* execParallel.c
* Support routines for parallel execution.
*
- * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* This file contains routines that are intended to support setting up,
#include "executor/execParallel.h"
#include "executor/executor.h"
+#include "executor/nodeCustom.h"
+#include "executor/nodeForeignscan.h"
+#include "executor/nodeSeqscan.h"
#include "executor/tqueue.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/planmain.h"
#include "optimizer/planner.h"
#include "storage/spin.h"
#include "tcop/tcopprot.h"
+#include "utils/dsa.h"
#include "utils/memutils.h"
#include "utils/snapmgr.h"
#define PARALLEL_KEY_BUFFER_USAGE UINT64CONST(0xE000000000000003)
#define PARALLEL_KEY_TUPLE_QUEUE UINT64CONST(0xE000000000000004)
#define PARALLEL_KEY_INSTRUMENTATION UINT64CONST(0xE000000000000005)
+#define PARALLEL_KEY_DSA UINT64CONST(0xE000000000000006)
#define PARALLEL_TUPLE_QUEUE_SIZE 65536
-/* DSM structure for accumulating per-PlanState instrumentation. */
-typedef struct SharedPlanStateInstrumentation
-{
- int plan_node_id;
- slock_t mutex;
- Instrumentation instr;
-} SharedPlanStateInstrumentation;
-
-/* DSM structure for accumulating per-PlanState instrumentation. */
+/*
+ * DSM structure for accumulating per-PlanState instrumentation.
+ *
+ * instrument_options: Same meaning here as in instrument.c.
+ *
+ * instrument_offset: Offset, relative to the start of this structure,
+ * of the first Instrumentation object. This will depend on the length of
+ * the plan_node_id array.
+ *
+ * num_workers: Number of workers.
+ *
+ * num_plan_nodes: Number of plan nodes.
+ *
+ * plan_node_id: Array of plan nodes for which we are gathering instrumentation
+ * from parallel workers. The length of this array is given by num_plan_nodes.
+ */
struct SharedExecutorInstrumentation
{
- int instrument_options;
- int ps_ninstrument; /* # of ps_instrument structures following */
- SharedPlanStateInstrumentation ps_instrument[FLEXIBLE_ARRAY_MEMBER];
+ int instrument_options;
+ int instrument_offset;
+ int num_workers;
+ int num_plan_nodes;
+ int plan_node_id[FLEXIBLE_ARRAY_MEMBER];
+ /* array of num_plan_nodes * num_workers Instrumentation objects follows */
};
+#define GetInstrumentationArray(sei) \
+ (AssertVariableIsOfTypeMacro(sei, SharedExecutorInstrumentation *), \
+ (Instrumentation *) (((char *) sei) + sei->instrument_offset))
/* Context object for ExecParallelEstimate. */
typedef struct ExecParallelEstimateContext
{
ParallelContext *pcxt;
- int nnodes;
+ int nnodes;
} ExecParallelEstimateContext;
-/* Context object for ExecParallelEstimate. */
+/* Context object for ExecParallelInitializeDSM. */
typedef struct ExecParallelInitializeDSMContext
{
ParallelContext *pcxt;
SharedExecutorInstrumentation *instrumentation;
- int nnodes;
+ int nnodes;
} ExecParallelInitializeDSMContext;
/* Helper functions that run in the parallel leader. */
static bool ExecParallelEstimate(PlanState *node,
ExecParallelEstimateContext *e);
static bool ExecParallelInitializeDSM(PlanState *node,
- ExecParallelInitializeDSMContext *d);
+ ExecParallelInitializeDSMContext *d);
static shm_mq_handle **ExecParallelSetupTupleQueues(ParallelContext *pcxt,
bool reinitialize);
static bool ExecParallelRetrieveInstrumentation(PlanState *planstate,
- SharedExecutorInstrumentation *instrumentation);
+ SharedExecutorInstrumentation *instrumentation);
/* Helper functions that run in the parallel worker. */
