# Very rudimentary test of threading module

import test.test_support

from test.test_support import verbose

import random

import re

import sys

import threading

import thread

import time

import unittest

import weakref

# A trivial mutable counter.

class Counter(object):

    def __init__(self):

        self.value = 0

    def inc(self):

        self.value += 1

    def dec(self):

        self.value -= 1

    def get(self):

        return self.value

class TestThread(threading.Thread):

    def __init__(self, name, testcase, sema, mutex, nrunning):

        threading.Thread.__init__(self, name=name)

        self.testcase = testcase

        self.sema = sema

        self.mutex = mutex

        self.nrunning = nrunning

    def run(self):

        delay = random.random() / 10000.0

        if verbose:

            print 'task %s will run for %.1f usec' % (

                self.name, delay * 1e6)

        with self.sema:

            with self.mutex:

                self.nrunning.inc()

                if verbose:

                    print self.nrunning.get(), 'tasks are running'

                self.testcase.assert_(self.nrunning.get() <= 3)

            time.sleep(delay)

            if verbose:

                print 'task', self.name, 'done'

            with self.mutex:

                self.nrunning.dec()

                self.testcase.assert_(self.nrunning.get() >= 0)

                if verbose:

                    print '%s is finished. %d tasks are running' % (

                        self.name, self.nrunning.get())

class ThreadTests(unittest.TestCase):

    # Create a bunch of threads, let each do some work, wait until all are

    # done.

    def test_various_ops(self):

        # This takes about n/3 seconds to run (about n/3 clumps of tasks,

        # times about 1 second per clump).

        NUMTASKS = 10

        # no more than 3 of the 10 can run at once

        sema = threading.BoundedSemaphore(value=3)

        mutex = threading.RLock()

        numrunning = Counter()

        threads = []

        for i in range(NUMTASKS):

            t = TestThread("<thread %d>"%i, self, sema, mutex, numrunning)

            threads.append(t)

            self.failUnlessEqual(t.ident, None)

            self.assert_(re.match('<TestThread\(.*, initial\)>', repr(t)))

            t.start()

        if verbose:

            print 'waiting for all tasks to complete'

        for t in threads:

            t.join(NUMTASKS)

            self.assert_(not t.is_alive())

            self.failIfEqual(t.ident, 0)

            self.assert_(re.match('<TestThread\(.*, \w+ -?\d+\)>', repr(t)))

        if verbose:

            print 'all tasks done'

        self.assertEqual(numrunning.get(), 0)

    # run with a small(ish) thread stack size (256kB)

    def test_various_ops_small_stack(self):

        if verbose:

            print 'with 256kB thread stack size...'

        try:

            threading.stack_size(262144)

        except thread.error:

            if verbose:

                print 'platform does not support changing thread stack size'

            return

        self.test_various_ops()

        threading.stack_size(0)

    # run with a large thread stack size (1MB)

    def test_various_ops_large_stack(self):

        if verbose:

            print 'with 1MB thread stack size...'

        try:

            threading.stack_size(0x100000)

        except thread.error:

            if verbose:

                print 'platform does not support changing thread stack size'

            return

        self.test_various_ops()

        threading.stack_size(0)

    def test_foreign_thread(self):

        # Check that a "foreign" thread can use the threading module.

        def f(mutex):

            # Acquiring an RLock forces an entry for the foreign

            # thread to get made in the threading._active map.

            r = threading.RLock()

            r.acquire()

            r.release()

            mutex.release()

        mutex = threading.Lock()

        mutex.acquire()

        tid = thread.start_new_thread(f, (mutex,))

        # Wait for the thread to finish.

        mutex.acquire()

        self.assert_(tid in threading._active)

        self.assert_(isinstance(threading._active[tid],

                                threading._DummyThread))

        del threading._active[tid]

    # PyThreadState_SetAsyncExc() is a CPython-only gimmick, not (currently)

    # exposed at the Python level.  This test relies on ctypes to get at it.

    def test_PyThreadState_SetAsyncExc(self):

        try:

            import ctypes

        except ImportError:

            if verbose:

                print "test_PyThreadState_SetAsyncExc can't import ctypes"

            return  # can't do anything

        set_async_exc = ctypes.pythonapi.PyThreadState_SetAsyncExc

        class AsyncExc(Exception):

            pass

        exception = ctypes.py_object(AsyncExc)

        # `worker_started` is set by the thread when it's inside a try/except

        # block waiting to catch the asynchronously set AsyncExc exception.

        # `worker_saw_exception` is set by the thread upon catching that

        # exception.

        worker_started = threading.Event()

        worker_saw_exception = threading.Event()

        class Worker(threading.Thread):

            def run(self):

                self.id = thread.get_ident()

                self.finished = False

                try:

                    while True:

