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in Technique[技术] by (71.8m points)

c# - Condition false, but code inside the if statement executed

I have the following method:

public bool ConnectAsync()
{
    if (IsConnected)
        throw new InvalidOperationException("Socket is already connected");

    if (IsConnecting)
    {
        throw new InvalidOperationException("Attempt to connect in progress");
    }

    . . .
}

Where:

    private readonly object padLock = new object();

    private bool isConnecting = false;

    public bool IsConnected
    {
        get
        {
            lock (padLock)
            { return socket.Connected; }
        }
    }

    public bool IsConnecting
    {
        get
        {
            lock (padLock)
            { return isConnecting; }
        }

        private set
        {
            lock (padLock)
            { isConnecting = value; }
        }
    }

enter image description here

Why the code inside the if statement is executed if my variable isConnecting is false?

Edit:
If I use the filed isConnecting instead of the property IsConnecting I have the same behavior. The code runs in the same thread anywhere.

Edit 2:

Finally this works:

lock (padLock)
{
    if (IsConnecting)
        throw new InvalidOperationException("Attempt to connect in progress");
}

And this works:

{
    if (IsConnecting)
        throw new InvalidOperationException("Attempt to connect in progress");
}

But why?

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1 Reply

0 votes
by (71.8m points)

This is probably an issue with the debugger and multiple threads, try putting the lock around the outside of the if statement rather than inside the property.


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