oh, i see and yet. 3, 4 Socket.send do the same thing like send syscall, but 1 definitly means send all "if one send did not send all data, send again"
the first send's [implementation](https://github.com/nim-lang/Nim/blob/version-1-6/lib/pure/asyncdispatch.nim#L1917-L1934) proc send*(socket: AsyncFD, buf: pointer, size: int, flags = {SocketFlag.SafeDisconn}): owned(Future[void]) = var retFuture = newFuture[void]("send") var written = 0 proc cb(sock: AsyncFD): bool = result = true let netSize = size-written var d = cast[cstring](buf) let res = send(sock.SocketHandle, addr d[written], netSize.cint, MSG_NOSIGNAL) if res < 0: let lastError = osLastError() if lastError.int32 != EINTR and lastError.int32 != EWOULDBLOCK and lastError.int32 != EAGAIN: if flags.isDisconnectionError(lastError): retFuture.complete() else: retFuture.fail(newOSError(lastError)) else: result = false # We still want this callback to be called. else: written.inc(res) if res != netSize: result = false # We still have data to send. else: retFuture.complete() # TODO: The following causes crashes. #if not cb(socket): addWrite(socket, cb) return retFuture Run
