extensions/browser/lazy_background_task_queue.cc - chromium/src.git - Git at Google

 // Copyright 2013 The Chromium Authors
 // 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 "base/check.h"
 #include "base/containers/contains.h"
 #include "base/notreached.h"
 #include "content/public/browser/browser_context.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_host.h"
 #include "extensions/browser/extensions_browser_client.h"
 #include "extensions/browser/lazy_background_task_queue_factory.h"
 #include "extensions/browser/lazy_context_id.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/mojom/view_type.mojom.h"

 namespace extensions {

 namespace {

 // Attempts to create a background host for a lazy background page. Returns true
 // if the background host is created.
 bool CreateLazyBackgroundHost(ProcessManager* pm, const Extension* extension) {
   pm->IncrementLazyKeepaliveCount(extension, Activity::LIFECYCLE_MANAGEMENT,
                                   Activity::kCreatePage);
   // Creating the background host may fail, e.g. if the extension isn't enabled
   // in incognito mode.
   return pm->CreateBackgroundHost(extension,
                                   BackgroundInfo::GetBackgroundURL(extension));
 }

 }  // namespace

 LazyBackgroundTaskQueue::LazyBackgroundTaskQueue(
     content::BrowserContext* browser_context)
     : browser_context_(browser_context) {
   extension_registry_observation_.Observe(
       ExtensionRegistry::Get(browser_context));
   extension_host_registry_observation_.Observe(
       ExtensionHostRegistry::Get(browser_context));
 }

 LazyBackgroundTaskQueue::~LazyBackgroundTaskQueue() {
 }

 // static
 LazyBackgroundTaskQueue* LazyBackgroundTaskQueue::Get(
     content::BrowserContext* browser_context) {
   return LazyBackgroundTaskQueueFactory::GetForBrowserContext(browser_context);
 }

 bool LazyBackgroundTaskQueue::ShouldEnqueueTask(
     content::BrowserContext* browser_context,
     const Extension* extension) {
   // Note: browser_context may not be the same as browser_context_ for incognito
   // extension tasks.
   DCHECK(extension);
   if (BackgroundInfo::HasBackgroundPage(extension)) {
     ProcessManager* pm = ProcessManager::Get(browser_context);
     ExtensionHost* background_host =
         pm->GetBackgroundHostForExtension(extension->id());
     if (!background_host || !background_host->has_loaded_once())
       return true;
     if (pm->IsBackgroundHostClosing(extension->id()))
       pm->CancelSuspend(extension);
   }

   return false;
 }

 void LazyBackgroundTaskQueue::AddPendingTask(const LazyContextId& context_id,
                                              PendingTask task) {
   if (ExtensionsBrowserClient::Get()->IsShuttingDown()) {
     std::move(task).Run(nullptr);
     return;
   }
   const ExtensionId& extension_id = context_id.extension_id();
   content::BrowserContext* const browser_context = context_id.browser_context();
   PendingTasksList* tasks_list = nullptr;
   auto it = pending_tasks_.find(context_id);
   if (it == pending_tasks_.end()) {
     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.
       if (!CreateLazyBackgroundHost(ProcessManager::Get(browser_context),
                                     extension)) {
         std::move(task).Run(nullptr);
         return;
       }
     }
     auto tasks_list_tmp = std::make_unique<PendingTasksList>();
     tasks_list = tasks_list_tmp.get();
     pending_tasks_[context_id] = std::move(tasks_list_tmp);
   } else {
     tasks_list = it->second.get();
   }

   tasks_list->push_back(std::move(task));
 }

 void LazyBackgroundTaskQueue::ProcessPendingTasks(
     ExtensionHost* host,
     content::BrowserContext* browser_context,
     const Extension* extension) {
   DCHECK(extension);

   if (!ExtensionsBrowserClient::Get()->IsSameContext(browser_context,
                                                      browser_context_))
     return;

   PendingTasksKey key(browser_context, extension->id());
   auto 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 (auto& task : tasks)
     std::move(task).Run(host ? std::make_unique<ContextInfo>(host) : nullptr);

   pending_tasks_.erase(key);

   // Balance the keepalive in CreateLazyBackgroundHost. 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)) {
     ProcessManager::Get(browser_context)
         ->DecrementLazyKeepaliveCount(extension, Activity::LIFECYCLE_MANAGEMENT,
                                       Activity::kCreatePage);
   }
 }

 void LazyBackgroundTaskQueue::NotifyTasksExtensionFailedToLoad(
     content::BrowserContext* browser_context,
     const Extension* extension) {
   ProcessPendingTasks(nullptr, browser_context, 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(nullptr,
                         browser_client->GetOffTheRecordContext(browser_context),
                         extension);
   }
 }

