Function ExecParallelCleanup

src/backend/executor/execParallel.c:1180–1210

* Accumulate instrumentation, and then clean up whatever ParallelExecutorInfo * resources still exist after ExecParallelFinish. We separate these * routines because someone might want to examine the contents of the DSM * after ExecParallelFinish and before calling this routine. */

 * after ExecParallelFinish and before calling this routine.
 */
void
ExecParallelCleanup(ParallelExecutorInfo *pei)
{
	/* Accumulate instrumentation, if any. */
	if (pei->instrumentation)
		ExecParallelRetrieveInstrumentation(pei->planstate,
											pei->instrumentation);

	/* Accumulate JIT instrumentation, if any. */
	if (pei->jit_instrumentation)
		ExecParallelRetrieveJitInstrumentation(pei->planstate,
											   pei->jit_instrumentation);

	/* Free any serialized parameters. */
	if (DsaPointerIsValid(pei->param_exec))
	{
		dsa_free(pei->area, pei->param_exec);
		pei->param_exec = InvalidDsaPointer;
	}
	if (pei->area != NULL)
	{
		dsa_detach(pei->area);
		pei->area = NULL;
	}
	if (pei->pcxt != NULL)
	{
		DestroyParallelContext(pei->pcxt);
		pei->pcxt = NULL;
	}
	pfree(pei);
}

/*
 * Create a DestReceiver to write tuples we produce to the shm_mq designated