Qt 从后台线程发出信号安全吗？

我需要从后台线程跟踪我的计算进度

我是这样做的：（摘自官方文件）

}

下面是

Worker:：run（）

void Worker:：run（）
{
如果（_data.size（）>0）
_data.clear（）；
int i=0；
对于（双x=_最小；x<_最大；x+=_步长，++i）
{
_数据推回（QPointF（x，getY（x））；
//进展报告（一）；
QThread:：msleep（10）；
}
发射计算数据；
}

如果我发出reportProgress（I），应用程序会因segfault而崩溃（在不同的函数中，上次是QAnimationTimer:：updateAnimationsTime）

MWE：

编辑：BT:

(gdb) bt
#0  0x0000000100caca62 in QAnimationTimer::updateAnimationsTime(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#1  0x0000000100cab5f7 in QUnifiedTimer::updateAnimationTimers(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#2  0x0000000100cad9fc in QAnimationDriver::advance() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#3  0x0000000100f04300 in QObject::event(QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#4  0x0000000100061dbb in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#5  0x0000000100065110 in QApplication::notify(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#6  0x0000000100ed8fb3 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#7  0x0000000100f2d3f6 in QTimerInfoList::activateTimers() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#8  0x0000000105799d12 in QCocoaEventDispatcherPrivate::activateTimersSourceCallback(void*) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#9  0x00007fff88cb2681 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#10 0x00007fff88ca48dc in __CFRunLoopDoSources0 () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#11 0x00007fff88ca3e3f in __CFRunLoopRun () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#12 0x00007fff88ca3858 in CFRunLoopRunSpecific () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#13 0x00007fff8b9daaef in RunCurrentEventLoopInMode () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#14 0x00007fff8b9da86a in ReceiveNextEventCommon () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#15 0x00007fff8b9da6ab in _BlockUntilNextEventMatchingListInModeWithFilter () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#16 0x00007fff91beff81 in _DPSNextEvent () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#17 0x00007fff91bef730 in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#18 0x00007fff91be3593 in -[NSApplication run] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#19 0x000000010579a92d in QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#20 0x0000000100ed65ad in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#21 0x0000000100ed958a in QCoreApplication::exec() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#22 0x0000000100003c69 in main (argc=1, argv=0x7fff5fbffa78) at ../qwt-test2/main.cpp:12
(gdb) 
#0  0x0000000100caca62 in QAnimationTimer::updateAnimationsTime(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#1  0x0000000100cab5f7 in QUnifiedTimer::updateAnimationTimers(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#2  0x0000000100cad9fc in QAnimationDriver::advance() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#3  0x0000000100f04300 in QObject::event(QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#4  0x0000000100061dbb in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#5  0x0000000100065110 in QApplication::notify(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#6  0x0000000100ed8fb3 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#7  0x0000000100f2d3f6 in QTimerInfoList::activateTimers() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#8  0x0000000105799d12 in QCocoaEventDispatcherPrivate::activateTimersSourceCallback(void*) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#9  0x00007fff88cb2681 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#10 0x00007fff88ca48dc in __CFRunLoopDoSources0 () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#11 0x00007fff88ca3e3f in __CFRunLoopRun () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#12 0x00007fff88ca3858 in CFRunLoopRunSpecific () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#13 0x00007fff8b9daaef in RunCurrentEventLoopInMode () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#14 0x00007fff8b9da86a in ReceiveNextEventCommon () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#15 0x00007fff8b9da6ab in _BlockUntilNextEventMatchingListInModeWithFilter () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#16 0x00007fff91beff81 in _DPSNextEvent () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#17 0x00007fff91bef730 in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#18 0x00007fff91be3593 in -[NSApplication run] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#19 0x000000010579a92d in QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#20 0x0000000100ed65ad in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#21 0x0000000100ed958a in QCoreApplication::exec() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#22 0x0000000100003c69 in main (argc=1, argv=0x7fff5fbffa78) at ../qwt-test2/main.cpp:12

