diff options
| author | Paul Olav Tvete <paul.tvete@digia.com> | 2014-09-03 09:57:58 +0200 |
|---|---|---|
| committer | Paul Olav Tvete <paul.tvete@digia.com> | 2014-09-03 15:18:49 +0200 |
| commit | 7e1e42cbf269c4fd5bbfa0411964bd14e5ae549c (patch) | |
| tree | a483883d57ecfeaf1c636bd9a566670e70d338ee /src | |
| parent | a02d798bbde691b8dd8f9c95aa54c9702cbad59a (diff) | |
Android: Avoid deadlocks on suspend
Get rid of the rendezvous at shutdown: the android thread does not
need to wait for the GUI thread. Since the GUI thread frequently does
blocking calls to the android thread, this fixes several known and
potential deadlocks.
Task-number: QTBUG-41072
Change-Id: Ia6fa8da026b1727e7352b22f4df4d72b63b8c847
Reviewed-by: BogDan Vatra <bogdan@kde.org>
Reviewed-by: Christian Stromme <christian.stromme@digia.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/plugins/platforms/android/qandroideventdispatcher.cpp | 21 | ||||
| -rw-r--r-- | src/plugins/platforms/android/qandroideventdispatcher.h | 2 |
2 files changed, 14 insertions, 9 deletions
diff --git a/src/plugins/platforms/android/qandroideventdispatcher.cpp b/src/plugins/platforms/android/qandroideventdispatcher.cpp index 074ba71f80..ab5070af9d 100644 --- a/src/plugins/platforms/android/qandroideventdispatcher.cpp +++ b/src/plugins/platforms/android/qandroideventdispatcher.cpp @@ -55,20 +55,26 @@ QAndroidEventDispatcher::~QAndroidEventDispatcher() QAndroidEventDispatcherStopper::instance()->removeEventDispatcher(this); } +enum States {Running = 0, StopRequest = 1, Stopping = 2}; + void QAndroidEventDispatcher::start() { - if (m_stopRequest.testAndSetAcquire(1, 0)) { - m_dispatcherSemaphore.release(); + int prevState = m_stopRequest.fetchAndStoreAcquire(Running); + if (prevState == Stopping) { + m_semaphore.release(); wakeUp(); + } else if (prevState == Running) { + qWarning("Error: start without corresponding stop"); } + //else if prevState == StopRequest, no action needed } void QAndroidEventDispatcher::stop() { - if (m_stopRequest.testAndSetAcquire(0, 1)) { + if (m_stopRequest.testAndSetAcquire(Running, StopRequest)) wakeUp(); - m_stopperSemaphore.acquire(); - } + else + qWarning("Error: start/stop out of sync"); } void QAndroidEventDispatcher::goingToStop(bool stop) @@ -80,9 +86,8 @@ void QAndroidEventDispatcher::goingToStop(bool stop) int QAndroidEventDispatcher::select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, timespec *timeout) { - if (m_stopRequest.load() == 1) { - m_stopperSemaphore.release(); - m_dispatcherSemaphore.acquire(); + if (m_stopRequest.testAndSetAcquire(StopRequest, Stopping)) { + m_semaphore.acquire(); wakeUp(); } diff --git a/src/plugins/platforms/android/qandroideventdispatcher.h b/src/plugins/platforms/android/qandroideventdispatcher.h index 8d1bcf2122..284c5fd392 100644 --- a/src/plugins/platforms/android/qandroideventdispatcher.h +++ b/src/plugins/platforms/android/qandroideventdispatcher.h @@ -66,7 +66,7 @@ protected: private: QAtomicInt m_stopRequest; QAtomicInt m_goingToStop; - QSemaphore m_dispatcherSemaphore, m_stopperSemaphore; + QSemaphore m_semaphore; }; class QAndroidEventDispatcherStopper |