Move library load/destory to seprate file

& improve autoclose debug setting

src/pypdfium2/__init__.py

@@ -1,16 +1,7 @@
 # SPDX-FileCopyrightText: 2023 geisserml <geisserml@gmail.com>
 # SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
 
-import atexit
-import logging
+import pypdfium2._library_scope
 from pypdfium2.version import *
 from pypdfium2._helpers import *
 from pypdfium2 import raw, internal
-
-logger = logging.getLogger(__name__)  # FIXME perhaps unnecessary?
-
-# Note: PDFium developers plan changes to the initialisation API (see https://crbug.com/pdfium/1446)
-raw.FPDF_InitLibrary()
-atexit.register(raw.FPDF_DestroyLibrary)
-
-del atexit, logging

src/pypdfium2/__main__.py

@@ -58,8 +58,7 @@ def get_parser():
 
 def setup_logging():
 
-    debug_autoclose = bool(int( os.environ.get("DEBUG_AUTOCLOSE", 0) ))
-    pdfium_i.set_autoclose_debug(debug_autoclose)
+    pdfium_i.DEBUG_AUTOCLOSE.value = bool(int( os.environ.get("DEBUG_AUTOCLOSE", 0) ))
 
     lib_logger = logging.getLogger("pypdfium2")
     lib_logger.addHandler(logging.StreamHandler())

src/pypdfium2/_library_scope.py

@@ -0,0 +1,21 @@
+# SPDX-FileCopyrightText: 2023 geisserml <geisserml@gmail.com>
+# SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
+
+import atexit
+import pypdfium2.raw as pdfium_c
+import pypdfium2.internal as pdfium_i
+
+
+def destroy_library():
+    if pdfium_i.DEBUG_AUTOCLOSE:
+        import os, sys
+        os.write(sys.stderr.fileno(), b"Destroy PDFium (auto)\n")
+    pdfium_c.FPDF_DestroyLibrary()
+
+# Load pdfium
+# Note: PDFium developers plan changes to the initialisation API (see https://crbug.com/pdfium/1446)
+pdfium_c.FPDF_InitLibrary()
+
+# Register an exit handler that will free pdfium
+# Trust in Python to call exit handlers only after all objects have been finalized
+atexit.register(destroy_library)

src/pypdfium2/internal/bases.py

@@ -1,7 +1,7 @@
 # SPDX-FileCopyrightText: 2023 geisserml <geisserml@gmail.com>
 # SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
 
-__all__ = ("AutoCastable", "AutoCloseable", "set_autoclose_debug")
+__all__ = ("AutoCastable", "AutoCloseable", "DEBUG_AUTOCLOSE")
 
 import os
 import sys
@@ -12,19 +12,15 @@
 
 logger = logging.getLogger(__name__)
 
-DEBUG_AUTOCLOSE = False
+
+DEBUG_AUTOCLOSE = ctypes.c_bool(False)  # mutable bool
 
 STATE_INVALID = -1
 STATE_AUTO = 0
 STATE_EXPLICIT = 1
 STATE_BYPARENT = 2
 
 
-def set_autoclose_debug(value=True):
-    global DEBUG_AUTOCLOSE
-    DEBUG_AUTOCLOSE = value
-
-
 class AutoCastable:
 
     @property