snapshot of https://github.com/ActivityWatch/aw-client.git (master, 2026-09-16; blobs > 131072B omitted)

aw_client/singleinstance.py

@@ -0,0 +1,47 @@
+import sys
+import os
+import logging
+
+if sys.platform != "win32":
+    import fcntl
+
+from aw_core.dirs import get_cache_dir
+
+logger = logging.getLogger(__name__)
+
+
+class SingleInstance:
+    """
+    This code is taken and modified form the tendo python package
+    (Python Software Foundation License Version 2)
+    http://pythonhosted.org/tendo/_modules/tendo/singleton.html
+    """
+
+    def __init__(self, client_name):
+        self.lockfile = os.path.join(get_cache_dir("client_locks"), client_name)
+        logger.debug("SingleInstance lockfile: " + self.lockfile)
+        if sys.platform == "win32":
+            try:
+                # file already exists, we try to remove (in case previous execution was interrupted)
+                if os.path.exists(self.lockfile):
+                    os.unlink(self.lockfile)
+                    self.fd = os.open(self.lockfile, os.O_CREAT | os.O_EXCL | os.O_RDWR)
+            except OSError as e:
+                if e.errno == 13:
+                    logger.error("Another instance is already running, quitting.")
+                    sys.exit(-1)
+                else:
+                    raise e
+        else:  # non Windows
+            self.fp = open(self.lockfile, "w")
+            try:
+                fcntl.lockf(self.fp, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            except OSError:
+                logger.error("Another instance is already running, quitting.")
+                sys.exit(-1)
+
+    def __del__(self):
+        if sys.platform == "win32":
+            if hasattr(self, "fd"):
+                os.close(self.fd)
+                os.unlink(self.lockfile)