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   void OnProcessCrashed(int exit_code) override;
  59   void OnProcessLaunchFailed() override;
  60   bool OnMessageReceived(const IPC::Message& message) override;
  61
  62   // IPC::Sender:
  63   bool Send(IPC::Message* msg) override;
  64
  65  private:
  66   ~PluginLoaderPosix() override;
  67
  68   // Called on the FILE thread to get the list of plugin paths to probe.
  69   void GetPluginsToLoad();
  70
  71   // Must be called on the IO thread.
  72   virtual void LoadPluginsInternal();
  73
  74   // Called after plugin loading has finished, if we don't know whether the
  75   // plugin list has been invalidated in the mean time.
  76   void GetPluginsWrapper(
  77       const PluginService::GetPluginsCallback& callback,
  78       const std::vector<WebPluginInfo>& plugins_unused);
  79
  80   // Message handlers.
  81   void OnPluginLoaded(uint32 index, const WebPluginInfo& plugin);
  82   void OnPluginLoadFailed(uint32 index, const base::FilePath& plugin_path);
  83
  84   // Returns an iterator to the plugin in |internal_plugins_| whose path
  85   // matches |plugin_path|.
  86   std::vector<WebPluginInfo>::iterator FindInternalPlugin(
  87       const base::FilePath& plugin_path);
  88
  89   // Runs all the registered callbacks on each's target loop if the condition
  90   // for ending the load process is done (i.e. the |next_load_index_| is outside
  91   // the range of the |canonical_list_|).
  92   bool MaybeRunPendingCallbacks();
  93
  94   // Returns true if there are no plugins left to load.
  95   bool IsFinishedLoadingPlugins();
  96
  97   // This method should be called when the plugins are finished loading.
  98   // It updates the PluginList's list of plugins, and runs the queued callbacks.
  99   void FinishedLoadingPlugins();
 100
 101   // Launches the utility process that loads the plugins.
 102   // Virtual for testing.
 103   virtual bool LaunchUtilityProcess();
 104
 105   // The process host for which this is a client.
 106   base::WeakPtr<UtilityProcessHost> process_host_;
 107
 108   // A list of paths to plugins which will be loaded by the utility process, in
 109   // the order specified by this vector.
 110   std::vector<base::FilePath> canonical_list_;
 111
 112   // The index in |canonical_list_| of the plugin that the child process will
 113   // attempt to load next.
 114   size_t next_load_index_;
 115
 116   // Internal plugins that have been registered at the time of loading.
 117   std::vector<WebPluginInfo> internal_plugins_;
 118
 119   // A vector of plugins that have been loaded successfully.
 120   std::vector<WebPluginInfo> loaded_plugins_;
 121
 122   // The callback and message loop on which the callback will be run when the
 123   // plugin loading process has been completed.
 124   std::vector<PluginService::GetPluginsCallback> callbacks_;
 125
 126   // True if there is (or is about to be) a utility process that loads plugins.
 127   bool loading_plugins_;
 128
 129   friend class MockPluginLoaderPosix;
 130   DISALLOW_COPY_AND_ASSIGN(PluginLoaderPosix);
 131 };
 132
 133 }  // namespace content
 134
 135 #endif  // CONTENT_BROWSER_PLUGIN_LOADER_POSIX_H_