#define PY_SSIZE_T_CLEAN
#include <Python.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

extern "C" {

static pthread_t t;

static void* DoWork(void* arg) {
  printf("Thread trying to acquire GIL\n");
  fflush(stdout);
  PyGILState_STATE py_threadstate = PyGILState_Ensure();   // Race here!!
  printf("Thread called with arg %p\n", arg);
  PyGILState_Release(py_threadstate);
  printf("Thread has released GIL\n");
  return arg;
}

static PyObject* SomeNumber(PyObject* module, PyObject* object) {
  if (pthread_create(&t, nullptr, DoWork, nullptr) != 0) {
    fprintf(stderr, "pthread_create failed\n");
    abort();
  }
  return PyLong_FromLong(reinterpret_cast<uintptr_t>(object));
}

static PyObject* AnotherNumber(PyObject* module, PyObject* object) {
  if (pthread_join(t, nullptr) != 0) {
    fprintf(stderr, "pthread_join failed\n");
    abort();
  }
  return PyLong_FromLong(reinterpret_cast<uintptr_t>(object));
}

}  // extern "C"

static PyMethodDef thbmod_methods[] = {
    {"some_number", SomeNumber, METH_O, "Makes a number."},
    {"another_number", AnotherNumber, METH_O, "Makes a number."},
    {nullptr, nullptr, 0, nullptr}        /* Sentinel */
};

static struct PyModuleDef thbmod = {
    PyModuleDef_HEAD_INIT,
    "thread_haver",   /* name of module */
    nullptr,          /* module documentation, may be NULL */
    1024,             /* size of per-interpreter state of the module,
                         or -1 if the module keeps state in global variables. */
    thbmod_methods,
};

PyMODINIT_FUNC PyInit_thread_haver() {
  return PyModule_Create(&thbmod);
}