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 <deque>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/time/time.h"
  15 #include "content/browser/plugin_service_impl.h"
  16 #include "content/public/browser/utility_process_host_client.h"
  17 #include "content/public/common/webplugininfo.h"
  18 #include "ipc/ipc_sender.h"
  19
  20 namespace base {
  21 class MessageLoopProxy;
  22 }
  23
  24 namespace content {
  25 class UtilityProcessHost;
  26
  27 // This class is responsible for managing the out-of-process plugin loading on
  28 // POSIX systems. It primarily lives on the IO thread, but has a brief stay on
  29 // the FILE thread to iterate over plugin directories when it is first
  30 // constructed.
  31 //
  32 // The following is the algorithm used to load plugins:
  33 // 1. This asks the PluginList for the list of all potential plugins to attempt
  34 //    to load. This is referred to as the canonical list.
  35 // 2. The child process this hosts is forked and the canonical list is sent to
  36 //    it.
  37 // 3. The child process iterates over the canonical list, attempting to load
  38 //    each plugin in the order specified by the list. It sends an IPC message
  39 //    to the browser after each load, indicating success or failure. The two
  40 //    processes synchronize the position in the vector that will be used to
  41 //    attempt to load the next plugin.
  42 // 4. If the child dies during this process, the host forks another child and
  43 //    resumes loading at the position past the plugin that it just attempted to
  44 //    load, bypassing the problematic plugin.
  45 // 5. This algorithm continues until the canonical list has been walked to the
  46 //    end, after which the list of loaded plugins is set on the PluginList and
  47 //    the completion callback is run.
  48 class CONTENT_EXPORT PluginLoaderPosix
  49     : public NON_EXPORTED_BASE(UtilityProcessHostClient),
  50       public IPC::Sender {
  51  public:
  52   PluginLoaderPosix();
  53
  54   // Must be called from the IO thread.
  55   void LoadPlugins(
  56       scoped_refptr<base::MessageLoopProxy> target_loop,
  57       const PluginService::GetPluginsCallback& callback);
  58
  59   // UtilityProcessHostClient:
  60   virtual void OnProcessCrashed(int exit_code) OVERRIDE;
  61   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  62
  63   // IPC::Sender:
  64   virtual bool Send(IPC::Message* msg) OVERRIDE;
  65
  66  private:
  67   struct PendingCallback {
  68     PendingCallback(scoped_refptr<base::MessageLoopProxy> target_loop,
  69                     const PluginService::GetPluginsCallback& callback);
  70     ~PendingCallback();
  71
  72     scoped_refptr<base::MessageLoopProxy> target_loop;
  73     PluginService::GetPluginsCallback callback;
  74   };
  75
  76   virtual ~PluginLoaderPosix();
  77
  78   // Called on the FILE thread to get the list of plugin paths to probe.
  79   void GetPluginsToLoad();
  80
  81   // Must be called on the IO thread.
  82   virtual void LoadPluginsInternal();
  83
  84   // Message handlers.
  85   void OnPluginLoaded(uint32 index, const WebPluginInfo& plugin);
  86   void OnPluginLoadFailed(uint32 index, const base::FilePath& plugin_path);
  87
  88   // Checks if the plugin path is an internal plugin, and, if it is, adds it to
  89   // |loaded_plugins_|.
  90   bool MaybeAddInternalPlugin(const base::FilePath& plugin_path);
  91
  92   // Runs all the registered callbacks on each's target loop if the condition
  93   // for ending the load process is done (i.e. the |next_load_index_| is outside
  94   // the range of the |canonical_list_|).
  95   bool MaybeRunPendingCallbacks();
  96
  97   // The process host for which this is a client.
  98   base::WeakPtr<UtilityProcessHost> process_host_;
  99
 100   // A list of paths to plugins which will be loaded by the utility process, in
 101   // the order specified by this vector.
 102   std::vector<base::FilePath> canonical_list_;
 103
 104   // The index in |canonical_list_| of the plugin that the child process will
 105   // attempt to load next.
 106   size_t next_load_index_;
 107
 108   // Internal plugins that have been registered at the time of loading.
 109   std::vector<WebPluginInfo> internal_plugins_;
 110
 111   // A vector of plugins that have been loaded successfully.
 112   std::vector<WebPluginInfo> loaded_plugins_;
 113
 114   // The callback and message loop on which the callback will be run when the
 115   // plugin loading process has been completed.
 116   std::deque<PendingCallback> callbacks_;
 117
 118   // The time at which plugin loading started.
 119   base::TimeTicks load_start_time_;
 120
 121   friend class MockPluginLoaderPosix;
 122   DISALLOW_COPY_AND_ASSIGN(PluginLoaderPosix);
 123 };
 124
 125 }  // namespace content
 126
 127 #endif  // CONTENT_BROWSER_PLUGIN_LOADER_POSIX_H_