First step to fix race condition about deleting QDBusPendingCallPrivate.
In a multithreaded application on a slow/single core cpu the following
race (and segmentation fault) can occur:
First thread A is running:
A: QDBusPendingReply<> reply = pi->asyncCallWithArgumentList(method, argumentList);
Then when the dbus answer arrives thread B will call:
B: QDBusConnectionPrivate::processFinishedCall()
B: ...
B: locker.unlock()
and runs until here, go on with thread A:
A: reply.waitForFinished();
A: QDBusPendingCallPrivate::waitForFinished()
A: {
A: QMutexLocker locker(&mutex);
A: if (replyMessage.type() != QDBusMessage::InvalidMessage)
A: return;
which returns immediately (mutex acquired, replyMessage alread set), now
reply goes out of scope (destructor called) and QDBusPendingCall::d's
destructor of type QExplicitlySharedDataPointer<QDBusPendingCallPrivate>
deletes the reference counted object QDBusPendingCallPrivate.
Now thread B continues, still in processFinishedCall()
B: if (call->watcherHelper)
B: call->watcherHelper->emitSignals(msg, call->sentMessage);
B:
B: if (msg.type() == QDBusMessage::ErrorMessage)
B: emit connection->callWithCallbackFailed(QDBusError(msg),
B: call->sentMessage);
accessing alread deleted object QDBusPendingCallPrivate via call->...
Fixed QDBusPendingCallPrivate deletion by proper reference counting
will be done in the next commit.
Task-number: QTBUG-27809
Change-Id: I15b3f0242471b62eaafadc763fb6a33339ff2fe1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Change copyrights and license headers from Nokia to Digia
Change-Id: If1cc974286d29fd01ec6c19dd4719a67f4c3f00e
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Moved waitingForFinished out from between two large-type variables to
save eight bytes per QDBusPendingCallPrivate on 64bit platforms.
Many a mickle makes a muckle.
Change-Id: I5612ad8bb907c6770be0245e667bdb2add30d38b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The variable waitingForFinished is only ever read under mutex protection, so
a volatile qualification isn't necessary.
Change-Id: I17ce3fbfb090c8ae5e43dd2a93e4f48810dbbff3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Change I00020eed fixed a bug present in 64-bit machines because it
tried to access QList<int>'s internal array data, assuming it was a
vector of ints. That worked in 32-bit, but not 64-bit.
The fix involves a conversion between QList and QVector. Now fix it
properly by changing everything to be QVector. The benefit is that on
64-bit, they are real vectors, not the 50%-overhead pointer array that
QList is.
Change-Id: I989ad279d0d8b2c9ab262a1eed413ab2365b5461
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
This is a semi-automatic search, so I'm
reasonably sure that all the exported ones
have been caught.
Change-Id: I314d341ad0db4e9d4bbf353a9537c9422ad8a54b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
As in the past, to avoid rewriting various autotests that contain
line-number information, an extra blank line has been inserted at the
end of the license text to ensure that this commit does not change the
total number of lines in the license header.
Change-Id: I311e001373776812699d6efc045b5f742890c689
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>
This is the beginning of revision history for this module. If you
want to look at revision history older than this, please refer to the
Qt Git wiki for how to use Git history grafting. At the time of
writing, this wiki is located here:
http://qt.gitorious.org/qt/pages/GitIntroductionWithQt
If you have already performed the grafting and you don't see any
history beyond this commit, try running "git log" with the "--follow"
argument.
Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12
