Brett Cannon's dummy_thread and dummy_threading modules (SF patch
622537), with some nitpicking editorial changes.
diff --git a/Lib/dummy_thread.py b/Lib/dummy_thread.py
new file mode 100644
index 0000000..b0ba0ce
--- /dev/null
+++ b/Lib/dummy_thread.py
@@ -0,0 +1,116 @@
+"""Drop-in replacement for the thread module.
+
+Meant to be used as a brain-dead substitute so that threaded code does
+not need to be rewritten for when the thread module is not present.
+
+Suggested usage is::
+
+ try:
+ import thread
+ except ImportError:
+ import dummy_thread as thread
+
+"""
+__author__ = "Brett Cannon"
+__email__ = "brett@python.org"
+
+# Exports only things specified by thread documentation
+# (skipping obsolete synonyms allocate(), start_new(), exit_thread())
+__all__ = ['error', 'start_new_thread', 'exit', 'get_ident', 'allocate_lock',
+ 'LockType']
+
+import traceback as _traceback
+
+class error(Exception):
+ """Dummy implementation of thread.error."""
+
+ def __init__(self, *args):
+ self.args = args
+
+def start_new_thread(function, args, kwargs={}):
+ """Dummy implementation of thread.start_new_thread().
+
+ Compatibility is maintained by making sure that ``args`` is a
+ tuple and ``kwargs`` is a dictionary. If an exception is raised
+ and it is SystemExit (which can be done by thread.exit()) it is
+ caught and nothing is done; all other exceptions are printed out
+ by using traceback.print_exc().
+
+ """
+ if type(args) != type(tuple()):
+ raise TypeError("2nd arg must be a tuple")
+ if type(kwargs) != type(dict()):
+ raise TypeError("3rd arg must be a dict")
+ try:
+ function(*args, **kwargs)
+ except SystemExit:
+ pass
+ except:
+ _traceback.print_exc()
+
+def exit():
+ """Dummy implementation of thread.exit()."""
+ raise SystemExit
+
+def get_ident():
+ """Dummy implementation of thread.get_ident().
+
+ Since this module should only be used when threadmodule is not
+ available, it is safe to assume that the current process is the
+ only thread. Thus a constant can be safely returned.
+ """
+ return -1
+
+def allocate_lock():
+ """Dummy implementation of thread.allocate_lock()."""
+ return LockType()
+
+class LockType(object):
+ """Class implementing dummy implementation of thread.LockType.
+
+ Compatibility is maintained by maintaining self.locked_status
+ which is a boolean that stores the state of the lock. Pickling of
+ the lock, though, should not be done since if the thread module is
+ then used with an unpickled ``lock()`` from here problems could
+ occur from this class not having atomic methods.
+
+ """
+
+ def __init__(self):
+ self.locked_status = False
+
+ def acquire(self, waitflag=None):
+ """Dummy implementation of acquire().
+
+ For blocking calls, self.locked_status is automatically set to
+ True and returned appropriately based on value of
+ ``waitflag``. If it is non-blocking, then the value is
+ actually checked and not set if it is already acquired. This
+ is all done so that threading.Condition's assert statements
+ aren't triggered and throw a little fit.
+
+ """
+ if waitflag is None:
+ self.locked_status = True
+ return None
+ elif not waitflag:
+ if not self.locked_status:
+ self.locked_status = True
+ return True
+ else:
+ return False
+ else:
+ self.locked_status = True
+ return True
+
+ def release(self):
+ """Release the dummy lock."""
+ # XXX Perhaps shouldn't actually bother to test? Could lead
+ # to problems for complex, threaded code.
+ if not self.locked_status:
+ raise error
+ self.locked_status = False
+ return True
+
+ def locked(self):
+ return self.locked_status