[iOS] Maintain the last Back/Forward cache entry when the application gets suspended
https://bugs.webkit.org/show_bug.cgi?id=203014
Reviewed by Geoffrey Garen.
Previously, we would clear all back/forward cache entries when the application is about to
be suspended. This means that we would lose fast-back when coming back to the application.
To be memory-friendly but maintain the fast-back when coming back to the application, we now
maintain the last back/forward cache entry when the application gets suspended.
* UIProcess/Cocoa/WebProcessPoolCocoa.mm:
(WebKit::WebProcessPool::applicationIsAboutToSuspend):
(WebKit::WebProcessPool::notifyProcessPoolsApplicationIsAboutToSuspend):
* UIProcess/WebBackForwardCache.cpp:
(WebKit::WebBackForwardCache::pruneToSize):
* UIProcess/WebBackForwardCache.h:
* UIProcess/WebProcessPool.h:
* UIProcess/ios/ProcessAssertionIOS.mm:
(-[WKProcessAssertionBackgroundTaskManager init]):
(-[WKProcessAssertionBackgroundTaskManager _releaseBackgroundTask]):
* WebProcess/WebProcess.cpp:
(WebKit::WebProcess::initializeWebProcess):
A WebProcess no longer clears its PageCache on suspension on iOS. We let the UIProcess's
back/forward cache control when PageCache entries should get destroyed. The back/forward
cache will properly wake up a suspended process to clear one of its PageCache entries if
needed.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@251174 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
index 0172a14..d87419c 100644
--- a/Source/WebKit/ChangeLog
+++ b/Source/WebKit/ChangeLog
@@ -1,3 +1,33 @@
+2019-10-15 Chris Dumez <cdumez@apple.com>
+
+ [iOS] Maintain the last Back/Forward cache entry when the application gets suspended
+ https://bugs.webkit.org/show_bug.cgi?id=203014
+
+ Reviewed by Geoffrey Garen.
+
+ Previously, we would clear all back/forward cache entries when the application is about to
+ be suspended. This means that we would lose fast-back when coming back to the application.
+ To be memory-friendly but maintain the fast-back when coming back to the application, we now
+ maintain the last back/forward cache entry when the application gets suspended.
+
+ * UIProcess/Cocoa/WebProcessPoolCocoa.mm:
+ (WebKit::WebProcessPool::applicationIsAboutToSuspend):
+ (WebKit::WebProcessPool::notifyProcessPoolsApplicationIsAboutToSuspend):
+ * UIProcess/WebBackForwardCache.cpp:
+ (WebKit::WebBackForwardCache::pruneToSize):
+ * UIProcess/WebBackForwardCache.h:
+ * UIProcess/WebProcessPool.h:
+ * UIProcess/ios/ProcessAssertionIOS.mm:
+ (-[WKProcessAssertionBackgroundTaskManager init]):
+ (-[WKProcessAssertionBackgroundTaskManager _releaseBackgroundTask]):
+
+ * WebProcess/WebProcess.cpp:
+ (WebKit::WebProcess::initializeWebProcess):
+ A WebProcess no longer clears its PageCache on suspension on iOS. We let the UIProcess's
+ back/forward cache control when PageCache entries should get destroyed. The back/forward
+ cache will properly wake up a suspended process to clear one of its PageCache entries if
+ needed.
+
2019-10-15 Andres Gonzalez <andresg_22@apple.com>
AX: Make AXIsolatedTree compile again
diff --git a/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm b/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
index 4b92b93..1a41cd1 100644
--- a/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
+++ b/Source/WebKit/UIProcess/Cocoa/WebProcessPoolCocoa.mm
@@ -37,6 +37,7 @@
#import "TextChecker.h"
#import "VersionChecks.h"
#import "WKBrowsingContextControllerInternal.h"
+#import "WebBackForwardCache.h"
#import "WebMemoryPressureHandler.h"
#import "WebPageGroup.h"
#import "WebPreferencesKeys.h"
@@ -585,11 +586,18 @@
#if PLATFORM(IOS_FAMILY)
void WebProcessPool::applicationIsAboutToSuspend()
{
- RELEASE_LOG(ProcessSuspension, "Application is about to suspend so we simulate memory pressure to terminate non-critical processes");
- // Simulate memory pressure handling so free as much memory as possible before suspending.
- // In particular, this will terminate prewarmed and PageCache processes.
