c# - synlock - ¿Por qué se bloquea MSDN sample from Threading Tutorial?

synlock c#

Question

Del ejemplo de muestra 4 de MSDN "Threading Tutorial"
Los siguientes errores de código en la línea comentados con "--- errors is here ---".
¿Qué está mal?

using System;
using System.Threading;
public class MutexSample
{
static Mutex gM1;
static Mutex gM2;
const int ITERS = 100;
static AutoResetEvent Event1 = new AutoResetEvent(false);
static AutoResetEvent Event2 = new AutoResetEvent(false);
static AutoResetEvent Event3 = new AutoResetEvent(false);
static AutoResetEvent Event4 = new AutoResetEvent(false);
public static void Main(String[] args)
{
Console.WriteLine("Mutex Sample ...");
// Create Mutex initialOwned, with name of "MyMutex".
gM1 = new Mutex(true, "MyMutex");
// Create Mutex initialOwned, with no name.
gM2 = new Mutex(true);
Console.WriteLine(" - Main Owns gM1 and gM2");
AutoResetEvent[] evs = new AutoResetEvent[4];
evs[0] = Event1; // Event for t1
evs[1] = Event2; // Event for t2
evs[2] = Event3; // Event for t3
evs[3] = Event4; // Event for t4
MutexSample tm = new MutexSample();
Thread thread1 = new Thread(new ThreadStart(tm.t1Start));
Thread thread2 = new Thread(new ThreadStart(tm.t2Start));
Thread thread3 = new Thread(new ThreadStart(tm.t3Start));
Thread thread4 = new Thread(new ThreadStart(tm.t4Start));
thread1.Start(); // Does Mutex.WaitAll(Mutex[] of gM1 and gM2)
thread2.Start(); // Does Mutex.WaitOne(Mutex gM1)
thread3.Start(); // Does Mutex.WaitAny(Mutex[] of gM1 and gM2)
thread4.Start(); // Does Mutex.WaitOne(Mutex gM2)
Thread.Sleep(2000);
Console.WriteLine(" - Main releases gM1");
gM1.ReleaseMutex(); // t2 and t3 will end and signal
Thread.Sleep(1000);
Console.WriteLine(" - Main releases gM2");
gM2.ReleaseMutex(); // t1 and t4 will end and signal
// Waiting until all four threads signal that they are done.
WaitHandle.WaitAll(evs);
Console.WriteLine("... Mutex Sample");
}
public void t1Start()
{
Console.WriteLine("t1Start started, Mutex.WaitAll(Mutex[])");
Mutex[] gMs = new Mutex[2];
gMs[0] = gM1; // Create and load an array of Mutex for WaitAll call
gMs[1] = gM2;
Mutex.WaitAll(gMs); // Waits until both gM1 and gM2 are released
Thread.Sleep(2000);
Console.WriteLine("t1Start finished, Mutex.WaitAll(Mutex[]) satisfied");
Event1.Set(); // AutoResetEvent.Set() flagging method is done
}
public void t2Start()
{
Console.WriteLine("t2Start started, gM1.WaitOne( )");
gM1.WaitOne(); // Waits until Mutex gM1 is released ---errors is here---
Console.WriteLine("t2Start finished, gM1.WaitOne( ) satisfied");
Event2.Set(); // AutoResetEvent.Set() flagging method is done
}
public void t3Start()
{
Console.WriteLine("t3Start started, Mutex.WaitAny(Mutex[])");
Mutex[] gMs = new Mutex[2];
gMs[0] = gM1; // Create and load an array of Mutex for WaitAny call
gMs[1] = gM2;
Mutex.WaitAny(gMs); // Waits until either Mutex is released
Console.WriteLine("t3Start finished, Mutex.WaitAny(Mutex[])");
Event3.Set(); // AutoResetEvent.Set() flagging method is done
}
public void t4Start()
{
Console.WriteLine("t4Start started, gM2.WaitOne( )");
gM2.WaitOne(); // Waits until Mutex gM2 is released
Console.WriteLine("t4Start finished, gM2.WaitOne( )");
Event4.Set(); // AutoResetEvent.Set() flagging method is done
}
}

Answer 1

Después de esperar en un Mutex tienes que liberarlo, usando

Mutex.ReleaseMutex()

antes de que los hilos salgan

fijo t1start - t4start

public void t1Start()
{
Console.WriteLine("t1Start started, Mutex.WaitAll(Mutex[])");
Mutex[] gMs = new Mutex[2];
gMs[0] = gM1; // Create and load an array of Mutex for WaitAll call
gMs[1] = gM2;
Mutex.WaitAll(gMs); // Waits until both gM1 and gM2 are released
Thread.Sleep(2000);
Console.WriteLine("t1Start finished, Mutex.WaitAll(Mutex[]) satisfied");
Event1.Set(); // AutoResetEvent.Set() flagging method is done
gM1.ReleaseMutex();
gM2.ReleaseMutex();
}
public void t2Start()
{
Console.WriteLine("t2Start started, gM1.WaitOne( )");
gM1.WaitOne(); // Waits until Mutex gM1 is released ---errors is here---
Console.WriteLine("t2Start finished, gM1.WaitOne( ) satisfied");
gM1.ReleaseMutex();
Event2.Set(); // AutoResetEvent.Set() flagging method is done
}
public void t3Start()
{
Console.WriteLine("t3Start started, Mutex.WaitAny(Mutex[])");
Mutex[] gMs = new Mutex[2];
gMs[0] = gM1; // Create and load an array of Mutex for WaitAny call
gMs[1] = gM2;
int result = Mutex.WaitAny(gMs); // Waits until either Mutex is released
gMs[result].ReleaseMutex();
Console.WriteLine("t3Start finished, Mutex.WaitAny(Mutex[])"); Event3.Set(); // AutoResetEvent.Set() flagging method is done
}
public void t4Start()
{
Console.WriteLine("t4Start started, gM2.WaitOne( )");
gM2.WaitOne(); // Waits until Mutex gM2 is released
Console.WriteLine("t4Start finished, gM2.WaitOne( )");
Event4.Set(); // AutoResetEvent.Set() flagging method is done
gM2.ReleaseMutex();
}