[meld] filediff: Delay as much thread and queue handling as possible to idle

[Kai Willadsen <kaiw src gnome org>]

commit 37fa668d2a79c9dfcdaeb6055f1e95dff8383aa7
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Mar 1 09:46:14 2015 +1000

    filediff: Delay as much thread and queue handling as possible to idle
    
    Because of interactions between the GIL, Python threads and the GObject
    main loop, we get very undesirable behaviour on startup where our
    threads behave as borderline synchronous code. By putting as much of
    this as possible in idle, we make this behaviour somewhat less
    pathological.

 meld/filediff.py |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)
---
diff --git a/meld/filediff.py b/meld/filediff.py
index e1851dd..c3b8cf7 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -60,7 +60,6 @@ class MatcherWorker(threading.Thread):
         self.tasks = tasks
         self.results = results
         self.daemon = True
-        self.start()
 
     def run(self):
         while True:
@@ -100,6 +99,7 @@ class CachedSequenceMatcher(object):
         self.thread = MatcherWorker(self.tasks, self.results)
         self.task_id = 1
         self.queued_matches = {}
+        GLib.idle_add(self.thread.start)
 
     def match(self, text1, textn, cb):
         texts = (text1, textn)
@@ -108,11 +108,14 @@ class CachedSequenceMatcher(object):
             opcodes = self.cache[texts][0]
             GLib.idle_add(lambda: cb(opcodes))
         except KeyError:
-            self.tasks.put((self.task_id, texts))
-            if not bool(self.queued_matches):
-                GLib.idle_add(self.check_results)
-            self.queued_matches[self.task_id] = (texts, cb)
-            self.task_id += 1
+            GLib.idle_add(lambda: self.enqueue_task(texts, cb))
+
+    def enqueue_task(self, texts, cb):
+        if not bool(self.queued_matches):
+            GLib.idle_add(self.check_results)
+        self.queued_matches[self.task_id] = (texts, cb)
+        self.tasks.put((self.task_id, texts))
+        self.task_id += 1
 
     def check_results(self):
         try: