Iterating generator from C

[sven.suursoho@gmail.com]

Does messing with signal handlers and longjmp affect Python
interpreter?

I'm trying to find solution for problem, described in

http://groups.google.com/group/comp.lang.python/browse_thread/thread/98cbae94ca4beefb/9d4d96fd0dd9fbc3

and came up with test application. It works well but i'm not sure it is
ok for long-running python interpreter?

#include <Python.h>
#include <signal.h>
#include <setjmp.h>

const char *py_source =
"def fn():\n"
" yield 1\n";

jmp_buf env;
enum _ { detect, no, yes } has_buggy_gen_i ternext = detect;

static sighandler_t old_abrt = SIG_DFL;

void
signal_handler (int sig)
{
if (sig == SIGABRT)
longjmp(env, 1);
}


int
main (int argc, char *argv[])
{
Py_Initialize() ;

PyObject *globals = PyDict_New();

// insert function code into interpreter
PyObject *code = PyRun_String(py _source, Py_file_input, globals,
NULL);
Py_DECREF(code) ;

// compile call to the function
code = Py_CompileStrin g("fn()", "<string>", Py_eval_input);

// do call
PyObject *gen = PyEval_EvalCode ((PyCodeObject *)code, globals, NULL);
gen = PyObject_GetIte r((PyObject *)gen);

// detect if we are using bad Python interpreter
if (has_buggy_gen_ iternext == detect) {
if (setjmp(env) == 0)
// first time, set signal handler
old_abrt = signal(SIGABRT, signal_handler) ;
else {
// jumped here from signal handler -- bad Python
has_buggy_gen_i ternext = yes;
signal(SIGABRT, old_abrt);
}
}

if (has_buggy_gen_ iternext == yes)
printf("generat ors are disabled\n");
else {
// iterate result
PyObject *item;
while ((item = PyIter_Next(gen ))) {
printf("> %ld\n", PyInt_AsLong(it em));
Py_DECREF(item) ;
}

if (has_buggy_gen_ iternext == detect) {
// ok, restore old signal handler
has_buggy_gen_i ternext = no;
signal(SIGABRT, old_abrt);
}
}

Py_DECREF(gen);
Py_DECREF(code) ;
Py_DECREF(globa ls);

Py_Finalize();
return 0;
}