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# Very rudimentary test of threading module

import test.test_support
from test.test_support import verbose, is_jython
import random
import re
import sys
thread = test.test_support.import_module('thread')
threading = test.test_support.import_module('threading')
import time
import unittest
import weakref
import os
import subprocess

from test import lock_tests

# 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.assertTrue(self.nrunning.get() <= 3)

            time.sleep(delay)
            if verbose:
                print 'task', self.name, 'done'

            with self.mutex:
                self.nrunning.dec()
                self.testcase.assertTrue(self.nrunning.get() >= 0)
                if verbose:
                    print '%s is finished. %d tasks are running' % (
                        self.name, self.nrunning.get())

class BaseTestCase(unittest.TestCase):
    def setUp(self):
        self._threads = test.test_support.threading_setup()

    def tearDown(self):
        test.test_support.threading_cleanup(*self._threads)
        test.test_support.reap_children()


class ThreadTests(BaseTestCase):

    # 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(""%i, self, sema, mutex, numrunning)
            threads.append(t)
            self.assertIsNotNone(t.ident)  # NOTE Java immediately assigns idents, unlike CPython
            self.assertTrue(re.match('', repr(t)))
            t.start()

        if verbose:
            print 'waiting for all tasks to complete'
        for t in threads:
            t.join(NUMTASKS)
            self.assertTrue(not t.is_alive())
            self.assertNotEqual(t.ident, 0)
            self.assertFalse(t.ident is None)
            self.assertTrue(re.match('', repr(t)))
        if verbose:
            print 'all tasks done'
        self.assertEqual(numrunning.get(), 0)

    def test_ident_of_no_threading_threads(self):
        # The ident still must work for the main thread and dummy threads.
        self.assertFalse(threading.currentThread().ident is None)
        def f():
            ident.append(threading.currentThread().ident)
            done.set()
        done = threading.Event()
        ident = []
        thread.start_new_thread(f, ())
        done.wait()
        self.assertFalse(ident[0] is None)
        # Kill the "immortal" _DummyThread
        del threading._active[ident[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)

    @unittest.skipIf(is_jython, "Does not apply to Jython")
    def test_foreign_thread(self):
        # Check that a "foreign" thread can use the threading module.
        def f(mutex):
            # Calling current_thread() forces an entry for the foreign
            # thread to get made in the threading._active map.
            threading.current_thread()
            mutex.release()

        mutex = threading.Lock()
        mutex.acquire()
        tid = thread.start_new_thread(f, (mutex,))
        # Wait for the thread to finish.
        mutex.acquire()
        self.assertIn(tid, threading._active)
        self.assertIsInstance(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.
    @unittest.skipIf(is_jython, "Does not apply to Jython")
    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)

        # First check it works when setting the exception from the same thread.
        tid = thread.get_ident()

        try:
            result = set_async_exc(ctypes.c_long(tid), exception)
            # The exception is async, so we might have to keep the VM busy until
            # it notices.
            while True:
                pass
        except AsyncExc:
            pass
        else:
            # This code is unreachable but it reflects the intent. If we wanted
            # to be smarter the above loop wouldn't be infinite.
            self.fail("AsyncExc not raised")
        try:
            self.assertEqual(result, 1) # one thread state modified
        except UnboundLocalError:
            # The exception was raised too quickly for us to get the result.
            pass

        # `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"
        ret = worker_started.wait()
        self.assertTrue(ret)
        if verbose:
            print "    verifying worker hasn't exited"
        self.assertTrue(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.assertTrue(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

    @unittest.skipIf(is_jython, "Does not apply to Jython")
    def test_limbo_cleanup(self):
        # Issue 7481: Failure to start thread should cleanup the limbo map.
        def fail_new_thread(*args):
            raise thread.error()
        _start_new_thread = threading._start_new_thread
        threading._start_new_thread = fail_new_thread
        try:
            t = threading.Thread(target=lambda: None)
            self.assertRaises(thread.error, t.start)
            self.assertFalse(
                t in threading._limbo,
                "Failed to cleanup _limbo map on failure of Thread.start().")
        finally:
            threading._start_new_thread = _start_new_thread

