ref: ff14019cd4713097c5e9e972fa573f7fc96f15b4
dir: /sys/src/cmd/python/Parser/intrcheck.c/
/* Check for interrupts */
#include "Python.h"
#ifdef QUICKWIN
#include <io.h>
void
PyOS_InitInterrupts(void)
{
}
void
PyOS_FiniInterrupts(void)
{
}
int
PyOS_InterruptOccurred(void)
{
	_wyield();
}
#define OK
#endif /* QUICKWIN */
#if defined(_M_IX86) && !defined(__QNX__)
#include <io.h>
#endif
#if defined(MSDOS) && !defined(QUICKWIN)
#ifdef __GNUC__
/* This is for DJGPP's GO32 extender.  I don't know how to trap
 * control-C  (There's no API for ctrl-C, and I don't want to mess with
 * the interrupt vectors.)  However, this DOES catch control-break.
 * --Amrit
 */
#include <go32.h>
void
PyOS_InitInterrupts(void)
{
	_go32_want_ctrl_break(1 /* TRUE */);
}
void
PyOS_FiniInterrupts(void)
{
}
int
PyOS_InterruptOccurred(void)
{
	return _go32_was_ctrl_break_hit();
}
#else /* !__GNUC__ */
/* This might work for MS-DOS (untested though): */
void
PyOS_InitInterrupts(void)
{
}
void
PyOS_FiniInterrupts(void)
{
}
int
PyOS_InterruptOccurred(void)
{
	int interrupted = 0;
	while (kbhit()) {
		if (getch() == '\003')
			interrupted = 1;
	}
	return interrupted;
}
#endif /* __GNUC__ */
#define OK
#endif /* MSDOS && !QUICKWIN */
#ifndef OK
/* Default version -- for real operating systems and for Standard C */
#include <stdio.h>
#include <string.h>
#include <signal.h>
static int interrupted;
void
PyErr_SetInterrupt(void)
{
	interrupted = 1;
}
extern int PyErr_CheckSignals(void);
static int
checksignals_witharg(void * arg)
{
	return PyErr_CheckSignals();
}
static void
intcatcher(int sig)
{
	extern void Py_Exit(int);
	static char message[] =
"python: to interrupt a truly hanging Python program, interrupt once more.\n";
	switch (interrupted++) {
	case 0:
		break;
	case 1:
#ifdef RISCOS
		fprintf(stderr, message);
#else
		write(2, message, strlen(message));
#endif
		break;
	case 2:
		interrupted = 0;
		Py_Exit(1);
		break;
	}
	PyOS_setsig(SIGINT, intcatcher);
	Py_AddPendingCall(checksignals_witharg, NULL);
}
static void (*old_siginthandler)(int) = SIG_DFL;
void
PyOS_InitInterrupts(void)
{
	if ((old_siginthandler = PyOS_setsig(SIGINT, SIG_IGN)) != SIG_IGN)
		PyOS_setsig(SIGINT, intcatcher);
}
void
PyOS_FiniInterrupts(void)
{
	PyOS_setsig(SIGINT, old_siginthandler);
}
int
PyOS_InterruptOccurred(void)
{
	if (!interrupted)
		return 0;
	interrupted = 0;
	return 1;
}
#endif /* !OK */
void
PyOS_AfterFork(void)
{
#ifdef WITH_THREAD
	PyEval_ReInitThreads();
#endif
}