Scheduler: add more info in docstring comments

This clarifies the purposes of _system_merge_started and _choose_pkg.

1 files changed, 7 insertions, 1 deletions

diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index 06eeed5b1..d557a1410 100644
--- 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: