PostgreSQL Source Code  git master
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros
nodeGather.h File Reference
#include "nodes/execnodes.h"
Include dependency graph for nodeGather.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions

GatherStateExecInitGather (Gather *node, EState *estate, int eflags)
 
TupleTableSlotExecGather (GatherState *node)
 
void ExecEndGather (GatherState *node)
 
void ExecShutdownGather (GatherState *node)
 
void ExecReScanGather (GatherState *node)
 

Function Documentation

void ExecEndGather ( GatherState node)

Definition at line 226 of file nodeGather.c.

References ExecClearTuple(), ExecEndNode(), ExecFreeExprContext(), ExecShutdownGather(), outerPlanState, GatherState::ps, and PlanState::ps_ResultTupleSlot.

Referenced by ExecEndNode().

227 {
228  ExecEndNode(outerPlanState(node)); /* let children clean up first */
229  ExecShutdownGather(node);
230  ExecFreeExprContext(&node->ps);
232 }
void ExecEndNode(PlanState *node)
Definition: execProcnode.c:654
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
void ExecFreeExprContext(PlanState *planstate)
Definition: execUtils.c:516
TupleTableSlot * ps_ResultTupleSlot
Definition: execnodes.h:861
#define outerPlanState(node)
Definition: execnodes.h:874
PlanState ps
Definition: execnodes.h:1894
void ExecShutdownGather(GatherState *node)
Definition: nodeGather.c:400
TupleTableSlot* ExecGather ( GatherState node)

Definition at line 124 of file nodeGather.c.

References ParallelWorkerInfo::bgwhandle, CreateTupleQueueReader(), ExprContext::ecxt_outertuple, ExecClearTuple(), ExecInitParallelPlan(), ExecProject(), ExecShutdownGatherWorkers(), GatherState::funnel_slot, gather_getnext(), i, GatherState::initialized, IsInParallelMode(), LaunchParallelWorkers(), PlanState::lefttree, GatherState::need_to_scan_locally, GatherState::nextreader, GatherState::nreaders, NULL, Gather::num_workers, ParallelContext::nworkers_launched, GatherState::nworkers_launched, palloc(), ParallelExecutorInfo::pcxt, GatherState::pei, PlanState::plan, GatherState::ps, PlanState::ps_ExprContext, PlanState::ps_ProjInfo, GatherState::reader, ResetExprContext, shm_mq_set_handle(), Gather::single_copy, PlanState::state, ParallelExecutorInfo::tqueue, TupleTableSlot::tts_tupleDescriptor, TupIsNull, and ParallelContext::worker.

Referenced by ExecProcNode().

