Attachment 339585 Details for Bug 185318 – Patch

[patch] Patch

bug-185318-20180504130131.patch (text/plain), 3.56 KB, created by Chris Dumez on 2018-05-04 13:01:32 PDT

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Creator: Chris Dumez

Created: 2018-05-04 13:01:32 PDT

Size: 3.56 KB

patch

obsolete

>Subversion Revision: 231334
>diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
>index dd5597fbb51b590e0185c9784b8478ecde38de7f..a2f4a168bb2d991124f5cba48b06635c337f39a7 100644
>--- a/Source/WebKit/ChangeLog
>+++ b/Source/WebKit/ChangeLog
>@@ -1,3 +1,22 @@
>+2018-05-04  Chris Dumez  <cdumez@apple.com>
>+
>+        [iOS] Apps that are not visible may not get suspended if they trigger page loads while in the background
>+        https://bugs.webkit.org/show_bug.cgi?id=185318
>+
>+        Reviewed by NOBODY (OOPS!).
>+
>+        Whenever there is a page load going on, we take a background process assertion to delay process
>+        suspension until this load completes. However, there is also a 3 seconds grace period after
>+        a load is complete to allow the app to trigger a new load shortly after. This grace period was
>+        introduced to support use cases where a visible app does loads in an offscreen view. However,
>+        it can be abused by apps running in the background as they could trigger new page loads while
>+        in the background to delay process suspension. This patch tightens the policy so that only
>+        apps that are currently visible get to use this grace period. Apps that are in the background
>+        get to finish their current load and will then get suspended.
>+
>+        * UIProcess/Cocoa/NavigationState.mm:
>+        (WebKit::NavigationState::didChangeIsLoading):
>+
> 2018-05-03  Justin Fan  <justin_fan@apple.com>
> 
>         [WebGL] Add runtime flag for enabling ASTC support in WebGL
>diff --git a/Source/WebKit/UIProcess/Cocoa/NavigationState.mm b/Source/WebKit/UIProcess/Cocoa/NavigationState.mm
>index 809e5a008d72b379fe9ae74837e8f8b85e02c793..203706afb66e833ca5967216bd2fb65ff13b2bad 100644
>--- a/Source/WebKit/UIProcess/Cocoa/NavigationState.mm
>+++ b/Source/WebKit/UIProcess/Cocoa/NavigationState.mm
>@@ -1157,17 +1157,23 @@ void NavigationState::didChangeIsLoading()
> {
> #if PLATFORM(IOS)
>     if (m_webView->_page->pageLoadState().isLoading()) {
>-        if (m_releaseActivityTimer.isActive())
>+        if (m_releaseActivityTimer.isActive()) {
>+            RELEASE_LOG_IF(m_webView->_page->isAlwaysOnLoggingAllowed(), ProcessSuspension, "%p - A new page load started while the UIProcess was still holding a page load background assertion", this);
>             m_releaseActivityTimer.stop();
>-        else {
>+        } else {
>             RELEASE_LOG_IF(m_webView->_page->isAlwaysOnLoggingAllowed(), ProcessSuspension, "%p - UIProcess is taking a background assertion because a page load started", this);
>             ASSERT(!m_activityToken);
>             m_activityToken = m_webView->_page->process().throttler().backgroundActivityToken();
>         }
>-    } else {
>-        // Delay releasing the background activity for 3 seconds to give the application a chance to start another navigation
>-        // before suspending the WebContent process <rdar://problem/27910964>.
>-        m_releaseActivityTimer.startOneShot(3_s);
>+    } else if (m_activityToken) {
>+        if (m_webView._isBackground)
>+            releaseNetworkActivityToken();
>+        else {
>+            // The application is visible so we delay releasing the background activity for 3 seconds to give it a chance to start another navigation
>+            // before suspending the WebContent process <rdar://problem/27910964>.
>+            RELEASE_LOG_IF(m_webView->_page->isAlwaysOnLoggingAllowed(), ProcessSuspension, "%p - Page load completed and UIProcess will be releasing background assertion soon unless a new load starts", this);
>+            m_releaseActivityTimer.startOneShot(3_s);
>+        }
>     }
> #endif
>

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