cython

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# mode: run
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# tag: pep489, subinterpreter
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PYTHON setup.py build_ext --inplace
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PYTHON -c "import subtest; subtest.run_main()"
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PYTHON -c "import subtest; subtest.run_sub()"
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PYTHON -c "import subtest; subtest.run_main(); subtest.run_sub()"
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######## setup.py ########
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from Cython.Build.Dependencies import cythonize
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from distutils.core import setup
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setup(
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    ext_modules = cythonize("**/*.pyx"),
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    )
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######## subtest.pyx ########
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cdef extern from *:
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    """
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    /* Copied from CPython's _testcapi.c module */
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    static PyObject *run_in_subinterpreter(const char *code) {
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        int r;
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        PyThreadState *substate, *mainstate;
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        mainstate = PyThreadState_Get();
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        PyThreadState_Swap(NULL);
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        substate = Py_NewInterpreter();
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        if (substate == NULL) {
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            /* Since no new thread state was created, there is no exception to
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               propagate; raise a fresh one after swapping in the old thread
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               state. */
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            PyThreadState_Swap(mainstate);
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            PyErr_SetString(PyExc_RuntimeError, "sub-interpreter creation failed");
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            return NULL;
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        }
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        r = PyRun_SimpleString(code);
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        Py_EndInterpreter(substate);
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        PyThreadState_Swap(mainstate);
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        return PyLong_FromLong(r);
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    }
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    """
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    object run_in_subinterpreter(const char *code)
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MAIN_HAS_IMPORTED = False
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def run_main():
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    global MAIN_HAS_IMPORTED
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    MAIN_HAS_IMPORTED = True
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    import package.subtest
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    from package import subtest
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def run_sub():
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    assert 0 == run_in_subinterpreter(b'1+1')
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    assert 0 == run_in_subinterpreter(b'2+2')
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    # The subinterpreter does not add the current working directory to
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    # sys.path, so we need to add it manually.
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    pre = b'import sys; sys.path.insert(0, "."); '
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    assert 0 == run_in_subinterpreter(pre + b'import package')
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    assert 0 == run_in_subinterpreter(pre + b'import package')
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    result = run_in_subinterpreter(pre + b'import package.subtest')
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    if not MAIN_HAS_IMPORTED:
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        assert result == 0, result  # imports only in subinterpreters are ok
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    else:
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        assert result == -1, result  # re-import in a different subinterpreter fails in Py3.5+ (with PEP-489)
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######## package/__init__.py ########
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######## package/subtest.pyx ########
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print("Module loaded: %s" % __name__)
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