（gdb）bt
#0 0x0000000100caca62，位于/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore中的QAnimationTimer:：updateAnimationsTime（long-long）（）中
#1 0x0000000100cab5f7，位于/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QAnimationDriver:：advance（）中的2 0x0000000100cad9fc
#来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QObject:：event（QEvent*）（）中的3 0x0000000100f04300
#QApplicationPrivate:：notify_helper（QObject*，QEvent*）（）中的4 0x0000000100061dbb来自/Users/pasha/Qt/5.4/clang_64/lib/qtwidts.framework/Versions/5/qtwidts
#来自/Users/pasha/Qt/5.4/clang_64/lib/qtwidts.framework/Versions/5/qtwidts的QApplication:：notify（QObject*，QEvent*）（）中的5 0x0000000100065110
#QCoreApplication:：notifyInternal（QObject*，QEvent*）（）中的6 0x0000000100ed8fb3来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#7 0x0000000100f2d3f6，位于/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QTimerInfoList:：activateTimers（）（）中
#8 0x0000000105799d12在QCocaeventdispatcherPrivate:：activateTimersSourceCallback（void*）中来自/Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcoca.dylib
#9 0x00007fff88cb2681 in uu\u CFRUNLOOP\u正在从/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation调用u OUT\u来执行函数
#10 0x00007fff88ca48dc，位于/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation的
#11 0x00007fff88ca3e3f位于/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation中的
#CFRunLoopRunSpecific（）中的12 0x00007fff88ca3858，来自/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#13 0x00007fff8b9daaef处于RunCurrentEventLoopInMode（）下，来自/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#14 0x00007fff8b9da86a在/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox的ReceiveNextEventCommon（）中
#15 0x00007fff8b9da6ab位于/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox中的_blockuntinexteventmatchinglistinmodewithfilter（）
#16 0x00007fff91beff81在/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit的_dpsnextent（）中
#17 0x00007fff91bef730 in-[NSApplication-nextEventMatchingMask:untilDate:inMode:dequeue:（）来自/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#18 0x00007fff91be3593 in-[NSApplication run]（）from/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#QCocoaEventDispatcher:：processEvents（QFlags）（）中的19 0x000000010579a92d，来自/Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcoca.dylib
#QEventLoop:：exec（QFlags）（）中的20 0x0000000100ed65ad来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QCoreApplication:：exec（）中的21 0x0000000100ed958a
#在../qwt-test2/main.cpp:12处的main中有22 0x0000000100003c69（argc=1，argv=0x7fff5fbffa78）
（gdb）
#0 0x0000000100caca62，位于/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore中的QAnimationTimer:：updateAnimationsTime（long-long）（）中
#1 0x0000000100cab5f7，位于/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QAnimationDriver:：advance（）中的2 0x0000000100cad9fc
#来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QObject:：event（QEvent*）（）中的3 0x0000000100f04300
#QApplicationPrivate:：notify_helper（QObject*，QEvent*）（）中的4 0x0000000100061dbb来自/Users/pasha/Qt/5.4/clang_64/lib/qtwidts.framework/Versions/5/qtwidts
#来自/Users/pasha/Qt/5.4/clang_64/lib/qtwidts.framework/Versions/5/qtwidts的QApplication:：notify（QObject*，QEvent*）（）中的5 0x0000000100065110
#QCoreApplication:：notifyInternal（QObject*，QEvent*）（）中的6 0x0000000100ed8fb3来自/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#7 0x0000000100f2d3f6，位于/Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore的QTimerInfoList:：activateTimers（）（）中
#8 0x0000000105799d12在QCocaeventdispatcherPrivate:：activateTimersSourceCallback（void*）中来自/Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcoca.dylib
#9 0x00007fff88cb2681 in uu\u CFRUNLOOP\u正在从/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation调用u OUT\u来执行函数
#10 0x00007fff88ca48dc，位于/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation的
#11 0x00007fff88ca3e3f位于/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation中的
#CFRunLoopRunSpecific（）中的12 0x00007fff88ca3858，来自/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#从/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.f以RunCurrentEventLoopInMode（）运行的13 0x00007fff8b9daaef
void Worker::run()
{
if (_data.size() > 0)
    _data.clear();
int i = 0;
for (double x = _min; x < _max; x += _step, ++i)
{
    _data.push_back(QPointF(x, getY(x)));
    //emit reportProgress(i);
    QThread::msleep(10);
 }
emit calculated(_data);
}

