extensions/browser/process_manager.cc

   1 // Copyright 2013 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 #include "extensions/browser/process_manager.h"
   6
   7 #include <vector>
   8
   9 #include "base/bind.h"
  10 #include "base/logging.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/metrics/histogram_macros.h"
  13 #include "base/stl_util.h"
  14 #include "base/time/time.h"
  15 #include "content/public/browser/browser_context.h"
  16 #include "content/public/browser/devtools_agent_host.h"
  17 #include "content/public/browser/notification_service.h"
  18 #include "content/public/browser/render_frame_host.h"
  19 #include "content/public/browser/render_process_host.h"
  20 #include "content/public/browser/render_view_host.h"
  21 #include "content/public/browser/site_instance.h"
  22 #include "content/public/browser/web_contents.h"
  23 #include "content/public/common/url_constants.h"
  24 #include "extensions/browser/extension_host.h"
  25 #include "extensions/browser/extension_registry.h"
  26 #include "extensions/browser/extension_system.h"
  27 #include "extensions/browser/extensions_browser_client.h"
  28 #include "extensions/browser/lazy_background_task_queue.h"
  29 #include "extensions/browser/notification_types.h"
  30 #include "extensions/browser/process_manager_delegate.h"
  31 #include "extensions/browser/process_manager_factory.h"
  32 #include "extensions/browser/process_manager_observer.h"
  33 #include "extensions/browser/view_type_utils.h"
  34 #include "extensions/common/constants.h"
  35 #include "extensions/common/extension.h"
  36 #include "extensions/common/extension_messages.h"
  37 #include "extensions/common/manifest_handlers/background_info.h"
  38 #include "extensions/common/manifest_handlers/incognito_info.h"
  39 #include "extensions/common/one_shot_event.h"
  40
  41 using content::BrowserContext;
  42
  43 namespace extensions {
  44
  45 namespace {
  46
  47 // The time to delay between an extension becoming idle and
  48 // sending a ShouldSuspend message.
  49 // Note: Must be sufficiently larger (e.g. 2x) than
  50 // kKeepaliveThrottleIntervalInSeconds in ppapi/proxy/plugin_globals.
  51 unsigned g_event_page_idle_time_msec = 10000;
  52
  53 // The time to delay between sending a ShouldSuspend message and
  54 // sending a Suspend message.
  55 unsigned g_event_page_suspending_time_msec = 5000;
  56
  57 std::string GetExtensionIdForSiteInstance(
  58     content::SiteInstance* site_instance) {
  59   if (!site_instance)
  60     return std::string();
  61
  62   // This works for both apps and extensions because the site has been
  63   // normalized to the extension URL for hosted apps.
  64   const GURL& site_url = site_instance->GetSiteURL();
  65
  66   if (!site_url.SchemeIs(kExtensionScheme) &&
  67       !site_url.SchemeIs(content::kGuestScheme))
  68     return std::string();
  69
  70   return site_url.host();
  71 }
  72
  73 std::string GetExtensionID(content::RenderFrameHost* render_frame_host) {
  74   CHECK(render_frame_host);
  75   return GetExtensionIdForSiteInstance(render_frame_host->GetSiteInstance());
  76 }
  77
  78 bool IsFrameInExtensionHost(ExtensionHost* extension_host,
  79                             content::RenderFrameHost* render_frame_host) {
  80   return content::WebContents::FromRenderFrameHost(render_frame_host) ==
  81       extension_host->host_contents();
  82 }
  83
  84 // Incognito profiles use this process manager. It is mostly a shim that decides
  85 // whether to fall back on the original profile's ProcessManager based
  86 // on whether a given extension uses "split" or "spanning" incognito behavior.
  87 // TODO(devlin): Given how little this does and the amount of cruft it adds to
  88 // the .h file (in the form of protected members), we should consider just
  89 // moving the incognito logic into the base class.
  90 class IncognitoProcessManager : public ProcessManager {
  91  public:
  92   IncognitoProcessManager(BrowserContext* incognito_context,
  93                           BrowserContext* original_context,
  94                           ExtensionRegistry* extension_registry);
  95   ~IncognitoProcessManager() override {}
  96   bool CreateBackgroundHost(const Extension* extension,
  97                             const GURL& url) override;
  98   scoped_refptr<content::SiteInstance> GetSiteInstanceForURL(const GURL& url)
  99       override;
 100
 101  private:
 102   DISALLOW_COPY_AND_ASSIGN(IncognitoProcessManager);
 103 };
 104
 105 static void CreateBackgroundHostForExtensionLoad(
 106     ProcessManager* manager, const Extension* extension) {
 107   DVLOG(1) << "CreateBackgroundHostForExtensionLoad";
 108   if (BackgroundInfo::HasPersistentBackgroundPage(extension))
 109     manager->CreateBackgroundHost(extension,
 110                                   BackgroundInfo::GetBackgroundURL(extension));
 111 }
 112
 113 void PropagateExtensionWakeResult(const base::Callback<void(bool)>& callback,
 114                                   extensions::ExtensionHost* host) {
 115   callback.Run(host != nullptr);
 116 }
 117
 118 }  // namespace
 119
 120 struct ProcessManager::BackgroundPageData {
 121   // The count of things keeping the lazy background page alive.
