Tweak 868584d so agent waits first, then does the work

hschmidt · Jan 8, 2017 · 56a2e8c · 56a2e8c
1 parent 210d351
commit 56a2e8c
Showing 1 changed file with 11 additions and 4 deletions.
diff --git a/EnvAgent/EnvAgent.m b/EnvAgent/EnvAgent.m
@@ -25,6 +25,17 @@
 int main( int argc, const char **argv )
 {
     NSLog( @"Started agent %s (%u)", argv[ 0 ], getpid() );
+    /*
+     * Work around weird issue with launchd starting the agent a second time if it finishes within
+     * 10 seconds, the default ThrottleInterval. We reduce the ThrottleInterval to 1s in the plist
+     * and wait a little longer here to avoid hitting that condition. We wait first, before doing
+     * any real work in order to consolidate potential bursts of changes to the environment plist.
+     *
+     * But let's not kid ourselves, this is still racy (a flaw inherent to launchd's WatchPaths
+     * mechanism) and we could miss updates if they happen after the plist is read and before
+     * launchd recognizes the agent's termination.
+     */
+    [NSThread sleepForTimeInterval: 1.1];
 
     NSError *error = nil;
     NSFileManager *fileManager = [NSFileManager defaultManager];
@@ -93,10 +104,6 @@ int main( int argc, const char **argv )
             NSLog( @"Failed to unload agent (%@)", agentLabel );
         }
     }
-    // Work around weird issue with launchd starting the agent a second time if it finishes within
-    // 10 seconds, the default ThrottleInterval. We reduce the ThrottleInterval to 1s in the plist
-    // and wait a little longer here to avoid hitting that condition.
-    [NSThread sleepForTimeInterval: 1.1];
     NSLog( @"Exiting agent %s (PID %u)", argv[ 0 ], getpid() );
     return 0;
 }