content/browser/child_process_launcher.h

   1 // Copyright (c) 2012 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 CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_
   6 #define CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/process_util.h"
  11 #include "content/common/content_export.h"
  12
  13 class CommandLine;
  14
  15 namespace content {
  16 class SandboxedProcessLauncherDelegate;
  17
  18 // Launches a process asynchronously and notifies the client of the process
  19 // handle when it's available.  It's used to avoid blocking the calling thread
  20 // on the OS since often it can take > 100 ms to create the process.
  21 class CONTENT_EXPORT ChildProcessLauncher {
  22  public:
  23   class CONTENT_EXPORT Client {
  24    public:
  25     // Will be called on the thread that the ChildProcessLauncher was
  26     // constructed on.
  27     virtual void OnProcessLaunched() = 0;
  28
  29    protected:
  30     virtual ~Client() {}
  31   };
  32
  33   // Launches the process asynchronously, calling the client when the result is
  34   // ready.  Deleting this object before the process is created is safe, since
  35   // the callback won't be called.  If the process is still running by the time
  36   // this object destructs, it will be terminated.
  37   // Takes ownership of cmd_line.
  38   ChildProcessLauncher(
  39 #if defined(OS_WIN)
  40       SandboxedProcessLauncherDelegate* delegate,
  41 #elif defined(OS_POSIX)
  42       bool use_zygote,
  43       const base::EnvironmentVector& environ,
  44       int ipcfd,
  45 #endif
  46       CommandLine* cmd_line,
  47       int child_process_id,
  48       Client* client);
  49   ~ChildProcessLauncher();
  50
  51   // True if the process is being launched and so the handle isn't available.
  52   bool IsStarting();
  53
  54   // Getter for the process handle.  Only call after the process has started.
  55   base::ProcessHandle GetHandle();
  56
  57   // Call this when the child process exits to know what happened to it.
  58   // |known_dead| can be true if we already know the process is dead as it can
  59   // help the implemention figure the proper TerminationStatus.
  60   // |exit_code| is the exit code of the process if it exited (e.g. status from
  61   // waitpid if on posix, from GetExitCodeProcess on Windows). |exit_code| may
  62   // be NULL.
  63   base::TerminationStatus GetChildTerminationStatus(bool known_dead,
  64                                                     int* exit_code);
  65
  66   // Changes whether the process runs in the background or not.  Only call
  67   // this after the process has started.
  68   void SetProcessBackgrounded(bool background);
  69
  70   // Controls whether the child process should be terminated on browser
  71   // shutdown.
  72   void SetTerminateChildOnShutdown(bool terminate_on_shutdown);
  73
  74  private:
  75   class Context;
  76
  77   scoped_refptr<Context> context_;
  78
  79   DISALLOW_COPY_AND_ASSIGN(ChildProcessLauncher);
  80 };
  81
  82 }  // namespace content
  83
  84 #endif  // CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_