Example: RecMutex, nested critical sections
public static int main (string[] args) {
if (Thread.supported () == false) {
print ("Threads are not supported.\n");
return 0;
}
// Mutex used to protect data:
RecMutex mutex = RecMutex ();
// Shared Data: Must not be accessed by more than one thread at once
int MAX = 100;
int shared = 0;
int thread_id = 0;
Func<string> inc_counter = (name) => {
// Enter the critical section: Other threads are locked out
// until unlock () is called
// RecMutex allows us to nest critical section without deadlock.
mutex.lock ();
int tmp = shared;
print ("%s=%d\n", name, tmp);
shared++;
mutex.unlock ();
// Leave the critical section
};
ThreadFunc<bool> worker_func = () => {
// Enter the critical section: Other threads are locked out
// until unlock () is called
mutex.lock ();
int id = thread_id;
thread_id++;
mutex.unlock ();
// Leave the critical section
while (shared < MAX) {
// ...
mutex.lock ();
inc_counter ("t%d".printf (id));
mutex.unlock ();
// ...
Thread.usleep (10000);
}
return true;
};
Thread<bool> thread1 = new Thread<bool> ("thread-1", worker_func);
Thread<bool> thread2 = new Thread<bool> ("thread-1", worker_func);
thread1.join ();
thread2.join ();
return 0;
}
valac --target-glib 2.32 --pkg glib-2.0 GLib.RecMutex.vala
See:
