Remove forking support

* Third-party plugins have to be fork-safe
* Not supported on Windows

radicale/log.py

@@ -24,21 +24,15 @@ Log messages are sent to the first available target of:
   - systemd-journald
   - stderr
 
-The logger is thread-safe and fork-safe.
-
 """
 
 import contextlib
 import io
 import logging
-import multiprocessing
 import os
 import sys
-import tempfile
 import threading
 
-from radicale import pathutils
-
 try:
     import systemd.journal
 except ImportError:
@@ -64,14 +58,10 @@ class IdentLogRecordFactory:
 
     def __init__(self, upstream_factory):
         self.upstream_factory = upstream_factory
-        self.main_pid = os.getpid()
 
     def __call__(self, *args, **kwargs):
         record = self.upstream_factory(*args, **kwargs)
-        pid = os.getpid()
-        ident = "%x" % self.main_pid
-        if pid != self.main_pid:
-            ident += "%+x" % (pid - self.main_pid)
+        ident = "%x" % os.getpid()
         main_thread = threading.main_thread()
         current_thread = threading.current_thread()
         if current_thread.name and main_thread != current_thread:
@@ -80,27 +70,6 @@ class IdentLogRecordFactory:
         return record
 
 
-class RwLockWrapper():
-
-    def __init__(self):
-        self._file = tempfile.NamedTemporaryFile()
-        self._lock = pathutils.RwLock(self._file.name)
-        self._cm = None
-
-    def acquire(self, blocking=True):
-        assert self._cm is None
-        if not blocking:
-            raise NotImplementedError
-        cm = self._lock.acquire("w")
-        cm.__enter__()
-        self._cm = cm
-
-    def release(self):
-        assert self._cm is not None
-        self._cm.__exit__(None, None, None)
-        self._cm = None
-
-
 class ThreadStreamsHandler(logging.Handler):
 
     terminator = "\n"
@@ -111,13 +80,6 @@ class ThreadStreamsHandler(logging.Handler):
         self.fallback_stream = fallback_stream
         self.fallback_handler = fallback_handler
 
-    def createLock(self):
-        try:
-            self.lock = multiprocessing.Lock()
-        except Exception:
-            # HACK: Workaround for Android
-            self.lock = RwLockWrapper()
-
     def setFormatter(self, fmt):
         super().setFormatter(fmt)
         self.fallback_handler.setFormatter(fmt)