Question

I need to use lock object, but it is already used by another thread. I wish to wait while the lock object will be free but have no idea how to do this.

I found sth like:

if(Monitor.TryEnter(_lock)
{
try
{
    // do work
}
finally
{
    Monitor.Exit(_lock);
}

}

But I it just check and go on, but I wish to wait until lock object is free.

Answer 1

Either use this:

Monitor.Enter(_lock)

try
{
    // do work
}
finally
{
    Monitor.Exit(_lock);
}

or – more preferably – the lock keyword:

lock(_lock)
{
    // do work
}

In fact, those code snippets will generate the same code. The compiler will translate the second code into the first one. However, the second one is preferred because it is far more readable.

UPDATE:
The lock belongs to the thread it was acquired in. That means, nested usage of the lock statement is possible:

void MethodA()
{
    lock(_lock)
    {
        // ...
        MethodB();
    }
}

void MethodB()
{
    lock(_lock)
    {
        // ...
    }
}

The above code will not block.