Avoid exiting the renderer process if it has a pending render view.

This addresses an issue for a future CL when we switch to swapping
RenderViewHosts in and out, rather than throwing them away each time.

BUG=65953
TEST=None

Review URL: http://codereview.chromium.org/6927014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85054 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 92 insertions, 1 deletions

diff --git a/content/browser/renderer_host/browser_render_process_host.cc b/content/browser/renderer_host/browser_render_process_host.cc
index 2bbfadd..4868e89 100644
--- a/content/browser/renderer_host/browser_render_process_host.cc
+++ b/content/browser/renderer_host/browser_render_process_host.cc
@@ -786,6 +786,8 @@ bool BrowserRenderProcessHost::OnMessageReceived(const IPC::Message& msg) {
     // Dispatch control messages.
     bool msg_is_ok = true;
     IPC_BEGIN_MESSAGE_MAP_EX(BrowserRenderProcessHost, msg, msg_is_ok)
+      IPC_MESSAGE_HANDLER(ChildProcessHostMsg_ShutdownRequest,
+                          OnShutdownRequest)
       IPC_MESSAGE_HANDLER(ViewHostMsg_UpdatedCacheStats,
                           OnUpdatedCacheStats)
       IPC_MESSAGE_HANDLER(ViewHostMsg_SuddenTerminationChanged,
@@ -825,6 +827,10 @@ void BrowserRenderProcessHost::OnChannelConnected(int32 peer_pid) {
   Send(new ChildProcessMsg_SetIPCLoggingEnabled(
       IPC::Logging::GetInstance()->Enabled()));
 #endif
+
+  // Make sure the child checks with us before exiting, so that we do not try
+  // to schedule a new navigation in a swapped out and exiting renderer.
+  Send(new ChildProcessMsg_AskBeforeShutdown());
 }
 
 void BrowserRenderProcessHost::OnChannelError() {
@@ -880,6 +886,20 @@ void BrowserRenderProcessHost::OnChannelError() {
   // TODO(darin): clean this up
 }
 
+void BrowserRenderProcessHost::OnShutdownRequest() {
+  // Don't shutdown if there are pending RenderViews being swapped back in.
+  if (pending_views_)
+    return;
+
+  // Notify any tabs that might have swapped out renderers from this process.
+  // They should not attempt to swap them back in.
+  NotificationService::current()->Notify(
+      NotificationType::RENDERER_PROCESS_CLOSING,
+      Source<RenderProcessHost>(this), NotificationService::NoDetails());
+
+  Send(new ChildProcessMsg_Shutdown());
+}
+
 void BrowserRenderProcessHost::OnUpdatedCacheStats(
     const WebCache::UsageStats& stats) {
   WebCacheManager::GetInstance()->ObserveStats(id(), stats);
diff --git a/content/browser/renderer_host/browser_render_process_host.h b/content/browser/renderer_host/browser_render_process_host.h
index c97648c..fb46c82 100644
--- a/content/browser/renderer_host/browser_render_process_host.h
+++ b/content/browser/renderer_host/browser_render_process_host.h
@@ -81,6 +81,7 @@ class BrowserRenderProcessHost : public RenderProcessHost,
   void CreateMessageFilters();
 
   // Control message handlers.
+  void OnShutdownRequest();
   void OnUpdatedCacheStats(const WebKit::WebCache::UsageStats& stats);
   void SuddenTerminationChanged(bool enabled);
   void OnUserMetricsRecordAction(const std::string& action);
diff --git a/content/browser/renderer_host/render_process_host.cc b/content/browser/renderer_host/render_process_host.cc
index f435e7c..5466004 100644
--- a/content/browser/renderer_host/render_process_host.cc
+++ b/content/browser/renderer_host/render_process_host.cc
@@ -95,6 +95,7 @@ RenderProcessHost::RenderProcessHost(Profile* profile)
       fast_shutdown_started_(false),
       deleting_soon_(false),
       is_extension_process_(false),
+      pending_views_(0),
       id_(ChildProcessInfo::GenerateChildProcessUniqueId()),
       profile_(profile),
       sudden_termination_allowed_(true),
@@ -144,6 +145,15 @@ void RenderProcessHost::ReportExpectingClose(int32 listener_id) {
   listeners_expecting_close_.insert(listener_id);
 }
 
