Mojo: Implement plumbing to support passing handles over MessagePipes.

mojo/public/system/core.h

 // Copyright 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 MOJO_PUBLIC_SYSTEM_CORE_H_
 #define MOJO_PUBLIC_SYSTEM_CORE_H_
 
 // Note: This header should be compilable as C.
 
 #include <stdint.h>
@@ skipping 71 matching lines @@
 //        error is similar to |MOJO_RESULT_FAILED_PRECONDITION|, but is more
 //        specific.)
 //    |MOJO_RESULT_UNIMPLEMENTED| - The operation is not implemented, supported,
 //        or enabled.
 //    |MOJO_RESULT_INTERNAL| - Internal error: this should never happen and
 //        indicates that some invariant expected by the system has been broken.
 //    |MOJO_RESULT_UNAVAILABLE| - The operation is (temporarily) currently
 //        unavailable. The caller may simply retry the operation (possibly with
 //        a backoff).
 //    |MOJO_RESULT_DATA_LOSS| - Unrecoverable data loss or corruption.
+//    |MOJO_RESULT_BUSY| - One of the resources involved is currently being used
+//        (possibly on another thread) in a way that prevents the current
+//        operation from proceeding, e.g., if the other operation may result in
+//        the resource being invalidated.
 //
 // Note that positive values are also available as success codes.
 //
 // The codes from |MOJO_RESULT_OK| to |MOJO_RESULT_DATA_LOSS| come from
 // Google3's canonical error codes.
 #ifdef __cplusplus
 const MojoResult MOJO_RESULT_OK = 0;
 const MojoResult MOJO_RESULT_CANCELLED = -1;
 const MojoResult MOJO_RESULT_UNKNOWN = -2;
 const MojoResult MOJO_RESULT_INVALID_ARGUMENT = -3;
 const MojoResult MOJO_RESULT_DEADLINE_EXCEEDED = -4;
 const MojoResult MOJO_RESULT_NOT_FOUND = -5;
 const MojoResult MOJO_RESULT_ALREADY_EXISTS = -6;
 const MojoResult MOJO_RESULT_PERMISSION_DENIED = -7;
 const MojoResult MOJO_RESULT_RESOURCE_EXHAUSTED = -8;
 const MojoResult MOJO_RESULT_FAILED_PRECONDITION = -9;
 const MojoResult MOJO_RESULT_ABORTED = -10;
 const MojoResult MOJO_RESULT_OUT_OF_RANGE = -11;
 const MojoResult MOJO_RESULT_UNIMPLEMENTED = -12;
 const MojoResult MOJO_RESULT_INTERNAL = -13;
 const MojoResult MOJO_RESULT_UNAVAILABLE = -14;
 const MojoResult MOJO_RESULT_DATA_LOSS = -15;
+const MojoResult MOJO_RESULT_BUSY = -16;
 #else
 #define MOJO_RESULT_OK ((MojoResult) 0)
 #define MOJO_RESULT_CANCELLED ((MojoResult) -1)
 #define MOJO_RESULT_UNKNOWN ((MojoResult) -2)
 #define MOJO_RESULT_INVALID_ARGUMENT ((MojoResult) -3)
 #define MOJO_RESULT_DEADLINE_EXCEEDED ((MojoResult) -4)
 #define MOJO_RESULT_NOT_FOUND ((MojoResult) -5)
 #define MOJO_RESULT_ALREADY_EXISTS ((MojoResult) -6)
 #define MOJO_RESULT_PERMISSION_DENIED ((MojoResult) -7)
 #define MOJO_RESULT_RESOURCE_EXHAUSTED ((MojoResult) -8)
 #define MOJO_RESULT_FAILED_PRECONDITION ((MojoResult) -9)
 #define MOJO_RESULT_ABORTED ((MojoResult) -10)
 #define MOJO_RESULT_OUT_OF_RANGE ((MojoResult) -11)
 #define MOJO_RESULT_UNIMPLEMENTED ((MojoResult) -12)
 #define MOJO_RESULT_INTERNAL ((MojoResult) -13)
 #define MOJO_RESULT_UNAVAILABLE ((MojoResult) -14)
 #define MOJO_RESULT_DATA_LOSS ((MojoResult) -15)
+#define MOJO_RESULT_BUSY ((MojoResult) -16)
 #endif
 
 // |MojoDeadline|:
 //    |MOJO_DEADLINE_INDEFINITE|
 #ifdef __cplusplus
 const MojoDeadline MOJO_DEADLINE_INDEFINITE = static_cast<MojoDeadline>(-1);
 #else
 #define MOJO_DEADLINE_INDEFINITE = ((MojoDeadline) -1);
 #endif
 
@@ skipping 166 matching lines @@
   return MojoReadMessage(handle.value,
                          bytes, num_bytes,
                          &handles[0].value, num_handles,
                          flags);
 }
 
 }  // namespace mojo
 #endif
 
 #endif  // MOJO_PUBLIC_SYSTEM_CORE_H_