+ RELEASE_LOG(ProcessSuspension, "WebProcessPool::applicationIsAboutToSuspend() Terminating non-critical processes");
+
+ m_backForwardCache->pruneToSize(1);
+ if (m_prewarmedProcess)
+ m_prewarmedProcess->shutDown();
+ m_webProcessCache->clear();
+}
+
+void WebProcessPool::notifyProcessPoolsApplicationIsAboutToSuspend()
+{
for (auto* processPool : allProcessPools())
- processPool->handleMemoryPressureWarning(Critical::Yes);
+ processPool->applicationIsAboutToSuspend();
}
#endif
diff --git a/Source/WebKit/UIProcess/WebBackForwardCache.cpp b/Source/WebKit/UIProcess/WebBackForwardCache.cpp
index e75a896..698504d 100644
--- a/Source/WebKit/UIProcess/WebBackForwardCache.cpp
+++ b/Source/WebKit/UIProcess/WebBackForwardCache.cpp
@@ -164,4 +164,11 @@
item->setBackForwardCacheEntry(nullptr);
}
+void WebBackForwardCache::pruneToSize(unsigned newSize)
+{
+ RELEASE_LOG(BackForwardCache, "WebBackForwardCache::pruneToSize(%u)", newSize);
+ while (size() > newSize)
+ removeOldestEntry();
+}
+
} // namespace WebKit.
diff --git a/Source/WebKit/UIProcess/WebBackForwardCache.h b/Source/WebKit/UIProcess/WebBackForwardCache.h
index c1e115a..be4bc4e 100644
--- a/Source/WebKit/UIProcess/WebBackForwardCache.h
+++ b/Source/WebKit/UIProcess/WebBackForwardCache.h
@@ -50,6 +50,7 @@
unsigned size() const { return m_itemsWithCachedPage.size(); }
void clear();
+ void pruneToSize(unsigned);
void removeEntriesForProcess(WebProcessProxy&);
void removeEntriesForPage(WebPageProxy&);
void removeEntriesForSession(PAL::SessionID);
diff --git a/Source/WebKit/UIProcess/WebProcessPool.h b/Source/WebKit/UIProcess/WebProcessPool.h
index 78bdc04..c6ba0fc 100644
--- a/Source/WebKit/UIProcess/WebProcessPool.h
+++ b/Source/WebKit/UIProcess/WebProcessPool.h
@@ -230,7 +230,8 @@
void populateVisitedLinks();
#if PLATFORM(IOS_FAMILY)
- static void applicationIsAboutToSuspend();
+ void applicationIsAboutToSuspend();
+ static void notifyProcessPoolsApplicationIsAboutToSuspend();
#endif
void handleMemoryPressureWarning(Critical);
diff --git a/Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm b/Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm
index 32fcf36..37a6982 100644
--- a/Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm
+++ b/Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm
@@ -84,7 +84,7 @@
_applicationIsBackgrounded = YES;
if (_backgroundTask == UIBackgroundTaskInvalid)
- WebKit::WebProcessPool::applicationIsAboutToSuspend();
+ WebKit::WebProcessPool::notifyProcessPoolsApplicationIsAboutToSuspend();
}];
return self;
@@ -188,7 +188,7 @@
RELEASE_LOG(ProcessSuspension, "%p - WKProcessAssertionBackgroundTaskManager - endBackgroundTask", self);
if (_applicationIsBackgrounded)
- WebKit::WebProcessPool::applicationIsAboutToSuspend();
+ WebKit::WebProcessPool::notifyProcessPoolsApplicationIsAboutToSuspend();
[[UIApplication sharedApplication] endBackgroundTask:_backgroundTask];
_backgroundTask = UIBackgroundTaskInvalid;
}
diff --git a/Source/WebKit/WebProcess/WebProcess.cpp b/Source/WebKit/WebProcess/WebProcess.cpp
index accd337..c66c805d 100644
--- a/Source/WebKit/WebProcess/WebProcess.cpp
+++ b/Source/WebKit/WebProcess/WebProcess.cpp
@@ -306,7 +306,7 @@
}
#endif
- auto maintainPageCache = m_isSuspending && hasPageRequiringPageCacheWhileSuspended() ? WebCore::MaintainPageCache::Yes : WebCore::MaintainPageCache::No;
+ auto maintainPageCache = m_isSuspending ? WebCore::MaintainPageCache::Yes : WebCore::MaintainPageCache::No;
auto maintainMemoryCache = m_isSuspending && m_hasSuspendedPageProxy ? WebCore::MaintainMemoryCache::Yes : WebCore::MaintainMemoryCache::No;
WebCore::releaseMemory(critical, synchronous, maintainPageCache, maintainMemoryCache);
});
