Function ExecParallelHashPopChunkQueue

src/backend/executor/nodeHash.c:4001–4020

* Take the next available chunk from the queue of chunks being worked on in * parallel. Return NULL if there are none left. Otherwise return a pointer * to the chunk, and set *shared to the DSA pointer to the chunk. */

 * to the chunk, and set *shared to the DSA pointer to the chunk.
 */
static HashMemoryChunk
ExecParallelHashPopChunkQueue(HashJoinTable hashtable, dsa_pointer *shared)
{
	ParallelHashJoinState *pstate = hashtable->parallel_state;
	HashMemoryChunk chunk;

	LWLockAcquire(&pstate->lock, LW_EXCLUSIVE);
	if (DsaPointerIsValid(pstate->chunk_work_queue))
	{
		*shared = pstate->chunk_work_queue;
		chunk = (HashMemoryChunk)
			dsa_get_address(hashtable->area, *shared);
		pstate->chunk_work_queue = chunk->next.shared;
	}
	else
		chunk = NULL;
	LWLockRelease(&pstate->lock);

	return chunk;
}

/*
 * Increase the space preallocated in this backend for a given inner batch by