Prevent reentrant destructors in the PluginModule.

webkit/plugins/ppapi/plugin_module.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/plugins/ppapi/plugin_module.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 349 matching lines @@
       shutdown_module(NULL) {
 }
 
 // PluginModule ----------------------------------------------------------------
 
 PluginModule::PluginModule(const std::string& name,
                            const FilePath& path,
                            PluginDelegate::ModuleLifetime* lifetime_delegate)
     : lifetime_delegate_(lifetime_delegate),
       callback_tracker_(new CallbackTracker),
+      is_in_destructor_(false),
       is_crashed_(false),
       broker_(NULL),
       library_(NULL),
       name_(name),
       path_(path),
       reserve_instance_id_(NULL) {
   memset(&entry_points_, 0, sizeof(entry_points_));
   pp_module_ = ResourceTracker::Get()->AddModule(this);
   GetMainThreadMessageLoop();  // Initialize the main thread message loop.
   GetLivePluginSet()->insert(this);
 }
 
 PluginModule::~PluginModule() {
+  // In the past there have been crashes reentering the plugin module
+  // destructor. Catch if that happens again earlier.
+  CHECK(!is_in_destructor_);
+  is_in_destructor_ = true;
+
   // When the module is being deleted, there should be no more instances still
   // holding a reference to us.
   DCHECK(instances_.empty());
 
   GetLivePluginSet()->erase(this);
 
   callback_tracker_->AbortAll();
 
   if (entry_points_.shutdown_module)
     entry_points_.shutdown_module();
 
   if (library_)
     base::UnloadNativeLibrary(library_);
 
+  // Notifications that we've been deleted should be last.
   ResourceTracker::Get()->ModuleDeleted(pp_module_);
+  if (!is_crashed_) {
+    // When the plugin crashes, we immediately tell the lifetime delegate that
+    // we're gone, so we don't want to tell it again.
+    lifetime_delegate_->PluginModuleDead(this);
+  }
 
-  // When the plugin crashes, we immediately tell the lifetime delegate that
-  // we're gone, so we don't want to tell it again.
-  if (!is_crashed_)
-    lifetime_delegate_->PluginModuleDead(this);
+  // Don't add stuff here, the two notifications that the module object has
+  // been deleted should be last. This allows, for example,
+  // PPB_Proxy.IsInModuleDestructor to map PP_Module to this class during the
+  // previous parts of the destructor.
 }
 
 bool PluginModule::InitAsInternalPlugin(const EntryPoints& entry_points) {
   if (InitializeModule(entry_points)) {
     entry_points_ = entry_points;
     return true;
   }
   return false;
 }
 
@@ skipping 125 matching lines @@
   int retval = entry_points.initialize_module(pp_module(), &GetInterface);
   if (retval != 0) {
     LOG(WARNING) << "PPP_InitializeModule returned failure " << retval;
     return false;
   }
   return true;
 }
 
 }  // namespace ppapi
 }  // namespace webkit