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 content {
  20 class UtilityProcessHost;
  21
  22 // This class is responsible for managing the out-of-process plugin loading on
  23 // POSIX systems. It primarily lives on the IO thread, but has a brief stay on
  24 // the FILE thread to iterate over plugin directories when it is first
  25 // constructed.
  26 //
  27 // The following is the algorithm used to load plugins:
  28 // 1. This asks the PluginList for the list of all potential plugins to attempt
  29 //    to load. This is referred to as the canonical list.
  30 // 2. The child process this hosts is forked and the canonical list is sent to
  31 //    it.
  32 // 3. The child process iterates over the canonical list, attempting to load
  33 //    each plugin in the order specified by the list. It sends an IPC message
  34 //    to the browser after each load, indicating success or failure. The two
  35 //    processes synchronize the position in the vector that will be used to
  36 //    attempt to load the next plugin.
  37 // 4. If the child dies during this process, the host forks another child and
  38 //    resumes loading at the position past the plugin that it just attempted to
  39 //    load, bypassing the problematic plugin.
  40 // 5. This algorithm continues until the canonical list has been walked to the
  41 //    end, after which the list of loaded plugins is set on the PluginList and
  42 //    the completion callback is run.
  43 class CONTENT_EXPORT PluginLoaderPosix
  44     : public NON_EXPORTED_BASE(UtilityProcessHostClient),
  45       public IPC::Sender {
  46  public:
  47   PluginLoaderPosix();
  48
  49   // Must be called from the IO thread. The |callback| will be called on the IO
  50   // thread too.
  51   void GetPlugins(const PluginService::GetPluginsCallback& callback);
  52
  53   // UtilityProcessHostClient:
  54   void OnProcessCrashed(int exit_code) override;
  55   void OnProcessLaunchFailed() override;
  56   bool OnMessageReceived(const IPC::Message& message) override;
  57
  58   // IPC::Sender:
  59   bool Send(IPC::Message* msg) override;
  60
  61  private:
  62   ~PluginLoaderPosix() override;
  63
  64   // Called on the FILE thread to get the list of plugin paths to probe.
  65   void GetPluginsToLoad();
  66
  67   // Must be called on the IO thread.
  68   virtual void LoadPluginsInternal();
  69
  70   // Called after plugin loading has finished, if we don't know whether the
  71   // plugin list has been invalidated in the mean time.
  72   void GetPluginsWrapper(
  73       const PluginService::GetPluginsCallback& callback,
  74       const std::vector<WebPluginInfo>& plugins_unused);
  75
  76   // Message handlers.
  77   void OnPluginLoaded(uint32 index, const WebPluginInfo& plugin);
  78   void OnPluginLoadFailed(uint32 index, const base::FilePath& plugin_path);
  79
  80   // Returns an iterator to the plugin in |internal_plugins_| whose path
  81   // matches |plugin_path|.
  82   std::vector<WebPluginInfo>::iterator FindInternalPlugin(
  83       const base::FilePath& plugin_path);
  84
  85   // Runs all the registered callbacks on each's target loop if the condition
  86   // for ending the load process is done (i.e. the |next_load_index_| is outside
  87   // the range of the |canonical_list_|).
  88   bool MaybeRunPendingCallbacks();
  89
  90   // Returns true if there are no plugins left to load.
  91   bool IsFinishedLoadingPlugins();
  92
  93   // This method should be called when the plugins are finished loading.
  94   // It updates the PluginList's list of plugins, and runs the queued callbacks.
  95   void FinishedLoadingPlugins();
  96
  97   // Launches the utility process that loads the plugins.
  98   // Virtual for testing.
  99   virtual bool LaunchUtilityProcess();
 100
 101   // The process host for which this is a client.
 102   base::WeakPtr<UtilityProcessHost> process_host_;
 103
 104   // A list of paths to plugins which will be loaded by the utility process, in
 105   // the order specified by this vector.
 106   std::vector<base::FilePath> canonical_list_;
 107
 108   // The index in |canonical_list_| of the plugin that the child process will
 109   // attempt to load next.
 110   size_t next_load_index_;
 111
 112   // Internal plugins that have been registered at the time of loading.
 113   std::vector<WebPluginInfo> internal_plugins_;
 114
 115   // A vector of plugins that have been loaded successfully.
 116   std::vector<WebPluginInfo> loaded_plugins_;
 117
 118   // The callback and message loop on which the callback will be run when the
 119   // plugin loading process has been completed.
 120   std::vector<PluginService::GetPluginsCallback> callbacks_;
 121
 122   // True if there is (or is about to be) a utility process that loads plugins.
 123   bool loading_plugins_;
 124
 125   friend class MockPluginLoaderPosix;
 126   DISALLOW_COPY_AND_ASSIGN(PluginLoaderPosix);
 127 };
 128
 129 }  // namespace content
 130
 131 #endif  // CONTENT_BROWSER_PLUGIN_LOADER_POSIX_H_