AsynchronousTask: add _async_wait method

For cases where _start returns synchronously, this method is a
convenient way to trigger an asynchronous call to self.wait()
(in order to notify exit listeners), avoiding excessive event
loop recursion (or stack overflow) that synchronous calling of
exit listeners can cause.

11 files changed, 32 insertions, 19 deletions

diff --git a/pym/_emerge/AbstractEbuildProcess.py b/pym/_emerge/AbstractEbuildProcess.py
index 597208f52..6d12cd999 100644
--- a/pym/_emerge/AbstractEbuildProcess.py
+++ b/pym/_emerge/AbstractEbuildProcess.py
@@ -56,7 +56,7 @@ class AbstractEbuildProcess(SpawnProcess):
 			(self.phase, self.settings['PORTAGE_BUILDDIR'])
 			self._eerror(textwrap.wrap(msg, 72))
 			self._set_returncode((self.pid, 1 << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		if self.background:
diff --git a/pym/_emerge/AsynchronousLock.py b/pym/_emerge/AsynchronousLock.py
index b4de779f9..5bb9663a1 100644
--- a/pym/_emerge/AsynchronousLock.py
+++ b/pym/_emerge/AsynchronousLock.py
@@ -49,7 +49,7 @@ class AsynchronousLock(AsynchronousTask):
 				pass
 			else:
 				self.returncode = os.EX_OK
-				self.wait()
+				self._async_wait()
 				return
 
 		if self._force_process or \
diff --git a/pym/_emerge/AsynchronousTask.py b/pym/_emerge/AsynchronousTask.py
index 7a193ce7d..b540575d8 100644
--- a/pym/_emerge/AsynchronousTask.py
+++ b/pym/_emerge/AsynchronousTask.py
@@ -60,6 +60,20 @@ class AsynchronousTask(SlotObject):
 	def _wait(self):
 		return self.returncode
 
+	def _async_wait(self):
+		"""
+		For cases where _start exits synchronously, this method is a
+		convenient way to trigger an asynchronous call to self.wait()
+		(in order to notify exit listeners), avoiding excessive event
+		loop recursion (or stack overflow) that synchronous calling of
+		exit listeners can cause.
+		"""
+		self.scheduler.idle_add(self._async_wait_cb)
+
+	def _async_wait_cb(self):
+		self.wait()
+		return False
+
 	def cancel(self):
 		"""
 		Cancel the task, but do not wait for exit status. If asynchronous exit
diff --git a/pym/_emerge/BinpkgFetcher.py b/pym/_emerge/BinpkgFetcher.py
index 14f2552cb..099d3c498 100644
--- a/pym/_emerge/BinpkgFetcher.py
+++ b/pym/_emerge/BinpkgFetcher.py
@@ -63,7 +63,7 @@ class BinpkgFetcher(SpawnProcess):
 		if pretend:
 			portage.writemsg_stdout("\n%s\n" % uri, noiselevel=-1)
 			self._set_returncode((self.pid, os.EX_OK << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		protocol = urllib_parse_urlparse(uri)[0]
diff --git a/pym/_emerge/BinpkgVerifier.py b/pym/_emerge/BinpkgVerifier.py
index 0052967f6..fd4f266a1 100644
--- a/pym/_emerge/BinpkgVerifier.py
+++ b/pym/_emerge/BinpkgVerifier.py
@@ -1,4 +1,4 @@
-# Copyright 1999-2011 Gentoo Foundation
+# Copyright 1999-2012 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 from _emerge.AsynchronousTask import AsynchronousTask
@@ -71,5 +71,4 @@ class BinpkgVerifier(AsynchronousTask):
 				background=self.background)
 
 		self.returncode = rval
-		self.wait()
-
+		self._async_wait()
diff --git a/pym/_emerge/EbuildBuild.py b/pym/_emerge/EbuildBuild.py
index cec63d992..599875a32 100644
--- a/pym/_emerge/EbuildBuild.py
+++ b/pym/_emerge/EbuildBuild.py
@@ -35,7 +35,7 @@ class EbuildBuild(CompositeTask):
 			if rval != os.EX_OK:
 				self.returncode = rval
 				self._current_task = None
-				self.wait()
+				self._async_wait()
 				return
 
 		root_config = pkg.root_config
@@ -60,7 +60,7 @@ class EbuildBuild(CompositeTask):
 		if not self._check_manifest():
 			self.returncode = 1
 			self._current_task = None
-			self.wait()
+			self._async_wait()
 			return
 
