don't freeze gui during long makepkg tasks and avoid zombis with pamac-tray

pamac-tray.py

@@ -19,9 +19,10 @@
 #   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 from gi.repository import Gtk, GObject, Notify
-from subprocess import Popen
+from subprocess import call
 import dbus
 from dbus.mainloop.glib import DBusGMainLoop
+from threading import Thread
 
 from pamac import common
 
@@ -64,10 +65,10 @@ class Tray:
 		self.update_icon(icon, info)
 
 	def execute_update(self, widget, event, data = None):
-		Popen(['/usr/bin/pamac-updater'])
+		Thread(target = call, args = (['/usr/bin/pamac-updater'],)).start()
 
 	def execute_manager(self, widget, event, data = None):
-		Popen(['/usr/bin/pamac-manager'])
+		Thread(target = call, args = (['/usr/bin/pamac-manager'],)).start()
 
 	def quit_tray(self, widget, data = None):
 		Gtk.main_quit()
@@ -80,7 +81,7 @@ class Tray:
 
 	def activate_cb(self, widget, data = None):
 		if icon == update_icon:
-			Popen(['/usr/bin/pamac-updater'])
+			Thread(target = call, args = (['/usr/bin/pamac-updater'],)).start()
 
 	def update_icon(self, icon, info):
 		self.statusIcon.set_from_file(icon)
@@ -90,7 +91,7 @@ class Tray:
 		self.statusIcon.set_visible(boolean)
 
 def refresh():
-	Popen(['/usr/bin/pamac-refresh'])
+	Thread(target = call, args = (['/usr/bin/pamac-refresh'],)).start()
 
 def set_icon(update_data):
 	global icon

pamac/transaction.py

@@ -29,6 +29,7 @@ import fnmatch
 #from urllib.parse import urlparse
 import dbus
 from dbus.mainloop.glib import DBusGMainLoop
+import signal
 
 from pamac import config, common, aur
 
@@ -134,18 +135,6 @@ def config_dbus_signals():
 	bus.add_signal_receiver(log_error, dbus_interface = "org.manjaro.pamac", signal_name = "EmitLogError")
 	bus.add_signal_receiver(log_warning, dbus_interface = "org.manjaro.pamac", signal_name = "EmitLogWarning")
 
-def write_to_buffer(fd, condition):
-	if condition == GObject.IO_IN: # if there's something interesting to read
-		line = fd.readline().decode(encoding='UTF-8')
-		#print(line.rstrip('\n'))
-		progress_buffer.insert_at_cursor(line)
-		progress_bar.pulse()
-		while Gtk.events_pending():
-			Gtk.main_iteration()
-		return True # FUNDAMENTAL, otherwise the callback isn't recalled
-	else:
-		return False # Raised an error: exit
-
 def action_handler(action):
 	progress_label.set_text(action)
 
@@ -468,16 +457,34 @@ def prepare(**trans_flags):
 	return(error)
 
 def check_finished_build(data):
+	def handle_timeout(*args):
+		raise Exception('timeout')
+	
 	global to_build
 	global build_proc
 	path = data[0]
 	pkg = data[1]
 	if build_proc.poll() is None:
+		# Build no finished : read stdout to push it to text_buffer
+		# add a timeout to stop reading stdout if too long
+		# so the gui won't freeze
+		signal.signal(signal.SIGALRM, handle_timeout)
+		signal.setitimer(signal.ITIMER_REAL, 0.05) # 50 ms timeout
+		try:
+			line = build_proc.stdout.readline().decode(encoding='UTF-8')
+			#print(line.rstrip('\n'))
+			progress_buffer.insert_at_cursor(line)
 			progress_bar.pulse()
 			while Gtk.events_pending():
 				Gtk.main_iteration()
+		except Exception:
+			while Gtk.events_pending():
+				Gtk.main_iteration()
+		finally:
+			signal.alarm(0)
 			return True
 	elif build_proc.poll() == 0:
+		# Build successfully finished
 		built = []
 		# parse again PKGBUILD to have new pkg objects in case of a pkgver() function
 		# was used so pkgver was changed during build process
@@ -525,6 +532,7 @@ def check_finished_build(data):
 			action_long_handler(_('Build process failed.'))
 		return False
 	elif build_proc.poll() == 1:
+		# Build finish with an error
 		ProgressCancelButton.set_visible(False)
 		ProgressCloseButton.set_visible(True)
 		action_long_handler(_('Build process failed.'))
@@ -625,10 +633,9 @@ def build_next():
 	progress_expander.set_expanded(True)
 	ProgressWindow.show()
 	build_proc = subprocess.Popen(["makepkg", "-cf"], cwd = path, stdout = subprocess.PIPE, stderr=subprocess.STDOUT)
-	GObject.io_add_watch(build_proc.stdout, GObject.IO_IN, write_to_buffer)
 	while Gtk.events_pending():
 		Gtk.main_iteration()
-	GObject.timeout_add(500, check_finished_build, (path, pkg))
+	GObject.timeout_add(100, check_finished_build, (path, pkg))
 
 def finalize():
 	if To_Add() or To_Remove():