[NaCl SDK] Support non blocking TCP/UDP

native_client_sdk/src/libraries/nacl_io/fifo_interface.h

+// 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.
+
+#ifndef LIBRARIES_NACL_IO_FIFO_INTERFACE_H_
+#define LIBRARIES_NACL_IO_FIFO_INTERFACE_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+
+namespace nacl_io {
+
+// FIFOInterface
+//
+// FIFOInterface provides a common interface for Emitters to update their
+// signalled state.  FIFOs do not have any internal locking and instead
+// reply on a parent (usually an emitter) to lock for them as appropriate.
+class FIFOInterface {
+ public:
+  virtual ~FIFOInterface() {};
+
+  virtual bool IsEmpty() = 0;
+  virtual bool IsFull() = 0;
+  virtual bool Resize(size_t len) = 0;
+
+  virtual uint32_t ReadAvailable() = 0;
+  virtual uint32_t WriteAvailable() = 0;
+};
+
+}  // namespace nacl_io
+
+#endif  // LIBRARIES_NACL_IO_FIFO_INTERFACE_H_