1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MOJO_SHELL_CHILD_PROCESS_HOST_H_ 6 #define MOJO_SHELL_CHILD_PROCESS_HOST_H_ 7 8 #include "base/macros.h" 9 #include "base/process/process_handle.h" 10 #include "mojo/embedder/platform_channel_pair.h" 11 #include "mojo/embedder/scoped_platform_handle.h" 12 #include "mojo/shell/child_process.h" // For |ChildProcess::Type|. 13 14 namespace mojo { 15 namespace shell { 16 17 class Context; 18 19 // (Base) class for a "child process host". Handles launching and connecting a 20 // platform-specific "pipe" to the child, and supports joining the child 21 // process. Intended for use as a base class, but may be used on its own in 22 // simple cases. 23 // 24 // This class is not thread-safe. It should be created/used/destroyed on a 25 // single thread. 26 // 27 // Note: Does not currently work on Windows before Vista. 28 class ChildProcessHost { 29 public: 30 class Delegate { 31 public: 32 virtual void WillStart() = 0; 33 virtual void DidStart(bool success) = 0; 34 }; 35 36 ChildProcessHost(Context* context, 37 Delegate* delegate, 38 ChildProcess::Type type); 39 virtual ~ChildProcessHost(); 40 41 // |Start()|s the child process; calls the delegate's |DidStart()| (on the 42 // thread on which |Start()| was called) when the child has been started (or 43 // failed to start). After calling |Start()|, this object must not be 44 // destroyed until |DidStart()| has been called. 45 // TODO(vtl): Consider using weak pointers and removing this requirement. 46 void Start(); 47 48 // Waits for the child process to terminate, and returns its exit code. 49 // Note: If |Start()| has been called, this must not be called until the 50 // callback has been called. 51 int Join(); 52 platform_channel()53 embedder::ScopedPlatformHandle* platform_channel() { 54 return &platform_channel_; 55 } 56 57 protected: context()58 Context* context() const { 59 return context_; 60 } 61 62 private: 63 bool DoLaunch(); 64 void DidLaunch(bool success); 65 66 Context* const context_; 67 Delegate* const delegate_; 68 const ChildProcess::Type type_; 69 70 base::ProcessHandle child_process_handle_; 71 72 embedder::PlatformChannelPair platform_channel_pair_; 73 74 // Platform-specific "pipe" to the child process. Valid immediately after 75 // creation. 76 embedder::ScopedPlatformHandle platform_channel_; 77 78 DISALLOW_COPY_AND_ASSIGN(ChildProcessHost); 79 }; 80 81 } // namespace shell 82 } // namespace mojo 83 84 #endif // MOJO_SHELL_CHILD_PROCESS_HOST_H_ 85