diff --git a/lib/assets/Lib/_thread.py b/lib/assets/Lib/_thread.py new file mode 100644 --- /dev/null +++ b/lib/assets/Lib/_thread.py @@ -0,0 +1,155 @@ +"""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 + +""" +# 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', + 'interrupt_main', 'LockType'] + +# A dummy value +TIMEOUT_MAX = 2**31 + +# NOTE: this module can be imported early in the extension building process, +# and so top level imports of other modules should be avoided. Instead, all +# imports are done when needed on a function-by-function basis. Since threads +# are disabled, the import lock should not be an issue anyway (??). + +error = RuntimeError + +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 the executed function calls interrupt_main the KeyboardInterrupt will be + raised when the function returns. + + """ + 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") + global _main + _main = False + try: + function(*args, **kwargs) + except SystemExit: + pass + except: + import traceback + traceback.print_exc() + _main = True + global _interrupt + if _interrupt: + _interrupt = False + raise KeyboardInterrupt + +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() + +def stack_size(size=None): + """Dummy implementation of _thread.stack_size().""" + if size is not None: + raise error("setting thread stack size not supported") + return 0 + +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, timeout=-1): + """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 or waitflag: + self.locked_status = True + return True + else: + if not self.locked_status: + self.locked_status = True + return True + else: + if timeout > 0: + import time + time.sleep(timeout) + return False + + __enter__ = acquire + + def __exit__(self, typ, val, tb): + self.release() + + 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 + +# Used to signal that interrupt_main was called in a "thread" +_interrupt = False +# True when not executing in a "thread" +_main = True + +def interrupt_main(): + """Set _interrupt flag to True to have start_new_thread raise + KeyboardInterrupt upon exiting.""" + if _main: + raise KeyboardInterrupt + else: + global _interrupt + _interrupt = True + +# Brython-specific to avoid circular references between threading and _threading_local +class _local: + pass \ No newline at end of file