Function pgstat_end_function_usage

src/backend/postmaster/pgstat.c:1997–2039

* Calculate function call usage and update stat counters. * Called by the executor after invoking a function. * * In the case of a set-returning function that runs in value-per-call mode, * we will see multiple pgstat_init_function_usage/pgstat_end_function_usage * calls for what the user considers a single call of the function. The * finalize flag should be TRUE on the last call. */

 * finalize flag should be TRUE on the last call.
 */
void
pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
{
	PgStat_FunctionCounts *fs = fcu->fs;
	instr_time	f_total;
	instr_time	f_others;
	instr_time	f_self;

	/* stats not wanted? */
	if (fs == NULL)
		return;

	/* total elapsed time in this function call */
	INSTR_TIME_SET_CURRENT(f_total);
	INSTR_TIME_SUBTRACT(f_total, fcu->f_start);

	/* self usage: elapsed minus anything already charged to other calls */
	f_others = total_func_time;
	INSTR_TIME_SUBTRACT(f_others, fcu->save_total);
	f_self = f_total;
	INSTR_TIME_SUBTRACT(f_self, f_others);

	/* update backend-wide total time */
	INSTR_TIME_ADD(total_func_time, f_self);

	/*
	 * Compute the new f_total_time as the total elapsed time added to the
	 * pre-call value of f_total_time.  This is necessary to avoid
	 * double-counting any time taken by recursive calls of myself.  (We do
	 * not need any similar kluge for self time, since that already excludes
	 * any recursive calls.)
	 */
	INSTR_TIME_ADD(f_total, fcu->save_f_total_time);

	/* update counters in function stats table */
	if (finalize)
		fs->f_numcalls++;
	fs->f_total_time = f_total;
	INSTR_TIME_ADD(fs->f_self_time, f_self);

	/* indicate that we have something to send */
	have_function_stats = true;
}


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