static void ParallelQueryMain(dsm_segment *seg, shm_toc *toc);
pstmt = makeNode(PlannedStmt);
pstmt->commandType = CMD_SELECT;
pstmt->queryId = 0;
- pstmt->hasReturning = 0;
- pstmt->hasModifyingCTE = 0;
- pstmt->canSetTag = 1;
- pstmt->transientPlan = 0;
+ pstmt->hasReturning = false;
+ pstmt->hasModifyingCTE = false;
+ pstmt->canSetTag = true;
+ pstmt->transientPlan = false;
+ pstmt->dependsOnRole = false;
+ pstmt->parallelModeNeeded = false;
pstmt->planTree = plan;
pstmt->rtable = estate->es_range_table;
pstmt->resultRelations = NIL;
- pstmt->utilityStmt = NULL;
pstmt->subplans = NIL;
pstmt->rewindPlanIDs = NULL;
pstmt->rowMarks = NIL;
- pstmt->nParamExec = estate->es_plannedstmt->nParamExec;
pstmt->relationOids = NIL;
pstmt->invalItems = NIL; /* workers can't replan anyway... */
- pstmt->hasRowSecurity = false;
+ pstmt->nParamExec = estate->es_plannedstmt->nParamExec;
+ pstmt->utilityStmt = NULL;
+ pstmt->stmt_location = -1;
+ pstmt->stmt_len = -1;
/* Return serialized copy of our dummy PlannedStmt. */
return nodeToString(pstmt);
/* Count this node. */
e->nnodes++;
- /*
- * XXX. Call estimators for parallel-aware nodes here, when we have
- * some.
- */
+ /* Call estimators for parallel-aware nodes. */
+ if (planstate->plan->parallel_aware)
+ {
+ switch (nodeTag(planstate))
+ {
+ case T_SeqScanState:
+ ExecSeqScanEstimate((SeqScanState *) planstate,
+ e->pcxt);
+ break;
+ case T_ForeignScanState:
+ ExecForeignScanEstimate((ForeignScanState *) planstate,
+ e->pcxt);
+ break;
+ case T_CustomScanState:
+ ExecCustomScanEstimate((CustomScanState *) planstate,
+ e->pcxt);
+ break;
+ default:
+ break;
+ }
+ }
return planstate_tree_walker(planstate, ExecParallelEstimate, e);
}
/*
- * Ordinary plan nodes won't do anything here, but parallel-aware plan nodes
- * may need to initialize shared state in the DSM before parallel workers
- * are available. They can allocate the space they previous estimated using
- * shm_toc_allocate, and add the keys they previously estimated using
- * shm_toc_insert, in each case targeting pcxt->toc.
+ * Initialize the dynamic shared memory segment that will be used to control
+ * parallel execution.
*/
static bool
ExecParallelInitializeDSM(PlanState *planstate,
if (planstate == NULL)
return false;
- /* If instrumentation is enabled, initialize array slot for this node. */
+ /* If instrumentation is enabled, initialize slot for this node. */
if (d->instrumentation != NULL)
- {
- SharedPlanStateInstrumentation *instrumentation;
-
- instrumentation = &d->instrumentation->ps_instrument[d->nnodes];
- Assert(d->nnodes < d->instrumentation->ps_ninstrument);
- instrumentation->plan_node_id = planstate->plan->plan_node_id;
- SpinLockInit(&instrumentation->mutex);
- InstrInit(&instrumentation->instr,
- d->instrumentation->instrument_options);
- }
+ d->instrumentation->plan_node_id[d->nnodes] =
+ planstate->plan->plan_node_id;
/* Count this node. */
d->nnodes++;
/*
- * XXX. Call initializers for parallel-aware plan nodes, when we have
- * some.
+ * Call initializers for parallel-aware plan nodes.
+ *
+ * Ordinary plan nodes won't do anything here, but parallel-aware plan
+ * nodes may need to initialize shared state in the DSM before parallel
+ * workers are available. They can allocate the space they previously
+ * estimated using shm_toc_allocate, and add the keys they previously
+ * estimated using shm_toc_insert, in each case targeting pcxt->toc.
