PollScheduler: add generic _main_loop()

4 files changed, 30 insertions, 27 deletions

diff --git a/pym/_emerge/MetadataRegen.py b/pym/_emerge/MetadataRegen.py
index 1ebc53268..340400119 100644
--- a/pym/_emerge/MetadataRegen.py
+++ b/pym/_emerge/MetadataRegen.py
@@ -82,18 +82,16 @@ class MetadataRegen(PollScheduler):
 					portdb=portdb, repo_path=repo_path,
 					settings=portdb.doebuild_settings)
 
+	def _keep_scheduling(self):
+		return self._remaining_tasks and not self._terminated_tasks
+
 	def run(self):
 
 		portdb = self._portdb
 		from portage.cache.cache_errors import CacheError
 		dead_nodes = {}
 
-		self._schedule()
-		while self._remaining_tasks and not self._terminated_tasks:
-			self.sched_iface.iteration()
-
-		while self._jobs:
-			self.sched_iface.iteration()
+		self._main_loop()
 
 		if self._terminated_tasks:
 			self.returncode = 1
diff --git a/pym/_emerge/PollScheduler.py b/pym/_emerge/PollScheduler.py
index eafb8a237..3b3ef67df 100644
--- a/pym/_emerge/PollScheduler.py
+++ b/pym/_emerge/PollScheduler.py
@@ -109,6 +109,28 @@ class PollScheduler(object):
 		finally:
 			self._scheduling = False
 
+	def _main_loop(self):
+		# Populate initial event sources. We only need to do
+		# this once here, since it can be called during the
+		# loop from within event handlers.
+		self._schedule()
+
+		# Loop while there are jobs to be scheduled.
+		while self._keep_scheduling():
+			self.sched_iface.iteration()
+
+		# Clean shutdown of previously scheduled jobs. In the
+		# case of termination, this allows for basic cleanup
+		# such as flushing of buffered output to logs.
+		while self._is_work_scheduled():
+			self.sched_iface.iteration()
+
+	def _keep_scheduling(self):
+		return False
+
+	def _is_work_scheduled(self):
+		return bool(self._running_job_count())
+
 	def _running_job_count(self):
 		return self._jobs
 
diff --git a/pym/_emerge/QueueScheduler.py b/pym/_emerge/QueueScheduler.py
index e34758a85..ba740c11f 100644
--- a/pym/_emerge/QueueScheduler.py
+++ b/pym/_emerge/QueueScheduler.py
@@ -44,15 +44,7 @@ class QueueScheduler(PollScheduler):
 				timeout, timeout_callback)
 
 		try:
-
-			while not (timeout_callback is not None and
-				timeout_callback.timed_out) and self._schedule():
-				self.sched_iface.iteration()
-
-			while not (timeout_callback is not None and
-				timeout_callback.timed_out) and self._running_job_count():
-				self.sched_iface.iteration()
-
+			self._main_loop()
 		except StopIteration:
 			pass
 		finally:
diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index 100d89d1c..66d76b1e0 100644
--- a/pym/_emerge/Scheduler.py
+++ b/pym/_emerge/Scheduler.py
@@ -1347,6 +1347,9 @@ class Scheduler(PollScheduler):
 
 	def _merge(self):
 
+		if self._opts_no_background.intersection(self.myopts):
+			self._set_max_jobs(1)
+
 		self._add_prefetchers()
 		self._add_packages()
 		failed_pkgs = self._failed_pkgs
@@ -1493,18 +1496,6 @@ class Scheduler(PollScheduler):
 	def _deallocate_config(self, settings):
 		self._config_pool[settings['EROOT']].append(settings)
 
-	def _main_loop(self):
-
-		if self._opts_no_background.intersection(self.myopts):
-			self._set_max_jobs(1)
-
-		self._schedule()
-		while self._keep_scheduling():
-			self.sched_iface.iteration()
-
-		while self._is_work_scheduled():
-			self.sched_iface.iteration()
-
 	def _keep_scheduling(self):
 		return bool(not self._terminated_tasks and self._pkg_queue and \
 			not (self._failed_pkgs and not self._build_opts.fetchonly))