content/browser/plugin_loader_posix.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_PLUGIN_LOADER_POSIX_H_
   6 #define CONTENT_BROWSER_PLUGIN_LOADER_POSIX_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/time/time.h"
  14 #include "content/browser/plugin_service_impl.h"
  15 #include "content/public/browser/utility_process_host_client.h"
  16 #include "content/public/common/webplugininfo.h"
  17 #include "ipc/ipc_sender.h"
  18
  19 namespace base {
  20 class MessageLoopProxy;
  21 }
  22
  23 namespace content {
  24 class UtilityProcessHost;
  25
  26 // This class is responsible for managing the out-of-process plugin loading on
  27 // POSIX systems. It primarily lives on the IO thread, but has a brief stay on
  28 // the FILE thread to iterate over plugin directories when it is first
  29 // constructed.
  30 //
  31 // The following is the algorithm used to load plugins:
  32 // 1. This asks the PluginList for the list of all potential plugins to attempt
  33 //    to load. This is referred to as the canonical list.
  34 // 2. The child process this hosts is forked and the canonical list is sent to
  35 //    it.
  36 // 3. The child process iterates over the canonical list, attempting to load
  37 //    each plugin in the order specified by the list. It sends an IPC message
  38 //    to the browser after each load, indicating success or failure. The two
  39 //    processes synchronize the position in the vector that will be used to
  40 //    attempt to load the next plugin.
  41 // 4. If the child dies during this process, the host forks another child and
  42 //    resumes loading at the position past the plugin that it just attempted to
  43 //    load, bypassing the problematic plugin.
  44 // 5. This algorithm continues until the canonical list has been walked to the
  45 //    end, after which the list of loaded plugins is set on the PluginList and
  46 //    the completion callback is run.
  47 class CONTENT_EXPORT PluginLoaderPosix
  48     : public NON_EXPORTED_BASE(UtilityProcessHostClient),
  49       public IPC::Sender {
  50  public:
  51   PluginLoaderPosix();
  52
  53   // Must be called from the IO thread. The |callback| will be called on the IO
  54   // thread too.
  55   void GetPlugins(const PluginService::GetPluginsCallback& callback);
  56
  57   // UtilityProcessHostClient:
  58   virtual void OnProcessCrashed(int exit_code) OVERRIDE;
  59   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  60
  61   // IPC::Sender:
  62   virtual bool Send(IPC::Message* msg) OVERRIDE;
  63
  64  private:
  65   virtual ~PluginLoaderPosix();
  66
  67   // Called on the FILE thread to get the list of plugin paths to probe.
  68   void GetPluginsToLoad();
  69
  70   // Must be called on the IO thread.
  71   virtual void LoadPluginsInternal();
  72
  73   // Called after plugin loading has finished, if we don't know whether the
  74   // plugin list has been invalidated in the mean time.
  75   void GetPluginsWrapper(
  76       const PluginService::GetPluginsCallback& callback,
  77       const std::vector<WebPluginInfo>& plugins_unused);
  78
  79   // Message handlers.
  80   void OnPluginLoaded(uint32 index, const WebPluginInfo& plugin);
  81   void OnPluginLoadFailed(uint32 index, const base::FilePath& plugin_path);
  82
  83   // Checks if the plugin path is an internal plugin, and, if it is, adds it to
  84   // |loaded_plugins_|.
  85   bool MaybeAddInternalPlugin(const base::FilePath& plugin_path);
  86
  87   // Runs all the registered callbacks on each's target loop if the condition
  88   // for ending the load process is done (i.e. the |next_load_index_| is outside
  89   // the range of the |canonical_list_|).
  90   bool MaybeRunPendingCallbacks();
  91
  92   // The process host for which this is a client.
  93   base::WeakPtr<UtilityProcessHost> process_host_;
  94
  95   // A list of paths to plugins which will be loaded by the utility process, in
  96   // the order specified by this vector.
  97   std::vector<base::FilePath> canonical_list_;
  98
  99   // The index in |canonical_list_| of the plugin that the child process will
 100   // attempt to load next.
 101   size_t next_load_index_;
 102
 103   // Internal plugins that have been registered at the time of loading.
 104   std::vector<WebPluginInfo> internal_plugins_;
 105
 106   // A vector of plugins that have been loaded successfully.
 107   std::vector<WebPluginInfo> loaded_plugins_;
 108
 109   // The callback and message loop on which the callback will be run when the
 110   // plugin loading process has been completed.
 111   std::vector<PluginService::GetPluginsCallback> callbacks_;
 112
 113   // The time at which plugin loading started.
 114   base::TimeTicks load_start_time_;
 115
 116   friend class MockPluginLoaderPosix;
 117   DISALLOW_COPY_AND_ASSIGN(PluginLoaderPosix);
 118 };
 119
 120 }  // namespace content
 121
 122 #endif  // CONTENT_BROWSER_PLUGIN_LOADER_POSIX_H_