 122   int lazy_keepalive_count;
 123
 124   // Tracks if an impulse event has occured since the last polling check.
 125   bool keepalive_impulse;
 126   bool previous_keepalive_impulse;
 127
 128   // True if the page responded to the ShouldSuspend message and is currently
 129   // dispatching the suspend event. During this time any events that arrive will
 130   // cancel the suspend process and an onSuspendCanceled event will be
 131   // dispatched to the page.
 132   bool is_closing;
 133
 134   // Stores the value of the incremented
 135   // ProcessManager::last_background_close_sequence_id_ whenever the extension
 136   // is active. A copy of the ID is also passed in the callbacks and IPC
 137   // messages leading up to CloseLazyBackgroundPageNow. The process is aborted
 138   // if the IDs ever differ due to new activity.
 139   uint64 close_sequence_id;
 140
 141   // Keeps track of when this page was last suspended. Used for perf metrics.
 142   linked_ptr<base::ElapsedTimer> since_suspended;
 143
 144   BackgroundPageData()
 145       : lazy_keepalive_count(0),
 146         keepalive_impulse(false),
 147         previous_keepalive_impulse(false),
 148         is_closing(false),
 149         close_sequence_id(0) {}
 150 };
 151
 152 // Data of a RenderFrameHost associated with an extension.
 153 struct ProcessManager::ExtensionRenderFrameData {
 154   // The type of the view.
 155   extensions::ViewType view_type;
 156
 157   // Whether the view is keeping the lazy background page alive or not.
 158   bool has_keepalive;
 159
 160   ExtensionRenderFrameData()
 161       : view_type(VIEW_TYPE_INVALID), has_keepalive(false) {}
 162
 163   // Returns whether the view can keep the lazy background page alive or not.
 164   bool CanKeepalive() const {
 165     switch (view_type) {
 166       case VIEW_TYPE_APP_WINDOW:
 167       case VIEW_TYPE_BACKGROUND_CONTENTS:
 168       case VIEW_TYPE_EXTENSION_DIALOG:
 169       case VIEW_TYPE_EXTENSION_POPUP:
 170       case VIEW_TYPE_LAUNCHER_PAGE:
 171       case VIEW_TYPE_PANEL:
 172       case VIEW_TYPE_TAB_CONTENTS:
 173       case VIEW_TYPE_VIRTUAL_KEYBOARD:
 174         return true;
 175
 176       case VIEW_TYPE_INVALID:
 177       case VIEW_TYPE_EXTENSION_BACKGROUND_PAGE:
 178         return false;
 179     }
 180     NOTREACHED();
 181     return false;
 182   }
 183 };
 184
 185 //
 186 // ProcessManager
 187 //
 188
 189 // static
 190 ProcessManager* ProcessManager::Get(BrowserContext* context) {
 191   return ProcessManagerFactory::GetForBrowserContext(context);
 192 }
 193
 194 // static
 195 ProcessManager* ProcessManager::Create(BrowserContext* context) {
 196   ExtensionRegistry* extension_registry = ExtensionRegistry::Get(context);
 197   ExtensionsBrowserClient* client = ExtensionsBrowserClient::Get();
 198   if (client->IsGuestSession(context)) {
 199     // In the guest session, there is a single off-the-record context.  Unlike
 200     // a regular incognito mode, background pages of extensions must be
 201     // created regardless of whether extensions use "spanning" or "split"
 202     // incognito behavior.
 203     BrowserContext* original_context = client->GetOriginalContext(context);
 204     return new ProcessManager(context, original_context, extension_registry);
 205   }
 206
 207   if (context->IsOffTheRecord()) {
 208     BrowserContext* original_context = client->GetOriginalContext(context);
 209     return new IncognitoProcessManager(
 210         context, original_context, extension_registry);
 211   }
 212
 213   return new ProcessManager(context, context, extension_registry);
 214 }
 215
 216 // static
 217 ProcessManager* ProcessManager::CreateForTesting(
 218     BrowserContext* context,
 219     ExtensionRegistry* extension_registry) {
 220   DCHECK(!context->IsOffTheRecord());
 221   return new ProcessManager(context, context, extension_registry);
 222 }
 223
 224 // static
 225 ProcessManager* ProcessManager::CreateIncognitoForTesting(
 226     BrowserContext* incognito_context,
 227     BrowserContext* original_context,
 228     ExtensionRegistry* extension_registry) {
 229   DCHECK(incognito_context->IsOffTheRecord());
 230   DCHECK(!original_context->IsOffTheRecord());
 231   return new IncognitoProcessManager(incognito_context,
 232                                      original_context,
 233                                      extension_registry);
 234 }
 235
 236 ProcessManager::ProcessManager(BrowserContext* context,
 237                                BrowserContext* original_context,
 238                                ExtensionRegistry* extension_registry)
 239     : extension_registry_(extension_registry),
 240       site_instance_(content::SiteInstance::Create(context)),
 241       browser_context_(context),
 242       startup_background_hosts_created_(false),
 243       last_background_close_sequence_id_(0),
 244       weak_ptr_factory_(this) {
 245   // ExtensionRegistry is shared between incognito and regular contexts.
 246   DCHECK_EQ(original_context, extension_registry_->browser_context());
 247   extension_registry_->AddObserver(this);
 248
 249   if (!context->IsOffTheRecord()) {
 250     // Only the original profile needs to listen for ready to create background
 251     // pages for all spanning extensions.
