• ap@apple.com's avatar
    Make SuspendableTimer safer · a2e319e6
    ap@apple.com authored
    https://bugs.webkit.org/show_bug.cgi?id=119127
    
    Reviewed by Sam Weinig.
    
    SuspendableTimer now enforces that it stays suspended until resumed (or until stopped
    and started again). To ensure this, TimerBase is now a private base class, and parts of
    its interface that clients use are reimplemented with suspend/resume in mind.
    
    Derived classes are still allowed to override TimerBase virtual functions (notably
    fired() and alignedFireTime()).
    
    * dom/DocumentEventQueue.cpp:
    (WebCore::DocumentEventQueueTimer): Removed an extraneous WTF_MAKE_NONCOPYABLE,
    TimerBase has it already.
    (WebCore::DocumentEventQueueTimer::create): Use our normal create() pattern.
    (WebCore::DocumentEventQueue::DocumentEventQueue): Made the constructor private, accordingly.
    (WebCore::DocumentEventQueue::cancelEvent): Use SuspendableTimer::cancel(), which
    is a new name to disambiguate TimerBase::stop() and ActiveDOMObject::stop().
    (WebCore::DocumentEventQueue::close): Ditto.
    
    * page/DOMTimer.cpp:
    (WebCore::DOMTimer::fired): Now that SuspendableTimer knows whether it's currently
    suspended, assert that it's not.
    (WebCore::DOMTimer::didStop): Separated ActiveDOMObject::stop() implementation from
    additional cleanup, allowing for better SuspendableTimer encapsulation.
    
    * page/DOMTimer.h: Added FINAL and OVVERIDE specifiers as appropriate.
    
    * page/SuspendableTimer.h: Added FINAL (and OVERRIDE) qualifiers to ActiveDOMObject
    methods. A derived class that wants to override current behavior is most likely not
    a timer, and thus shouldn't be a derived class.
    (WebCore::SuspendableTimer::isActive): SuspendableTimer with a next fire time is
    active even if suspended, we shouldn't overwrite its saved data thinking that it's
    inactive.
    (WebCore::SuspendableTimer::isSuspended): Exposed to clients (m_suspended is no
    longer debug only).
    
    * page/SuspendableTimer.cpp:
    (WebCore::SuspendableTimer::SuspendableTimer): Updated for new variable names.
    (WebCore::SuspendableTimer::stop): This is ActiveDOMObject::stop(), which is called
    before final destruction. We don't track this state directly, but can approximate
    with setting m_suspended, so even if someone tries to start the timer afterwards,
    it won't fire.
    (WebCore::SuspendableTimer::suspend): Updated for new names.
    (WebCore::SuspendableTimer::resume): Ditto.
    (WebCore::SuspendableTimer::didStop): No-op default implementation for client hook.
    (WebCore::SuspendableTimer::cancel): Equivalent of TimerBase::stop(), which also
    works when suspended.
    (WebCore::SuspendableTimer::startRepeating): Replacement for TimerBase function with
    the same name, which works correctly when suspended. We don't want to actually start
    the timer in this case.
    (WebCore::SuspendableTimer::startOneShot): Ditto.
    (WebCore::SuspendableTimer::repeatInterval): Ditto.
    (WebCore::SuspendableTimer::augmentFireInterval): Ditto.
    (WebCore::SuspendableTimer::augmentRepeatInterval): Ditto.
    
    
    git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153406 268f45cc-cd09-0410-ab3c-d52691b4dbfc
    a2e319e6
DOMTimer.h 2.92 KB