comparison mercurial/lock.py @ 43798:888bd39ed555

lock: pass "success" boolean to _afterlock callbacks

This lets the callback decide if it should actually run or not. I suspect that
most callbacks (and hooks) *should not* run in this scenario, but I'm trying
to not break any existing behavior. `persistmanifestcache`, however, seems
actively dangerous to run: we just encountered an exception and the repo is in
an unknown state (hopefully a consistent one due to transactions, but this is
not 100% guaranteed), and the data we cache may be based on this unknown
state.

This was observed by our users since we wrap some of the functions that
persistmanifestcache calls and it expects that the repo object is in a certain
state that we'd set up earlier. If the user hits ctrl-c before we establish
that state, we end up crashing there. I'm going to  make that extension
resilient to this issue, but figured it might be a common issue and should be
handled here as well instead of just working around the issue.

Differential Revision: https://phab.mercurial-scm.org/D7459

43797:c8e9a3636abe

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, exc_tb):
        self.release()

    def __del__(self):
        if self.held:
            warnings.warn(
                "use lock.release instead of del lock",

        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
        delayed to the last release call."""
        if self.held > 1:

                        pass
            # The postrelease functions typically assume the lock is not held
            # at all.
            if not self._parentheld:
                for callback in self.postrelease:
                    callback()
                # Prevent double usage and help clear cycles.
                self.postrelease = None


def release(*locks):

43798:888bd39ed555

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, exc_tb):
        success = all(a is None for a in (exc_type, exc_value, exc_tb))
        self.release(success=success)

    def __del__(self):
        if self.held:
            warnings.warn(
                "use lock.release instead of del lock",

        finally:
            if self.acquirefn:
                self.acquirefn()
            self._inherited = False

    def release(self, success=True):
        """release the lock and execute callback function if any

        If the lock has been acquired multiple times, the actual release is
        delayed to the last release call."""
        if self.held > 1:

                        pass
            # The postrelease functions typically assume the lock is not held
            # at all.
            if not self._parentheld:
                for callback in self.postrelease:
                    callback(success)
                # Prevent double usage and help clear cycles.
                self.postrelease = None


def release(*locks):