src/include/storage/procnumber.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * procnumber.h
   4  *        definition of process number
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * src/include/storage/procnumber.h
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef PROCNUMBER_H
  15 #define PROCNUMBER_H
  16
  17 /*
  18  * ProcNumber uniquely identifies an active backend or auxiliary process.
  19  * It's assigned at backend startup after authentication, when the process
  20  * adds itself to the proc array.  It is an index into the proc array,
  21  * starting from 0. Note that a ProcNumber can be reused for a different
  22  * backend immediately after a backend exits.
  23  */
  24 typedef int ProcNumber;
  25
  26 #define INVALID_PROC_NUMBER             (-1)
  27
  28 /*
  29  * Proc number of this backend (same as GetNumberFromPGProc(MyProc))
  30  */
  31 extern PGDLLIMPORT ProcNumber MyProcNumber;
  32
  33 /* proc number of our parallel session leader, or INVALID_PROC_NUMBER if none */
  34 extern PGDLLIMPORT ProcNumber ParallelLeaderProcNumber;
  35
  36 /*
  37  * The ProcNumber to use for our session's temp relations is normally our own,
  38  * but parallel workers should use their leader's proc number.
  39  */
  40 #define ProcNumberForTempRelations() \
  41         (ParallelLeaderProcNumber == INVALID_PROC_NUMBER ? MyProcNumber : ParallelLeaderProcNumber)
  42
  43 #endif                                                  /* PROCNUMBER_H */