 252     registrar_.Add(this,
 253                  extensions::NOTIFICATION_EXTENSIONS_READY_DEPRECATED,
 254                  content::Source<BrowserContext>(original_context));
 255   }
 256   registrar_.Add(this,
 257                  extensions::NOTIFICATION_EXTENSION_HOST_DESTROYED,
 258                  content::Source<BrowserContext>(context));
 259   registrar_.Add(this,
 260                  extensions::NOTIFICATION_EXTENSION_HOST_VIEW_SHOULD_CLOSE,
 261                  content::Source<BrowserContext>(context));
 262   devtools_callback_ = base::Bind(&ProcessManager::OnDevToolsStateChanged,
 263                                   weak_ptr_factory_.GetWeakPtr());
 264   content::DevToolsAgentHost::AddAgentStateCallback(devtools_callback_);
 265
 266   OnKeepaliveImpulseCheck();
 267 }
 268
 269 ProcessManager::~ProcessManager() {
 270   extension_registry_->RemoveObserver(this);
 271   CloseBackgroundHosts();
 272   DCHECK(background_hosts_.empty());
 273   content::DevToolsAgentHost::RemoveAgentStateCallback(devtools_callback_);
 274 }
 275
 276 void ProcessManager::RegisterRenderFrameHost(
 277     content::WebContents* web_contents,
 278     content::RenderFrameHost* render_frame_host,
 279     const Extension* extension) {
 280   ExtensionRenderFrameData* data = &all_extension_frames_[render_frame_host];
 281   data->view_type = GetViewType(web_contents);
 282
 283   // Keep the lazy background page alive as long as any non-background-page
 284   // extension views are visible. Keepalive count balanced in
 285   // UnregisterRenderFrame.
 286   AcquireLazyKeepaliveCountForFrame(render_frame_host);
 287
 288   FOR_EACH_OBSERVER(ProcessManagerObserver,
 289                     observer_list_,
 290                     OnExtensionFrameRegistered(extension->id(),
 291                                                render_frame_host));
 292 }
 293
 294 void ProcessManager::UnregisterRenderFrameHost(
 295     content::RenderFrameHost* render_frame_host) {
 296   ExtensionRenderFrames::iterator frame =
 297       all_extension_frames_.find(render_frame_host);
 298
 299   if (frame != all_extension_frames_.end()) {
 300     std::string extension_id = GetExtensionID(render_frame_host);
 301     // Keepalive count, balanced in RegisterRenderFrame.
 302     ReleaseLazyKeepaliveCountForFrame(render_frame_host);
 303     all_extension_frames_.erase(frame);
 304
 305     FOR_EACH_OBSERVER(ProcessManagerObserver,
 306                       observer_list_,
 307                       OnExtensionFrameUnregistered(extension_id,
 308                                                    render_frame_host));
 309   }
 310 }
 311
 312 scoped_refptr<content::SiteInstance> ProcessManager::GetSiteInstanceForURL(
 313     const GURL& url) {
 314   return make_scoped_refptr(site_instance_->GetRelatedSiteInstance(url));
 315 }
 316
 317 const ProcessManager::FrameSet ProcessManager::GetAllFrames() const {
 318   FrameSet result;
 319   for (const auto& key_value : all_extension_frames_)
 320     result.insert(key_value.first);
 321   return result;
 322 }
 323
 324 ProcessManager::FrameSet ProcessManager::GetRenderFrameHostsForExtension(
 325     const std::string& extension_id) {
 326   FrameSet result;
 327   scoped_refptr<content::SiteInstance> site_instance(GetSiteInstanceForURL(
 328       Extension::GetBaseURLFromExtensionId(extension_id)));
 329   if (!site_instance.get())
 330     return result;
 331
 332   // Gather up all the frames for that site.
 333   for (const auto& key_value : all_extension_frames_) {
 334     if (key_value.first->GetSiteInstance() == site_instance)
 335       result.insert(key_value.first);
 336   }
 337
 338   return result;
 339 }
 340
 341 void ProcessManager::AddObserver(ProcessManagerObserver* observer) {
 342   observer_list_.AddObserver(observer);
 343 }
 344
 345 void ProcessManager::RemoveObserver(ProcessManagerObserver* observer) {
 346   observer_list_.RemoveObserver(observer);
 347 }
 348
 349 bool ProcessManager::CreateBackgroundHost(const Extension* extension,
 350                                           const GURL& url) {
 351   // Hosted apps are taken care of from BackgroundContentsService. Ignore them
 352   // here.
 353   if (extension->is_hosted_app())
 354     return false;
 355
 356   // Don't create hosts if the embedder doesn't allow it.
 357   ProcessManagerDelegate* delegate =
 358       ExtensionsBrowserClient::Get()->GetProcessManagerDelegate();
 359   if (delegate && !delegate->IsBackgroundPageAllowed(browser_context_))
 360     return false;
 361
 362   // Don't create multiple background hosts for an extension.
 363   if (GetBackgroundHostForExtension(extension->id()))
 364     return true;  // TODO(kalman): return false here? It might break things...
