feat(esp-idf-monitor): Add --open-port-attempts flag

esp-idf-monitor frequently fails when trying to open the serial port of a device
which deep-sleeps often:

$ idf.py monitor -p /dev/cu.usbmodem6101
--- esp-idf-monitor 1.4.0 on /dev/cu.usbmodem6101 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
[Errno 2] could not open port: [...] No such file or directory: '/dev/cu.usbmodem6101'
Connection to /dev/cu.usbmodem6101 failed. Available ports:
/dev/cu.usbmodemF554393F21402

This commit adds a new flag `--open-port-attempts` which retries opening the port indefinitely
until the device shows up:

$ idf.py monitor -p /dev/cu.usbmodem6101 --open-port-attempts 0
--- esp-idf-monitor 1.4.0 on /dev/cu.usbmodem6101 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
[Errno 2] could not open port: [...] No such file or directory: '/dev/cu.usbmodem6101'
Retrying to open port ......
ESP-ROM:esp32s3-20210327

Also, add option to reconfigure reopening retry period.
This will greatly increase the chance of catching more logs in devices which deep-sleep.

Closes #15

esp_idf_monitor/base/argument_parser.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 
 import argparse
@@ -139,4 +139,12 @@ def get_parser():  # type: () -> argparse.ArgumentParser
         default=False,
         action='store_true')
 
+    parser.add_argument(
+        '--open-port-attempts',
+        help='Number of attempts to wait for the port to appear (useful if the device is not connected or in deep sleep).'
+        'Use 0 for infinite attempts.',
+        default=1,
+        type=int
+    )
+
     return parser

esp_idf_monitor/base/constants.py

@@ -1,6 +1,8 @@
-# SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 
+from esp_idf_monitor.base.key_config import cfg
+
 # Control-key characters
 CTRL_C = '\x03'
 CTRL_H = '\x08'
@@ -45,6 +47,7 @@
 EVENT_QUEUE_TIMEOUT = 0.03  # timeout before raising queue.Empty exception in case of empty event queue
 
 ESPPORT_ENVIRON = str('ESPPORT')
+ESPTOOL_OPEN_PORT_ATTEMPTS_ENVIRON = str('ESPTOOL_OPEN_PORT_ATTEMPTS')
 MAKEFLAGS_ENVIRON = 'MAKEFLAGS'
 
 GDB_UART_CONTINUE_COMMAND = '+$c#63'
@@ -55,7 +58,7 @@
 LAST_LINE_THREAD_INTERVAL = 0.1
 
 MINIMAL_EN_LOW_DELAY = 0.005
-RECONNECT_DELAY = 0.5  # timeout between reconnect tries
+RECONNECT_DELAY = cfg.getint('reconnect_delay', 0.5)  # timeout between reconnect tries
 CHECK_ALIVE_FLAG_TIMEOUT = 0.25  # timeout for checking alive flags (currently used by serial reader)
 
 # closing wait timeout for serial port

esp_idf_monitor/base/serial_reader.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 
 import queue  # noqa: F401
@@ -25,14 +25,15 @@ class SerialReader(Reader):
     event queue, until stopped.
     """
 