(gdb) bt
#0  0x0000000100caca62 in QAnimationTimer::updateAnimationsTime(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#1  0x0000000100cab5f7 in QUnifiedTimer::updateAnimationTimers(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#2  0x0000000100cad9fc in QAnimationDriver::advance() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#3  0x0000000100f04300 in QObject::event(QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#4  0x0000000100061dbb in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#5  0x0000000100065110 in QApplication::notify(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#6  0x0000000100ed8fb3 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#7  0x0000000100f2d3f6 in QTimerInfoList::activateTimers() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#8  0x0000000105799d12 in QCocoaEventDispatcherPrivate::activateTimersSourceCallback(void*) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#9  0x00007fff88cb2681 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#10 0x00007fff88ca48dc in __CFRunLoopDoSources0 () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#11 0x00007fff88ca3e3f in __CFRunLoopRun () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#12 0x00007fff88ca3858 in CFRunLoopRunSpecific () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#13 0x00007fff8b9daaef in RunCurrentEventLoopInMode () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#14 0x00007fff8b9da86a in ReceiveNextEventCommon () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#15 0x00007fff8b9da6ab in _BlockUntilNextEventMatchingListInModeWithFilter () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#16 0x00007fff91beff81 in _DPSNextEvent () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#17 0x00007fff91bef730 in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#18 0x00007fff91be3593 in -[NSApplication run] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#19 0x000000010579a92d in QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#20 0x0000000100ed65ad in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#21 0x0000000100ed958a in QCoreApplication::exec() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#22 0x0000000100003c69 in main (argc=1, argv=0x7fff5fbffa78) at ../qwt-test2/main.cpp:12
(gdb) 
#0  0x0000000100caca62 in QAnimationTimer::updateAnimationsTime(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#1  0x0000000100cab5f7 in QUnifiedTimer::updateAnimationTimers(long long) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#2  0x0000000100cad9fc in QAnimationDriver::advance() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#3  0x0000000100f04300 in QObject::event(QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#4  0x0000000100061dbb in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#5  0x0000000100065110 in QApplication::notify(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtWidgets.framework/Versions/5/QtWidgets
#6  0x0000000100ed8fb3 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#7  0x0000000100f2d3f6 in QTimerInfoList::activateTimers() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#8  0x0000000105799d12 in QCocoaEventDispatcherPrivate::activateTimersSourceCallback(void*) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#9  0x00007fff88cb2681 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#10 0x00007fff88ca48dc in __CFRunLoopDoSources0 () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#11 0x00007fff88ca3e3f in __CFRunLoopRun () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#12 0x00007fff88ca3858 in CFRunLoopRunSpecific () from /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
#13 0x00007fff8b9daaef in RunCurrentEventLoopInMode () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#14 0x00007fff8b9da86a in ReceiveNextEventCommon () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#15 0x00007fff8b9da6ab in _BlockUntilNextEventMatchingListInModeWithFilter () from /System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox
#16 0x00007fff91beff81 in _DPSNextEvent () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#17 0x00007fff91bef730 in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#18 0x00007fff91be3593 in -[NSApplication run] () from /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
#19 0x000000010579a92d in QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/plugins/platforms/libqcocoa.dylib
#20 0x0000000100ed65ad in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#21 0x0000000100ed958a in QCoreApplication::exec() () from /Users/pasha/Qt/5.4/clang_64/lib/QtCore.framework/Versions/5/QtCore
#22 0x0000000100003c69 in main (argc=1, argv=0x7fff5fbffa78) at ../qwt-test2/main.cpp:12

connect(worker, &Worker::reportProgress, this,
      [this] (int x) {
    bar->setValue(x);
}, Qt::QueuedConnection);

connect(worker, &Worker::reportProgress,
       [this] (int x) {
      bar->setValue(x);});