Merge pull request #25 from BrianPugh/infinite-retry

Infinitely attempt to reconnect if attempts is set to a negative number

belay/device.py

@@ -23,7 +23,7 @@
     SpecialFunctionNameError,
 )
 from .inspect import getsource
-from .pyboard import Pyboard, PyboardException
+from .pyboard import Pyboard, PyboardError, PyboardException
 from .webrepl import WebreplToSerial
 
 # Typing
@@ -531,26 +531,32 @@ def sync(
             progress_update(description="Cleaning up...")
         self._exec_snippet("sync_end")
 
-    def close(self):
+    def close(self) -> None:
         """Close the connection to device."""
         return self._board.close()
 
-    def reconnect(self, attempts: Optional[int] = None):
+    def reconnect(self, attempts: Optional[int] = None) -> None:
         """Reconnect to the device and replay the command history.
 
         Parameters
         ----------
         attempts : int
             Number of times to attempt to connect to board with a 1 second delay in-between.
-            If ``None``, defaults to whatever value was supplied to init (1).
+            If ``None``, defaults to whatever value was supplied to init.
+            If init value is 0, then defaults to 1.
         """
         if len(self._cmd_history) == self.MAX_CMD_HISTORY_LEN:
             raise MaxHistoryLengthError
 
         kwargs = self._board_kwargs.copy()
-        kwargs["attempts"] = self.attempts if attempts is None else attempts
+        kwargs["attempts"] = attempts
+        if kwargs["attempts"] is None:
+            kwargs["attempts"] = self.attempts if self.attempts else 1
 
-        self._connect_to_board(**kwargs)
+        try:
+            self._connect_to_board(**kwargs)
+        except PyboardError as e:
+            raise ConnectionLost from e
 
         # Playback the history
         for cmd in self._cmd_history:

belay/pyboard.py

@@ -68,6 +68,7 @@
 """
 
 import ast
+import itertools
 import os
 import sys
 import time
@@ -267,19 +268,32 @@ def inWaiting(self):
 class Pyboard:
     def __init__(
         self,
-        device,
-        baudrate=115200,
-        user="micro",
-        password="python",
-        attempts=1,
-        exclusive=True,
+        device: str,
+        baudrate: int = 115200,
+        user: str = "micro",
+        password: str = "python",
+        attempts: int = 1,
+        exclusive: bool = True,
     ):
         """
         Parameters
         ----------
-        wait: int
-            (N-1) of attempts to try and connect
+        device: str
+            Some device specificier like ``'/dev/ttyACM0'`` or ``'192.168.1.1'``.
+        baudrate: int
+            If a serial-like connection, this baudrate will be used.
+        user: str
+            If connection requires a username, this will be used.
+        password: str
+            If connection requires a password, this will be used.
+        attempts: int
+            Number of attempts to try and connect to board.
+            If a ``<0`` value is provided, will infinitely try to connect.
+        exclusive: bool
+            If a serial-like connection, this configures the ``exclusive`` flag.
         """
+        if attempts == 0:
+            raise ValueError('"attempts" cannot be 0.')
         self.in_raw_repl = False
         self.use_raw_paste = True
         if device.startswith("exec:"):
@@ -304,16 +318,17 @@ def __init__(
             if serial.__version__ >= "3.3":
                 serial_kwargs["exclusive"] = exclusive
 
-            for _ in range(attempts):
+            for attempt_count in itertools.count(start=1):
                 try:
                     self.serial = serial.Serial(device, **serial_kwargs)
                     break
                 except (OSError, IOError):  # Py2 and Py3 have different errors
-                    if attempts == 1:
-                        continue
+                    pass
+
+                if attempt_count == attempts:
+                    raise PyboardError("failed to access " + device)
+
                 time.sleep(1.0)
-            else:
-                raise PyboardError("failed to access " + device)
 
     def close(self):
         self.serial.close()

docs/source/Connections.rst

@@ -23,6 +23,7 @@ Example:
    device = Device("/dev/ttyUSB0", attempts=10)
 
 By default, ``attempts=0``, meaning that Belay will **not** attempt to reconnect with the device.
+If ``attempts`` is set to a negative value, Belay will infinitely attempt to reconnect with the device.
 If using a serial connection, a serial device __might__ not be assigned to the name upon reconnecting.
 See the `UDev Rules`_ section for ways to ensure the same name is assigned upon reconnection.