schedule path check directly on file change, instead of through an immediately fired...

diff --git a/windows/PathWatcher.cs b/windows/PathWatcher.cs
index 7a23102c5bcdd4203bf5e397bc860d86c9480c05..10187aaa663baa48d8bfac5c8335cd0aaddb21f5 100755 (executable)
--- a/windows/PathWatcher.cs
+++ b/windows/PathWatcher.cs
@@ -44,25 +44,7 @@ namespace Graphviz
                        _lastChange = DateTime.MinValue;\r
                        _checker = new Timer(delegate(object state)\r
                        {\r
-                               _synchronizingObject.BeginInvoke((ThreadStart)delegate()\r
-                               {\r
-                                       if (Changed != null)\r
-                                       {\r
-                                               /* debounce file watch changes: if last write time hadn't actually changed, don't bother notifying */\r
-                                               DateTime thisChange = File.GetLastWriteTimeUtc(_watched);\r
-                                               if (_lastChange != thisChange)\r
-                                               {\r
-                                                       /* if any registered delegate didn't cancel the event, ask checker to check it again after a while */\r
-                                                       CancelEventArgs eventArgs = new CancelEventArgs(true);\r
-                                                       Changed(this, eventArgs);\r
-                                                       if (eventArgs.Cancel)\r
-                                                               _lastChange = thisChange;\r
-                                                       else\r
-                                                               _checker.Change(RECHECK_DELAY, Timeout.Infinite);\r
-                                               }\r
-                                       }\r
-                               },\r
-                               new object[0]);\r
+                               CheckPath();\r
                        });\r
 \r
                        _watcher = new FileSystemWatcher(Path.GetDirectoryName(watched), Path.GetFileName(watched));\r
@@ -70,18 +52,18 @@ namespace Graphviz
                        _watcher.Changed += delegate(object sender, FileSystemEventArgs eventArgs)\r
                        {\r
                                /* check now */\r
-                               _checker.Change(0, Timeout.Infinite);\r
+                               CheckPath();\r
                        };\r
                        _watcher.Created += delegate(object sender, FileSystemEventArgs eventArgs)\r
                        {\r
                                /* check now */\r
-                               _checker.Change(0, Timeout.Infinite);\r
+                               CheckPath();\r
                        };\r
                        _watcher.Renamed += delegate(object sender, RenamedEventArgs eventArgs)\r
                        {\r
                                /* if file got changed to our name, check now */\r
                                if (eventArgs.Name == _watcher.Filter)\r
-                                       _checker.Change(0, Timeout.Infinite);\r
+                                       CheckPath();\r
                        };\r
                }\r
                \r
@@ -95,6 +77,30 @@ namespace Graphviz
                        _checker.Dispose();\r
                }\r
                \r
+               private void CheckPath()\r
+               {\r
+                       /* schedule a check for the path on the synchronizing object, usually a window */\r
+                       _synchronizingObject.BeginInvoke((ThreadStart)delegate()\r
+                       {\r
+                               if (Changed != null)\r
+                               {\r
+                                       /* debounce file watch changes: if last write time hadn't actually changed, don't bother notifying */\r
+                                       /* NOTE: we only mutate _lastChange via this synchronized code, so there should be no race condition */\r
+                                       DateTime thisChange = File.GetLastWriteTimeUtc(_watched);\r
+                                       if (_lastChange != thisChange)\r
+                                       {\r
+                                               /* if any registered delegate didn't cancel the event, ask checker to check it again after a while */\r
+                                               CancelEventArgs eventArgs = new CancelEventArgs(true);\r
+                                               Changed(this, eventArgs);\r
+                                               if (eventArgs.Cancel)\r
+                                                       _lastChange = thisChange;\r
+                                               else\r
+                                                       _checker.Change(RECHECK_DELAY, Timeout.Infinite);\r
+                                       }\r
+                               }\r
+                       }, new object[0]);\r
+               \r
+               }\r
                private const int RECHECK_DELAY = 100;\r
                \r
                private readonly string _watched;\r