Improvements for MachMultiprocess

util/test/mac/mach_multiprocess.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 13 matching lines @@
 namespace test {
 
 namespace internal {
 struct MachMultiprocessInfo;
 }  // namespace internal
 
 //! \brief Manages a Mach-aware multiprocess test.
 //!
 //! These tests are `fork()`-based. The parent process has access to the child
 //! process’ task port. The parent and child processes are able to communicate
-//! via Mach IPC, and the child process can also send messages to the parent
-//! process via a POSIX pipe.
+//! via Mach IPC, and via a pair of POSIX pipes.
 //!
 //! Subclasses are expected to implement the parent and child by overriding the
 //! appropriate methods.
 class MachMultiprocess {
  public:
   MachMultiprocess();
 
   //! \brief Runs the test.
   //!
   //! This method establishes the proper testing environment and calls
@@ skipping 26 matching lines @@
   //! `FAIL()`, etc.
   //!
   //! Subclasses must implement this method to define how the child operates.
   virtual void Child() = 0;
 
   //! \brief Returns the child process’ process ID.
   //!
   //! This method may only be called by the parent process.
   pid_t ChildPID() const;
 
-  //! \brief Returns the pipe’s file descriptor.
+  //! \brief Returns the read pipe’s file descriptor.
   //!
-  //! This method may be called by either the parent or the child process. In
-  //! the parent process, the pipe is read-only, and in the child process, it is
-  //! write-only.
-  int PipeFD() const;
+  //! This method may be called by either the parent or the child process.
+  //! Anything written to the write pipe in the partner process will appear
+  //! on the this file descriptor in this process.
+  int ReadPipeFD() const;
+
+  //! \brief Returns the write pipe’s file descriptor.
+  //!
+  //! This method may be called by either the parent or the child process.
+  //! Anything written to this file descriptor in this process will appear on
+  //! the read pipe in the partner process.
+  int WritePipeFD() const;
 
   //! \brief Returns a receive right for the local port.
   //!
   //! This method may be called by either the parent or the child process. It
   //! returns a receive right, with a corresponding send right held in the
   //! opposing process.
   mach_port_t LocalPort() const;
 
   //! \brief Returns a send right for the remote port.
   //!
@@ skipping 26 matching lines @@
 
   internal::MachMultiprocessInfo* info_;
 
   DISALLOW_COPY_AND_ASSIGN(MachMultiprocess);
 };
 
 }  // namespace test
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_TEST_MAC_MACH_MULTIPROCESS_H_