Mojo: Add signal for new data pipe consumer data

mojo/public/c/system/types.h

 // Copyright 2014 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.
 
 // This file contains types and constants/macros common to different Mojo system
 // APIs.
 //
 // Note: This header should be compilable as C.
 
 #ifndef MOJO_PUBLIC_C_SYSTEM_TYPES_H_
@@ skipping 131 matching lines @@
 #endif
 
 // |MojoHandleSignals|: Used to specify signals that can be waited on for a
 // handle (and which can be triggered), e.g., the ability to read or write to
 // the handle.
 //   |MOJO_HANDLE_SIGNAL_NONE| - No flags. |MojoWait()|, etc. will return
 //       |MOJO_RESULT_FAILED_PRECONDITION| if you attempt to wait on this.
 //   |MOJO_HANDLE_SIGNAL_READABLE| - Can read (e.g., a message) from the handle.
 //   |MOJO_HANDLE_SIGNAL_WRITABLE| - Can write (e.g., a message) to the handle.
 //   |MOJO_HANDLE_SIGNAL_PEER_CLOSED| - The peer handle is closed.
+//   |MOJO_HANDLE_SIGNAL_NEW_DATA_READABLE| - Can read data from a data pipe
+//       consumer handle (implying MOJO_HANDLE_SIGNAL_READABLE is also set),
+//       AND there is some nonzero quantity of new data available on the pipe
+//       since the last |MojoReadData()| or |MojoBeginReadData()| call on the
+//       handle.
 
 typedef uint32_t MojoHandleSignals;
 
 #ifdef __cplusplus
 const MojoHandleSignals MOJO_HANDLE_SIGNAL_NONE = 0;
 const MojoHandleSignals MOJO_HANDLE_SIGNAL_READABLE = 1 << 0;
 const MojoHandleSignals MOJO_HANDLE_SIGNAL_WRITABLE = 1 << 1;
 const MojoHandleSignals MOJO_HANDLE_SIGNAL_PEER_CLOSED = 1 << 2;
+const MojoHandleSignals MOJO_HANDLE_SIGNAL_NEW_DATA_READABLE = 1 << 3;
 #else
 #define MOJO_HANDLE_SIGNAL_NONE ((MojoHandleSignals)0)
 #define MOJO_HANDLE_SIGNAL_READABLE ((MojoHandleSignals)1 << 0)
 #define MOJO_HANDLE_SIGNAL_WRITABLE ((MojoHandleSignals)1 << 1)
 #define MOJO_HANDLE_SIGNAL_PEER_CLOSED ((MojoHandleSignals)1 << 2)
+#define MOJO_HANDLE_SIGNAL_NEW_DATA_READABLE ((MojoHandleSignals)1 << 3);
 #endif
 
 // |MojoHandleSignalsState|: Returned by wait functions to indicate the
 // signaling state of handles. Members are as follows:
 //   - |satisfied signals|: Bitmask of signals that were satisfied at some time
 //         before the call returned.
 //   - |satisfiable signals|: These are the signals that are possible to
 //         satisfy. For example, if the return value was
 //         |MOJO_RESULT_FAILED_PRECONDITION|, you can use this field to
 //         determine which, if any, of the signals can still be satisfied.
@@ skipping 35 matching lines @@
 //       users should refrain from making sync calls.
 typedef uint32_t MojoPropertyType;
 
 #ifdef __cplusplus
 const MojoPropertyType MOJO_PROPERTY_TYPE_SYNC_CALL_ALLOWED = 0;
 #else
 #define MOJO_PROPERTY_TYPE_SYNC_CALL_ALLOWED ((MojoPropertyType)0)
 #endif
 
 #endif  // MOJO_PUBLIC_C_SYSTEM_TYPES_H_