 void LazyBackgroundTaskQueue::OnExtensionHostCompletedFirstLoad(
     content::BrowserContext* browser_context,
     ExtensionHost* host) {
   // If an on-demand background page finished loading, dispatch queued up
   // events for it.
   if (host->extension_host_type() ==
       mojom::ViewType::kExtensionBackgroundPage) {
     CHECK(host->has_loaded_once());
     ProcessPendingTasks(host, host->browser_context(), host->extension());
   }
 }

 void LazyBackgroundTaskQueue::OnExtensionHostDestroyed(
     content::BrowserContext* browser_context,
     ExtensionHost* host) {
   // 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.
   if (host->extension() && host->extension_host_type() ==
                                mojom::ViewType::kExtensionBackgroundPage) {
     ProcessPendingTasks(nullptr, browser_context, host->extension());
   }
 }

 void LazyBackgroundTaskQueue::OnExtensionLoaded(
     content::BrowserContext* browser_context,
     const Extension* extension) {
   // If there are pending tasks for a lazy background page, and its background
   // host has not been created yet, then create it. This can happen if a pending
   // task was added while the extension is not yet enabled (e.g., component
   // extension crashed and waiting to reload, https://crbug.com/835017).
   if (!BackgroundInfo::HasLazyBackgroundPage(extension))
     return;

   CreateLazyBackgroundHostOnExtensionLoaded(browser_context, extension);

   // Also try to create the background host for the off-the-record context.
   ExtensionsBrowserClient* browser_client = ExtensionsBrowserClient::Get();
   if (browser_client->HasOffTheRecordContext(browser_context)) {
     CreateLazyBackgroundHostOnExtensionLoaded(
         browser_client->GetOffTheRecordContext(browser_context), extension);
   }
 }

 void LazyBackgroundTaskQueue::OnExtensionUnloaded(
     content::BrowserContext* browser_context,
     const Extension* extension,
     UnloadedExtensionReason reason) {
   NotifyTasksExtensionFailedToLoad(browser_context, extension);
 }

 void LazyBackgroundTaskQueue::CreateLazyBackgroundHostOnExtensionLoaded(
     content::BrowserContext* browser_context,
     const Extension* extension) {
   PendingTasksKey key(browser_context, extension->id());
   if (!base::Contains(pending_tasks_, key))
     return;

   ProcessManager* pm = ProcessManager::Get(browser_context);

   // Background host already created, just wait for it to finish loading.
   if (pm->GetBackgroundHostForExtension(extension->id()))
     return;

   if (!CreateLazyBackgroundHost(pm, extension))
     ProcessPendingTasks(nullptr, browser_context, extension);
 }

 }  // namespace extensions
	// Copyright 2013 The Chromium Authors
	// 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 "base/check.h"
	#include "base/containers/contains.h"
	#include "base/notreached.h"
	#include "content/public/browser/browser_context.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_host.h"
	#include "extensions/browser/extensions_browser_client.h"
	#include "extensions/browser/lazy_background_task_queue_factory.h"
	#include "extensions/browser/lazy_context_id.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/mojom/view_type.mojom.h"

	namespace extensions {

	namespace {

	// Attempts to create a background host for a lazy background page. Returns true
	// if the background host is created.
	bool CreateLazyBackgroundHost(ProcessManager* pm, const Extension* extension) {
	pm->IncrementLazyKeepaliveCount(extension, Activity::LIFECYCLE_MANAGEMENT,
	Activity::kCreatePage);
	// Creating the background host may fail, e.g. if the extension isn't enabled
	// in incognito mode.
	return pm->CreateBackgroundHost(extension,
	BackgroundInfo::GetBackgroundURL(extension));
	}

	} // namespace

	LazyBackgroundTaskQueue::LazyBackgroundTaskQueue(
	content::BrowserContext* browser_context)
	: browser_context_(browser_context) {
	extension_registry_observation_.Observe(
	ExtensionRegistry::Get(browser_context));
	extension_host_registry_observation_.Observe(
	ExtensionHostRegistry::Get(browser_context));
	}

	LazyBackgroundTaskQueue::~LazyBackgroundTaskQueue() {
	}

	// static
	LazyBackgroundTaskQueue* LazyBackgroundTaskQueue::Get(
	content::BrowserContext* browser_context) {
	return LazyBackgroundTaskQueueFactory::GetForBrowserContext(browser_context);
	}

	bool LazyBackgroundTaskQueue::ShouldEnqueueTask(
	content::BrowserContext* browser_context,
	const Extension* extension) {
	// Note: browser_context may not be the same as browser_context_ for incognito
	// extension tasks.
	DCHECK(extension);
	if (BackgroundInfo::HasBackgroundPage(extension)) {
	ProcessManager* pm = ProcessManager::Get(browser_context);
	ExtensionHost* background_host =
	pm->GetBackgroundHostForExtension(extension->id());
	if (!background_host \|\| !background_host->has_loaded_once())
	return true;
	if (pm->IsBackgroundHostClosing(extension->id()))
	pm->CancelSuspend(extension);
	}

