Mac: Other approach for IPCing child task_ts.

base/mach_ipc_mac.h

 // Copyright (c) 2006-2008 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 BASE_MACH_IPC_MAC_H_
 #define BASE_MACH_IPC_MAC_H_
 
 #include <mach/mach.h>
 #include <mach/message.h>
 #include <servers/bootstrap.h>
@@ skipping 240 matching lines @@
   MachReceiveMessage(void *storage, size_t storage_length)
       : MachMessage(storage, storage_length) {}
 
  private:
     DISALLOW_COPY_AND_ASSIGN(MachReceiveMessage);
 };
 
 //==============================================================================
 class MachSendMessage : public MachMessage {
  public:
-  MachSendMessage(int32_t message_id);
+  explicit MachSendMessage(int32_t message_id);
   MachSendMessage(void *storage, size_t storage_length, int32_t message_id);
 
  private:
   void Initialize(int32_t message_id);
 
   DISALLOW_COPY_AND_ASSIGN(MachSendMessage);
 };
 
 //==============================================================================
 // Represents a mach port for which we have receive rights
 class ReceivePort {
  public:
   // Creates a new mach port for receiving messages and registers a name for it
-  ReceivePort(const char *receive_port_name);
+  explicit ReceivePort(const char *receive_port_name);
 
   // Given an already existing mach port, use it.  We take ownership of the
   // port and deallocate it in our destructor.
-  ReceivePort(mach_port_t receive_port);
+  explicit ReceivePort(mach_port_t receive_port);
 
   // Create a new mach port for receiving messages
   ReceivePort();
 
   ~ReceivePort();
 
   // Waits on the mach port until message received or timeout
   kern_return_t WaitForMessage(MachReceiveMessage *out_message,
                                mach_msg_timeout_t timeout);
 
   // The underlying mach port that we wrap
   mach_port_t  GetPort() const { return port_; }
 
  private:
   mach_port_t   port_;
   kern_return_t init_result_;
 
   DISALLOW_COPY_AND_ASSIGN(ReceivePort);
 };
 
 //==============================================================================
 // Represents a mach port for which we have send rights
 class MachPortSender {
  public:
   // get a port with send rights corresponding to a named registered service
-  MachPortSender(const char *receive_port_name);
+  explicit MachPortSender(const char *receive_port_name);
 
 
-  // Given an already existing mach port, use it.
-  MachPortSender(mach_port_t send_port);
+  // Given an already existing mach port, use it. Does not take ownership of
+  // |send_port|.
+  explicit MachPortSender(mach_port_t send_port);
 
   kern_return_t SendMessage(MachSendMessage &message,
                             mach_msg_timeout_t timeout);
 
  private:
   mach_port_t   send_port_;
   kern_return_t init_result_;
 
   DISALLOW_COPY_AND_ASSIGN(MachPortSender);
 };
 
 #endif // BASE_MACH_IPC_MAC_H_