Function ImmediateCheckpointRequested

src/backend/postmaster/checkpointer.c:678–690

* Returns true if an immediate checkpoint request is pending. (Note that * this does not check the *current* checkpoint's IMMEDIATE flag, but whether * there is one pending behind it.) */

 * there is one pending behind it.)
 */
static bool
ImmediateCheckpointRequested(void)
{
	volatile CheckpointerShmemStruct *cps = CheckpointerShmem;

	/*
	 * We don't need to acquire the ckpt_lck in this case because we're only
	 * looking at a single flag bit.
	 */
	if (cps->ckpt_flags & CHECKPOINT_IMMEDIATE)
		return true;
	return false;
}

/*
 * CheckpointWriteDelay -- control rate of checkpoint