comparison mercurial/lock.py @ 26473:5f94e64f182c

lock: turn prepinherit/reacquire into a single context manager

Review feedback from Pierre-Yves David. This makes the overall code cleaner and
less error-prone, and makes a previously explicitly checked error state
impossible.

26472:406a654b41cb

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import errno
import os
import socket
import time
import warnings

        """
        locker = self._readlock()
        return self._testlock(locker)

    def prepinherit(self):
        """prepare for the lock to be inherited by a Mercurial subprocess

        Returns a string that will be recognized by the lock in the
        subprocess. Communicating this string to the subprocess needs to be done
        separately -- typically by an environment variable.
        """
        if not self.held:
            raise error.LockInheritanceContractViolation(
                'prepinherit can only be called while lock is held')
        if self._inherited:
            raise error.LockInheritanceContractViolation(
                'prepinherit cannot be called while lock is already inherited')
        if self.releasefn:
            self.releasefn()
        if self._parentheld:
            lockname = self.parentlock
        else:
            lockname = '%s:%s' % (lock._host, self.pid)
        self._inherited = True
        return lockname

    def reacquire(self):
        if not self._inherited:
            raise error.LockInheritanceContractViolation(
                'reacquire can only be called after prepinherit')
        if self.acquirefn:
            self.acquirefn()
        self._inherited = False

    def release(self):
        """release the lock and execute callback function if any

        If the lock has been acquired multiple times, the actual release is

26473:5f94e64f182c

# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import contextlib
import errno
import os
import socket
import time
import warnings

        """
        locker = self._readlock()
        return self._testlock(locker)

    @contextlib.contextmanager
    def inherit(self):
        """context for the lock to be inherited by a Mercurial subprocess.

        Yields a string that will be recognized by the lock in the subprocess.
        Communicating this string to the subprocess needs to be done separately
        -- typically by an environment variable.
        """
        if not self.held:
            raise error.LockInheritanceContractViolation(
                'inherit can only be called while lock is held')
        if self._inherited:
            raise error.LockInheritanceContractViolation(
                'inherit cannot be called while lock is already inherited')
        if self.releasefn:
            self.releasefn()
        if self._parentheld:
            lockname = self.parentlock
        else:
            lockname = '%s:%s' % (lock._host, self.pid)
        self._inherited = True
        try:
            yield lockname
        finally:
            if self.acquirefn:
                self.acquirefn()
            self._inherited = False

    def release(self):
        """release the lock and execute callback function if any

        If the lock has been acquired multiple times, the actual release is