X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=lockfile.py;h=38134b20d02f00f8d419b5ddfef669c5002a4abf;hb=31c81f6539969a5eba864d3305f9fb7bf716a367;hp=7f10cc1f5894155c65ca352183afc0ea6d81fa37;hpb=b454ad295eb3024a238d32bf2aef1ebc3c496b44;p=python_utils.git diff --git a/lockfile.py b/lockfile.py index 7f10cc1..38134b2 100644 --- a/lockfile.py +++ b/lockfile.py @@ -1,29 +1,26 @@ #!/usr/bin/env python3 -from dataclasses import dataclass import datetime import json import logging import os import signal import sys -from typing import Optional import warnings +from dataclasses import dataclass +from typing import Optional import config import datetime_utils import decorator_utils - -cfg = config.add_commandline_args( - f'Lockfile ({__file__})', - 'Args related to lockfiles') +cfg = config.add_commandline_args(f'Lockfile ({__file__})', 'Args related to lockfiles') cfg.add_argument( '--lockfile_held_duration_warning_threshold_sec', type=float, default=10.0, metavar='SECONDS', - help='If a lock is held for longer than this threshold we log a warning' + help='If a lock is held for longer than this threshold we log a warning', ) logger = logging.getLogger(__name__) @@ -36,7 +33,7 @@ class LockFileException(Exception): class LockFileContents: pid: int commandline: str - expiration_timestamp: float + expiration_timestamp: Optional[float] class LockFile(object): @@ -50,13 +47,14 @@ class LockFile(object): # some logic for detecting stale locks. """ + def __init__( - self, - lockfile_path: str, - *, - do_signal_cleanup: bool = True, - expiration_timestamp: Optional[float] = None, - override_command: Optional[str] = None, + self, + lockfile_path: str, + *, + do_signal_cleanup: bool = True, + expiration_timestamp: Optional[float] = None, + override_command: Optional[str] = None, ) -> None: self.is_locked = False self.lockfile = lockfile_path @@ -90,20 +88,18 @@ class LockFile(object): pass msg = f'Could not acquire {self.lockfile}.' logger.warning(msg) - warnings.warn(msg) return False def acquire_with_retries( - self, - *, - initial_delay: float = 1.0, - backoff_factor: float = 2.0, - max_attempts = 5 + self, + *, + initial_delay: float = 1.0, + backoff_factor: float = 2.0, + max_attempts=5, ) -> bool: - - @decorator_utils.retry_if_false(tries = max_attempts, - delay_sec = initial_delay, - backoff = backoff_factor) + @decorator_utils.retry_if_false( + tries=max_attempts, delay_sec=initial_delay, backoff=backoff_factor + ) def _try_acquire_lock_with_retries() -> bool: success = self.try_acquire_lock_once() if not success and os.path.exists(self.lockfile): @@ -127,14 +123,16 @@ class LockFile(object): return self msg = f"Couldn't acquire {self.lockfile}; giving up." logger.warning(msg) - warnings.warn(msg) raise LockFileException(msg) def __exit__(self, type, value, traceback): if self.locktime: ts = datetime.datetime.now().timestamp() duration = ts - self.locktime - if duration >= config.config['lockfile_held_duration_warning_threshold_sec']: + if ( + duration + >= config.config['lockfile_held_duration_warning_threshold_sec'] + ): str_duration = datetime_utils.describe_duration_briefly(duration) msg = f'Held {self.lockfile} for {str_duration}' logger.warning(msg) @@ -154,11 +152,10 @@ class LockFile(object): cmd = self.override_command else: cmd = ' '.join(sys.argv) - print(cmd) contents = LockFileContents( - pid = os.getpid(), - commandline = cmd, - expiration_timestamp = self.expiration_timestamp, + pid=os.getpid(), + commandline=cmd, + expiration_timestamp=self.expiration_timestamp, ) return json.dumps(contents.__dict__) @@ -178,16 +175,14 @@ class LockFile(object): except OSError: msg = f'Lockfile {self.lockfile}\'s pid ({contents.pid}) is stale; force acquiring' logger.warning(msg) - warnings.warn(msg) self.release() # Has the lock expiration expired? if contents.expiration_timestamp is not None: now = datetime.datetime.now().timestamp() - if now > contents.expiration_datetime: + if now > contents.expiration_timestamp: msg = f'Lockfile {self.lockfile} expiration time has passed; force acquiring' logger.warning(msg) - warnings.warn(msg) self.release() except Exception: pass