+void RenderProcessHost::AddPendingView() {
+  pending_views_++;
+}
+
+void RenderProcessHost::RemovePendingView() {
+  DCHECK(pending_views_);
+  pending_views_--;
+}
+
 void RenderProcessHost::UpdateMaxPageID(int32 page_id) {
   if (page_id > max_page_id_)
     max_page_id_ = page_id;
diff --git a/content/browser/renderer_host/render_process_host.h b/content/browser/renderer_host/render_process_host.h
index 4a76d1f..9d3b8fc 100644
--- a/content/browser/renderer_host/render_process_host.h
+++ b/content/browser/renderer_host/render_process_host.h
@@ -104,6 +104,12 @@ class RenderProcessHost : public IPC::Channel::Sender,
   // goes away we'll know that it was intentional rather than a crash.
   void ReportExpectingClose(int32 listener_id);
 
+  // Track the count of pending views that are being swapped back in.  Called
+  // by listeners to register and unregister pending views to prevent the
+  // process from exiting.
+  void AddPendingView();
+  void RemovePendingView();
+
   // Allows iteration over this RenderProcessHost's RenderViewHost listeners.
   // Use from UI thread only.
   typedef IDMap<IPC::Channel::Listener>::const_iterator listeners_iterator;
@@ -282,6 +288,11 @@ class RenderProcessHost : public IPC::Channel::Sender,
   // when running in single-process mode.
   bool is_extension_process_;
 
+  // The count of currently swapped out but pending RenderViews.  We have
+  // started to swap these in, so the renderer process should not exit if
+  // this count is non-zero.
+  int32 pending_views_;
+
  private:
   // The globally-unique identifier for this RPH.
   int id_;
diff --git a/content/browser/tab_contents/render_view_host_manager.cc b/content/browser/tab_contents/render_view_host_manager.cc
index 7effc09..442e91c8 100644
--- a/content/browser/tab_contents/render_view_host_manager.cc
+++ b/content/browser/tab_contents/render_view_host_manager.cc
@@ -62,6 +62,10 @@ void RenderViewHostManager::Init(Profile* profile,
   render_view_host_ = RenderViewHostFactory::Create(
       site_instance, render_view_delegate_, routing_id, delegate_->
       GetControllerForRenderManager().session_storage_namespace());
+
+  // Keep track of renderer processes as they start to shut down.
+  registrar_.Add(this, NotificationType::RENDERER_PROCESS_CLOSING,
+                 NotificationService::AllSources());
 }
 
 RenderWidgetHostView* RenderViewHostManager::GetRenderWidgetHostView() const {
@@ -215,6 +219,12 @@ void RenderViewHostManager::RendererAbortedProvisionalLoad(
   // the response is not a download.
 }
 
+void RenderViewHostManager::RendererProcessClosing(
+    RenderProcessHost* render_process_host) {
+  // TODO(creis): Don't schedule new navigations in RenderViewHosts of this
+  // process.  (Part of http://crbug.com/65953.)
+}
+
 void RenderViewHostManager::ShouldClosePage(bool for_cross_site_transition,
                                             bool proceed) {
   if (for_cross_site_transition) {
@@ -278,6 +288,19 @@ void RenderViewHostManager::OnCrossSiteNavigationCanceled() {
     CancelPending();
 }
 
+void RenderViewHostManager::Observe(NotificationType type,
+                                    const NotificationSource& source,
+                                    const NotificationDetails& details) {
+  switch (type.value) {
+    case NotificationType::RENDERER_PROCESS_CLOSING:
+      RendererProcessClosing(Source<RenderProcessHost>(source).ptr());
+      break;
+
+    default:
+      NOTREACHED();
+  }
+}
+
 bool RenderViewHostManager::ShouldTransitionCrossSite() {
   // True if we are using process-per-site-instance (default) or
   // process-per-site (kProcessPerSite).
@@ -463,6 +486,9 @@ bool RenderViewHostManager::CreatePendingRenderView(
       instance, render_view_delegate_, MSG_ROUTING_NONE, delegate_->
       GetControllerForRenderManager().session_storage_namespace());
 