-    def __init__(self, serial_instance, event_queue, reset, target):
-        #  type: (serial.Serial, queue.Queue, bool, str) -> None
+    def __init__(self, serial_instance, event_queue, reset, open_port_attempts, target):
+        #  type: (serial.Serial, queue.Queue, bool, int, str) -> None
         super(SerialReader, self).__init__()
         self.baud = serial_instance.baudrate
         self.serial = serial_instance
         self.event_queue = event_queue
         self.gdb_exit = False
         self.reset = reset
+        self.open_port_attempts = open_port_attempts
         self.reset_strategy = Reset(serial_instance, target)
         if not hasattr(self.serial, 'cancel_read'):
             # enable timeout for checking alive flag,
@@ -46,40 +47,51 @@ def run(self):
             try:
                 # We can come to this thread at startup or from external application line GDB.
                 # If we come from GDB we would like to continue to run without reset.
-                self.open_serial(reset=not self.gdb_exit and self.reset)
+                self.reset = not self.gdb_exit and self.reset
+                self.open_serial(reset=self.reset)
+                # Successfully connected, so any further reconnections should occur without a reset.
+                self.reset = False
             except serial.SerialException as e:
                 print(e)
-                # if connection to port fails suggest other available ports
-                port_list = '\n'.join(
-                    [
-                        p.device
-                        for p in list_ports.comports()
-                        if not p.device.endswith(FILTERED_PORTS)
-                    ]
-                )
-                yellow_print(f'Connection to {self.serial.portstr} failed. Available ports:\n{port_list}')
-                return
+                if self.open_port_attempts == 1:
+                    # If the connection to the port fails and --open-port-attempts was not specified,
+                    # recommend other available ports and exit.
+                    port_list = '\n'.join(
+                        [
+                            p.device
+                            for p in list_ports.comports()
+                            if not p.device.endswith(FILTERED_PORTS)
+                        ]
+                    )
+                    yellow_print(f'Connection to {self.serial.portstr} failed. Available ports:\n{port_list}')
+                    return
             self.gdb_exit = False
         try:
             while self.alive:
                 try:
-                    data = self.serial.read(self.serial.in_waiting or 1)
-                except (serial.SerialException, IOError) as e:
+                    if self.serial.is_open:
+                        # in_waiting assumes the port is already open
+                        data = self.serial.read(self.serial.in_waiting or 1)
+                    else:
+                        raise serial.PortNotOpenError
+                except (serial.SerialException, IOError, OSError) as e:
                     data = b''
                     # self.serial.open() was successful before, therefore, this is an issue related to
                     # the disappearance of the device
-                    red_print(e.strerror)
+                    red_print(str(e))
                     yellow_print('Waiting for the device to reconnect', newline='')
                     self.close_serial()
                     while self.alive:  # so that exiting monitor works while waiting
                         try:
                             time.sleep(RECONNECT_DELAY)
                             # reset on reconnect can be unexpected for wakeup from deepsleep using JTAG
-                            self.open_serial(reset=False)
+                            self.open_serial(reset=self.reset)
+                            self.reset = False
                             break  # device connected
-                        except serial.SerialException:
+                        except (serial.SerialException, IOError, OSError):
                             yellow_print('.', newline='')
                             sys.stderr.flush()
+
                     yellow_print('')  # go to new line
                 if data:
                     self.event_queue.put((TAG_SERIAL, data), False)

esp_idf_monitor/config.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD,
+# SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD,
 # other contributors as noted.
 #
 # SPDX-License-Identifier: Apache-2.0
@@ -20,6 +20,7 @@
     'chip_reset_bootloader_key',
     'exit_menu_key',
     'skip_menu_key',
+    'reconnect_delay',
     'custom_reset_sequence',  # from esptool config
 ]
 

esp_idf_monitor/idf_monitor.py

@@ -9,7 +9,7 @@
 # - If core dump output is detected, it is converted to a human-readable report
 #   by espcoredump.py.
 #
-# SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 #
 # Contains elements taken from miniterm "Very simple serial terminal" which
@@ -44,6 +44,7 @@
                                             DEFAULT_TARGET_RESET,
                                             DEFAULT_TOOLCHAIN_PREFIX,
                                             ESPPORT_ENVIRON,
+                                            ESPTOOL_OPEN_PORT_ATTEMPTS_ENVIRON,
                                             EVENT_QUEUE_TIMEOUT,
                                             FILTERED_PORTS, GDB_EXIT_TIMEOUT,
                                             GDB_UART_CONTINUE_COMMAND,
@@ -90,6 +91,7 @@ def __init__(
         make='make',  # type: str
         encrypted=False,  # type: bool
         reset=DEFAULT_TARGET_RESET,  # type: bool
+        open_port_attempts=1,  # type: int
         toolchain_prefix=DEFAULT_TOOLCHAIN_PREFIX,  # type: str
         eol='CRLF',  # type: str
         decode_coredumps=COREDUMP_DECODE_INFO,  # type: str
@@ -128,7 +130,7 @@ def __init__(
             # testing hook: when running tests, input from console is ignored
             socket_test_mode = os.environ.get('ESP_IDF_MONITOR_TEST') == '1'
             self.serial = serial_instance
-            self.serial_reader = SerialReader(self.serial, self.event_queue, reset, target)  # type: Reader
+            self.serial_reader = SerialReader(self.serial, self.event_queue, reset, open_port_attempts, target)  # type: Reader
 
             self.gdb_helper = GDBHelper(toolchain_prefix, websocket_client, self.elf_file, self.serial.port,
                                         self.serial.baudrate) if self.elf_exists else None
@@ -403,7 +405,7 @@ def main() -> None:
             # has a check for this).
             # To make sure the key as well as the value are str type, by the requirements of subprocess
             espport_val = str(args.port)
-            os.environ.update({ESPPORT_ENVIRON: espport_val})
+            os.environ.update({ESPPORT_ENVIRON: espport_val, ESPTOOL_OPEN_PORT_ATTEMPTS_ENVIRON: str(args.open_port_attempts)})
 
             cls = SerialMonitor
             yellow_print('--- esp-idf-monitor {v} on {p.name} {p.baudrate} ---'.format(v=__version__, p=serial_instance))
@@ -414,6 +416,7 @@ def main() -> None:
                       args.make,
                       args.encrypted,
                       not args.no_reset,
+                      args.open_port_attempts,
                       args.toolchain_prefix,
                       args.eol,
                       args.decode_coredumps,