Refactor ChildProcess and related classes to create a framework outside of br...

base/mp/mp_child_process_launcher.h

+// Copyright (c) 2010 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_MP_CHILD_PROCESS_LAUNCHER_H_
+#define BASE_MP_CHILD_PROCESS_LAUNCHER_H_
+
+#include "base/basictypes.h"
+#include "base/mp/mp_child_process_context.h"
+#include "base/process_util.h"
+#include "base/ref_counted.h"
+
+class CommandLine;
+class MessageLoop;
+
+namespace base {
+
+// Launches a process asynchronously and notifies the client of the process
+// handle when it's available.  It's used to avoid blocking the calling thread
+// on the OS since often it can take > 100 ms to create the process.
+class MpChildProcessLauncher {
+ public:
+  class Client {
+   public:
+    // Will be called on the thread that the MpChildProcessLauncher was
+    // constructed on.
+    virtual void OnProcessLaunched() = 0;
+  };
+
+  // Launches the process asynchronously, calling the client when the result is
+  // ready.  Deleting this object before the process is created is safe, since
+  // the callback won't be called.  If the process is still running by the time
+  // this object destructs, it will be terminated.
+  // Takes ownership of cmd_line.
+  MpChildProcessLauncher(
+#if defined(OS_WIN)
+      const FilePath& exposed_dir,
+#elif defined(OS_POSIX)
+      bool use_zygote,
+      const base::environment_vector& environ,
+      int ipcfd,
+#endif
+      CommandLine* cmd_line,
+      MpChildProcessContext* context,
+      Client* client);
+  virtual ~MpChildProcessLauncher();
+
+  // True if the process is being launched and so the handle isn't available.
+  bool IsStarting();
+
+  // Getter for the process handle.  Only call after the process has started.
+  base::ProcessHandle GetHandle();
+
+  // Call this when the process exits to know if a process crashed or not.
+  bool DidProcessCrash();
+
+  // Changes whether the process runs in the background or not.  Only call
+  // this after the process has started.
+  void SetProcessBackgrounded(bool background);
+
+ private:
+  class Context;
+
+  scoped_refptr<Context> context_;
+  MpChildProcessContext* process_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(MpChildProcessLauncher);
+};
+
+}  // namespace base
+
+#endif  // BASE_MP_CHILD_PROCESS_LAUNCHER_H_