posix: allow calling cancel functions w/o error if port is closed
diff --git a/serial/serialposix.py b/serial/serialposix.py
index 195ecd4..afe5062 100644
--- a/serial/serialposix.py
+++ b/serial/serialposix.py
@@ -518,10 +518,12 @@
return bytes(read)
def cancel_read(self):
- os.write(self.pipe_abort_read_w, b"x")
+ if self.is_open:
+ os.write(self.pipe_abort_read_w, b"x")
def cancel_write(self):
- os.write(self.pipe_abort_write_w, b"x")
+ if self.is_open:
+ os.write(self.pipe_abort_write_w, b"x")
def write(self, data):
"""Output the given byte string over the serial port."""