[NaCl SDK] Support non blocking TCP/UDP

native_client_sdk/src/libraries/nacl_io/event_emitter_udp.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "nacl_io/event_emitter_udp.h"
+
+#include <poll.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "sdk_util/auto_lock.h"
+
+namespace nacl_io {
+
+EventEmitterUDP::EventEmitterUDP(size_t rsize, size_t wsize)
+    : rx_fifo_(std::max<size_t>(1, rsize)),
+      tx_fifo_(std::max<size_t>(1, wsize)) {
+  UpdateStatus_Locked();
+}
+
+Packet* EventEmitterUDP::ReadRXPacket_Locked() {
+  Packet* packet = rx_fifo_.ReadPacket();
+
+  UpdateStatus_Locked();
+  return packet;
+}
+
+void EventEmitterUDP::WriteRXPacket_Locked(Packet* packet) {
+  rx_fifo_.WritePacket(packet);
+
+  UpdateStatus_Locked();
+}
+
+Packet* EventEmitterUDP::ReadTXPacket_Locked() {
+  Packet* packet = tx_fifo_.ReadPacket();
+
+  UpdateStatus_Locked();
+  return packet;
+}
+
+void EventEmitterUDP::WriteTXPacket_Locked(Packet* packet) {
+  tx_fifo_.WritePacket(packet);
+
+  UpdateStatus_Locked();
+}
+
+}  // namespace nacl_io
+
+