From a5e6c50ef45e9b75867e1730c510f5739b00f176 Mon Sep 17 00:00:00 2001 From: Allan Sandfeld Jensen Date: Thu, 1 Oct 2020 09:56:16 +0200 Subject: Fix race condition in QThreadPool::clear Since we drop the lock while deleting threads, we need to handle the queue possibly being accessed and changed by the pool threads while clear() is running. Fixes: QTBUG-87092 Change-Id: I7611edab90520454278502a58621e299f9cd1f6e Reviewed-by: Sona Kurazyan (cherry picked from commit fe36d47b371b71ad5fec30d4b5d7bf0baa0205ea) Reviewed-by: Allan Sandfeld Jensen --- .../corelib/thread/qthreadpool/tst_qthreadpool.cpp | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'tests') diff --git a/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp b/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp index 49ce918caf..cd245030db 100644 --- a/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp +++ b/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp @@ -93,6 +93,7 @@ private slots: void priorityStart(); void waitForDone(); void clear(); + void clearWithAutoDelete(); #if QT_DEPRECATED_SINCE(5, 9) void cancel(); #endif @@ -976,6 +977,31 @@ void tst_QThreadPool::clear() QCOMPARE(count.loadRelaxed(), threadPool.maxThreadCount()); } +void tst_QThreadPool::clearWithAutoDelete() +{ + class MyRunnable : public QRunnable + { + public: + MyRunnable() {} + void run() override { QThread::usleep(30); } + }; + + QThreadPool threadPool; + threadPool.setMaxThreadCount(4); + const int loopCount = 20; + const int batchSize = 500; + // Should not crash see QTBUG-87092 + for (int i = 0; i < loopCount; i++) { + threadPool.clear(); + for (int j = 0; j < batchSize; j++) { + auto *runnable = new MyRunnable(); + runnable->setAutoDelete(true); + threadPool.start(runnable); + } + } + QVERIFY(threadPool.waitForDone()); +} + #if QT_DEPRECATED_SINCE(5, 9) void tst_QThreadPool::cancel() { -- cgit v1.2.3