Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Includes/cpython/pystate.pxd

+# Thread and interpreter state structures and their interfaces
+
+from cpython.ref cimport PyObject
+
+cdef extern from "Python.h":
+
+    # We make these an opague types. If the user wants specific attributes,
+    # they can be declared manually.
+
+    ctypedef struct PyInterpreterState:
+        pass
+
+    ctypedef struct PyThreadState:
+        pass
+
+    ctypedef struct PyFrameObject:
+        pass
+
+    # This is not actually a struct, but make sure it can never be coerced to
+    # an int or used in arithmetic expressions
+    ctypedef struct PyGILState_STATE
+
+    # The type of the trace function registered using PyEval_SetProfile() and
+    # PyEval_SetTrace().
+    # Py_tracefunc return -1 when raising an exception, or 0 for success.
+    ctypedef int (*Py_tracefunc)(PyObject *, PyFrameObject *, int, PyObject *)
+
+    # The following values are used for 'what' for tracefunc functions
+    enum:
+        PyTrace_CALL
+        PyTrace_EXCEPTION
+        PyTrace_LINE
+        PyTrace_RETURN
+        PyTrace_C_CALL
+        PyTrace_C_EXCEPTION
+        PyTrace_C_RETURN
+
+
+    PyInterpreterState * PyInterpreterState_New()
+    void PyInterpreterState_Clear(PyInterpreterState *)
+    void PyInterpreterState_Delete(PyInterpreterState *)
+
+    PyThreadState * PyThreadState_New(PyInterpreterState *)
+    void PyThreadState_Clear(PyThreadState *)
+    void PyThreadState_Delete(PyThreadState *)
+
+    PyThreadState * PyThreadState_Get()
+    PyThreadState * PyThreadState_Swap(PyThreadState *)
+    PyObject * PyThreadState_GetDict()
+    int PyThreadState_SetAsyncExc(long, PyObject *)
+
+    # Ensure that the current thread is ready to call the Python
+    # C API, regardless of the current state of Python, or of its
+    # thread lock.  This may be called as many times as desired
+    # by a thread so long as each call is matched with a call to
+    # PyGILState_Release().  In general, other thread-state APIs may
+    # be used between _Ensure() and _Release() calls, so long as the
+    # thread-state is restored to its previous state before the Release().
+    # For example, normal use of the Py_BEGIN_ALLOW_THREADS/
+    # Py_END_ALLOW_THREADS macros are acceptable.
+
+    # The return value is an opaque "handle" to the thread state when
+    # PyGILState_Ensure() was called, and must be passed to
+    # PyGILState_Release() to ensure Python is left in the same state. Even
+    # though recursive calls are allowed, these handles can *not* be shared -
+    # each unique call to PyGILState_Ensure must save the handle for its
+    # call to PyGILState_Release.
+
+    # When the function returns, the current thread will hold the GIL.
+
+    # Failure is a fatal error.
+    PyGILState_STATE PyGILState_Ensure()
+
+    # Release any resources previously acquired.  After this call, Python's
+    # state will be the same as it was prior to the corresponding
+    # PyGILState_Ensure() call (but generally this state will be unknown to
+    # the caller, hence the use of the GILState API.)
+
+    # Every call to PyGILState_Ensure must be matched by a call to
+    # PyGILState_Release on the same thread.
+    void PyGILState_Release(PyGILState_STATE)
+
+    # Routines for advanced debuggers, requested by David Beazley.
+    # Don't use unless you know what you are doing!
+    PyInterpreterState * PyInterpreterState_Head()
+    PyInterpreterState * PyInterpreterState_Next(PyInterpreterState *)
+    PyThreadState * PyInterpreterState_ThreadHead(PyInterpreterState *)
+    PyThreadState * PyThreadState_Next(PyThreadState *)