    @unittest.skipIf(is_jython, "Does not apply to Jython")
    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

        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
        p = subprocess.Popen([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)
            """],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE)
        self.addCleanup(p.stdout.close)
        self.addCleanup(p.stderr.close)
        stdout, stderr = p.communicate()
        rc = p.returncode
        self.assertFalse(rc == 2, "interpreted was blocked")
        self.assertTrue(rc == 0,
                        "Unexpected error: " + repr(stderr))

    def test_join_nondaemon_on_shutdown(self):
        # Issue 1722344
        # Raising SystemExit skipped threading._shutdown
        p = subprocess.Popen([sys.executable, "-c", """if 1:
                import threading
                from time import sleep

                def child():
                    sleep(1)
                    # As a non-daemon thread we SHOULD wake up and nothing
                    # should be torn down yet
                    print "Woke up, sleep function is:", sleep

                threading.Thread(target=child).start()
                raise SystemExit
            """],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE)
        self.addCleanup(p.stdout.close)
        self.addCleanup(p.stderr.close)
        stdout, stderr = p.communicate()
        self.assertTrue(stdout.strip().startswith(
            "Woke up, sleep function is:  0:
                os.waitpid(pid, 0)
            else:
                os._exit(0)

        # start a bunch of threads that will fork() child processes
        threads = []
        for i in range(16):
            t = threading.Thread(target=do_fork_and_wait)
            threads.append(t)
            t.start()

        for t in threads:
            t.join()


class ThreadingExceptionTests(BaseTestCase):
    # 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_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)


class LockTests(lock_tests.LockTests):
    locktype = staticmethod(threading.Lock)

class RLockTests(lock_tests.RLockTests):
    locktype = staticmethod(threading.RLock)

class EventTests(lock_tests.EventTests):
    eventtype = staticmethod(threading.Event)

class ConditionAsRLockTests(lock_tests.RLockTests):
    # An Condition uses an RLock by default and exports its API.
    locktype = staticmethod(threading.Condition)

class ConditionTests(lock_tests.ConditionTests):
    condtype = staticmethod(threading.Condition)

class SemaphoreTests(lock_tests.SemaphoreTests):
    semtype = staticmethod(threading.Semaphore)

class BoundedSemaphoreTests(lock_tests.BoundedSemaphoreTests):
    semtype = staticmethod(threading.BoundedSemaphore)

    @unittest.skipUnless(sys.platform == 'darwin', 'test macosx problem')
    def test_recursion_limit(self):
        # Issue 9670
        # test that excessive recursion within a non-main thread causes
        # an exception rather than crashing the interpreter on platforms
        # like Mac OS X or FreeBSD which have small default stack sizes
        # for threads
        script = """if True:
            import threading

            def recurse():
                return recurse()

            def outer():
                try:
                    recurse()
                except RuntimeError:
                    pass

            w = threading.Thread(target=outer)
            w.start()
            w.join()
            print('end of main thread')
            """
        expected_output = "end of main thread\n"
        p = subprocess.Popen([sys.executable, "-c", script],
                             stdout=subprocess.PIPE)
        stdout, stderr = p.communicate()
        data = stdout.decode().replace('\r', '')
        self.assertEqual(p.returncode, 0, "Unexpected error")
        self.assertEqual(data, expected_output)

def test_main():
    test.test_support.run_unittest(LockTests, RLockTests, EventTests,
                                   ConditionAsRLockTests, ConditionTests,
                                   SemaphoreTests, BoundedSemaphoreTests,
                                   ThreadTests,
                                   ThreadJoinOnShutdown,
                                   ThreadingExceptionTests,
                                   )

if __name__ == "__main__":
    test_main()




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