*/
+ if (planstate->plan->parallel_aware)
+ {
+ switch (nodeTag(planstate))
+ {
+ case T_SeqScanState:
+ ExecSeqScanInitializeDSM((SeqScanState *) planstate,
+ d->pcxt);
+ break;
+ case T_ForeignScanState:
+ ExecForeignScanInitializeDSM((ForeignScanState *) planstate,
+ d->pcxt);
+ break;
+ case T_CustomScanState:
+ ExecCustomScanInitializeDSM((CustomScanState *) planstate,
+ d->pcxt);
+ break;
+ default:
+ break;
+ }
+ }
return planstate_tree_walker(planstate, ExecParallelInitializeDSM, d);
}
if (!reinitialize)
tqueuespace =
shm_toc_allocate(pcxt->toc,
- PARALLEL_TUPLE_QUEUE_SIZE * pcxt->nworkers);
+ mul_size(PARALLEL_TUPLE_QUEUE_SIZE,
+ pcxt->nworkers));
else
tqueuespace = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_TUPLE_QUEUE);
{
shm_mq *mq;
- mq = shm_mq_create(tqueuespace + i * PARALLEL_TUPLE_QUEUE_SIZE,
+ mq = shm_mq_create(tqueuespace +
+ ((Size) i) * PARALLEL_TUPLE_QUEUE_SIZE,
(Size) PARALLEL_TUPLE_QUEUE_SIZE);
shm_mq_set_receiver(mq, MyProc);
}
/*
- * Re-initialize the response queues for backend workers to return tuples
- * to the main backend and start the workers.
+ * Re-initialize the parallel executor info such that it can be reused by
+ * workers.
*/
-shm_mq_handle **
-ExecParallelReinitializeTupleQueues(ParallelContext *pcxt)
+void
+ExecParallelReinitialize(ParallelExecutorInfo *pei)
{
- return ExecParallelSetupTupleQueues(pcxt, true);
+ ReinitializeParallelDSM(pei->pcxt);
+ pei->tqueue = ExecParallelSetupTupleQueues(pei->pcxt, true);
+ pei->finished = false;
}
/*
int pstmt_len;
int param_len;
int instrumentation_len = 0;
+ int instrument_offset = 0;
+ Size dsa_minsize = dsa_minimum_size();
/* Allocate object for return value. */
pei = palloc0(sizeof(ParallelExecutorInfo));
+ pei->finished = false;
pei->planstate = planstate;
/* Fix up and serialize plan to be sent to workers. */
* looking at pgBufferUsage, so do it unconditionally.
*/
shm_toc_estimate_chunk(&pcxt->estimator,
- sizeof(BufferUsage) * pcxt->nworkers);
+ mul_size(sizeof(BufferUsage), pcxt->nworkers));
shm_toc_estimate_keys(&pcxt->estimator, 1);
/* Estimate space for tuple queues. */
shm_toc_estimate_chunk(&pcxt->estimator,
- PARALLEL_TUPLE_QUEUE_SIZE * pcxt->nworkers);
+ mul_size(PARALLEL_TUPLE_QUEUE_SIZE, pcxt->nworkers));
shm_toc_estimate_keys(&pcxt->estimator, 1);
/*
- * Give parallel-aware nodes a chance to add to the estimates, and get
- * a count of how many PlanState nodes there are.
+ * Give parallel-aware nodes a chance to add to the estimates, and get a
+ * count of how many PlanState nodes there are.