                        worker_started.set()

                        time.sleep(0.1)

                except AsyncExc:

                    self.finished = True

                    worker_saw_exception.set()

        t = Worker()

        t.daemon = True # so if this fails, we don't hang Python at shutdown

        t.start()

        if verbose:

            print "    started worker thread"

        # Try a thread id that doesn't make sense.

        if verbose:

            print "    trying nonsensical thread id"

        result = set_async_exc(ctypes.c_long(-1), exception)

        self.assertEqual(result, 0)  # no thread states modified

        # Now raise an exception in the worker thread.

        if verbose:

            print "    waiting for worker thread to get started"

        worker_started.wait()

        if verbose:

            print "    verifying worker hasn't exited"

        self.assert_(not t.finished)

        if verbose:

            print "    attempting to raise asynch exception in worker"

        result = set_async_exc(ctypes.c_long(t.id), exception)

        self.assertEqual(result, 1) # one thread state modified

        if verbose:

            print "    waiting for worker to say it caught the exception"

        worker_saw_exception.wait(timeout=10)

        self.assert_(t.finished)

        if verbose:

            print "    all OK -- joining worker"

        if t.finished:

            t.join()

        # else the thread is still running, and we have no way to kill it

    def test_finalize_runnning_thread(self):

        # Issue 1402: the PyGILState_Ensure / _Release functions may be called

        # very late on python exit: on deallocation of a running thread for

        # example.

        try:

            import ctypes

        except ImportError:

            if verbose:

                print("test_finalize_with_runnning_thread can't import ctypes")

            return  # can't do anything

        import subprocess

        rc = subprocess.call([sys.executable, "-c", """if 1:

            import ctypes, sys, time, thread

            # This lock is used as a simple event variable.

            ready = thread.allocate_lock()

            ready.acquire()

            # Module globals are cleared before __del__ is run

            # So we save the functions in class dict

            class C:

                ensure = ctypes.pythonapi.PyGILState_Ensure

                release = ctypes.pythonapi.PyGILState_Release

                def __del__(self):

                    state = self.ensure()

                    self.release(state)

            def waitingThread():

                x = C()

                ready.release()

                time.sleep(100)

            thread.start_new_thread(waitingThread, ())

            ready.acquire()  # Be sure the other thread is waiting.

            sys.exit(42)

            """])

        self.assertEqual(rc, 42)

    def test_finalize_with_trace(self):

        # Issue1733757

        # Avoid a deadlock when sys.settrace steps into threading._shutdown

        import subprocess

        rc = subprocess.call([sys.executable, "-c", """if 1:

            import sys, threading

            # A deadlock-killer, to prevent the

            # testsuite to hang forever

            def killer():

                import os, time

                time.sleep(2)

                print 'program blocked; aborting'

                os._exit(2)

            t = threading.Thread(target=killer)

            t.daemon = True

            t.start()

            # This is the trace function

            def func(frame, event, arg):

                threading.current_thread()

                return func

            sys.settrace(func)

            """])

        self.failIf(rc == 2, "interpreted was blocked")

        self.failUnless(rc == 0, "Unexpected error")

    def test_enumerate_after_join(self):

        # Try hard to trigger #1703448: a thread is still returned in

        # threading.enumerate() after it has been join()ed.

        enum = threading.enumerate

        old_interval = sys.getcheckinterval()

        try:

            for i in xrange(1, 100):

                # Try a couple times at each thread-switching interval

                # to get more interleavings.

                sys.setcheckinterval(i // 5)

                t = threading.Thread(target=lambda: None)

                t.start()

                t.join()

                l = enum()

                self.assertFalse(t in l,

                    "#1703448 triggered after %d trials: %s" % (i, l))

        finally:

            sys.setcheckinterval(old_interval)

    def test_no_refcycle_through_target(self):

        class RunSelfFunction(object):

            def __init__(self, should_raise):

