System.IO.Ports.SerialPort: Under Linux, closing the port while writing cause a deadlock. #100690
Description
Description
If you write from one thread and close the port from another, it is possible for the Write to lockup and never return.
It doesn't repro on Windows.
Reproduction Steps
The following reproduces the issue very quickly.
using System.IO.Ports;
var s = new SerialPort();
s.PortName = args[0];
Console.WriteLine("Using port {0}",s.PortName);
var t = new Thread(() =>
{
while (true)
{
try {
Console.WriteLine("Say hello");
s.Write("Hello World");
} catch (Exception e)
{}
}
});
t.Start();
while (true)
{
s.Open();
Thread.Sleep(1);
s.Close();
}
In SerialStreamUnix.cs:
Write eventually calls WriteAsync which queues a SerialStreamWriteRequest then calls EnsureIOLoopRunning.
EnsureIOLoopRunning acquires a lock (_ioLoopLock), however, Dispose does not, stops the ioLoop and writes to _ioLoop.
The IOLoop is stopped, and the request never completes.
Expected behavior
Write should always return or throw.
Actual behavior
it locks up after only a few iteration
Regression?
No response
Known Workarounds
- add lock around Close and Write
- Set a WriteTimeout
Configuration
tested with:
.NET 7.0.17
Linux ARM64
Other information
No response