src/backend/executor/instrument.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * instrument.c
   4  *       functions for instrumentation of plan execution
   5  *
   6  *
   7  * Copyright (c) 2001-2008, PostgreSQL Global Development Group
   8  *
   9  * IDENTIFICATION
  10  *        $PostgreSQL$
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #include "postgres.h"
  15
  16 #include <unistd.h>
  17
  18 #include "executor/instrument.h"
  19
  20
  21 /* Allocate new instrumentation structure(s) */
  22 Instrumentation *
  23 InstrAlloc(int n)
  24 {
  25         Instrumentation *instr = palloc0(n * sizeof(Instrumentation));
  26
  27         /* we don't need to do any initialization except zero 'em */
  28
  29         return instr;
  30 }
  31
  32 /* Entry to a plan node */
  33 void
  34 InstrStartNode(Instrumentation *instr)
  35 {
  36         if (INSTR_TIME_IS_ZERO(instr->starttime))
  37                 INSTR_TIME_SET_CURRENT(instr->starttime);
  38         else
  39                 elog(DEBUG2, "InstrStartNode called twice in a row");
  40 }
  41
  42 /* Exit from a plan node */
  43 void
  44 InstrStopNode(Instrumentation *instr, double nTuples)
  45 {
  46         instr_time      endtime;
  47
  48         /* count the returned tuples */
  49         instr->tuplecount += nTuples;
  50
  51         if (INSTR_TIME_IS_ZERO(instr->starttime))
  52         {
  53                 elog(DEBUG2, "InstrStopNode called without start");
  54                 return;
  55         }
  56
  57         INSTR_TIME_SET_CURRENT(endtime);
  58         INSTR_TIME_ACCUM_DIFF(instr->counter, endtime, instr->starttime);
  59
  60         INSTR_TIME_SET_ZERO(instr->starttime);
  61
  62         /* Is this the first tuple of this cycle? */
  63         if (!instr->running)
  64         {
  65                 instr->running = true;
  66                 instr->firsttuple = INSTR_TIME_GET_DOUBLE(instr->counter);
  67         }
  68 }
  69
  70 /* Finish a run cycle for a plan node */
  71 void
  72 InstrEndLoop(Instrumentation *instr)
  73 {
  74         double          totaltime;
  75
  76         /* Skip if nothing has happened, or already shut down */
  77         if (!instr->running)
  78                 return;
  79
  80         if (!INSTR_TIME_IS_ZERO(instr->starttime))
  81                 elog(DEBUG2, "InstrEndLoop called on running node");
  82
  83         /* Accumulate per-cycle statistics into totals */
  84         totaltime = INSTR_TIME_GET_DOUBLE(instr->counter);
  85
  86         instr->startup += instr->firsttuple;
  87         instr->total += totaltime;
  88         instr->ntuples += instr->tuplecount;
  89         instr->nloops += 1;
  90
  91         /* Reset for next cycle (if any) */
  92         instr->running = false;
  93         INSTR_TIME_SET_ZERO(instr->starttime);
  94         INSTR_TIME_SET_ZERO(instr->counter);
  95         instr->firsttuple = 0;
  96         instr->tuplecount = 0;
  97 }