void plot_history::new_page() { if (!_replaying) { auto previous_plot = get_active(); if (previous_plot != nullptr) { pGEDevDesc ge_dev_desc = Rf_desc2GEDesc(_device_desc); util::protected_sexp snapshot(ge_dev_desc->savedSnapshot); if (previous_plot->has_pending_render()) { previous_plot->set_snapshot(snapshot); previous_plot->render(false); } } // Create a plot object for this new page append(std::make_unique<plot>(_device_desc)); } }
/* * ContinuousQueryWorkerStartup * * Launches a CQ worker, which continuously generates partial query results to send * back to the combiner process. */ void ContinuousQueryWorkerRun(Portal portal, ContinuousViewState *state, QueryDesc *queryDesc, ResourceOwner owner) { EState *estate = NULL; DestReceiver *dest; CmdType operation; MemoryContext oldcontext; int timeoutms = state->maxwaitms; MemoryContext runcontext; CQProcEntry *entry = GetCQProcEntry(MyCQId); ResourceOwner cqowner = ResourceOwnerCreate(NULL, "CQResourceOwner"); bool savereadonly = XactReadOnly; cq_stat_initialize(state->viewid, MyProcPid); dest = CreateDestReceiver(DestCombiner); SetCombinerDestReceiverParams(dest, MyCQId); /* workers only need read-only transactions */ XactReadOnly = true; runcontext = AllocSetContextCreate(TopMemoryContext, "CQRunContext", ALLOCSET_DEFAULT_MINSIZE, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE); elog(LOG, "\"%s\" worker %d running", queryDesc->plannedstmt->cq_target->relname, MyProcPid); MarkWorkerAsRunning(MyCQId, MyWorkerId); pgstat_report_activity(STATE_RUNNING, queryDesc->sourceText); TupleBufferInitLatch(WorkerTupleBuffer, MyCQId, MyWorkerId, &MyProc->procLatch); oldcontext = MemoryContextSwitchTo(runcontext); retry: PG_TRY(); { bool xact_commit = true; TimestampTz last_process = GetCurrentTimestamp(); TimestampTz last_commit = GetCurrentTimestamp(); start_executor(queryDesc, runcontext, cqowner); CurrentResourceOwner = cqowner; estate = queryDesc->estate; operation = queryDesc->operation; /* * Initialize context that lives for the duration of a single iteration * of the main worker loop */ CQExecutionContext = AllocSetContextCreate(estate->es_query_cxt, "CQExecutionContext", ALLOCSET_DEFAULT_MINSIZE, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE); estate->es_lastoid = InvalidOid; /* * Startup combiner receiver */ (*dest->rStartup) (dest, operation, queryDesc->tupDesc); for (;;) { if (!TupleBufferHasUnreadSlots()) { if (TimestampDifferenceExceeds(last_process, GetCurrentTimestamp(), state->emptysleepms)) { /* force stats flush */ cq_stat_report(true); pgstat_report_activity(STATE_IDLE, queryDesc->sourceText); TupleBufferWait(WorkerTupleBuffer, MyCQId, MyWorkerId); pgstat_report_activity(STATE_RUNNING, queryDesc->sourceText); } else pg_usleep(Min(WAIT_SLEEP_MS, state->emptysleepms) * 1000); } TupleBufferResetNotify(WorkerTupleBuffer, MyCQId, MyWorkerId); if (xact_commit) StartTransactionCommand(); set_snapshot(estate, cqowner); CurrentResourceOwner = cqowner; MemoryContextSwitchTo(estate->es_query_cxt); estate->es_processed = 0; estate->es_filtered = 0; /* * Run plan on a microbatch */ ExecutePlan(estate, queryDesc->planstate, operation, true, 0, timeoutms, ForwardScanDirection, dest); IncrementCQExecutions(1); TupleBufferClearPinnedSlots(); if (state->long_xact) { if (TimestampDifferenceExceeds(last_commit, GetCurrentTimestamp(), LONG_RUNNING_XACT_DURATION)) xact_commit = true; else xact_commit = false; } unset_snapshot(estate, cqowner); if (xact_commit) { CommitTransactionCommand(); last_commit = GetCurrentTimestamp(); } MemoryContextResetAndDeleteChildren(CQExecutionContext); MemoryContextSwitchTo(runcontext); CurrentResourceOwner = cqowner; if (estate->es_processed || estate->es_filtered) { /* * If the CV query is such that the select does not return any tuples * ex: select id where id=99; and id=99 does not exist, then this reset * will fail. What will happen is that the worker will block at the latch for every * allocated slot, TILL a cv returns a non-zero tuple, at which point * the worker will resume a simple sleep for the threshold time. */ last_process = GetCurrentTimestamp(); /* * Send stats to the collector */ cq_stat_report(false); } /* Has the CQ been deactivated? */ if (!entry->active) { if (ActiveSnapshotSet()) unset_snapshot(estate, cqowner); if (IsTransactionState()) CommitTransactionCommand(); break; } } CurrentResourceOwner = cqowner; /* * The cleanup functions below expect these things to be registered */ RegisterSnapshotOnOwner(estate->es_snapshot, cqowner); RegisterSnapshotOnOwner(queryDesc->snapshot, cqowner); RegisterSnapshotOnOwner(queryDesc->crosscheck_snapshot, cqowner); /* cleanup */ ExecutorFinish(queryDesc); ExecutorEnd(queryDesc); FreeQueryDesc(queryDesc); } PG_CATCH(); { EmitErrorReport(); FlushErrorState(); /* Since the worker is read-only, we can simply commit the transaction. */ if (ActiveSnapshotSet()) unset_snapshot(estate, cqowner); if (IsTransactionState()) CommitTransactionCommand(); TupleBufferUnpinAllPinnedSlots(); TupleBufferClearReaders(); /* This resets the es_query_ctx and in turn the CQExecutionContext */ MemoryContextResetAndDeleteChildren(runcontext); IncrementCQErrors(1); if (continuous_query_crash_recovery) goto retry; } PG_END_TRY(); (*dest->rShutdown) (dest); MemoryContextSwitchTo(oldcontext); MemoryContextDelete(runcontext); XactReadOnly = savereadonly; /* * Remove proc-level stats */ cq_stat_report(true); cq_stat_send_purge(state->viewid, MyProcPid, CQ_STAT_WORKER); CurrentResourceOwner = owner; }