Merge pull request #15677 from abadger/ziploader-cache-lock-dict-fix

Fix the mapping of module_name to Locks

lib/ansible/executor/module_common.py

@@ -34,7 +34,10 @@ from ansible.release import __version__, __author__
 from ansible import constants as C
 from ansible.errors import AnsibleError
 from ansible.utils.unicode import to_bytes, to_unicode
-from ansible.plugins.strategy import action_write_locks
+# Must import strategy and use write_locks from there
+# If we import write_locks directly then we end up binding a
+# variable to the object and then it never gets updated.
+from ansible.plugins import strategy
 
 try:
     from __main__ import display
@@ -552,14 +555,29 @@ def _find_snippet_imports(module_name, module_data, module_path, module_args, ta
         zipdata = None
         # Optimization -- don't lock if the module has already been cached
         if os.path.exists(cached_module_filename):
+            display.debug('ZIPLOADER: using cached module: %s' % cached_module_filename)
             zipdata = open(cached_module_filename, 'rb').read()
             # Fool the check later... I think we should just remove the check
             py_module_names.add(('basic',))
         else:
-            with action_write_locks[module_name]:
+            if module_name in strategy.action_write_locks:
+                display.debug('ZIPLOADER: Using lock for %s' % module_name)
+                lock = strategy.action_write_locks[module_name]
+            else:
+                # If the action plugin directly invokes the module (instead of
+                # going through a strategy) then we don't have a cross-process
+                # Lock specifically for this module.  Use the "unexpected
+                # module" lock instead
+                display.debug('ZIPLOADER: Using generic lock for %s' % module_name)
+                lock = strategy.action_write_locks[None]
+
+            display.debug('ZIPLOADER: Acquiring lock')
+            with lock:
+                display.debug('ZIPLOADER: Lock acquired: %s' % id(lock))
                 # Check that no other process has created this while we were
                 # waiting for the lock
                 if not os.path.exists(cached_module_filename):
+                    display.debug('ZIPLOADER: Creating module')
                     # Create the module zip data
                     zipoutput = BytesIO()
                     zf = zipfile.ZipFile(zipoutput, mode='w', compression=compression_method)
@@ -580,15 +598,19 @@ def _find_snippet_imports(module_name, module_data, module_path, module_args, ta
                         # Note -- if we have a global function to setup, that would
                         # be a better place to run this
                         os.mkdir(lookup_path)
+                    display.debug('ZIPLOADER: Writing module')
                     with open(cached_module_filename + '-part', 'w') as f:
                         f.write(zipdata)
 
                     # Rename the file into its final position in the cache so
                     # future users of this module can read it off the
                     # filesystem instead of constructing from scratch.
+                    display.debug('ZIPLOADER: Renaming module')
                     os.rename(cached_module_filename + '-part', cached_module_filename)
+                    display.debug('ZIPLOADER: Done creating module')
 
             if zipdata is None:
+                display.debug('ZIPLOADER: Reading module after lock')
                 # Another process wrote the file while we were waiting for
                 # the write lock.  Go ahead and read the data from disk
                 # instead of re-creating it.

lib/ansible/plugins/strategy/__init__.py

@@ -36,6 +36,7 @@ from ansible.executor.process.worker import WorkerProcess
 from ansible.executor.task_result import TaskResult
 from ansible.inventory.host import Host
 from ansible.inventory.group import Group
+from ansible.module_utils.facts import Facts
 from ansible.playbook.helpers import load_list_of_blocks
 from ansible.playbook.included_file import IncludedFile
 from ansible.plugins import action_loader, connection_loader, filter_loader, lookup_loader, module_loader, test_loader
@@ -52,8 +53,24 @@ except ImportError:
 
 __all__ = ['StrategyBase']
 
-action_write_locks = defaultdict(Lock)
-
+if 'action_write_locks' not in globals():
+    # Do not initialize this more than once because it seems to bash
+    # the existing one.  multiprocessing must be reloading the module
+    # when it forks?
+    action_write_locks = dict()
+
+    # Below is a Lock for use when we weren't expecting a named module.
+    # It gets used when an action plugin directly invokes a module instead
+    # of going through the strategies.  Slightly less efficient as all
+    # processes with unexpected module names will wait on this lock
+    action_write_locks[None] = Lock()
+
+    # These plugins are called directly by action plugins (not going through
+    # a strategy).  We precreate them here as an optimization
+    mods = set(p['name'] for p in Facts.PKG_MGRS)
+    mods.update(('copy', 'file', 'setup', 'slurp', 'stat'))
+    for mod_name in mods:
+        action_write_locks[mod_name] = Lock()
 
 # TODO: this should probably be in the plugins/__init__.py, with
 #       a smarter mechanism to set all of the attributes based on
@@ -144,18 +161,19 @@ class StrategyBase:
 
         display.debug("entering _queue_task() for %s/%s" % (host, task))
 
-         # Add a write lock for tasks.
-         # Maybe this should be added somewhere further up the call stack but
-         # this is the earliest in the code where we have task (1) extracted
-         # into its own variable and (2) there's only a single code path
-         # leading to the module being run.  This is called by three
-         # functions: __init__.py::_do_handler_run(), linear.py::run(), and
-         # free.py::run() so we'd have to add to all three to do it there.
-         # The next common higher level is __init__.py::run() and that has
-         # tasks inside of play_iterator so we'd have to extract them to do it
-         # there.
-        if not action_write_locks[task.action]:
-            display.warning('Python defaultdict did not create the Lock for us.  Creating manually')
+        # Add a write lock for tasks.
+        # Maybe this should be added somewhere further up the call stack but
+        # this is the earliest in the code where we have task (1) extracted
+        # into its own variable and (2) there's only a single code path
+        # leading to the module being run.  This is called by three
+        # functions: __init__.py::_do_handler_run(), linear.py::run(), and
+        # free.py::run() so we'd have to add to all three to do it there.
+        # The next common higher level is __init__.py::run() and that has
+        # tasks inside of play_iterator so we'd have to extract them to do it
+        # there.
+        global action_write_locks
+        if task.action not in action_write_locks:
+            display.debug('Creating lock for %s' % task.action)
             action_write_locks[task.action] = Lock()
 
         # and then queue the new task