 365
 366   ExtensionHost* host =
 367       new ExtensionHost(extension, GetSiteInstanceForURL(url).get(), url,
 368                         VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
 369   host->CreateRenderViewSoon();
 370   OnBackgroundHostCreated(host);
 371   return true;
 372 }
 373
 374 void ProcessManager::MaybeCreateStartupBackgroundHosts() {
 375   if (startup_background_hosts_created_)
 376     return;
 377
 378   // The embedder might disallow background pages entirely.
 379   ProcessManagerDelegate* delegate =
 380       ExtensionsBrowserClient::Get()->GetProcessManagerDelegate();
 381   if (delegate && !delegate->IsBackgroundPageAllowed(browser_context_))
 382     return;
 383
 384   // The embedder might want to defer background page loading. For example,
 385   // Chrome defers background page loading when it is launched to show the app
 386   // list, then triggers a load later when a browser window opens.
 387   if (delegate &&
 388       delegate->DeferCreatingStartupBackgroundHosts(browser_context_))
 389     return;
 390
 391   CreateStartupBackgroundHosts();
 392   startup_background_hosts_created_ = true;
 393
 394   // Background pages should only be loaded once. To prevent any further loads
 395   // occurring, we remove the notification listeners.
 396   BrowserContext* original_context =
 397       ExtensionsBrowserClient::Get()->GetOriginalContext(browser_context_);
 398   if (registrar_.IsRegistered(
 399           this,
 400           extensions::NOTIFICATION_EXTENSIONS_READY_DEPRECATED,
 401           content::Source<BrowserContext>(original_context))) {
 402     registrar_.Remove(this,
 403                       extensions::NOTIFICATION_EXTENSIONS_READY_DEPRECATED,
 404                       content::Source<BrowserContext>(original_context));
 405   }
 406 }
 407
 408 ExtensionHost* ProcessManager::GetBackgroundHostForExtension(
 409     const std::string& extension_id) {
 410   for (ExtensionHost* host : background_hosts_) {
 411     if (host->extension_id() == extension_id)
 412       return host;
 413   }
 414   return nullptr;
 415 }
 416
 417 bool ProcessManager::IsEventPageSuspended(const std::string& extension_id) {
 418   return GetBackgroundHostForExtension(extension_id) == nullptr;
 419 }
 420
 421 bool ProcessManager::WakeEventPage(const std::string& extension_id,
 422                                    const base::Callback<void(bool)>& callback) {
 423   if (GetBackgroundHostForExtension(extension_id)) {
 424     // Run the callback immediately if the extension is already awake.
 425     return false;
 426   }
 427   LazyBackgroundTaskQueue* queue =
 428       ExtensionSystem::Get(browser_context_)->lazy_background_task_queue();
 429   queue->AddPendingTask(browser_context_, extension_id,
 430                         base::Bind(&PropagateExtensionWakeResult, callback));
 431   return true;
 432 }
 433
 434 bool ProcessManager::IsBackgroundHostClosing(const std::string& extension_id) {
 435   ExtensionHost* host = GetBackgroundHostForExtension(extension_id);
 436   return (host && background_page_data_[extension_id].is_closing);
 437 }
 438
 439 const Extension* ProcessManager::GetExtensionForRenderFrameHost(
 440     content::RenderFrameHost* render_frame_host) {
 441   return extension_registry_->enabled_extensions().GetByID(
 442       GetExtensionID(render_frame_host));
 443 }
 444
 445 const Extension* ProcessManager::GetExtensionForWebContents(
 446     content::WebContents* web_contents) {
 447   if (!web_contents->GetSiteInstance())
 448     return nullptr;
 449   return extension_registry_->enabled_extensions().GetByID(
 450       GetExtensionIdForSiteInstance(web_contents->GetSiteInstance()));
 451 }
 452
 453 int ProcessManager::GetLazyKeepaliveCount(const Extension* extension) {
 454   if (!BackgroundInfo::HasLazyBackgroundPage(extension))
 455     return 0;
 456
 457   return background_page_data_[extension->id()].lazy_keepalive_count;
 458 }
 459
 460 void ProcessManager::IncrementLazyKeepaliveCount(const Extension* extension) {
 461   if (BackgroundInfo::HasLazyBackgroundPage(extension)) {
 462     int& count = background_page_data_[extension->id()].lazy_keepalive_count;
 463     if (++count == 1)
 464       OnLazyBackgroundPageActive(extension->id());
 465   }
 466 }
 467
 468 void ProcessManager::DecrementLazyKeepaliveCount(const Extension* extension) {
 469   if (BackgroundInfo::HasLazyBackgroundPage(extension))
 470     DecrementLazyKeepaliveCount(extension->id());
 471 }
 472
 473 // This implementation layers on top of the keepalive count. An impulse sets
 474 // a per extension flag. On a regular interval that flag is checked. Changes
 475 // from the flag not being set to set cause an IncrementLazyKeepaliveCount.
