[bugfix] Remove unnecessary file locks

reframe/frontend/autodetect.py

@@ -3,7 +3,6 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-import fcntl
 import json
 import jsonschema
 import os
@@ -80,8 +79,7 @@ def _validate_info(info, schema):
 def _load_info(filename, schema=None):
     try:
         with open(filename) as fp:
-            with osext.lock_file(fp, fcntl.LOCK_SH):
-                return _validate_info(json.load(fp), schema)
+            return _validate_info(json.load(fp), schema)
     except OSError as e:
         getlogger().warning(
             f'could not load file: {filename!r}: {e}'
@@ -100,8 +98,7 @@ def _save_info(filename, topo_info):
     os.makedirs(os.path.dirname(filename), exist_ok=True)
     try:
         with open(filename, 'w') as fp:
-            with osext.lock_file(fp, fcntl.LOCK_EX):
-                json.dump(topo_info, fp, indent=2)
+            json.dump(topo_info, fp, indent=2)
     except OSError as e:
         getlogger().warning(
             f'could not save topology file: {filename!r}: {e}'

reframe/utility/osext.py

@@ -9,7 +9,6 @@
 
 import collections.abc
 import errno
-import fcntl
 import getpass
 import grp
 import os
@@ -305,28 +304,6 @@ def rmtree(*args, max_retries=3, **kwargs):
                 raise
 
 
-# FIXME: Need a proper unit test for this
-class lock_file:
-    def __init__(self, fp, mode):
-        '''Lock file pointed to by file pointer fp.
-
-        This call is blocking.
-        '''
-
-        self._mode = mode
-        if isinstance(fp, int):
-            # Treat fp as a file descriptor
-            self._fd = fp
-        else:
-            self._fd = fp.fileno()
-
-    def __enter__(self):
-        fcntl.flock(self._fd, self._mode)
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        fcntl.flock(self._fd, fcntl.LOCK_UN)
-
-
 def inpath(entry, pathvar):
     '''Check if entry is in path.