PollScheduler: use local EventLoop (thread safe)

For API consumers, this makes the doebuild() function compatible with
threads, avoiding a ValueError raised by the signal module, as reported
at http://bugs.sabayon.org/show_bug.cgi?id=3305. Classes derived from
PollScheduler still use the signal module when possible.

5 files changed, 19 insertions, 9 deletions

diff --git a/pym/_emerge/MetadataRegen.py b/pym/_emerge/MetadataRegen.py
index 79446ee79..e82015fd1 100644
--- a/pym/_emerge/MetadataRegen.py
+++ b/pym/_emerge/MetadataRegen.py
@@ -11,7 +11,7 @@ class MetadataRegen(PollScheduler):
 
 	def __init__(self, portdb, cp_iter=None, consumer=None,
 		max_jobs=None, max_load=None):
-		PollScheduler.__init__(self)
+		PollScheduler.__init__(self, main=True)
 		self._portdb = portdb
 		self._global_cleanse = False
 		if cp_iter is None:
diff --git a/pym/_emerge/PollScheduler.py b/pym/_emerge/PollScheduler.py
index 1c631c3f2..965dc20ee 100644
--- a/pym/_emerge/PollScheduler.py
+++ b/pym/_emerge/PollScheduler.py
@@ -13,6 +13,7 @@ from portage import _encodings
 from portage import _unicode_encode
 from portage.util import writemsg_level
 from portage.util.SlotObject import SlotObject
+from portage.util._eventloop.EventLoop import EventLoop
 from portage.util._eventloop.global_event_loop import global_event_loop
 
 from _emerge.getloadavg import getloadavg
@@ -26,7 +27,13 @@ class PollScheduler(object):
 			"output", "register", "run",
 			"source_remove", "timeout_add", "unregister")
 
-	def __init__(self):
+	def __init__(self, main=False):
+		"""
+		@param main: If True then use global_event_loop(), otherwise use
+			a local EventLoop instance (default is False, for safe use in
+			a non-main thread)
+		@type main: bool
+		"""
 		self._terminated = threading.Event()
 		self._terminated_tasks = False
 		self._max_jobs = 1
@@ -34,7 +41,10 @@ class PollScheduler(object):
 		self._jobs = 0
 		self._scheduling = False
 		self._background = False
-		self._event_loop = global_event_loop()
+		if main:
+			self._event_loop = global_event_loop()
+		else:
+			self._event_loop = EventLoop(main=False)
 		self.sched_iface = self._sched_iface_class(
 			IO_ERR=self._event_loop.IO_ERR,
 			IO_HUP=self._event_loop.IO_HUP,
diff --git a/pym/_emerge/QueueScheduler.py b/pym/_emerge/QueueScheduler.py
index 9d73b7826..206087c7a 100644
--- a/pym/_emerge/QueueScheduler.py
+++ b/pym/_emerge/QueueScheduler.py
@@ -10,8 +10,8 @@ class QueueScheduler(PollScheduler):
 	run() method returns when no tasks remain.
 	"""
 
-	def __init__(self, max_jobs=None, max_load=None):
-		PollScheduler.__init__(self)
+	def __init__(self, main=True, max_jobs=None, max_load=None):
+		PollScheduler.__init__(self, main=main)
 
 		if max_jobs is None:
 			max_jobs = 1
diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index 5500acfbb..30a7e101b 100644
--- a/pym/_emerge/Scheduler.py
+++ b/pym/_emerge/Scheduler.py
@@ -137,7 +137,7 @@ class Scheduler(PollScheduler):
 	def __init__(self, settings, trees, mtimedb, myopts,
 		spinner, mergelist=None, favorites=None, graph_config=None,
 		uninstall_only=False):
-		PollScheduler.__init__(self)
+		PollScheduler.__init__(self, main=True)
 
 		if mergelist is not None:
 			warnings.warn("The mergelist parameter of the " + \
diff --git a/pym/_emerge/TaskScheduler.py b/pym/_emerge/TaskScheduler.py
index 71ac80f14..583bfe323 100644
--- a/pym/_emerge/TaskScheduler.py
+++ b/pym/_emerge/TaskScheduler.py
@@ -1,4 +1,4 @@
-# Copyright 1999-2009 Gentoo Foundation
+# Copyright 1999-2012 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 from _emerge.QueueScheduler import QueueScheduler
@@ -11,9 +11,9 @@ class TaskScheduler(object):
 	add tasks and call run(). The run() method returns when no tasks remain.
 	"""
 
-	def __init__(self, max_jobs=None, max_load=None):
+	def __init__(self, main=True, max_jobs=None, max_load=None):
 		self._queue = SequentialTaskQueue(max_jobs=max_jobs)
-		self._scheduler = QueueScheduler(
+		self._scheduler = QueueScheduler(main=main,
 			max_jobs=max_jobs, max_load=max_load)
 		self.sched_iface = self._scheduler.sched_iface
 		self.run = self._scheduler.run