 476 void ProcessManager::KeepaliveImpulse(const Extension* extension) {
 477   if (!BackgroundInfo::HasLazyBackgroundPage(extension))
 478     return;
 479
 480   BackgroundPageData& bd = background_page_data_[extension->id()];
 481
 482   if (!bd.keepalive_impulse) {
 483     bd.keepalive_impulse = true;
 484     if (!bd.previous_keepalive_impulse) {
 485       IncrementLazyKeepaliveCount(extension);
 486     }
 487   }
 488
 489   if (!keepalive_impulse_callback_for_testing_.is_null()) {
 490     ImpulseCallbackForTesting callback_may_clear_callbacks_reentrantly =
 491       keepalive_impulse_callback_for_testing_;
 492     callback_may_clear_callbacks_reentrantly.Run(extension->id());
 493   }
 494 }
 495
 496 // static
 497 void ProcessManager::OnKeepaliveFromPlugin(int render_process_id,
 498                                            int render_frame_id,
 499                                            const std::string& extension_id) {
 500   content::RenderFrameHost* render_frame_host =
 501       content::RenderFrameHost::FromID(render_process_id, render_frame_id);
 502   if (!render_frame_host)
 503     return;
 504
 505   content::SiteInstance* site_instance = render_frame_host->GetSiteInstance();
 506   if (!site_instance)
 507     return;
 508
 509   BrowserContext* browser_context = site_instance->GetBrowserContext();
 510   const Extension* extension =
 511       ExtensionRegistry::Get(browser_context)->enabled_extensions().GetByID(
 512           extension_id);
 513   if (!extension)
 514     return;
 515
 516   ProcessManager::Get(browser_context)->KeepaliveImpulse(extension);
 517 }
 518
 519 void ProcessManager::OnShouldSuspendAck(const std::string& extension_id,
 520                                         uint64 sequence_id) {
 521   ExtensionHost* host = GetBackgroundHostForExtension(extension_id);
 522   if (host &&
 523       sequence_id == background_page_data_[extension_id].close_sequence_id) {
 524     host->render_process_host()->Send(new ExtensionMsg_Suspend(extension_id));
 525   }
 526 }
 527
 528 void ProcessManager::OnSuspendAck(const std::string& extension_id) {
 529   background_page_data_[extension_id].is_closing = true;
 530   uint64 sequence_id = background_page_data_[extension_id].close_sequence_id;
 531   base::MessageLoop::current()->PostDelayedTask(
 532       FROM_HERE,
 533       base::Bind(&ProcessManager::CloseLazyBackgroundPageNow,
 534                  weak_ptr_factory_.GetWeakPtr(),
 535                  extension_id,
 536                  sequence_id),
 537       base::TimeDelta::FromMilliseconds(g_event_page_suspending_time_msec));
 538 }
 539
 540 void ProcessManager::OnNetworkRequestStarted(
 541     content::RenderFrameHost* render_frame_host,
 542     uint64 request_id) {
 543   ExtensionHost* host = GetBackgroundHostForExtension(
 544       GetExtensionID(render_frame_host));
 545   if (host && IsFrameInExtensionHost(host, render_frame_host)) {
 546     IncrementLazyKeepaliveCount(host->extension());
 547     host->OnNetworkRequestStarted(request_id);
 548   }
 549 }
 550
 551 void ProcessManager::OnNetworkRequestDone(
 552     content::RenderFrameHost* render_frame_host,
 553     uint64 request_id) {
 554   ExtensionHost* host = GetBackgroundHostForExtension(
 555       GetExtensionID(render_frame_host));
 556   if (host && IsFrameInExtensionHost(host, render_frame_host)) {
 557     host->OnNetworkRequestDone(request_id);
 558     DecrementLazyKeepaliveCount(host->extension());
 559   }
 560 }
 561
 562 void ProcessManager::CancelSuspend(const Extension* extension) {
 563   bool& is_closing = background_page_data_[extension->id()].is_closing;
 564   ExtensionHost* host = GetBackgroundHostForExtension(extension->id());
 565   if (host && is_closing) {
 566     is_closing = false;
 567     host->render_process_host()->Send(
 568         new ExtensionMsg_CancelSuspend(extension->id()));
 569     // This increment / decrement is to simulate an instantaneous event. This
 570     // has the effect of invalidating close_sequence_id, preventing any in
 571     // progress closes from completing and starting a new close process if
 572     // necessary.
 573     IncrementLazyKeepaliveCount(extension);
 574     DecrementLazyKeepaliveCount(extension);
 575   }
 576 }
 577
 578 void ProcessManager::CloseBackgroundHosts() {
 579   STLDeleteElements(&background_hosts_);
 580 }
 581
 582 void ProcessManager::SetKeepaliveImpulseCallbackForTesting(
 583     const ImpulseCallbackForTesting& callback) {
 584   keepalive_impulse_callback_for_testing_ = callback;
 585 }
 586
 587 void ProcessManager::SetKeepaliveImpulseDecrementCallbackForTesting(
 588     const ImpulseCallbackForTesting& callback) {
 589   keepalive_impulse_decrement_callback_for_testing_ = callback;
 590 }
 591
 592 // static
 593 void ProcessManager::SetEventPageIdleTimeForTesting(unsigned idle_time_msec) {
 594   CHECK_GT(idle_time_msec, 0u);  // OnKeepaliveImpulseCheck requires non zero.
 595   g_event_page_idle_time_msec = idle_time_msec;
 596 }
 597
 598 // static
 599 void ProcessManager::SetEventPageSuspendingTimeForTesting(
 600     unsigned suspending_time_msec) {
 601   g_event_page_suspending_time_msec = suspending_time_msec;
 602 }
 603
 604 ////////////////////////////////////////////////////////////////////////////////
 605 // Private
 606
 607 void ProcessManager::Observe(int type,
 608                              const content::NotificationSource& source,
 609                              const content::NotificationDetails& details) {
 610   TRACE_EVENT0("browser,startup", "ProcessManager::Observe");
 611   switch (type) {
 612     case extensions::NOTIFICATION_EXTENSIONS_READY_DEPRECATED: {
 613       // TODO(jamescook): Convert this to use ExtensionSystem::ready() instead
 614       // of a notification.
