Make AsynchronousTask subclasses override _wait() and _poll() so that calls

to public methods can be wrapped for implementing hooks such as exit listener
notification.

svn path=/main/trunk/; revision=10956

diff --git a/pym/_emerge/__init__.py b/pym/_emerge/__init__.py
index 49d345ba1934299daa841ec355bbaa8cd432cbb1..cc4ae29960a743985391f79f6b128ba2eccf7c0b 100644 (file)
--- a/pym/_emerge/__init__.py
+++ b/pym/_emerge/__init__.py
@@ -1455,6 +1455,12 @@ class EbuildFetchPretend(SlotObject):
                return retval
 
 class AsynchronousTask(SlotObject):
+       """
+       Subclasses override _wait() and _poll() so that calls
+       to public methods can be wrapped for implementing
+       hooks such as exit listener notification.
+       """
+
        __slots__ = ("cancelled", "returncode") + ("_exit_listeners",)
 
        def start(self):
@@ -1467,14 +1473,21 @@ class AsynchronousTask(SlotObject):
                return self.returncode is None
 
        def poll(self):
-               if self.returncode is not None:
-                       self._wait_hook()
+               return self._poll
+
+       def _poll(self):
+               self._wait_hook()
                return self.returncode
 
        def wait(self):
+               if self.returncode is None:
+                       self._wait()
                self._wait_hook()
                return self.returncode
 
+       def _wait(self):
+               return self.returncode
+
        def cancel(self):
                self.cancelled = True
                self.wait()
@@ -1497,7 +1510,8 @@ class AsynchronousTask(SlotObject):
                used to trigger exit listeners when the returncode first
                becomes available.
                """
-               if self._exit_listeners is not None:
+               if self.returncode is not None and \
+                       self._exit_listeners is not None:
                        for f in self._exit_listeners:
                                f(self)
                        self._exit_listeners = None
@@ -1514,7 +1528,7 @@ class CompositeTask(AsynchronousTask):
                if self._current_task is not None:
                        self._current_task.cancel()
 
-       def wait(self):
+       def _wait(self):
 
                while True:
                        task = self._current_task
@@ -1524,7 +1538,6 @@ class CompositeTask(AsynchronousTask):
                                self.scheduler.schedule(task.reg_id)
                        task.wait()
 
-               self._wait_hook()
                return self.returncode
 
        def _assert_current(self, task):
@@ -1617,14 +1630,13 @@ class TaskSequence(CompositeTask):
 class SubProcess(AsynchronousTask):
        __slots__ = ("pid",)
 
-       def poll(self):
+       def _poll(self):
                if self.returncode is not None:
                        return self.returncode
                retval = os.waitpid(self.pid, os.WNOHANG)
                if retval == (0, 0):
                        return None
                self._set_returncode(retval)
-               self._wait_hook()
                return self.returncode
 
        def cancel(self):
@@ -1639,11 +1651,10 @@ class SubProcess(AsynchronousTask):
                return self.pid is not None and \
                        self.returncode is None
 
-       def wait(self):
+       def _wait(self):
                if self.returncode is not None:
                        return self.returncode
                self._set_returncode(os.waitpid(self.pid, 0))
-               self._wait_hook()
                return self.returncode
 
        def _set_returncode(self, wait_retval):
@@ -1907,7 +1918,7 @@ class EbuildBuild(CompositeTask):
                                        pkg=pkg, settings=settings)
                                retval = fetcher.execute()
                                self.returncode = retval
-                               self._wait_hook()
+                               self.wait()
 
                        else:
                                fetcher = EbuildFetcher(pkg=pkg, scheduler=scheduler)