+  // Prevent the process from exiting while we're trying to use it.
+  pending_render_view_host_->process()->AddPendingView();
+
   bool success = InitRenderView(pending_render_view_host_, entry);
   if (success) {
     // Don't show the view until we get a DidNavigate from it.
@@ -521,6 +547,9 @@ void RenderViewHostManager::CommitPending() {
   render_view_host_ = pending_render_view_host_;
   pending_render_view_host_ = NULL;
 
+  // The process will no longer try to exit, so we can decrement the count.
+  render_view_host_->process()->RemovePendingView();
+
   // If the view is gone, then this RenderViewHost died while it was hidden.
   // We ignored the RenderViewGone call at the time, so we should send it now
   // to make sure the sad tab shows up, etc.
@@ -655,6 +684,10 @@ RenderViewHost* RenderViewHostManager::UpdateRendererStateForNavigate(
 
 void RenderViewHostManager::CancelPending() {
   RenderViewHost* pending_render_view_host = pending_render_view_host_;
+
+  // We no longer need to prevent the process from exiting.
+  pending_render_view_host->process()->RemovePendingView();
+
   pending_render_view_host_ = NULL;
   pending_render_view_host->Shutdown();
 
diff --git a/content/browser/tab_contents/render_view_host_manager.h b/content/browser/tab_contents/render_view_host_manager.h
index 01ddbc8..e2033d15 100644
--- a/content/browser/tab_contents/render_view_host_manager.h
+++ b/content/browser/tab_contents/render_view_host_manager.h
@@ -10,6 +10,7 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/browser/renderer_host/render_view_host_delegate.h"
+#include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
 
 class WebUI;
@@ -25,7 +26,8 @@ class SiteInstance;
 // it is easy to do. But we can also have transitions of processes (and hence
 // RenderViewHosts) that can get complex.
 class RenderViewHostManager
-    : public RenderViewHostDelegate::RendererManagement {
+    : public RenderViewHostDelegate::RendererManagement,
+      public NotificationObserver {
  public:
   // Functions implemented by our owner that we need.
   //
@@ -171,6 +173,11 @@ class RenderViewHostManager
                                    int new_request_id);
   virtual void OnCrossSiteNavigationCanceled();
 
+  // NotificationObserver implementation.
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
   // Called when a RenderViewHost is about to be deleted.
   void RenderViewDeleted(RenderViewHost* rvh);
 
@@ -224,6 +231,10 @@ class RenderViewHostManager
 
   RenderViewHost* UpdateRendererStateForNavigate(const NavigationEntry& entry);
 
+  // Called when a renderer process is starting to close.  We should not
+  // schedule new navigations in its swapped out RenderViewHosts after this.
+  void RendererProcessClosing(RenderProcessHost* render_process_host);
+
   // Our delegate, not owned by us. Guaranteed non-NULL.
   Delegate* delegate_;
 
diff --git a/content/common/notification_type.h b/content/common/notification_type.h
index 85a829b..c7e4d6a 100644
--- a/content/common/notification_type.h
+++ b/content/common/notification_type.h
@@ -408,6 +408,11 @@ class NotificationType {
     // RenderProcessHost that corresponds to the process.
     RENDERER_PROCESS_TERMINATED,
 
+    // Indicates that a render process is starting to exit, such that it should
+    // not be used for future navigations.  The source will be the
+    // RenderProcessHost that corresponds to the process.
+    RENDERER_PROCESS_CLOSING,
+
     // Indicates that a render process was closed (meaning it exited, but the
     // RenderProcessHost might be reused).  The source will be the corresponding
     // RenderProcessHost.  The details will be a RendererClosedDetails struct.