Function FlushOneBuffer

src/backend/storage/buffer/bufmgr.c:3960–3975

* Flush a previously, shared or exclusively, locked and pinned buffer to the * OS. */

 * OS.
 */
void
FlushOneBuffer(Buffer buffer)
{
	BufferDesc *bufHdr;

	/* currently not needed, but no fundamental reason not to support */
	Assert(!BufferIsLocal(buffer));

	Assert(BufferIsPinned(buffer));

	bufHdr = GetBufferDescriptor(buffer - 1);

	Assert(LWLockHeldByMe(BufferDescriptorGetContentLock(bufHdr)));

	FlushBuffer(bufHdr, NULL);
}

/*
 * ReleaseBuffer -- release the pin on a buffer