Scheduler: add more info in docstring comments

This clarifies the purposes of _system_merge_started and _choose_pkg.

diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index 06eeed5b108a9c3c170fc16a0b3d4f224d8db1b9..d557a14102949ba7af8dd63990ce223b46518249 100644 (file)
--- a/pym/_emerge/Scheduler.py
+++ b/pym/_emerge/Scheduler.py
@@ -1375,6 +1375,10 @@ class Scheduler(PollScheduler):
        def _system_merge_started(self, merge):
                """
                Add any unsatisfied runtime deps to self._unsatisfied_system_deps.
+               In general, this keeps track of installed system packages with
+               unsatisfied RDEPEND or PDEPEND (circular dependencies). It can be
+               a fragile situation, so we don't execute any unrelated builds until
+               the circular dependencies are built and intstalled.
                """
                graph = self._digraph
                if graph is None:
@@ -1554,7 +1558,9 @@ class Scheduler(PollScheduler):
 
        def _choose_pkg(self):
                """
-               Choose a task that has all it's dependencies satisfied.
+               Choose a task that has all its dependencies satisfied. This is used
+               for parallel build scheduling, and ensures that we don't build
+               anything with deep dependencies that have yet to be merged.
                """
 
                if self._choose_pkg_return_early: