socket: sync error handling with posix version

fixes pyserial#220

Author: zsquareplusc

serial/urlhandler/protocol_socket.py

@@ -170,14 +170,15 @@ def read(self, size=1):
                 read.extend(buf)
             except OSError as e:
                 # this is for Python 3.x where select.error is a subclass of
-                # OSError ignore EAGAIN errors. other errors are shown
-                if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS):
+                # OSError ignore BlockingIOErrors and EINTR. other errors are shown
+                # https://www.python.org/dev/peps/pep-0475.
+                if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
                     raise SerialException('read failed: {}'.format(e))
             except (select.error, socket.error) as e:
                 # this is for Python 2.x
-                # ignore EAGAIN errors. all other errors are shown
+                # ignore BlockingIOErrors and EINTR. all errors are shown
                 # see also http://www.python.org/dev/peps/pep-3151/#select
-                if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS):
+                if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
                     raise SerialException('read failed: {}'.format(e))
             if timeout.expired():
                 break
@@ -220,12 +221,20 @@ def write(self, data):
                 tx_len -= n
             except SerialException:
                 raise
-            except OSError as v:
-                if v.errno != errno.EAGAIN:
-                    raise SerialException('write failed: {}'.format(v))
-                # still calculate and check timeout
-                if timeout.expired():
-                    raise writeTimeoutError
+            except OSError as e:
+                # this is for Python 3.x where select.error is a subclass of
+                # OSError ignore BlockingIOErrors and EINTR. other errors are shown
+                # https://www.python.org/dev/peps/pep-0475.
+                if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
+                    raise SerialException('write failed: {}'.format(e))
+            except select.error as e:
+                # this is for Python 2.x
+                # ignore BlockingIOErrors and EINTR. all errors are shown
+                # see also http://www.python.org/dev/peps/pep-3151/#select
+                if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
+                    raise SerialException('write failed: {}'.format(e))
+            if not timeout.is_non_blocking and timeout.expired():
+                raise writeTimeoutError
         return length - len(d)
 
     def reset_input_buffer(self):
@@ -241,15 +250,16 @@ def reset_input_buffer(self):
                 self._socket.recv(4096)
             except OSError as e:
                 # this is for Python 3.x where select.error is a subclass of
-                # OSError ignore EAGAIN errors. all other errors are shown
-                if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS):
-                    raise SerialException('reset_input_buffer failed: {}'.format(e))
+                # OSError ignore BlockingIOErrors and EINTR. other errors are shown
+                # https://www.python.org/dev/peps/pep-0475.
+                if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
+                    raise SerialException('read failed: {}'.format(e))
             except (select.error, socket.error) as e:
                 # this is for Python 2.x
-                # ignore EAGAIN errors. all other errors are shown
+                # ignore BlockingIOErrors and EINTR. all errors are shown
                 # see also http://www.python.org/dev/peps/pep-3151/#select
-                if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS):
-                    raise SerialException('reset_input_buffer failed: {}'.format(e))
+                if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
+                    raise SerialException('read failed: {}'.format(e))
 
     def reset_output_buffer(self):
         """\