125 {
126  TupleTableSlot *fslot = node->funnel_slot;
127  int i;
128  TupleTableSlot *slot;
129  ExprContext *econtext;
130 
131  /*
132  * Initialize the parallel context and workers on first execution. We do
133  * this on first execution rather than during node initialization, as it
134  * needs to allocate a large dynamic segment, so it is better to do it
135  * only if it is really needed.
136  */
137  if (!node->initialized)
138  {
139  EState *estate = node->ps.state;
140  Gather *gather = (Gather *) node->ps.plan;
141 
142  /*
143  * Sometimes we might have to run without parallelism; but if parallel
144  * mode is active then we can try to fire up some workers.
145  */
146  if (gather->num_workers > 0 && IsInParallelMode())
147  {
148  ParallelContext *pcxt;
149 
150  /* Initialize the workers required to execute Gather node. */
151  if (!node->pei)
152  node->pei = ExecInitParallelPlan(node->ps.lefttree,
153  estate,
154  gather->num_workers);
155 
156  /*
157  * Register backend workers. We might not get as many as we
158  * requested, or indeed any at all.
159  */
160  pcxt = node->pei->pcxt;
161  LaunchParallelWorkers(pcxt);
162  node->nworkers_launched = pcxt->nworkers_launched;
163 
164  /* Set up tuple queue readers to read the results. */
165  if (pcxt->nworkers_launched > 0)
166  {
167  node->nreaders = 0;
168  node->nextreader = 0;
169  node->reader =
170  palloc(pcxt->nworkers_launched * sizeof(TupleQueueReader *));
171 
172  for (i = 0; i < pcxt->nworkers_launched; ++i)
173  {
174  shm_mq_set_handle(node->pei->tqueue[i],
175  pcxt->worker[i].bgwhandle);
176  node->reader[node->nreaders++] =
178  fslot->tts_tupleDescriptor);
179  }
180  }
181  else
182  {
183  /* No workers? Then never mind. */
185  }
186  }
187 
188  /* Run plan locally if no workers or not single-copy. */
189  node->need_to_scan_locally = (node->reader == NULL)
190  || !gather->single_copy;
191  node->initialized = true;
192  }
193 
194  /*
195  * Reset per-tuple memory context to free any expression evaluation
196  * storage allocated in the previous tuple cycle. This will also clear
197  * any previous tuple returned by a TupleQueueReader; to make sure we
198  * don't leave a dangling pointer around, clear the working slot first.
199  */
200  ExecClearTuple(fslot);
201  econtext = node->ps.ps_ExprContext;
202  ResetExprContext(econtext);
203 
204  /*
205  * Get next tuple, either from one of our workers, or by running the plan
206  * ourselves.
207  */
208  slot = gather_getnext(node);
209  if (TupIsNull(slot))
210  return NULL;
211 
212  /*
213  * Form the result tuple using ExecProject(), and return it.
214  */
215  econtext->ecxt_outertuple = slot;
216  return ExecProject(node->ps.ps_ProjInfo);
217 }
ParallelContext * pcxt
Definition: execParallel.h:27
int nworkers_launched
Definition: execnodes.h:1899
ProjectionInfo * ps_ProjInfo
Definition: execnodes.h:863
ExprContext * ps_ExprContext
Definition: execnodes.h:862
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
bool need_to_scan_locally
Definition: execnodes.h:1902
struct TupleQueueReader ** reader
Definition: execnodes.h:1900
ParallelExecutorInfo * ExecInitParallelPlan(PlanState *planstate, EState *estate, int nworkers)
Definition: execParallel.c:384
EState * state
Definition: execnodes.h:834
struct PlanState * lefttree
Definition: execnodes.h:847
ParallelWorkerInfo * worker
Definition: parallel.h:45
bool IsInParallelMode(void)
Definition: xact.c:913
bool initialized
Definition: execnodes.h:1895
static void ExecShutdownGatherWorkers(GatherState *node)
Definition: nodeGather.c:372
bool single_copy
Definition: plannodes.h:834
struct ParallelExecutorInfo * pei
Definition: execnodes.h:1896
BackgroundWorkerHandle * bgwhandle
Definition: parallel.h:27
#define TupIsNull(slot)
Definition: tuptable.h:138
PlanState ps
Definition: execnodes.h:1894
int nworkers_launched
Definition: parallel.h:37
void LaunchParallelWorkers(ParallelContext *pcxt)
Definition: parallel.c:417
TupleDesc tts_tupleDescriptor
Definition: tuptable.h:121
TupleTableSlot * funnel_slot
Definition: execnodes.h:1901
void shm_mq_set_handle(shm_mq_handle *mqh, BackgroundWorkerHandle *handle)
Definition: shm_mq.c:311
Plan * plan
Definition: execnodes.h:832
int num_workers
Definition: plannodes.h:833
TupleTableSlot * ecxt_outertuple
Definition: execnodes.h:199
#define NULL
Definition: c.h:229
static TupleTableSlot * gather_getnext(GatherState *gatherstate)
Definition: nodeGather.c:240
int nextreader
Definition: execnodes.h:1898
void * palloc(Size size)
Definition: mcxt.c:849
int i
TupleQueueReader * CreateTupleQueueReader(shm_mq_handle *handle, TupleDesc tupledesc)
Definition: tqueue.c:633
shm_mq_handle ** tqueue
Definition: execParallel.h:30
static TupleTableSlot * ExecProject(ProjectionInfo *projInfo)
Definition: executor.h:310
#define ResetExprContext(econtext)
Definition: executor.h:451
GatherState* ExecInitGather ( Gather node,
EState estate,
int  eflags 
)

Definition at line 56 of file nodeGather.c.

References Assert, ExecAssignExprContext(), ExecAssignProjectionInfo(), ExecAssignResultTypeFromTL(), ExecContextForcesOids(), ExecInitExtraTupleSlot(), ExecInitNode(), ExecInitQual(), ExecInitResultTupleSlot(), ExecSetSlotDescriptor(), ExecTypeFromTL(), GatherState::funnel_slot, innerPlan, makeNode, GatherState::need_to_scan_locally, NULL, outerPlan, outerPlanState, PlanState::plan, Gather::plan, GatherState::ps, Plan::qual, PlanState::qual, Gather::single_copy, PlanState::state, and Plan::targetlist.

Referenced by ExecInitNode().

