execParallel.h

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/*--------------------------------------------------------------------
 * execParallel.h
 *      POSTGRES parallel execution interface
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *      src/include/executor/execParallel.h
 *--------------------------------------------------------------------
 */

#ifndef EXECPARALLEL_H
#define EXECPARALLEL_H

#include "access/parallel.h"
#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
#include "nodes/plannodes.h"
#include "utils/dsa.h"

typedef struct SharedExecutorInstrumentation SharedExecutorInstrumentation;

typedef struct ParallelExecutorInfo
{
    PlanState  *planstate;      /* plan subtree we're running in parallel */
    ParallelContext *pcxt;      /* parallel context we're using */
    BufferUsage *buffer_usage;  /* points to bufusage area in DSM */
    SharedExecutorInstrumentation *instrumentation; /* optional */
    dsa_area   *area;           /* points to DSA area in DSM */
    bool        finished;       /* set true by ExecParallelFinish */
    /* These two arrays have pcxt->nworkers_launched entries: */
    shm_mq_handle **tqueue;     /* tuple queues for worker output */
    struct TupleQueueReader **reader;   /* tuple reader/writer support */
} ParallelExecutorInfo;

extern ParallelExecutorInfo *ExecInitParallelPlan(PlanState *planstate,
                     EState *estate, int nworkers, int64 tuples_needed);
extern void ExecParallelCreateReaders(ParallelExecutorInfo *pei);
extern void ExecParallelFinish(ParallelExecutorInfo *pei);
extern void ExecParallelCleanup(ParallelExecutorInfo *pei);
extern void ExecParallelReinitialize(PlanState *planstate,
                         ParallelExecutorInfo *pei);

extern void ParallelQueryMain(dsm_segment *seg, shm_toc *toc);

#endif                          /* EXECPARALLEL_H */