Function ExplainCreateWorkersState

src/backend/commands/explain.c:5222–5234

* Create a per-plan-node workspace for collecting per-worker data. * * Output related to each worker will be temporarily "set aside" into a * separate buffer, which we'll merge into the main output stream once * we've processed all data for the plan node. This makes it feasible to * generate a coherent sub-group of fields for each worker, even though the * code that produces the fields is i

 * ExplainOpenSetAsideGroup and ExplainSaveGroup/ExplainRestoreGroup.
 */
static ExplainWorkersState *
ExplainCreateWorkersState(int num_workers)
{
	ExplainWorkersState *wstate;

	wstate = (ExplainWorkersState *) palloc(sizeof(ExplainWorkersState));
	wstate->num_workers = num_workers;
	wstate->worker_inited = (bool *) palloc0(num_workers * sizeof(bool));
	wstate->worker_str = (StringInfoData *)
		palloc0(num_workers * sizeof(StringInfoData));
	wstate->worker_state_save = (int *) palloc(num_workers * sizeof(int));
	return wstate;
}

/*
 * Begin or resume output into the set-aside group for worker N.