cpython/Lib/test/test_capi.py

# Run the _testcapi module tests (tests for the Python/C API):  by defn,
# these are all functions _testcapi exports whose name begins with 'test_'.

from __future__ import with_statement
import os
import pickle
import random
import subprocess
import sys
import time
import unittest
from test import support
try:
    import threading
except ImportError:
    threading = None
import _testcapi


def testfunction(self):
    """some doc"""
    return self

class InstanceMethod:
    id = _testcapi.instancemethod(id)
    testfunction = _testcapi.instancemethod(testfunction)

class CAPITest(unittest.TestCase):

    def test_instancemethod(self):
        inst = InstanceMethod()
        self.assertEqual(id(inst), inst.id())
        self.assertTrue(inst.testfunction() is inst)
        self.assertEqual(inst.testfunction.__doc__, testfunction.__doc__)
        self.assertEqual(InstanceMethod.testfunction.__doc__, testfunction.__doc__)

        InstanceMethod.testfunction.attribute = "test"
        self.assertEqual(testfunction.attribute, "test")
        self.assertRaises(AttributeError, setattr, inst.testfunction, "attribute", "test")

    @unittest.skipUnless(threading, 'Threading required for this test.')
    def test_no_FatalError_infinite_loop(self):
        p = subprocess.Popen([sys.executable, "-c",
                              'import _testcapi;'
                              '_testcapi.crash_no_current_thread()'],
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE)
        (out, err) = p.communicate()
        self.assertEqual(out, b'')
        # This used to cause an infinite loop.
        self.assertTrue(err.rstrip().startswith(
                         b'Fatal Python error:'
                         b' PyThreadState_Get: no current thread'))

    def test_memoryview_from_NULL_pointer(self):
        self.assertRaises(ValueError, _testcapi.make_memoryview_from_NULL_pointer)

    def test_exc_info(self):
        raised_exception = ValueError("5")
        new_exc = TypeError("TEST")
        try:
            raise raised_exception
        except ValueError as e:
            tb = e.__traceback__
            orig_sys_exc_info = sys.exc_info()
            orig_exc_info = _testcapi.set_exc_info(new_exc.__class__, new_exc, None)
            new_sys_exc_info = sys.exc_info()
            new_exc_info = _testcapi.set_exc_info(*orig_exc_info)
            reset_sys_exc_info = sys.exc_info()

            self.assertEqual(orig_exc_info[1], e)

            self.assertSequenceEqual(orig_exc_info, (raised_exception.__class__, raised_exception, tb))
            self.assertSequenceEqual(orig_sys_exc_info, orig_exc_info)
            self.assertSequenceEqual(reset_sys_exc_info, orig_exc_info)
            self.assertSequenceEqual(new_exc_info, (new_exc.__class__, new_exc, None))
            self.assertSequenceEqual(new_sys_exc_info, new_exc_info)
        else:
            self.assertTrue(False)

@unittest.skipUnless(threading, 'Threading required for this test.')
class TestPendingCalls(unittest.TestCase):

    def pendingcalls_submit(self, l, n):
        def callback():
            #this function can be interrupted by thread switching so let's
            #use an atomic operation
            l.append(None)

        for i in range(n):
            time.sleep(random.random()*0.02) #0.01 secs on average
            #try submitting callback until successful.
            #rely on regular interrupt to flush queue if we are
            #unsuccessful.
            while True:
                if _testcapi._pending_threadfunc(callback):
                    break;

    def pendingcalls_wait(self, l, n, context = None):
        #now, stick around until l[0] has grown to 10
        count = 0;
        while len(l) != n:
            #this busy loop is where we expect to be interrupted to
            #run our callbacks.  Note that callbacks are only run on the
            #main thread
            if False and support.verbose:
                print("(%i)"%(len(l),),)
            for i in range(1000):
                a = i*i
            if context and not context.event.is_set():
                continue
            count += 1
            self.assertTrue(count < 10000,
                "timeout waiting for %i callbacks, got %i"%(n, len(l)))
        if False and support.verbose:
            print("(%i)"%(len(l),))

    def test_pendingcalls_threaded(self):

        #do every callback on a separate thread
        n = 32 #total callbacks
        threads = []
        class foo(object):pass
        context = foo()
        context.l = []
        context.n = 2 #submits per thread
        context.nThreads = n // context.n
        context.nFinished = 0
        context.lock = threading.Lock()
        context.event = threading.Event()

        for i in range(context.nThreads):
            t = threading.Thread(target=self.pendingcalls_thread, args = (context,))
            t.start()
            threads.append(t)

        self.pendingcalls_wait(context.l, n, context)

        for t in threads:
            t.join()

    def pendingcalls_thread(self, context):
        try:
            self.pendingcalls_submit(context.l, context.n)
        finally:
            with context.lock:
                context.nFinished += 1
                nFinished = context.nFinished
                if False and support.verbose:
                    print("finished threads: ", nFinished)
            if nFinished == context.nThreads:
                context.event.set()

    def test_pendingcalls_non_threaded(self):
        #again, just using the main thread, likely they will all be dispatched at
        #once.  It is ok to ask for too many, because we loop until we find a slot.
        #the loop can be interrupted to dispatch.
        #there are only 32 dispatch slots, so we go for twice that!
        l = []
        n = 64
        self.pendingcalls_submit(l, n)
        self.pendingcalls_wait(l, n)

    def test_subinterps(self):
        # XXX this test leaks in refleak runs
        import builtins
        r, w = os.pipe()
        code = """if 1:
            import sys, builtins, pickle
            with open({:d}, "wb") as f:
                pickle.dump(id(sys.modules), f)
                pickle.dump(id(builtins), f)
            """.format(w)
        with open(r, "rb") as f:
            ret = _testcapi.run_in_subinterp(code)
            self.assertEqual(ret, 0)
            self.assertNotEqual(pickle.load(f), id(sys.modules))
            self.assertNotEqual(pickle.load(f), id(builtins))