 615       SCOPED_UMA_HISTOGRAM_TIMER("Extensions.ProcessManagerStartupHostsTime");
 616       MaybeCreateStartupBackgroundHosts();
 617       break;
 618     }
 619     case extensions::NOTIFICATION_EXTENSION_HOST_DESTROYED: {
 620       ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
 621       if (background_hosts_.erase(host)) {
 622         ClearBackgroundPageData(host->extension()->id());
 623         background_page_data_[host->extension()->id()].since_suspended.reset(
 624             new base::ElapsedTimer());
 625       }
 626       break;
 627     }
 628     case extensions::NOTIFICATION_EXTENSION_HOST_VIEW_SHOULD_CLOSE: {
 629       ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
 630       if (host->extension_host_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
 631         CloseBackgroundHost(host);
 632       }
 633       break;
 634     }
 635     default:
 636       NOTREACHED();
 637   }
 638 }
 639
 640 void ProcessManager::OnExtensionLoaded(BrowserContext* browser_context,
 641                                        const Extension* extension) {
 642   if (ExtensionSystem::Get(browser_context)->ready().is_signaled()) {
 643     // The extension system is ready, so create the background host.
 644     CreateBackgroundHostForExtensionLoad(this, extension);
 645   }
 646 }
 647
 648 void ProcessManager::OnExtensionUnloaded(
 649     BrowserContext* browser_context,
 650     const Extension* extension,
 651     UnloadedExtensionInfo::Reason reason) {
 652   ExtensionHost* host = GetBackgroundHostForExtension(extension->id());
 653   if (host != nullptr)
 654     CloseBackgroundHost(host);
 655   UnregisterExtension(extension->id());
 656 }
 657
 658 void ProcessManager::CreateStartupBackgroundHosts() {
 659   DCHECK(!startup_background_hosts_created_);
 660   for (const scoped_refptr<const Extension>& extension :
 661            extension_registry_->enabled_extensions()) {
 662     CreateBackgroundHostForExtensionLoad(this, extension.get());
 663     FOR_EACH_OBSERVER(ProcessManagerObserver,
 664                       observer_list_,
 665                       OnBackgroundHostStartup(extension.get()));
 666   }
 667 }
 668
 669 void ProcessManager::OnBackgroundHostCreated(ExtensionHost* host) {
 670   DCHECK_EQ(browser_context_, host->browser_context());
 671   background_hosts_.insert(host);
 672
 673   if (BackgroundInfo::HasLazyBackgroundPage(host->extension())) {
 674     linked_ptr<base::ElapsedTimer> since_suspended(
 675         background_page_data_[host->extension()->id()].
 676             since_suspended.release());
 677     if (since_suspended.get()) {
 678       UMA_HISTOGRAM_LONG_TIMES("Extensions.EventPageIdleTime",
 679                                since_suspended->Elapsed());
 680     }
 681   }
 682   FOR_EACH_OBSERVER(ProcessManagerObserver, observer_list_,
 683                     OnBackgroundHostCreated(host));
 684 }
 685
 686 void ProcessManager::CloseBackgroundHost(ExtensionHost* host) {
 687   ExtensionId extension_id = host->extension_id();
 688   CHECK(host->extension_host_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
 689   delete host;
 690   // |host| should deregister itself from our structures.
 691   CHECK(background_hosts_.find(host) == background_hosts_.end());
 692
 693   FOR_EACH_OBSERVER(ProcessManagerObserver,
 694                     observer_list_,
 695                     OnBackgroundHostClose(extension_id));
 696 }
 697
 698 void ProcessManager::AcquireLazyKeepaliveCountForFrame(
 699     content::RenderFrameHost* render_frame_host) {
 700   ExtensionRenderFrames::iterator it =
 701       all_extension_frames_.find(render_frame_host);
 702   if (it == all_extension_frames_.end())
 703     return;
 704
 705   ExtensionRenderFrameData& data = it->second;
 706   if (data.CanKeepalive() && !data.has_keepalive) {
 707     const Extension* extension =
 708         GetExtensionForRenderFrameHost(render_frame_host);
 709     if (extension) {
 710       IncrementLazyKeepaliveCount(extension);
 711       data.has_keepalive = true;
 712     }
 713   }
 714 }
 715
 716 void ProcessManager::ReleaseLazyKeepaliveCountForFrame(
 717     content::RenderFrameHost* render_frame_host) {
 718   ExtensionRenderFrames::iterator iter =
 719       all_extension_frames_.find(render_frame_host);
 720   if (iter == all_extension_frames_.end())
 721     return;
 722
 723   ExtensionRenderFrameData& data = iter->second;
 724   if (data.CanKeepalive() && data.has_keepalive) {
 725     const Extension* extension =
 726         GetExtensionForRenderFrameHost(render_frame_host);
 727     if (extension) {
 728       DecrementLazyKeepaliveCount(extension);
 729       data.has_keepalive = false;
 730     }
 731   }
 732 }
 733
 734 void ProcessManager::DecrementLazyKeepaliveCount(
 735     const std::string& extension_id) {
 736   int& count = background_page_data_[extension_id].lazy_keepalive_count;
 737   DCHECK(count > 0 ||
 738          !extension_registry_->enabled_extensions().Contains(extension_id));
 739
 740   // If we reach a zero keepalive count when the lazy background page is about
 741   // to be closed, incrementing close_sequence_id will cancel the close
 742   // sequence and cause the background page to linger. So check is_closing
 743   // before initiating another close sequence.