*/
e.pcxt = pcxt;
e.nnodes = 0;
if (estate->es_instrument)
{
instrumentation_len =
- offsetof(SharedExecutorInstrumentation, ps_instrument)
- + sizeof(SharedPlanStateInstrumentation) * e.nnodes;
+ offsetof(SharedExecutorInstrumentation, plan_node_id) +
+ sizeof(int) * e.nnodes;
+ instrumentation_len = MAXALIGN(instrumentation_len);
+ instrument_offset = instrumentation_len;
+ instrumentation_len +=
+ mul_size(sizeof(Instrumentation),
+ mul_size(e.nnodes, nworkers));
shm_toc_estimate_chunk(&pcxt->estimator, instrumentation_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
+ /* Estimate space for DSA area. */
+ shm_toc_estimate_chunk(&pcxt->estimator, dsa_minsize);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
/* Everyone's had a chance to ask for space, so now create the DSM. */
InitializeParallelDSM(pcxt);
/* Allocate space for each worker's BufferUsage; no need to initialize. */
bufusage_space = shm_toc_allocate(pcxt->toc,
- sizeof(BufferUsage) * pcxt->nworkers);
+ mul_size(sizeof(BufferUsage), pcxt->nworkers));
shm_toc_insert(pcxt->toc, PARALLEL_KEY_BUFFER_USAGE, bufusage_space);
pei->buffer_usage = bufusage_space;
pei->tqueue = ExecParallelSetupTupleQueues(pcxt, false);
/*
- * If instrumentation options were supplied, allocate space for the
- * data. It only gets partially initialized here; the rest happens
- * during ExecParallelInitializeDSM.
+ * If instrumentation options were supplied, allocate space for the data.
+ * It only gets partially initialized here; the rest happens during
+ * ExecParallelInitializeDSM.
*/
if (estate->es_instrument)
{
+ Instrumentation *instrument;
+ int i;
+
instrumentation = shm_toc_allocate(pcxt->toc, instrumentation_len);
instrumentation->instrument_options = estate->es_instrument;
- instrumentation->ps_ninstrument = e.nnodes;
+ instrumentation->instrument_offset = instrument_offset;
+ instrumentation->num_workers = nworkers;
+ instrumentation->num_plan_nodes = e.nnodes;
+ instrument = GetInstrumentationArray(instrumentation);
+ for (i = 0; i < nworkers * e.nnodes; ++i)
+ InstrInit(&instrument[i], estate->es_instrument);
shm_toc_insert(pcxt->toc, PARALLEL_KEY_INSTRUMENTATION,
instrumentation);
pei->instrumentation = instrumentation;
}
+ /*
+ * Create a DSA area that can be used by the leader and all workers.
+ * (However, if we failed to create a DSM and are using private memory
+ * instead, then skip this.)
+ */
+ if (pcxt->seg != NULL)
+ {
+ char *area_space;
+
+ area_space = shm_toc_allocate(pcxt->toc, dsa_minsize);
+ shm_toc_insert(pcxt->toc, PARALLEL_KEY_DSA, area_space);
+ pei->area = dsa_create_in_place(area_space, dsa_minsize,
+ LWTRANCHE_PARALLEL_QUERY_DSA,
+ pcxt->seg);
+ }
+
+ /*
+ * Make the area available to executor nodes running in the leader. See
+ * also ParallelQueryMain which makes it available to workers.
+ */
+ estate->es_query_dsa = pei->area;
+
/*
* Give parallel-aware nodes a chance to initialize their shared data.
* This also initializes the elements of instrumentation->ps_instrument,
}
/*
- * Copy instrumentation information about this node and its descendents from
+ * Copy instrumentation information about this node and its descendants from
* dynamic shared memory.
*/
static bool
ExecParallelRetrieveInstrumentation(PlanState *planstate,
- SharedExecutorInstrumentation *instrumentation)
+ SharedExecutorInstrumentation *instrumentation)
{
- int i;
- int plan_node_id = planstate->plan->plan_node_id;
- SharedPlanStateInstrumentation *ps_instrument;
+ Instrumentation *instrument;
+ int i;
+ int n;
+ int ibytes;
+ int plan_node_id = planstate->plan->plan_node_id;
+ MemoryContext oldcontext;
/* Find the instumentation for this node. */
- for (i = 0; i < instrumentation->ps_ninstrument; ++i)
- if (instrumentation->ps_instrument[i].plan_node_id == plan_node_id)
+ for (i = 0; i < instrumentation->num_plan_nodes; ++i)
+ if (instrumentation->plan_node_id[i] == plan_node_id)
break;
- if (i >= instrumentation->ps_ninstrument)
+ if (i >= instrumentation->num_plan_nodes)
elog(ERROR, "plan node %d not found", plan_node_id);
- /* No need to acquire the spinlock here; workers have exited already. */
- ps_instrument = &instrumentation->ps_instrument[i];
- InstrAggNode(planstate->instrument, &ps_instrument->instr);
+ /* Accumulate the statistics from all workers. */
+ instrument = GetInstrumentationArray(instrumentation);
+ instrument += i * instrumentation->num_workers;
+ for (n = 0; n < instrumentation->num_workers; ++n)
+ InstrAggNode(planstate->instrument, &instrument[n]);
+
+ /*
+ * Also store the per-worker detail.
