStateEntries->numSession <= AllSessionStateEntries->maxSession);

		acquired->sessionId = sessionId;
		acquired->runawayStatus = RunawayStatus_NotRunaway;
		acquired->sessionVmemRunaway = 0;
		acquired->commandCountRunaway = 0;
		acquired->pinCount = 0;
		acquired->sessionVmem = 0;
		acquired->cleanupCountdown = CLEANUP_COUNTDOWN_BEFORE_RUNAWAY;
		acquired->activeProcessCount = 0;
		acquired->idle_start = 0;
		acquired->resGroupSlot = NULL;

#ifdef USE_ASSERT_CHECKING
		acquired->isModifiedSessionId = false;
#endif

		/*
		 * Make sure that the lock is reset to released. Note: this doesn't
		 * have a matching SpinLockAcquire. We are just resetting the lock
		 * as part of initialization
		 */
		SpinLockRelease(&acquired->spinLock);
	}

	Assert(NULL != acquired);
	int pinCount = pg_atomic_add_fetch_u32((pg_atomic_uint32 *) &acquired->pinCount, 1);

	ereport(gp_sessionstate_loglevel, (errmsg("SessionState_Acquire: pinCount: %d, activeProcessCount: %d",
			pinCount, acquired->activeProcessCount), errprintstack(true)));

	LWLockRelease(SessionStateLock);

	return acquired;
}
Exemple #11
0
/*
 * Releases the pinCount of a SessionState entry. If the pinCount
 * drops to 0, it puts the entry back to the freeList for reuse.
 */
static void
SessionState_Release(SessionState *acquired)
{
	if (!sessionStateInited)
	{
		Assert(NULL == acquired);
		return;
	}

	Assert(NULL != acquired);
	Assert(0 < acquired->pinCount);
	Assert(acquired->sessionId == gp_session_id || acquired->isModifiedSessionId);

	LWLockAcquire(SessionStateLock, LW_EXCLUSIVE);

	Assert(!isProcessActive);
	Assert(acquired->activeProcessCount < acquired->pinCount);

	int pinCount = pg_atomic_sub_fetch_u32((pg_atomic_uint32 *) &acquired->pinCount, 1);

	ereport(gp_sessionstate_loglevel, (errmsg("SessionState_Release: pinCount: %d, activeProcessCount: %d",
			pinCount, acquired->activeProcessCount), errprintstack(true)));

	    /* Before this point the process should have been deactivated */
	Assert(acquired->activeProcessCount <= acquired->pinCount);
	Assert(0 <= acquired->pinCount);

	if (0 == acquired->pinCount)
	{
		RunawayCleaner_RunawayCleanupDoneForSession();

		acquired->sessionId = INVALID_SESSION_ID;

		Assert(acquired->runawayStatus == RunawayStatus_NotRunaway);
		Assert(CLEANUP_COUNTDOWN_BEFORE_RUNAWAY == acquired->cleanupCountdown);
		Assert(0 == acquired->activeProcessCount);

		acquired->sessionVmem = 0;
		acquired->runawayStatus = RunawayStatus_NotRunaway;
		acquired->sessionVmemRunaway = 0;
		acquired->commandCountRunaway = 0;
		acquired->cleanupCountdown = CLEANUP_COUNTDOWN_BEFORE_RUNAWAY;
		acquired->activeProcessCount = 0;
		acquired->idle_start = 0;
		acquired->resGroupSlot = NULL;

#ifdef USE_ASSERT_CHECKING
		acquired->isModifiedSessionId = false;
#endif

		SessionState *cur = AllSessionStateEntries->usedList;
		SessionState *prev = NULL;

		while (cur != acquired && cur != NULL)
		{
			prev = cur;
			cur = cur->next;
		}

		Assert(cur == acquired);

		/* grabbed is at the head of used list */
		if (NULL == prev)
		{
			Assert(AllSessionStateEntries->usedList == acquired);
			AllSessionStateEntries->usedList = acquired->next;
		}
		else
		{
			prev->next = cur->next;
		}

		acquired->next = AllSessionStateEntries->freeList;
		AllSessionStateEntries->freeList = acquired;
		AllSessionStateEntries->numSession--;
		Assert(AllSessionStateEntries->numSession >= 0);
	}

