Bug 200897 – NetworkDataTask is being ref'd / deref'd from several threads and is not ThreadSafeRefCounted

• Component: WebKit2
• Status: RESOLVED FIXED

[Chris Dumez]

NetworkDataTask is being ref'd / deref'd from several threads and is not ThreadSafeRefCounted.

See the makeRef() calls below:

void NetworkDataTaskCocoa::resume()
{
    if (m_scheduledFailureType != NoFailure)
        m_failureTimer.startOneShot(0_s);

    auto& cocoaSession = static_cast<NetworkSessionCocoa&>(*m_session);
    if (cocoaSession.deviceManagementRestrictionsEnabled() && m_isForMainResourceNavigationForAnyFrame) {
        auto didDetermineDeviceRestrictionPolicyForURL = makeBlockPtr([this, protectedThis = makeRef(*this)](BOOL isBlocked) {
            callOnMainThread([this, protectedThis = makeRef(*this), isBlocked] {
                if (isBlocked) {
                    scheduleFailure(RestrictedURLFailure);
                    return;
                }

                [m_task resume];
            });
        });

[Chris Dumez]

cc'ing Tim as he added this code. I am still confirming if this can really get called on a background thread or if the callOnMainThread() call is merely to make things asynchronous.

[Chris Dumez]

(In reply to Chris Dumez from comment #1)
> cc'ing Tim as he added this code. I am still confirming if this can really
> get called on a background thread or if the callOnMainThread() call is
> merely to make things asynchronous.

Ouch, definitely not called on the main thread. There is indeed a bug here.

[Chris Dumez]

Created attachment 376712 [details]
Patch

[Geoffrey Garen]

Comment on attachment 376712 [details]
Patch

r=me

[WebKit Commit Bot]

Comment on attachment 376712 [details]
Patch

Clearing flags on attachment: 376712

Committed r248874: <https://trac.webkit.org/changeset/248874>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/54487810>