Add support to set thread priority to QThreadPool

Currently, QThreadPool's generated threads inherit the priority from the
thread they are created and that cannot be changed. This merge request
adds a property to QThreadPool so that the priority of the threads can
be different.

The default behavior does not change.

[ChangeLog][QtCore][QThreadPool] QThreadPool can now be configured to
use a different thread priority when creating new threads than the one
it inherits from the thread it was created in. This will only apply to
the threads started after the property is changed.

Fixes: QTBUG-3481
Change-Id: Ic98d4312d055a3357771abb656516ebd0715918d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp b/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp
index 3c50c6315b..0fb4bfbe56 100644
--- a/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp
+++ b/tests/auto/corelib/thread/qthreadpool/tst_qthreadpool.cpp
@@ -75,6 +75,7 @@ private slots:
     void singleton();
     void destruction();
     void threadRecycling();
+    void threadPriority();
     void expiryTimeout();
     void expiryTimeoutRace();
 #ifndef QT_NO_EXCEPTIONS
@@ -323,6 +324,25 @@ void tst_QThreadPool::threadRecycling()
     QCOMPARE(thread2, thread3);
 }
 
+/*
+    Test that the thread priority from the thread created by the pool matches
+    the one configured on the pool.
+*/
+void tst_QThreadPool::threadPriority()
+{
+    QThread::Priority priority = QThread::HighPriority;
+    QThreadPool threadPool;
+    threadPool.setThreadPriority(priority);
+
+    threadPool.start(new ThreadRecorderTask());
+    threadRecyclingSemaphore.acquire();
+    QThread *thread = recycledThread;
+
+    QTest::qSleep(100);
+
+    QCOMPARE(thread->priority(), priority);
+}
+
 class ExpiryTimeoutTask : public QRunnable
 {
 public: