Race condition in PCRE and QRegularExpression on Windows

static HANDLE global_mutex = 0;

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_FUNC sljit_grab_lock(void)
{
	/* No idea what to do if an error occures. Static mutexes should never fail... */
	if (!global_mutex)
		global_mutex = CreateMutex(NULL, TRUE, NULL);
	else
		WaitForSingleObject(global_mutex, INFINITE);
}

#include <QApplication>
#include <QSemaphore>
#include <QThread>
#include <QRegularExpression>

QSemaphore sem1, sem2;

struct Worker : public QThread {
    virtual void run() override {
        sem1.acquire();
        QRegularExpression("\\d+").optimize();
        sem2.release();
    }
    static void msleep(int ms) { QThread::msleep(ms); }
};

int main(int argc, char* argv[]) {
    QApplication app(argc, argv);
    const int N = 100;
    for (int i = 0; i < N; i++)
        (new Worker)->start();
    Worker::msleep(1000);
    sem1.release(N);
    sem2.acquire(N);
    return 0;
}