                # The links in this refcycle from Thread back to self

                # should be cleaned up when the thread completes.

                self.should_raise = should_raise

                self.thread = threading.Thread(target=self._run,

                                               args=(self,),

                                               kwargs={'yet_another':self})

                self.thread.start()

            def _run(self, other_ref, yet_another):

                if self.should_raise:

                    raise SystemExit

        cyclic_object = RunSelfFunction(should_raise=False)

        weak_cyclic_object = weakref.ref(cyclic_object)

        cyclic_object.thread.join()

        del cyclic_object

        self.assertEquals(None, weak_cyclic_object(),

                          msg=('%d references still around' %

                               sys.getrefcount(weak_cyclic_object())))

        raising_cyclic_object = RunSelfFunction(should_raise=True)

        weak_raising_cyclic_object = weakref.ref(raising_cyclic_object)

        raising_cyclic_object.thread.join()

        del raising_cyclic_object

        self.assertEquals(None, weak_raising_cyclic_object(),

                          msg=('%d references still around' %

                               sys.getrefcount(weak_raising_cyclic_object())))

class ThreadJoinOnShutdown(unittest.TestCase):

    def _run_and_join(self, script):

        script = """if 1:

            import sys, os, time, threading

            # a thread, which waits for the main program to terminate

            def joiningfunc(mainthread):

                mainthread.join()

                print 'end of thread'

        \n""" + script

        import subprocess

        p = subprocess.Popen([sys.executable, "-c", script], stdout=subprocess.PIPE)

        rc = p.wait()

        data = p.stdout.read().replace('\r', '')

        self.assertEqual(data, "end of main\nend of thread\n")

        self.failIf(rc == 2, "interpreter was blocked")

        self.failUnless(rc == 0, "Unexpected error")

    def test_1_join_on_shutdown(self):

        # The usual case: on exit, wait for a non-daemon thread

        script = """if 1:

            import os

            t = threading.Thread(target=joiningfunc,

                                 args=(threading.current_thread(),))

            t.start()

            time.sleep(0.1)

            print 'end of main'

            """

        self._run_and_join(script)

    def test_2_join_in_forked_process(self):

        # Like the test above, but from a forked interpreter

        import os

        if not hasattr(os, 'fork'):

            return

        script = """if 1:

            childpid = os.fork()

            if childpid != 0:

                os.waitpid(childpid, 0)

                sys.exit(0)

            t = threading.Thread(target=joiningfunc,

                                 args=(threading.current_thread(),))

            t.start()

            print 'end of main'

            """

        self._run_and_join(script)

    def test_3_join_in_forked_from_thread(self):

        # Like the test above, but fork() was called from a worker thread

        # In the forked process, the main Thread object must be marked as stopped.

        import os

        if not hasattr(os, 'fork'):

            return

        # Skip platforms with known problems forking from a worker thread.

        # See http://bugs.python.org/issue3863.

        if sys.platform in ('freebsd4', 'freebsd5', 'freebsd6', 'os2emx'):

            print >>sys.stderr, ('Skipping test_3_join_in_forked_from_thread'

                                 ' due to known OS bugs on'), sys.platform

            return

        script = """if 1:

            main_thread = threading.current_thread()

            def worker():

                childpid = os.fork()

                if childpid != 0:

                    os.waitpid(childpid, 0)

                    sys.exit(0)

                t = threading.Thread(target=joiningfunc,

                                     args=(main_thread,))

                print 'end of main'

                t.start()

                t.join() # Should not block: main_thread is already stopped

            w = threading.Thread(target=worker)

            w.start()

            """

        self._run_and_join(script)

class ThreadingExceptionTests(unittest.TestCase):

    # A RuntimeError should be raised if Thread.start() is called

    # multiple times.

    def test_start_thread_again(self):

        thread = threading.Thread()

        thread.start()

        self.assertRaises(RuntimeError, thread.start)

    def test_releasing_unacquired_rlock(self):

        rlock = threading.RLock()

        self.assertRaises(RuntimeError, rlock.release)

    def test_waiting_on_unacquired_condition(self):

        cond = threading.Condition()

        self.assertRaises(RuntimeError, cond.wait)

    def test_notify_on_unacquired_condition(self):

        cond = threading.Condition()

        self.assertRaises(RuntimeError, cond.notify)

    def test_semaphore_with_negative_value(self):

        self.assertRaises(ValueError, threading.Semaphore, value = -1)

        self.assertRaises(ValueError, threading.Semaphore, value = -sys.maxint)

    def test_joining_current_thread(self):

        current_thread = threading.current_thread()

        self.assertRaises(RuntimeError, current_thread.join);

    def test_joining_inactive_thread(self):

        thread = threading.Thread()

        self.assertRaises(RuntimeError, thread.join)

    def test_daemonize_active_thread(self):

        thread = threading.Thread()

        thread.start()

        self.assertRaises(RuntimeError, setattr, thread, "daemon", True)

def test_main():

    test.test_support.run_unittest(ThreadTests,

                                   ThreadJoinOnShutdown,

                                   ThreadingExceptionTests,

                                   )

if __name__ == "__main__":

    test_main()