Fix a bug in QProcess. QProcess was not reentrant on Unix

QProcess is supposed to be reentrant but was not on Unix. The
constructor of QProcessManager could be exectued several time when
QProcess is created. The construction is now protected by a mutex.

Task-number: 254246
Reviewed-by: Olivier Goffart

2 files changed, 12 insertions, 2 deletions

diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 607b734..168eac2 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -162,7 +162,17 @@ private:
     QMap<int, QProcessInfo *> children;
 };
 
-Q_GLOBAL_STATIC(QProcessManager, processManager)
+
+Q_GLOBAL_STATIC(QMutex, processManagerGlobalMutex)
+
+static QProcessManager *processManager() {
+    // The constructor of QProcessManager should be called only once
+    // so we cannot use Q_GLOBAL_STATIC directly for QProcessManager
+    QMutex *mutex = processManagerGlobalMutex();
+    QMutexLocker locker(mutex);
+    static QProcessManager processManager;
+    return &processManager;
+}
 
 QProcessManager::QProcessManager()
 {
diff --git a/tests/auto/qprocess/tst_qprocess.cpp b/tests/auto/qprocess/tst_qprocess.cpp
index d235dff..1ffa360 100644
--- a/tests/auto/qprocess/tst_qprocess.cpp
+++ b/tests/auto/qprocess/tst_qprocess.cpp
@@ -1224,7 +1224,7 @@ private:
 //-----------------------------------------------------------------------------
 void tst_QProcess::processInAThread()
 {
-    for (int i = 0; i < 3; ++i) {
+    for (int i = 0; i < 10; ++i) {
         TestThread thread;
         thread.start();
         QVERIFY(thread.wait(10000));