57 {
58  GatherState *gatherstate;
59  Plan *outerNode;
60  bool hasoid;
61  TupleDesc tupDesc;
62 
63  /* Gather node doesn't have innerPlan node. */
64  Assert(innerPlan(node) == NULL);
65 
66  /*
67  * create state structure
68  */
69  gatherstate = makeNode(GatherState);
70  gatherstate->ps.plan = (Plan *) node;
71  gatherstate->ps.state = estate;
72  gatherstate->need_to_scan_locally = !node->single_copy;
73 
74  /*
75  * Miscellaneous initialization
76  *
77  * create expression context for node
78  */
79  ExecAssignExprContext(estate, &gatherstate->ps);
80 
81  /*
82  * initialize child expressions
83  */
84  gatherstate->ps.qual =
85  ExecInitQual(node->plan.qual, (PlanState *) gatherstate);
86 
87  /*
88  * tuple table initialization
89  */
90  gatherstate->funnel_slot = ExecInitExtraTupleSlot(estate);
91  ExecInitResultTupleSlot(estate, &gatherstate->ps);
92 
93  /*
94  * now initialize outer plan
95  */
96  outerNode = outerPlan(node);
97  outerPlanState(gatherstate) = ExecInitNode(outerNode, estate, eflags);
98 
99  /*
100  * Initialize result tuple type and projection info.
101  */
102  ExecAssignResultTypeFromTL(&gatherstate->ps);
103  ExecAssignProjectionInfo(&gatherstate->ps, NULL);
104 
105  /*
106  * Initialize funnel slot to same tuple descriptor as outer plan.
107  */
108  if (!ExecContextForcesOids(&gatherstate->ps, &hasoid))
109  hasoid = false;
110  tupDesc = ExecTypeFromTL(outerNode->targetlist, hasoid);
111  ExecSetSlotDescriptor(gatherstate->funnel_slot, tupDesc);
112 
113  return gatherstate;
114 }
List * qual
Definition: plannodes.h:145
TupleTableSlot * ExecInitExtraTupleSlot(EState *estate)
Definition: execTuples.c:852
bool need_to_scan_locally
Definition: execnodes.h:1902
EState * state
Definition: execnodes.h:834
ExprState * ExecInitQual(List *qual, PlanState *parent)
Definition: execExpr.c:160
void ExecAssignResultTypeFromTL(PlanState *planstate)
Definition: execUtils.c:440
Plan plan
Definition: plannodes.h:832
bool single_copy
Definition: plannodes.h:834
void ExecInitResultTupleSlot(EState *estate, PlanState *planstate)
Definition: execTuples.c:832
#define outerPlanState(node)
Definition: execnodes.h:874
#define innerPlan(node)
Definition: plannodes.h:173
void ExecAssignProjectionInfo(PlanState *planstate, TupleDesc inputDesc)
Definition: execUtils.c:487
PlanState ps
Definition: execnodes.h:1894
TupleDesc ExecTypeFromTL(List *targetList, bool hasoid)
Definition: execTuples.c:888
#define outerPlan(node)
Definition: plannodes.h:174
void ExecSetSlotDescriptor(TupleTableSlot *slot, TupleDesc tupdesc)
Definition: execTuples.c:247
TupleTableSlot * funnel_slot
Definition: execnodes.h:1901
Plan * plan
Definition: execnodes.h:832
#define makeNode(_type_)
Definition: nodes.h:557
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
void ExecAssignExprContext(EState *estate, PlanState *planstate)
Definition: execUtils.c:418
List * targetlist
Definition: plannodes.h:144
ExprState * qual
Definition: execnodes.h:846
bool ExecContextForcesOids(PlanState *planstate, bool *hasoids)
Definition: execMain.c:1487
PlanState * ExecInitNode(Plan *node, EState *estate, int eflags)
Definition: execProcnode.c:140
void ExecReScanGather ( GatherState node)

Definition at line 424 of file nodeGather.c.

References ExecParallelReinitialize(), ExecReScan(), ExecShutdownGatherWorkers(), GatherState::initialized, PlanState::lefttree, GatherState::pei, and GatherState::ps.

Referenced by ExecReScan().

425 {
426  /*
427  * Re-initialize the parallel workers to perform rescan of relation. We
428  * want to gracefully shutdown all the workers so that they should be able
429  * to propagate any error or other information to master backend before
430  * dying. Parallel context will be reused for rescan.
431  */
433 
434  node->initialized = false;
435 
436  if (node->pei)
438 
439  ExecReScan(node->ps.lefttree);
440 }
void ExecReScan(PlanState *node)
Definition: execAmi.c:75
struct PlanState * lefttree
Definition: execnodes.h:847
bool initialized
Definition: execnodes.h:1895
static void ExecShutdownGatherWorkers(GatherState *node)
Definition: nodeGather.c:372
struct ParallelExecutorInfo * pei
Definition: execnodes.h:1896
PlanState ps
Definition: execnodes.h:1894
void ExecParallelReinitialize(ParallelExecutorInfo *pei)
Definition: execParallel.c:372
void ExecShutdownGather ( GatherState node)

Definition at line 400 of file nodeGather.c.

References ExecParallelCleanup(), ExecShutdownGatherWorkers(), NULL, and GatherState::pei.

Referenced by ExecEndGather(), and ExecShutdownNode().

401 {
403 
404  /* Now destroy the parallel context. */
405  if (node->pei != NULL)
406  {
407  ExecParallelCleanup(node->pei);
408  node->pei = NULL;
409  }
410 }
static void ExecShutdownGatherWorkers(GatherState *node)
Definition: nodeGather.c:372
struct ParallelExecutorInfo * pei
Definition: execnodes.h:1896
void ExecParallelCleanup(ParallelExecutorInfo *pei)
Definition: execParallel.c:662
#define NULL
Definition: c.h:229