From 05e32593ec570670b18ed92c11f5b724e7e8be13 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 18 Mar 2008 22:25:17 +0000
Subject: [PATCH] Implement unique application instance checks

---
 src/libprs500/__init__.py  | 13 +++++++++++--
 src/libprs500/gui2/main.py |  2 +-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/libprs500/__init__.py b/src/libprs500/__init__.py
index f38ac46594..5662a29002 100644
--- a/src/libprs500/__init__.py
+++ b/src/libprs500/__init__.py
@@ -411,7 +411,16 @@ def relpath(target, base=os.curdir):
     rel_list = [os.pardir] * (len(base_list)-i) + target_list[i:]
     return os.path.join(*rel_list)
 
-_lock_file = None
+def _clean_lock_file(file):
+    try:
+        file.close()
+    except:
+        pass
+    try:
+        os.remove(file.name)
+    except:
+        pass
+    
 def singleinstance(name):
     '''
     Return True if no other instance of the application identified by name is running, 
@@ -435,7 +444,7 @@ def singleinstance(name):
         try:
             f = open(path, 'w')
             fcntl.lockf(f.fileno(), fcntl.LOCK_EX|fcntl.LOCK_NB)
-            _lock_file = f
+            atexit.register(_clean_lock_file, f)
             return True
         except IOError:
             return False
diff --git a/src/libprs500/gui2/main.py b/src/libprs500/gui2/main.py
index 36d0090f3a..22e4498380 100644
--- a/src/libprs500/gui2/main.py
+++ b/src/libprs500/gui2/main.py
@@ -1016,7 +1016,7 @@ def main(args=sys.argv):
         app = QApplication(args)    
         QCoreApplication.setOrganizationName(ORG_NAME)
         QCoreApplication.setApplicationName(APP_UID)
-        if not singleinstance('main GUI'):
+        if not singleinstance('mainGUI'):
             QMessageBox.critical(None, 'Cannot Start '+__appname__, 
                                  '<p>%s is already running.</p>'%__appname__)
             return 1