# Bug #6012
class Test6012(unittest.TestCase):
    def test(self):
        self.assertEqual(_testcapi.argparsing("Hello", "World"), 1)


class EmbeddingTest(unittest.TestCase):

    @unittest.skipIf(
        sys.platform.startswith('win'),
        "test doesn't work under Windows")
    def test_subinterps(self):
        # XXX only tested under Unix checkouts
        basepath = os.path.dirname(os.path.dirname(os.path.dirname(__file__)))
        oldcwd = os.getcwd()
        # This is needed otherwise we get a fatal error:
        # "Py_Initialize: Unable to get the locale encoding
        # LookupError: no codec search functions registered: can't find encoding"
        os.chdir(basepath)
        try:
            exe = os.path.join(basepath, "Modules", "_testembed")
            if not os.path.exists(exe):
                self.skipTest("%r doesn't exist" % exe)
            p = subprocess.Popen([exe],
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE)
            (out, err) = p.communicate()
            self.assertEqual(p.returncode, 0,
                             "bad returncode %d, stderr is %r" %
                             (p.returncode, err))
            if support.verbose:
                print()
                print(out.decode('latin1'))
                print(err.decode('latin1'))
        finally:
            os.chdir(oldcwd)

class SkipitemTest(unittest.TestCase):

    def test_skipitem(self):
        """
        If this test failed, you probably added a new "format unit"
        in Python/getargs.c, but neglected to update our poor friend
        skipitem() in the same file.  (If so, shame on you!)

        This function brute-force tests all** ASCII characters (1 to 127
        inclusive) as format units, checking to see that
        PyArg_ParseTupleAndKeywords() return consistent errors both when
        the unit is attempted to be used and when it is skipped.  If the
        format unit doesn't exist, we'll get one of two specific error
        messages (one for used, one for skipped); if it does exist we
        *won't* get that error--we'll get either no error or some other
        error.  If we get the "does not exist" error for one test and
        not for the other, there's a mismatch, and the test fails.

          ** Okay, it actually skips some ASCII characters.  Some characters
             have special funny semantics, and it would be difficult to
             accomodate them here.
        """
        empty_tuple = ()
        tuple_1 = (0,)
        dict_b = {'b':1}
        keywords = ["a", "b"]

        # Python C source files must be ASCII,
        # therefore we'll never have a format unit > 127
        for i in range(1, 128):
            c = chr(i)

            # skip non-printable characters, no one is insane enough to define
            #    one as a format unit
            # skip parentheses, the error reporting is inconsistent about them
            # skip 'e', it's always a two-character code
            # skip '|' and '$', they don't represent arguments anyway
            if (not c.isprintable()) or (c in '()e|$'):
                continue

            # test the format unit when not skipped
            format = c + "i"
            try:
                # (note: the format string must be bytes!)
                _testcapi.parse_tuple_and_keywords(tuple_1, dict_b,
                    format.encode("ascii"), keywords)
                when_not_skipped = False
            except TypeError as e:
                s = "argument 1 must be impossible<bad format char>, not int"
                when_not_skipped = (str(e) == s)
            except RuntimeError as e:
                when_not_skipped = False

            # test the format unit when skipped
            optional_format = "|" + format
            try:
                _testcapi.parse_tuple_and_keywords(empty_tuple, dict_b,
                    optional_format.encode("ascii"), keywords)
                when_skipped = False
            except RuntimeError as e:
                s = "impossible<bad format char>: '{}'".format(format)
                when_skipped = (str(e) == s)

            message = ("test_skipitem_parity: "
                "detected mismatch between convertsimple and skipitem "
                "for format unit '{}' ({}), not skipped {}, skipped {}".format(
                    c, i, when_skipped, when_not_skipped))
            self.assertIs(when_skipped, when_not_skipped, message)

def test_main():
    support.run_unittest(CAPITest, TestPendingCalls,
                         Test6012, EmbeddingTest, SkipitemTest)

    for name in dir(_testcapi):
        if name.startswith('test_'):
            test = getattr(_testcapi, name)
            if support.verbose:
                print("internal", name)
            test()

    # some extra thread-state tests driven via _testcapi
    def TestThreadState():
        if support.verbose:
            print("auto-thread-state")

        idents = []

        def callback():
            idents.append(threading.get_ident())

        _testcapi._test_thread_state(callback)
        a = b = callback
        time.sleep(1)
        # Check our main thread is in the list exactly 3 times.
        if idents.count(threading.get_ident()) != 3:
            raise support.TestFailed(
                        "Couldn't find main thread correctly in the list")

    if threading:
        import time
        TestThreadState()
        t = threading.Thread(target=TestThreadState)
        t.start()
        t.join()


if __name__ == "__main__":
    test_main()