 744   if (--count == 0 && !background_page_data_[extension_id].is_closing) {
 745     background_page_data_[extension_id].close_sequence_id =
 746         ++last_background_close_sequence_id_;
 747     base::MessageLoop::current()->PostDelayedTask(
 748         FROM_HERE,
 749         base::Bind(&ProcessManager::OnLazyBackgroundPageIdle,
 750                    weak_ptr_factory_.GetWeakPtr(),
 751                    extension_id,
 752                    last_background_close_sequence_id_),
 753         base::TimeDelta::FromMilliseconds(g_event_page_idle_time_msec));
 754   }
 755 }
 756
 757 // DecrementLazyKeepaliveCount is called when no calls to KeepaliveImpulse
 758 // have been made for at least g_event_page_idle_time_msec. In the best case an
 759 // impulse was made just before being cleared, and the decrement will occur
 760 // g_event_page_idle_time_msec later, causing a 2 * g_event_page_idle_time_msec
 761 // total time for extension to be shut down based on impulses. Worst case is
 762 // an impulse just after a clear, adding one check cycle and resulting in 3x
 763 // total time.
 764 void ProcessManager::OnKeepaliveImpulseCheck() {
 765   for (BackgroundPageDataMap::iterator i = background_page_data_.begin();
 766        i != background_page_data_.end();
 767        ++i) {
 768     if (i->second.previous_keepalive_impulse && !i->second.keepalive_impulse) {
 769       DecrementLazyKeepaliveCount(i->first);
 770       if (!keepalive_impulse_decrement_callback_for_testing_.is_null()) {
 771         ImpulseCallbackForTesting callback_may_clear_callbacks_reentrantly =
 772             keepalive_impulse_decrement_callback_for_testing_;
 773         callback_may_clear_callbacks_reentrantly.Run(i->first);
 774       }
 775     }
 776
 777     i->second.previous_keepalive_impulse = i->second.keepalive_impulse;
 778     i->second.keepalive_impulse = false;
 779   }
 780
 781   // OnKeepaliveImpulseCheck() is always called in constructor, but in unit
 782   // tests there will be no message loop. In that event don't schedule tasks.
 783   if (base::MessageLoop::current()) {
 784     base::MessageLoop::current()->PostDelayedTask(
 785         FROM_HERE,
 786         base::Bind(&ProcessManager::OnKeepaliveImpulseCheck,
 787                    weak_ptr_factory_.GetWeakPtr()),
 788         base::TimeDelta::FromMilliseconds(g_event_page_idle_time_msec));
 789   }
 790 }
 791
 792 void ProcessManager::OnLazyBackgroundPageIdle(const std::string& extension_id,
 793                                               uint64 sequence_id) {
 794   ExtensionHost* host = GetBackgroundHostForExtension(extension_id);
 795   if (host && !background_page_data_[extension_id].is_closing &&
 796       sequence_id == background_page_data_[extension_id].close_sequence_id) {
 797     // Tell the renderer we are about to close. This is a simple ping that the
 798     // renderer will respond to. The purpose is to control sequencing: if the
 799     // extension remains idle until the renderer responds with an ACK, then we
 800     // know that the extension process is ready to shut down. If our
 801     // close_sequence_id has already changed, then we would ignore the
 802     // ShouldSuspendAck, so we don't send the ping.
 803     host->render_process_host()->Send(new ExtensionMsg_ShouldSuspend(
 804         extension_id, sequence_id));
 805   }
 806 }
 807
 808 void ProcessManager::OnLazyBackgroundPageActive(
 809     const std::string& extension_id) {
 810   if (!background_page_data_[extension_id].is_closing) {
 811     // Cancel the current close sequence by changing the close_sequence_id,
 812     // which causes us to ignore the next ShouldSuspendAck.
 813     background_page_data_[extension_id].close_sequence_id =
 814         ++last_background_close_sequence_id_;
 815   }
 816 }
 817
 818 void ProcessManager::CloseLazyBackgroundPageNow(const std::string& extension_id,
 819                                                 uint64 sequence_id) {
 820   ExtensionHost* host = GetBackgroundHostForExtension(extension_id);
 821   if (host &&
 822       sequence_id == background_page_data_[extension_id].close_sequence_id) {
 823     // Close remaining views.
