The current synchronization mechanism was racy: decrementing waitingThreads
and then hoping that the wakeOne will wake a thread before its expiry
timeout happens. In other words, on timeout, a just-assigned task would
never run. And then no other task would run, if maxThreadCount is reached.
Fixed by using a queue of waiting threads (rather than just a count), and by
moving the wait condition into the thread itself, so we know precisely
which one we're waking up, and we can remove it from the set of waiting threads
before waking it up, and therefore it can determine on wakeup whether it
has work to do (caller removed it from the queue) or it expired (it's still
in the queue). This is reliable, whereas the return value from QWaitCondition::wait
isn't reliable, when the main thread has already decided that this thread
has work to do.
Task-number: QTBUG-3786
Change-Id: I1eac5d6c309daed7f483ac7a8074297bfda6ee32
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(dacf9961da)
In order to see 2 active threads, we must check activeThreadCount() before
the runnable finishes.
Change-Id: I1a48b41e0c1fd81a65d915b9bd1e741ff267ed2b
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
QTBUG-21051 has a testcase where activeThreadCount() could actually
end up at -1 (converted to an autotest in this commit).
The reason was: start() calls tryStart() which returns false due to
too many active threads (reserveThread() causes this), so it calls
enqueueTask() - which actually wakes up the waiting thread, but
it didn't decrement the number of waiting threads.
Note that tryStart() is "if I can grab a waiting thread, enqueue task and wake it"
while start(), in case tryStart() fails, wants to "enqueue, and then if I can grab
a waiting thread, wake it". This is why enqueue shouldn't wake; waking must happen
only if we can grab a thread (d->waitingThreads > 0).
Task-number: QTBUG-21051
Change-Id: I3d98337103031c9bdf0bf365295f245be0c66aa7
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
QThreadPool::clear() method removes all queued QRunnable.
When a large number of long-running tasks are queud in a
QThreadPool its destruction, which calls waitForDone(), can
be quite long.
QThreadPool:clear() removes (and deletes when appropriate)
all QRunnable that have yet to be started from the queue
enabling a faster interruption.
Change-Id: Ie5d6028ad3cfe7e439d1db068c8d0936ff818db9
Reviewed-by: David Faure <david.faure@kdab.com>
The optimisation done in cbaf52b099 for Qt
5.0 got the order wrong of the comparison. The queue must be sorted in
decreasing priority order. But since higher numbers mean higher
priority, that means the queue must be sorted in decreasing priority
number order.
Task-number: QTBUG-29163
Change-Id: Iaf3424b9bb445bf5c71518927f37253cead454f3
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Remove all trailing whitespace from the following list of files:
*.cpp *.h *.conf *.qdoc *.pro *.pri *.mm *.rc *.pl *.qps *.xpm *.txt *README
excluding 3rdparty, test-data and auto generated code.
Note A): the only non 3rdparty c++-files that still
have trailing whitespace after this change are:
* src/corelib/codecs/cp949codetbl_p.h
* src/corelib/codecs/qjpunicode.cpp
* src/corelib/codecs/qbig5codec.cpp
* src/corelib/xml/qxmlstream_p.h
* src/tools/qdoc/qmlparser/qqmljsgrammar.cpp
* src/tools/uic/ui4.cpp
* tests/auto/other/qtokenautomaton/tokenizers/*
* tests/benchmarks/corelib/tools/qstring/data.cpp
* util/lexgen/tokenizer.cpp
Note B): in about 30 files some overlapping 'leading tab' and
'TAB character in non-leading whitespace' issues have been fixed
to make the sanity bot happy. Plus some general ws-fixes here
and there as asked for during review.
Change-Id: Ia713113c34d82442d6ce4d93d8b1cf545075d11d
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Qt 4.8 shows frequent crashes in runMultiple apparently caused
by the QMutex construction in the free functions by different
threads. Use a common QMutex class member instead.
Change-Id: I851d4e2d3637a7b4f404ed843f5360c10caa21f5
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
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>
Qt 5.0 beta requires changing the default to the 5.0 API, disabling
the deprecated code. However, tests should test (and often do) the
compatibility API too, so turn it back on.
Task-number: QTBUG-25053
Change-Id: I8129c3ef3cb58541c95a32d083850d9e7f768927
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
