_LockProcess: handle process failure if cancelled

diff --git a/pym/_emerge/AsynchronousLock.py b/pym/_emerge/AsynchronousLock.py
index 6fa2bf632d2ff8b40af853dc7409212e1fa4c649..b62b684f1af9f3d56ac0be56d61b1048f0fba99c 100644 (file)
--- a/pym/_emerge/AsynchronousLock.py
+++ b/pym/_emerge/AsynchronousLock.py
@@ -176,7 +176,7 @@ class _LockProcess(AbstractPollTask):
        """
 
        __slots__ = ('path', 'scheduler',) + \
-               ('_proc', '_files', '_reg_id')
+               ('_proc', '_files', '_reg_id', '_unlocked')
 
        def _start(self):
                in_pr, in_pw = os.pipe()
@@ -201,8 +201,14 @@ class _LockProcess(AbstractPollTask):
                os.close(in_pw)
 
        def _proc_exit(self, proc):
-               if proc.returncode != os.EX_OK:
-                       # There's no good reason for locks to fail.
+               if proc.returncode != os.EX_OK and \
+                       not self.cancelled and \
+                       not self._unlocked:
+                       # Typically, lock process failure should only happen
+                       # if it's killed by a signal. We don't want lost
+                       # locks going unnoticed, so it's only safe to ignore
+                       # if either the cancel() or unlock() methods have
+                       # been previously called.
                        raise AssertionError('lock process failed with returncode %s' \
                                % (proc.returncode,))
 
@@ -244,6 +250,7 @@ class _LockProcess(AbstractPollTask):
                        raise AssertionError('not locked')
                if self.returncode is None:
                        raise AssertionError('lock not acquired yet')
+               self._unlocked = True
                self._files['pipe_out'].write(b'\0')
                self._files['pipe_out'].close()
                self._files = None