 		prefetcher = self.prefetcher
diff --git a/pym/_emerge/EbuildFetcher.py b/pym/_emerge/EbuildFetcher.py
index 3cbe1b899..df790b0d3 100644
--- a/pym/_emerge/EbuildFetcher.py
+++ b/pym/_emerge/EbuildFetcher.py
@@ -117,13 +117,13 @@ class EbuildFetcher(ForkProcess):
 			msg_lines.append(msg)
 			self._eerror(msg_lines)
 			self._set_returncode((self.pid, 1 << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		if not uri_map:
 			# Nothing to fetch.
 			self._set_returncode((self.pid, os.EX_OK << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		settings = self.config_pool.allocate()
@@ -135,7 +135,7 @@ class EbuildFetcher(ForkProcess):
 			self._prefetch_size_ok(uri_map, settings, ebuild_path):
 			self.config_pool.deallocate(settings)
 			self._set_returncode((self.pid, os.EX_OK << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		nocolor = settings.get("NOCOLOR")
diff --git a/pym/_emerge/EbuildMetadataPhase.py b/pym/_emerge/EbuildMetadataPhase.py
index cc8d77593..89734e045 100644
--- a/pym/_emerge/EbuildMetadataPhase.py
+++ b/pym/_emerge/EbuildMetadataPhase.py
@@ -51,14 +51,14 @@ class EbuildMetadataPhase(SubProcess):
 			# An empty EAPI setting is invalid.
 			self._eapi_invalid(None)
 			self._set_returncode((self.pid, 1 << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		self.eapi_supported = portage.eapi_is_supported(parsed_eapi)
 		if not self.eapi_supported:
 			self.metadata = {"EAPI": parsed_eapi}
 			self._set_returncode((self.pid, os.EX_OK << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		settings = self.settings
@@ -114,7 +114,7 @@ class EbuildMetadataPhase(SubProcess):
 			# doebuild failed before spawning
 			self._unregister()
 			self._set_returncode((self.pid, retval << 8))
-			self.wait()
+			self._async_wait()
 			return
 
 		self.pid = retval[0]
diff --git a/pym/_emerge/MergeListItem.py b/pym/_emerge/MergeListItem.py
index 371e2e2e2..172dfccdf 100644
--- a/pym/_emerge/MergeListItem.py
+++ b/pym/_emerge/MergeListItem.py
@@ -32,7 +32,7 @@ class MergeListItem(CompositeTask):
 		if pkg.installed:
 			# uninstall,  executed by self.merge()
 			self.returncode = os.EX_OK
-			self.wait()
+			self._async_wait()
 			return
 
 		args_set = self.args_set
diff --git a/pym/_emerge/PackageUninstall.py b/pym/_emerge/PackageUninstall.py
index eb6a947a5..16c2f749b 100644
--- a/pym/_emerge/PackageUninstall.py
+++ b/pym/_emerge/PackageUninstall.py
@@ -1,4 +1,4 @@
-# Copyright 1999-2011 Gentoo Foundation
+# Copyright 1999-2012 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 import logging
@@ -33,7 +33,7 @@ class PackageUninstall(CompositeTask):
 			# Apparently the package got uninstalled
 			# already, so we can safely return early.
 			self.returncode = os.EX_OK
-			self.wait()
+			self._async_wait()
 			return
 
 		self.settings.setcpv(self.pkg)
@@ -67,7 +67,7 @@ class PackageUninstall(CompositeTask):
 		if retval != os.EX_OK:
 			self._builddir_lock.unlock()
 			self.returncode = retval
-			self.wait()
+			self._async_wait()
 			return
 
 		self._writemsg_level(">>> Unmerging %s...\n" % (self.pkg.cpv,),
diff --git a/pym/_emerge/SpawnProcess.py b/pym/_emerge/SpawnProcess.py
index 45d709517..2045b2e7b 100644
--- a/pym/_emerge/SpawnProcess.py
+++ b/pym/_emerge/SpawnProcess.py
@@ -96,7 +96,7 @@ class SpawnProcess(SubProcess):
 			# spawn failed
 			self._unregister()
 			self._set_returncode((self.pid, retval))
-			self.wait()
+			self._async_wait()
 			return
 
 		self.pid = retval[0]