+ *
+ * Worker instrumentation should be allocated in the same context as
+ * the regular instrumentation information, which is the per-query
+ * context. Switch into per-query memory context.
+ */
+ oldcontext = MemoryContextSwitchTo(planstate->state->es_query_cxt);
+ ibytes = mul_size(instrumentation->num_workers, sizeof(Instrumentation));
+ planstate->worker_instrument =
+ palloc(ibytes + offsetof(WorkerInstrumentation, instrument));
+ MemoryContextSwitchTo(oldcontext);
+
+ planstate->worker_instrument->num_workers = instrumentation->num_workers;
+ memcpy(&planstate->worker_instrument->instrument, instrument, ibytes);
return planstate_tree_walker(planstate, ExecParallelRetrieveInstrumentation,
instrumentation);
void
ExecParallelFinish(ParallelExecutorInfo *pei)
{
- int i;
+ int i;
+
+ if (pei->finished)
+ return;
/* First, wait for the workers to finish. */
WaitForParallelWorkersToFinish(pei->pcxt);
/* Next, accumulate buffer usage. */
- for (i = 0; i < pei->pcxt->nworkers; ++i)
+ for (i = 0; i < pei->pcxt->nworkers_launched; ++i)
InstrAccumParallelQuery(&pei->buffer_usage[i]);
/* Finally, accumulate instrumentation, if any. */
if (pei->instrumentation)
ExecParallelRetrieveInstrumentation(pei->planstate,
pei->instrumentation);
+
+ pei->finished = true;
}
/*
- * Clean up whatever ParallelExecutreInfo resources still exist after
+ * Clean up whatever ParallelExecutorInfo resources still exist after
* ExecParallelFinish. We separate these routines because someone might
* want to examine the contents of the DSM after ExecParallelFinish and
* before calling this routine.
void
ExecParallelCleanup(ParallelExecutorInfo *pei)
{
+ if (pei->area != NULL)
+ {
+ dsa_detach(pei->area);
+ pei->area = NULL;
+ }
if (pei->pcxt != NULL)
{
DestroyParallelContext(pei->pcxt);
}
/*
- * Copy instrumentation information from this node and its descendents into
+ * Copy instrumentation information from this node and its descendants into
* dynamic shared memory, so that the parallel leader can retrieve it.
*/
static bool
ExecParallelReportInstrumentation(PlanState *planstate,
- SharedExecutorInstrumentation *instrumentation)
+ SharedExecutorInstrumentation *instrumentation)
{
- int i;
- int plan_node_id = planstate->plan->plan_node_id;
- SharedPlanStateInstrumentation *ps_instrument;
+ int i;
+ int plan_node_id = planstate->plan->plan_node_id;
+ Instrumentation *instrument;
+
+ InstrEndLoop(planstate->instrument);
/*
* If we shuffled the plan_node_id values in ps_instrument into sorted
- * order, we could use binary search here. This might matter someday
- * if we're pushing down sufficiently large plan trees. For now, do it
- * the slow, dumb way.
+ * order, we could use binary search here. This might matter someday if
+ * we're pushing down sufficiently large plan trees. For now, do it the
+ * slow, dumb way.
*/
- for (i = 0; i < instrumentation->ps_ninstrument; ++i)
- if (instrumentation->ps_instrument[i].plan_node_id == plan_node_id)
+ for (i = 0; i < instrumentation->num_plan_nodes; ++i)
+ if (instrumentation->plan_node_id[i] == plan_node_id)
break;
- if (i >= instrumentation->ps_ninstrument)
+ if (i >= instrumentation->num_plan_nodes)
elog(ERROR, "plan node %d not found", plan_node_id);
/*
- * There's one SharedPlanStateInstrumentation per plan_node_id, so we
- * must use a spinlock in case multiple workers report at the same time.
