diff options
| -rw-r--r-- | src/corelib/thread/qthread_unix.cpp | 4 | ||||
| -rw-r--r-- | tests/auto/corelib/thread/qthread/tst_qthread.cpp | 53 |
2 files changed, 57 insertions, 0 deletions
diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp index 640906f4c1..8fa4e939f8 100644 --- a/src/corelib/thread/qthread_unix.cpp +++ b/src/corelib/thread/qthread_unix.cpp @@ -391,6 +391,8 @@ void QThreadPrivate::finish(void *arg) d->interruptionRequested = false; d->isInFinish = false; + d->data->threadId.storeRelaxed(nullptr); + d->thread_done.wakeAll(); } #ifndef QT_NO_EXCEPTIONS @@ -773,6 +775,8 @@ bool QThread::wait(QDeadlineTimer deadline) if (!d->thread_done.wait(locker.mutex(), deadline)) return false; } + Q_ASSERT(d->data->threadId.loadRelaxed() == nullptr); + return true; } diff --git a/tests/auto/corelib/thread/qthread/tst_qthread.cpp b/tests/auto/corelib/thread/qthread/tst_qthread.cpp index 0631070d22..704eb14e14 100644 --- a/tests/auto/corelib/thread/qthread/tst_qthread.cpp +++ b/tests/auto/corelib/thread/qthread/tst_qthread.cpp @@ -111,6 +111,7 @@ private slots: void quitLock(); void create(); + void threadIdReuse(); }; enum { one_minute = 60 * 1000, five_minutes = 5 * one_minute }; @@ -1628,5 +1629,57 @@ void tst_QThread::requestTermination() QVERIFY(!thread.isInterruptionRequested()); } +/* + This is a regression test for QTBUG-96846. + + Incorrect system thread ID cleanup can cause QThread::wait() to report that + a thread is trying to wait for itself. +*/ +void tst_QThread::threadIdReuse() +{ + // It's important that those thread ID's are not accessed concurrently + Qt::HANDLE threadId1; + + auto thread1Fn = [&threadId1]() -> void { threadId1 = QThread::currentThreadId(); }; + QScopedPointer<QThread> thread1(QThread::create(thread1Fn)); + thread1->start(); + QVERIFY(thread1->wait()); + + // If the system thread allocated for thread1 is destroyed before thread2 is started, + // at least on some versions of Linux the system thread ID for thread2 would be the + // same as one that was used for thread1. + + // The system thread may be alive for some time after returning from QThread::wait() + // because the implementation is using detachable threads, so some additional time is + // required for the system thread to terminate. Not waiting long enough here would result + // in a new system thread ID being allocated for thread2 and this test passing even without + // a fix for QTBUG-96846. + bool threadIdReused = false; + + for (int i = 0; i < 42; i++) { + QThread::msleep(1); + + Qt::HANDLE threadId2; + auto waitForThread1 = [&thread1, &threadId2]() -> void { + threadId2 = QThread::currentThreadId(); + QVERIFY(thread1->wait()); + }; + + QScopedPointer<QThread> thread2(QThread::create(waitForThread1)); + thread2->start(); + QVERIFY(thread2->wait()); + + if (threadId1 == threadId2) { + qDebug("Thread ID reused at iteration %d", i); + threadIdReused = true; + break; + } + } + + if (!threadIdReused) { + QSKIP("Thread ID was not reused"); + } +} + QTEST_MAIN(tst_QThread) #include "tst_qthread.moc" |