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// Copyright 2013 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 "extensions/browser/lazy_background_task_queue.h"
#include "base/callback.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/extensions/extension_host.h"
#include "chrome/common/extensions/extension_messages.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/site_instance.h"
#include "content/public/browser/web_contents.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/browser/extension_system.h"
#include "extensions/browser/extensions_browser_client.h"
#include "extensions/browser/process_manager.h"
#include "extensions/browser/process_map.h"
#include "extensions/common/extension.h"
#include "extensions/common/manifest_handlers/background_info.h"
#include "extensions/common/view_type.h"
namespace extensions {
LazyBackgroundTaskQueue::LazyBackgroundTaskQueue(
content::BrowserContext* browser_context)
: browser_context_(browser_context) {
registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_HOST_DID_STOP_LOADING,
content::NotificationService::AllBrowserContextsAndSources());
registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_HOST_DESTROYED,
content::NotificationService::AllBrowserContextsAndSources());
registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
content::Source<content::BrowserContext>(browser_context));
}
LazyBackgroundTaskQueue::~LazyBackgroundTaskQueue() {
}
bool LazyBackgroundTaskQueue::ShouldEnqueueTask(
content::BrowserContext* browser_context,
const Extension* extension) {
DCHECK(extension);
if (BackgroundInfo::HasBackgroundPage(extension)) {
ProcessManager* pm = ExtensionSystem::Get(
browser_context)->process_manager();
DCHECK(pm);
ExtensionHost* background_host =
pm->GetBackgroundHostForExtension(extension->id());
if (!background_host || !background_host->did_stop_loading())
return true;
if (pm->IsBackgroundHostClosing(extension->id()))
pm->CancelSuspend(extension);
}
return false;
}
void LazyBackgroundTaskQueue::AddPendingTask(
content::BrowserContext* browser_context,
const std::string& extension_id,
const PendingTask& task) {
if (ExtensionsBrowserClient::Get()->IsShuttingDown()) {
task.Run(NULL);
return;
}
PendingTasksList* tasks_list = NULL;
PendingTasksKey key(browser_context, extension_id);
PendingTasksMap::iterator it = pending_tasks_.find(key);
if (it == pending_tasks_.end()) {
tasks_list = new PendingTasksList();
pending_tasks_[key] = linked_ptr<PendingTasksList>(tasks_list);
const Extension* extension =
ExtensionRegistry::Get(browser_context)->enabled_extensions().GetByID(
extension_id);
if (extension && BackgroundInfo::HasLazyBackgroundPage(extension)) {
// If this is the first enqueued task, and we're not waiting for the
// background page to unload, ensure the background page is loaded.
ProcessManager* pm = ExtensionSystem::Get(
browser_context)->process_manager();
pm->IncrementLazyKeepaliveCount(extension);
// Creating the background host may fail, e.g. if |profile| is incognito
// but the extension isn't enabled in incognito mode.
if (!pm->CreateBackgroundHost(
extension, BackgroundInfo::GetBackgroundURL(extension))) {
task.Run(NULL);
return;
}
}
} else {
tasks_list = it->second.get();
}
tasks_list->push_back(task);
}
void LazyBackgroundTaskQueue::ProcessPendingTasks(
ExtensionHost* host,
content::BrowserContext* browser_context,
const Extension* extension) {
if (!ExtensionsBrowserClient::Get()->IsSameContext(browser_context,
browser_context_))
return;
PendingTasksKey key(browser_context, extension->id());
PendingTasksMap::iterator map_it = pending_tasks_.find(key);
if (map_it == pending_tasks_.end()) {
if (BackgroundInfo::HasLazyBackgroundPage(extension))
CHECK(!host); // lazy page should not load without any pending tasks
return;
}
// Swap the pending tasks to a temporary, to avoid problems if the task
// list is modified during processing.
PendingTasksList tasks;
tasks.swap(*map_it->second);
for (PendingTasksList::const_iterator it = tasks.begin();
it != tasks.end(); ++it) {
it->Run(host);
}
pending_tasks_.erase(key);
// Balance the keepalive in AddPendingTask. Note we don't do this on a
// failure to load, because the keepalive count is reset in that case.
if (host && BackgroundInfo::HasLazyBackgroundPage(extension)) {
ExtensionSystem::Get(browser_context)->process_manager()->
DecrementLazyKeepaliveCount(extension);
}
}
void LazyBackgroundTaskQueue::Observe(
int type,
const content::NotificationSource& source,
const content::NotificationDetails& details) {
switch (type) {
case chrome::NOTIFICATION_EXTENSION_HOST_DID_STOP_LOADING: {
// If an on-demand background page finished loading, dispatch queued up
// events for it.
ExtensionHost* host =
content::Details<ExtensionHost>(details).ptr();
if (host->extension_host_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
CHECK(host->did_stop_loading());
ProcessPendingTasks(host, host->browser_context(), host->extension());
}
break;
}
case chrome::NOTIFICATION_EXTENSION_HOST_DESTROYED: {
// Notify consumers about the load failure when the background host dies.
// This can happen if the extension crashes. This is not strictly
// necessary, since we also unload the extension in that case (which
// dispatches the tasks below), but is a good extra precaution.
content::BrowserContext* browser_context =
content::Source<content::BrowserContext>(source).ptr();
ExtensionHost* host =
content::Details<ExtensionHost>(details).ptr();
if (host->extension_host_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
ProcessPendingTasks(NULL, browser_context, host->extension());
}
break;
}
case chrome::NOTIFICATION_EXTENSION_UNLOADED: {
// Notify consumers that the page failed to load.
content::BrowserContext* browser_context =
content::Source<content::BrowserContext>(source).ptr();
UnloadedExtensionInfo* unloaded =
content::Details<UnloadedExtensionInfo>(details).ptr();
ProcessPendingTasks(NULL, browser_context, unloaded->extension);
// If this extension is also running in an off-the-record context,
// notify that task queue as well.
ExtensionsBrowserClient* browser_client = ExtensionsBrowserClient::Get();
if (browser_client->HasOffTheRecordContext(browser_context)) {
ProcessPendingTasks(
NULL,
browser_client->GetOffTheRecordContext(browser_context),
unloaded->extension);
}
break;
}
default:
NOTREACHED();
break;
}
}
} // namespace extensions
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