 824     std::vector<content::RenderFrameHost*> frames_to_close;
 825     for (const auto& key_value : all_extension_frames_) {
 826       if (key_value.second.CanKeepalive() &&
 827           GetExtensionID(key_value.first) == extension_id) {
 828         DCHECK(!key_value.second.has_keepalive);
 829         frames_to_close.push_back(key_value.first);
 830       }
 831     }
 832     for (content::RenderFrameHost* frame : frames_to_close) {
 833       frame->GetRenderViewHost()->ClosePage();
 834       // RenderViewHost::ClosePage() may result in calling
 835       // UnregisterRenderViewHost() asynchronously and may cause race conditions
 836       // when the background page is reloaded.
 837       // To avoid this, unregister the view now.
 838       UnregisterRenderFrameHost(frame);
 839     }
 840
 841     ExtensionHost* host = GetBackgroundHostForExtension(extension_id);
 842     if (host)
 843       CloseBackgroundHost(host);
 844   }
 845 }
 846
 847 void ProcessManager::OnDevToolsStateChanged(
 848     content::DevToolsAgentHost* agent_host,
 849     bool attached) {
 850   content::WebContents* web_contents = agent_host->GetWebContents();
 851   // Ignore unrelated notifications.
 852   if (!web_contents || web_contents->GetBrowserContext() != browser_context_)
 853     return;
 854   if (GetViewType(web_contents) != VIEW_TYPE_EXTENSION_BACKGROUND_PAGE)
 855     return;
 856   const Extension* extension =
 857       extension_registry_->enabled_extensions().GetByID(
 858           GetExtensionIdForSiteInstance(web_contents->GetSiteInstance()));
 859   if (!extension)
 860     return;
 861   if (attached) {
 862     // Keep the lazy background page alive while it's being inspected.
 863     CancelSuspend(extension);
 864     IncrementLazyKeepaliveCount(extension);
 865   } else {
 866     DecrementLazyKeepaliveCount(extension);
 867   }
 868 }
 869
 870 void ProcessManager::UnregisterExtension(const std::string& extension_id) {
 871   // The lazy_keepalive_count may be greater than zero at this point because
 872   // RenderFrameHosts are still alive. During extension reloading, they will
 873   // decrement the lazy_keepalive_count to negative for the new extension
 874   // instance when they are destroyed. Since we are erasing the background page
 875   // data for the unloaded extension, unregister the RenderFrameHosts too.
 876   for (ExtensionRenderFrames::iterator it = all_extension_frames_.begin();
 877        it != all_extension_frames_.end(); ) {
 878     content::RenderFrameHost* host = it->first;
 879     if (GetExtensionID(host) == extension_id) {
 880       all_extension_frames_.erase(it++);
 881       FOR_EACH_OBSERVER(ProcessManagerObserver,
 882                         observer_list_,
 883                         OnExtensionFrameUnregistered(extension_id, host));
 884     } else {
 885       ++it;
 886     }
 887   }
 888
 889   background_page_data_.erase(extension_id);
 890 }
 891
 892 void ProcessManager::ClearBackgroundPageData(const std::string& extension_id) {
 893   background_page_data_.erase(extension_id);
 894
 895   // Re-register all RenderViews for this extension. We do this to restore
 896   // the lazy_keepalive_count (if any) to properly reflect the number of open
 897   // views.
 898   for (const auto& key_value : all_extension_frames_) {
 899     // Do not increment the count when |has_keepalive| is false
 900     // (i.e. ReleaseLazyKeepaliveCountForView() was called).
 901     if (GetExtensionID(key_value.first) == extension_id &&
 902         key_value.second.has_keepalive) {
 903       const Extension* extension =
 904           GetExtensionForRenderFrameHost(key_value.first);
 905       if (extension)
 906         IncrementLazyKeepaliveCount(extension);
 907     }
 908   }
 909 }
 910
 911 //
 912 // IncognitoProcessManager
 913 //
 914
 915 IncognitoProcessManager::IncognitoProcessManager(
 916     BrowserContext* incognito_context,
 917     BrowserContext* original_context,
 918     ExtensionRegistry* extension_registry)
 919     : ProcessManager(incognito_context, original_context, extension_registry) {
 920   DCHECK(incognito_context->IsOffTheRecord());
 921 }
 922
 923 bool IncognitoProcessManager::CreateBackgroundHost(const Extension* extension,
 924                                                    const GURL& url) {
 925   if (IncognitoInfo::IsSplitMode(extension)) {
 926     if (ExtensionsBrowserClient::Get()->IsExtensionIncognitoEnabled(
 927             extension->id(), browser_context()))
 928       return ProcessManager::CreateBackgroundHost(extension, url);
 929   } else {
 930     // Do nothing. If an extension is spanning, then its original-profile
 931     // background page is shared with incognito, so we don't create another.
 932   }
 933   return false;
 934 }
 935
 936 scoped_refptr<content::SiteInstance>
 937 IncognitoProcessManager::GetSiteInstanceForURL(const GURL& url) {
 938   const Extension* extension =
 939       extension_registry_->enabled_extensions().GetExtensionOrAppByURL(url);
 940   if (extension && !IncognitoInfo::IsSplitMode(extension)) {
 941     BrowserContext* original_context =
 942         ExtensionsBrowserClient::Get()->GetOriginalContext(browser_context());
 943     return ProcessManager::Get(original_context)->GetSiteInstanceForURL(url);
 944   }
 945
 946   return ProcessManager::GetSiteInstanceForURL(url);
 947 }
 948
 949 }  // namespace extensions