Description

We can use File.Exists to check whether the pipe exists, just as the code:

File.Exists(@"\\.\pipe\" + PipeName);

But after we use the File.Exists method, the NamedPipeClientStream may connect fail.

Reproduction Steps

Step 1: Using NamedPipeServerStream to create the Pipe

void StartServer()
{
    var server = new NamedPipeServerStream(PipeName,
        PipeDirection.InOut, 1, PipeTransmissionMode.Byte, PipeOptions.Asynchronous, 1024, 1024);

    server.BeginWaitForConnection(OnWaitForConnection, server);
}

Step 2: Using File.Exists to check the pipe exists.

File.Exists(@"\\.\pipe\" + PipeName);

Step 3: Using NamedPipeClientStream to connect the pipe.

void StartClient()
{
    var localServer = ".";
    var pipeDirection = PipeDirection.InOut;
    var client = new NamedPipeClientStream(localServer,
        PipeName, pipeDirection, PipeOptions.Asynchronous);

    var timeout = 1000 * 5;
    client.Connect(timeout);
}

And you can find the client.Connect(timeout); throw the TimeoutException

All the demo code in: https://github.com/lindexi/lindexi_gd/tree/e26bdd0bced93db8edf8be18f1062e571f3d1861/HallwhallkernarbafejaNakeldibi

Expected behavior

The NamedPipeClientStream can connect the pipe.

Actual behavior

The client.Connect will throw timeout exception.

Regression?

No response

Known Workarounds

No response

Configuration

.NET 6 (all version)

Windows 10.

Other information

Is my method of use wrong?