PIIODevice::waitThreadedReadFinished now periodically (100 ms) call interrupt()

libs/main/io_devices/piiodevice.cpp

@@ -232,7 +232,16 @@ void PIIODevice::terminateThreadedRead() {
 
 
 bool PIIODevice::waitThreadedReadFinished(int timeout_ms) {
-	return read_thread.waitForFinish(timeout_ms);
+	PITimeMeasurer tm, tm_intr;
+	while (read_thread.isRunning()) {
+		if (tm.elapsed_m() > timeout_ms) return false;
+		if (tm_intr.elapsed_m() > 100.) {
+			tm_intr.reset();
+			interrupt();
+		}
+		piMinSleep();
+	}
+	return true;
 }