+ * Add our statistics to the per-node, per-worker totals. It's possible
+ * that this could happen more than once if we relaunched workers.
*/
- ps_instrument = &instrumentation->ps_instrument[i];
- SpinLockAcquire(&ps_instrument->mutex);
- InstrAggNode(&ps_instrument->instr, planstate->instrument);
- SpinLockRelease(&ps_instrument->mutex);
+ instrument = GetInstrumentationArray(instrumentation);
+ instrument += i * instrumentation->num_workers;
+ Assert(IsParallelWorker());
+ Assert(ParallelWorkerNumber < instrumentation->num_workers);
+ InstrAggNode(&instrument[ParallelWorkerNumber], planstate->instrument);
return planstate_tree_walker(planstate, ExecParallelReportInstrumentation,
instrumentation);
}
+/*
+ * Initialize the PlanState and its descendants with the information
+ * retrieved from shared memory. This has to be done once the PlanState
+ * is allocated and initialized by executor; that is, after ExecutorStart().
+ */
+static bool
+ExecParallelInitializeWorker(PlanState *planstate, shm_toc *toc)
+{
+ if (planstate == NULL)
+ return false;
+
+ /* Call initializers for parallel-aware plan nodes. */
+ if (planstate->plan->parallel_aware)
+ {
+ switch (nodeTag(planstate))
+ {
+ case T_SeqScanState:
+ ExecSeqScanInitializeWorker((SeqScanState *) planstate, toc);
+ break;
+ case T_ForeignScanState:
+ ExecForeignScanInitializeWorker((ForeignScanState *) planstate,
+ toc);
+ break;
+ case T_CustomScanState:
+ ExecCustomScanInitializeWorker((CustomScanState *) planstate,
+ toc);
+ break;
+ default:
+ break;
+ }
+ }
+
+ return planstate_tree_walker(planstate, ExecParallelInitializeWorker, toc);
+}
+
/*
* Main entrypoint for parallel query worker processes.
*
- * We reach this function from ParallelMain, so the setup necessary to create
- * a sensible parallel environment has already been done; ParallelMain worries
- * about stuff like the transaction state, combo CID mappings, and GUC values,
- * so we don't need to deal with any of that here.
+ * We reach this function from ParallelWorkerMain, so the setup necessary to
+ * create a sensible parallel environment has already been done;
+ * ParallelWorkerMain worries about stuff like the transaction state, combo
+ * CID mappings, and GUC values, so we don't need to deal with any of that
+ * here.
*
* Our job is to deal with concerns specific to the executor. The parallel
* group leader will have stored a serialized PlannedStmt, and it's our job
QueryDesc *queryDesc;
SharedExecutorInstrumentation *instrumentation;
int instrument_options = 0;
+ void *area_space;
+ dsa_area *area;
/* Set up DestReceiver, SharedExecutorInstrumentation, and QueryDesc. */
receiver = ExecParallelGetReceiver(seg, toc);
/* Prepare to track buffer usage during query execution. */
InstrStartParallelQuery();
- /* Start up the executor, have it run the plan, and then shut it down. */
+ /* Attach to the dynamic shared memory area. */
+ area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA);
+ area = dsa_attach_in_place(area_space, seg);
+
+ /* Start up the executor */
ExecutorStart(queryDesc, 0);
+
+ /* Special executor initialization steps for parallel workers */
+ queryDesc->planstate->state->es_query_dsa = area;
+ ExecParallelInitializeWorker(queryDesc->planstate, toc);
+
+ /* Run the plan */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
+
+ /* Shut down the executor */
ExecutorFinish(queryDesc);
/* Report buffer usage during parallel execution. */
ExecutorEnd(queryDesc);
/* Cleanup. */
+ dsa_detach(area);
FreeQueryDesc(queryDesc);
(*receiver->rDestroy) (receiver);
}
projects / postgresql / blobdiff