	return false;
	}

	void LazyBackgroundTaskQueue::AddPendingTask(const LazyContextId& context_id,
	PendingTask task) {
	if (ExtensionsBrowserClient::Get()->IsShuttingDown()) {
	std::move(task).Run(nullptr);
	return;
	}
	const ExtensionId& extension_id = context_id.extension_id();
	content::BrowserContext* const browser_context = context_id.browser_context();
	PendingTasksList* tasks_list = nullptr;
	auto it = pending_tasks_.find(context_id);
	if (it == pending_tasks_.end()) {
	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.
	if (!CreateLazyBackgroundHost(ProcessManager::Get(browser_context),
	extension)) {
	std::move(task).Run(nullptr);
	return;
	}
	}
	auto tasks_list_tmp = std::make_unique<PendingTasksList>();
	tasks_list = tasks_list_tmp.get();
	pending_tasks_[context_id] = std::move(tasks_list_tmp);
	} else {
	tasks_list = it->second.get();
	}

	tasks_list->push_back(std::move(task));
	}

	void LazyBackgroundTaskQueue::ProcessPendingTasks(
	ExtensionHost* host,
	content::BrowserContext* browser_context,
	const Extension* extension) {
	DCHECK(extension);

	if (!ExtensionsBrowserClient::Get()->IsSameContext(browser_context,
	browser_context_))
	return;

	PendingTasksKey key(browser_context, extension->id());
	auto 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 (auto& task : tasks)
	std::move(task).Run(host ? std::make_unique<ContextInfo>(host) : nullptr);

	pending_tasks_.erase(key);

	// Balance the keepalive in CreateLazyBackgroundHost. 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)) {
	ProcessManager::Get(browser_context)
	->DecrementLazyKeepaliveCount(extension, Activity::LIFECYCLE_MANAGEMENT,
	Activity::kCreatePage);
	}
	}

	void LazyBackgroundTaskQueue::NotifyTasksExtensionFailedToLoad(
	content::BrowserContext* browser_context,
	const Extension* extension) {
	ProcessPendingTasks(nullptr, browser_context, 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(nullptr,
	browser_client->GetOffTheRecordContext(browser_context),
	extension);
	}
	}

	void LazyBackgroundTaskQueue::OnExtensionHostCompletedFirstLoad(
	content::BrowserContext* browser_context,
	ExtensionHost* host) {
	// If an on-demand background page finished loading, dispatch queued up
	// events for it.
	if (host->extension_host_type() ==
	mojom::ViewType::kExtensionBackgroundPage) {
	CHECK(host->has_loaded_once());
	ProcessPendingTasks(host, host->browser_context(), host->extension());
	}
	}

	void LazyBackgroundTaskQueue::OnExtensionHostDestroyed(
	content::BrowserContext* browser_context,
	ExtensionHost* host) {
	// 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.
	if (host->extension() && host->extension_host_type() ==
	mojom::ViewType::kExtensionBackgroundPage) {
	ProcessPendingTasks(nullptr, browser_context, host->extension());
	}
	}

	void LazyBackgroundTaskQueue::OnExtensionLoaded(
	content::BrowserContext* browser_context,
	const Extension* extension) {
	// If there are pending tasks for a lazy background page, and its background
	// host has not been created yet, then create it. This can happen if a pending
	// task was added while the extension is not yet enabled (e.g., component
	// extension crashed and waiting to reload, https://crbug.com/835017).
	if (!BackgroundInfo::HasLazyBackgroundPage(extension))
	return;

	CreateLazyBackgroundHostOnExtensionLoaded(browser_context, extension);

	// Also try to create the background host for the off-the-record context.
	ExtensionsBrowserClient* browser_client = ExtensionsBrowserClient::Get();
	if (browser_client->HasOffTheRecordContext(browser_context)) {
	CreateLazyBackgroundHostOnExtensionLoaded(
	browser_client->GetOffTheRecordContext(browser_context), extension);
	}
	}

	void LazyBackgroundTaskQueue::OnExtensionUnloaded(
	content::BrowserContext* browser_context,
	const Extension* extension,
	UnloadedExtensionReason reason) {
	NotifyTasksExtensionFailedToLoad(browser_context, extension);
	}

	void LazyBackgroundTaskQueue::CreateLazyBackgroundHostOnExtensionLoaded(
	content::BrowserContext* browser_context,
	const Extension* extension) {
	PendingTasksKey key(browser_context, extension->id());
	if (!base::Contains(pending_tasks_, key))
	return;

	ProcessManager* pm = ProcessManager::Get(browser_context);

	// Background host already created, just wait for it to finish loading.
	if (pm->GetBackgroundHostForExtension(extension->id()))
	return;

	if (!CreateLazyBackgroundHost(pm, extension))
	ProcessPendingTasks(nullptr, browser_context, extension);
	}

	} // namespace extensions