components/browser_watcher/watcher_client_win.h

   1 // Copyright (c) 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 COMPONENTS_BROWSER_WATCHER_WATCHER_CLIENT_WIN_H_
   6 #define COMPONENTS_BROWSER_WATCHER_WATCHER_CLIENT_WIN_H_
   7
   8 #include "base/command_line.h"
   9 #include "base/macros.h"
  10 #include "base/process/process.h"
  11
  12 namespace browser_watcher {
  13
  14 // An interface class to take care of the details in launching a browser
  15 // watch process.
  16 class WatcherClient {
  17  public:
  18   // Constructs a watcher client with a |base_command_line|, which should be
  19   // a command line sufficient to invoke the watcher process. This command
  20   // line will be augmented with the value of the inherited handle.
  21   explicit WatcherClient(const base::CommandLine& base_command_line);
  22
  23   // Launches the watcher process.
  24   void LaunchWatcher();
  25
  26   // Accessors, exposed only for testing.
  27   bool use_legacy_launch() const { return use_legacy_launch_; }
  28   void set_use_legacy_launch(bool use_legacy_launch) {
  29       use_legacy_launch_ = use_legacy_launch;
  30   }
  31   base::ProcessHandle process() const { return process_.Handle(); }
  32
  33  private:
  34   // Launches |cmd_line| such that the child process is able to inherit
  35   // |handle|. If |use_legacy_launch_| is true, this uses a non-threadsafe
  36   // legacy launch mode that's compatible with Windows XP.
  37   // Returns a handle to the child process.
  38   void LaunchWatcherProcess(const base::CommandLine& cmd_line,
  39                             base::Process self);
  40
  41   // If true, the watcher process will be launched with XP legacy handle
  42   // inheritance. This is not thread safe and can leak random handles into the
  43   // child process, but it's the best we can do on XP.
  44   bool use_legacy_launch_;
  45
  46   // The base command line passed to the constructor.
  47   base::CommandLine base_command_line_;
  48
  49   // A handle to the launched watcher process. Valid after a successful
  50   // LaunchWatcher() call.
  51   base::Process process_;
  52
  53   DISALLOW_COPY_AND_ASSIGN(WatcherClient);
  54 };
  55
  56 }  // namespace browser_watcher
  57
  58 #endif  // COMPONENTS_BROWSER_WATCHER_WATCHER_CLIENT_WIN_H_