content/browser/utility_process_host.h

   1 // Copyright (c) 2011 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_UTILITY_PROCESS_HOST_H_
   6 #define CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_
   7 #pragma once
   8
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "content/browser/browser_child_process_host.h"
  15 #include "content/browser/browser_thread.h"
  16
  17 // This class acts as the browser-side host to a utility child process.  A
  18 // utility process is a short-lived sandboxed process that is created to run
  19 // a specific task.  This class lives solely on the IO thread.
  20 // If you need a single method call in the sandbox, use StartFooBar(p).
  21 // If you need multiple batches of work to be done in the sandboxed process,
  22 // use StartBatchMode(), then multiple calls to StartFooBar(p),
  23 // then finish with EndBatchMode().
  24 class UtilityProcessHost : public BrowserChildProcessHost {
  25  public:
  26   // An interface to be implemented by consumers of the utility process to
  27   // get results back.  All functions are called on the thread passed along
  28   // to UtilityProcessHost.
  29   class Client : public base::RefCountedThreadSafe<Client> {
  30    public:
  31     Client();
  32
  33     // Called when the process has crashed.
  34     virtual void OnProcessCrashed(int exit_code);
  35
  36     // Allow the client to filter IPC messages.
  37     virtual bool OnMessageReceived(const IPC::Message& message);
  38
  39    protected:
  40     friend class base::RefCountedThreadSafe<Client>;
  41
  42     virtual ~Client();
  43
  44    private:
  45     friend class UtilityProcessHost;
  46
  47     DISALLOW_COPY_AND_ASSIGN(Client);
  48   };
  49
  50   UtilityProcessHost(Client* client, BrowserThread::ID client_thread_id);
  51   virtual ~UtilityProcessHost();
  52
  53   // BrowserChildProcessHost override
  54   virtual bool Send(IPC::Message* message);
  55
  56   // Starts utility process in batch mode. Caller must call EndBatchMode()
  57   // to finish the utility process.
  58   bool StartBatchMode();
  59
  60   // Ends the utility process. Must be called after StartBatchMode().
  61   void EndBatchMode();
  62
  63   void set_exposed_dir(const FilePath& dir) { exposed_dir_ = dir; }
  64
  65  protected:
  66   // Allow these methods to be overridden for tests.
  67   virtual FilePath GetUtilityProcessCmd();
  68
  69  private:
  70   // Starts a process if necessary.  Returns true if it succeeded or a process
  71   // has already been started via StartBatchMode().
  72   bool StartProcess();
  73
  74   // IPC messages:
  75   virtual bool OnMessageReceived(const IPC::Message& message);
  76
  77   // BrowserChildProcessHost:
  78   virtual void OnProcessCrashed(int exit_code);
  79   virtual bool CanShutdown();
  80
  81   // A pointer to our client interface, who will be informed of progress.
  82   scoped_refptr<Client> client_;
  83   BrowserThread::ID client_thread_id_;
  84   // True when running in batch mode, i.e., StartBatchMode() has been called
  85   // and the utility process will run until EndBatchMode().
  86   bool is_batch_mode_;
  87
  88   // Allows a directory to be opened through the sandbox, in case it's needed by
  89   // the operation.
  90   FilePath exposed_dir_;
  91
  92   bool started_;
  93
  94   DISALLOW_COPY_AND_ASSIGN(UtilityProcessHost);
  95 };
  96
  97 #endif  // CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_