/* vim:set noet ts=8 sw=8 : */

/* Greenlet object interface */

#ifndef Py_GREENLETOBJECT_H
#define Py_GREENLETOBJECT_H

#include <Python.h>

#ifdef __cplusplus
extern "C" {
#endif

#define GREENLET_VERSION "0.4.0"

typedef struct _greenlet {
  PyObject_HEAD char* stack_start;
  char* stack_stop;
  char* stack_copy;
  intptr_t stack_saved;
  struct _greenlet* stack_prev;
  struct _greenlet* parent;
  PyObject* run_info;
  struct _frame* top_frame;
  int recursion_depth;
  PyObject* weakreflist;
  PyObject* exc_type;
  PyObject* exc_value;
  PyObject* exc_traceback;
  PyObject* dict;
} PyGreenlet;

#define PyGreenlet_Check(op) PyObject_TypeCheck(op, &PyGreenlet_Type)
#define PyGreenlet_MAIN(op) (((PyGreenlet*)(op))->stack_stop == (char*)-1)
#define PyGreenlet_STARTED(op) (((PyGreenlet*)(op))->stack_stop != NULL)
#define PyGreenlet_ACTIVE(op) (((PyGreenlet*)(op))->stack_start != NULL)
#define PyGreenlet_GET_PARENT(op) (((PyGreenlet*)(op))->parent)

#if (PY_MAJOR_VERSION == 2 && PY_MINOR_VERSION >= 7) || \
    (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 1) || PY_MAJOR_VERSION > 3
#define GREENLET_USE_PYCAPSULE
#endif

/* C API functions */

/* Total number of symbols that are exported */
#define PyGreenlet_API_pointers 8

#define PyGreenlet_Type_NUM 0
#define PyExc_GreenletError_NUM 1
#define PyExc_GreenletExit_NUM 2

#define PyGreenlet_New_NUM 3
#define PyGreenlet_GetCurrent_NUM 4
#define PyGreenlet_Throw_NUM 5
#define PyGreenlet_Switch_NUM 6
#define PyGreenlet_SetParent_NUM 7

#ifndef GREENLET_MODULE
/* This section is used by modules that uses the greenlet C API */
static void** _PyGreenlet_API = NULL;

#define PyGreenlet_Type (*(PyTypeObject*)_PyGreenlet_API[PyGreenlet_Type_NUM])

#define PyExc_GreenletError \
  ((PyObject*)_PyGreenlet_API[PyExc_GreenletError_NUM])

#define PyExc_GreenletExit ((PyObject*)_PyGreenlet_API[PyExc_GreenletExit_NUM])

/*
 * PyGreenlet_New(PyObject *args)
 *
 * greenlet.greenlet(run, parent=None)
 */
#define PyGreenlet_New                                      \
  (*(PyGreenlet * (*)(PyObject * run, PyGreenlet * parent)) \
       _PyGreenlet_API[PyGreenlet_New_NUM])

/*
 * PyGreenlet_GetCurrent(void)
 *
 * greenlet.getcurrent()
 */
#define PyGreenlet_GetCurrent \
  (*(PyGreenlet * (*)(void)) _PyGreenlet_API[PyGreenlet_GetCurrent_NUM])

/*
 * PyGreenlet_Throw(
 *         PyGreenlet *greenlet,
 *         PyObject *typ,
 *         PyObject *val,
 *         PyObject *tb)
 *
 * g.throw(...)
 */
#define PyGreenlet_Throw                                               \
  (*(PyObject * (*)(PyGreenlet * self, PyObject * typ, PyObject * val, \
                    PyObject * tb)) _PyGreenlet_API[PyGreenlet_Throw_NUM])

/*
 * PyGreenlet_Switch(PyGreenlet *greenlet, PyObject *args)
 *
 * g.switch(*args, **kwargs)
 */
#define PyGreenlet_Switch                                            \
  (*(PyObject *                                                      \
     (*)(PyGreenlet * greenlet, PyObject * args, PyObject * kwargs)) \
       _PyGreenlet_API[PyGreenlet_Switch_NUM])

/*
 * PyGreenlet_SetParent(PyObject *greenlet, PyObject *new_parent)
 *
 * g.parent = new_parent
 */
#define PyGreenlet_SetParent                                      \
  (*(PyObject * (*)(PyGreenlet * greenlet, PyGreenlet * nparent)) \
       _PyGreenlet_API[PyGreenlet_SetParent_NUM])

/* Macro that imports greenlet and initializes C API */
#ifdef GREENLET_USE_PYCAPSULE
#define PyGreenlet_Import() \
  { _PyGreenlet_API = (void**)PyCapsule_Import("greenlet._C_API", 0); }
#else
#define PyGreenlet_Import()                                              \
  {                                                                      \
    PyObject* module = PyImport_ImportModule("greenlet");                \
    if (module != NULL) {                                                \
      PyObject* c_api_object = PyObject_GetAttrString(module, "_C_API"); \
      if (c_api_object != NULL && PyCObject_Check(c_api_object)) {       \
        _PyGreenlet_API = (void**)PyCObject_AsVoidPtr(c_api_object);     \
        Py_DECREF(c_api_object);                                         \
      }                                                                  \
      Py_DECREF(module);                                                 \
    }                                                                    \
  }
#endif

#endif /* GREENLET_MODULE */

#ifdef __cplusplus
}
#endif
#endif /* !Py_GREENLETOBJECT_H */
