Changeset 232884 in webkit

Timestamp:

Jun 15, 2018 11:47:32 AM (6 years ago)

Author:

pvollan@apple.com

Message:

DisplayRefreshMonitorMac should hold a weak pointer to WebPage.
​https://bugs.webkit.org/show_bug.cgi?id=186683

Reviewed by Brent Fulgham.

Instead of DisplayRefreshMonitorMac having a RefPtr to WebPage, it should have a weak pointer.
Having a RefPtr could in theory create reference cycles. This potential problem has not been
observed in practice, but it is safer to use a weak pointer.

• WebProcess/WebPage/WebPage.h:
• WebProcess/WebPage/mac/DrawingAreaMac.cpp:

(WebKit::DisplayRefreshMonitorMac::DisplayRefreshMonitorMac):
(WebKit::DisplayRefreshMonitorMac::~DisplayRefreshMonitorMac):
(WebKit::DisplayRefreshMonitorMac::requestRefreshCallback):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• WebProcess/WebPage/WebPage.h (modified) (1 diff)
• WebProcess/WebPage/mac/DrawingAreaMac.cpp (modified) (4 diffs)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2018-06-15  Per Arne Vollan  <pvollan@apple.com>
+
+        DisplayRefreshMonitorMac should hold a weak pointer to WebPage.
+        https://bugs.webkit.org/show_bug.cgi?id=186683
+
+        Reviewed by Brent Fulgham.
+
+        Instead of DisplayRefreshMonitorMac having a RefPtr to WebPage, it should have a weak pointer.
+        Having a RefPtr could in theory create reference cycles. This potential problem has not been
+        observed in practice, but it is safer to use a weak pointer.
+
+        * WebProcess/WebPage/WebPage.h:
+        * WebProcess/WebPage/mac/DrawingAreaMac.cpp:
+        (WebKit::DisplayRefreshMonitorMac::DisplayRefreshMonitorMac):
+        (WebKit::DisplayRefreshMonitorMac::~DisplayRefreshMonitorMac):
+        (WebKit::DisplayRefreshMonitorMac::requestRefreshCallback):
+
 2018-06-15  Carlos Alberto Lopez Perez  <clopez@igalia.com>
 

trunk/Source/WebKit/WebProcess/WebPage/WebPage.h

@@ -247 +247 @@
 using WKEventModifiers = uint32_t;
 
-class WebPage : public API::ObjectImpl<API::Object::Type::BundlePage>, public IPC::MessageReceiver, public IPC::MessageSender {
+class WebPage : public API::ObjectImpl<API::Object::Type::BundlePage>, public IPC::MessageReceiver, public IPC::MessageSender, public CanMakeWeakPtr<WebPage> {
 public:
     static Ref<WebPage> create(uint64_t pageID, WebPageCreationParameters&&);

trunk/Source/WebKit/WebProcess/WebPage/mac/DrawingAreaMac.cpp

@@ -58 +58 @@
     bool hasRequestedRefreshCallback() const override { return m_hasSentMessage; }
 
-    Ref<WebPage> m_webPage;
+    WeakPtr<WebPage> m_webPage;
     bool m_hasSentMessage { false };
     unsigned m_observerID;
@@ -70 +70 @@
 DisplayRefreshMonitorMac::DisplayRefreshMonitorMac(PlatformDisplayID displayID, WebPage& webPage)
     : DisplayRefreshMonitor(displayID)
-    , m_webPage(webPage)
+    , m_webPage(makeWeakPtr(webPage))
     , m_observerID(++m_counterID)
 {
@@ -77 +77 @@
 DisplayRefreshMonitorMac::~DisplayRefreshMonitorMac()
 {
+    ASSERT(m_webPage);
+    if (!m_webPage)
+        return;
+    
     m_webPage->send(Messages::WebPageProxy::StopDisplayLink(m_observerID));
 }
@@ -82 +86 @@
 bool DisplayRefreshMonitorMac::requestRefreshCallback()
 {
+    ASSERT(m_webPage);
+    if (!m_webPage)
+        return false;
+
     if (!isActive())
         return false;