[NaCl SDK] Support non blocking TCP/UDP

native_client_sdk/src/libraries/nacl_io/event_emitter_stream.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_stream.h"
+
+#include <poll.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "nacl_io/fifo_interface.h"
+#include "sdk_util/auto_lock.h"
+
+namespace nacl_io {
+
+EventEmitterStream::EventEmitterStream() : stream_(NULL) {}
+
+void EventEmitterStream::AttachStream(MountNodeStream* stream) {
+  AUTO_LOCK(GetLock());
+  stream_ = stream;
+}
+
+void EventEmitterStream::DetachStream() {
+  AUTO_LOCK(GetLock());
+
+  RaiseEvents_Locked(POLLHUP);
+  stream_ = NULL;
+}
+
+void EventEmitterStream::UpdateStatus_Locked() {
+  uint32_t status = 0;
+  if (!in_fifo()->IsEmpty())
+    status |= POLLIN;
+
+  if (!out_fifo()->IsFull())
+    status |= POLLOUT;
+
+  ClearEvents_Locked(~status);
+  RaiseEvents_Locked(status);
+}
+
+
+}  // namespace nacl_io
+
+