	LWLockRelease(SessionStateLock);
}
/*
 * Entry point for the Local Versioning Event Handler. This gets called
 * for every message that is executed locally at a backend.
 */
extern void
mdver_localhandler_new_event(SharedInvalidationMessage *msg)
{
	Assert(NULL != msg);
	Assert(SHAREDVERSIONINGMSG_ID == msg->id);

#ifdef MD_VERSIONING_INSTRUMENTATION
	char *mdev_str = mdver_event_str(&msg->ve.verEvent);
	ereport(gp_mdversioning_loglevel,
			(errmsg("LocalExecuteVE: got %s event %s",
					msg->ve.local ? "LOCAL" : "REMOTE",
					mdev_str),
					errprintstack(false)));
	pfree(mdev_str);
#endif

	/*
	 * There are some cases where we don't have a transInvalInfo structure,
	 * and thus we don't have a Local MDVSN. For example:
	 *  - an auxiliary process (fts prober comes to mind) that queries
	 *    catalog tables directly using heap functions (no transaction)
	 *  - updating persistent tables during transaction commit
	 *    (transInvalInfo has already been reset).
	 *  - bootstrap
	 *
	 * In other cases, we simply don't have a Local MDVSN since we don't
	 * cache versions:
	 *  - a QE process running on the master or segments will have a
	 *    syscache, but not a Metadata Version cache
	 *
	 * In those cases we don't care about versioning, so skip adding
	 * to local MDVSN.
	 */

	mdver_local_mdvsn *local_mdvsn = GetCurrentLocalMDVSN();
	if (NULL != local_mdvsn)
	{

		mdver_event *event = &msg->ve.verEvent;

		if (mdver_is_nuke_event(event))
		{
			elog(gp_mdversioning_loglevel, "Local VE Handler: Received NUKE event");
			mdver_local_mdvsn_nuke(local_mdvsn);
			return;
		}

		if (msg->ve.local)
		{
			/*
			 * Locally generated event, we must add or update the version
			 * in the Local MDVSN.
			 */
			mdver_entry entry;
			entry.key = event->key;

			/* FIXME gcaragea 7/4/2014: Can we assert anything here? */
			entry.ddl_version = event->new_ddl_version;
			entry.dml_version = event->new_dml_version;

			mdver_local_mdvsn_add(local_mdvsn, &entry, msg->ve.local);
		}
		else
		{
			/*
			 * An event coming from the global queue (GVQ)
			 * If we are interested in this object, add / update
			 * version in Local MDVSN.
			 *
			 */

			mdver_entry *local_entry = mdver_local_mdvsn_find(local_mdvsn, event->key);
			if (NULL != local_entry)
			{

				/*
				 * A VE came from SVQ for a key that we already have locally.
				 * Need to reconcile and record.
				 */
				mdver_localhandler_reconcile(event, local_entry);
			}
			else
			{
				elog(gp_mdversioning_loglevel, "Local VE Handler: Ignoring remote event for object not of interest key=%d", event->key);
			}

			/* TODO gcaragea 5/27/2014: For subtransactions, keep all messages (MPP-22935) */
		}

	}
}
Exemple #13
0
void ProcNewMppSessionId(int *newSessionId)
{
	Assert(newSessionId != NULL);

    *newSessionId = MyProc->mppSessionId =
		gp_atomic_add_32(&ProcGlobal->mppLocalProcessCounter, 1);

    /*
     * Make sure that our SessionState entry correctly records our
     * new session id.
     */
    if (NULL != MySessionState)
    {
    	/* This should not happen outside of dispatcher on the master */
    	Assert(GpIdentity.segindex == MASTER_CONTENT_ID && Gp_role == GP_ROLE_DISPATCH);

    	ereport(gp_sessionstate_loglevel, (errmsg("ProcNewMppSessionId: changing session id (old: %d, new: %d), pinCount: %d, activeProcessCount: %d",
    			MySessionState->sessionId, *newSessionId, MySessionState->pinCount, MySessionState->activeProcessCount), errprintstack(true)));

#ifdef USE_ASSERT_CHECKING
    	MySessionState->isModifiedSessionId = true;
#endif

    	MySessionState->sessionId = *newSessionId;
    }
}