mirror of https://github.com/python/cpython.git
567 lines
13 KiB
C
567 lines
13 KiB
C
/***********************************************************
|
||
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
|
||
The Netherlands.
|
||
|
||
All Rights Reserved
|
||
|
||
Permission to use, copy, modify, and distribute this software and its
|
||
documentation for any purpose and without fee is hereby granted,
|
||
provided that the above copyright notice appear in all copies and that
|
||
both that copyright notice and this permission notice appear in
|
||
supporting documentation, and that the names of Stichting Mathematisch
|
||
Centrum or CWI or Corporation for National Research Initiatives or
|
||
CNRI not be used in advertising or publicity pertaining to
|
||
distribution of the software without specific, written prior
|
||
permission.
|
||
|
||
While CWI is the initial source for this software, a modified version
|
||
is made available by the Corporation for National Research Initiatives
|
||
(CNRI) at the Internet address ftp://ftp.python.org.
|
||
|
||
STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
|
||
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
|
||
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
|
||
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
|
||
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
||
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
|
||
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
||
PERFORMANCE OF THIS SOFTWARE.
|
||
|
||
******************************************************************/
|
||
|
||
/* Signal module -- many thanks to Lance Ellinghaus */
|
||
|
||
#include "Python.h"
|
||
#include "intrcheck.h"
|
||
|
||
#ifdef HAVE_UNISTD_H
|
||
#include <unistd.h>
|
||
#endif
|
||
|
||
#include <signal.h>
|
||
|
||
#ifndef SIG_ERR
|
||
#define SIG_ERR ((RETSIGTYPE (*)())-1)
|
||
#endif
|
||
|
||
#ifndef NSIG
|
||
#define NSIG (_SIGMAX + 1) /* For QNX */
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
NOTES ON THE INTERACTION BETWEEN SIGNALS AND THREADS
|
||
|
||
When threads are supported, we want the following semantics:
|
||
|
||
- only the main thread can set a signal handler
|
||
- any thread can get a signal handler
|
||
- signals are only delivered to the main thread
|
||
|
||
I.e. we don't support "synchronous signals" like SIGFPE (catching
|
||
this doesn't make much sense in Python anyway) nor do we support
|
||
signals as a means of inter-thread communication, since not all
|
||
thread implementations support that (at least our thread library
|
||
doesn't).
|
||
|
||
We still have the problem that in some implementations signals
|
||
generated by the keyboard (e.g. SIGINT) are delivered to all
|
||
threads (e.g. SGI), while in others (e.g. Solaris) such signals are
|
||
delivered to one random thread (an intermediate possibility would
|
||
be to deliver it to the main thread -- POSIX?). For now, we have
|
||
a working implementation that works in all three cases -- the
|
||
handler ignores signals if getpid() isn't the same as in the main
|
||
thread. XXX This is a hack.
|
||
|
||
*/
|
||
|
||
#ifdef WITH_THREAD
|
||
#include "thread.h"
|
||
static long main_thread;
|
||
static pid_t main_pid;
|
||
#endif
|
||
|
||
static struct {
|
||
int tripped;
|
||
PyObject *func;
|
||
} Handlers[NSIG];
|
||
|
||
static int is_tripped = 0; /* Speed up sigcheck() when none tripped */
|
||
|
||
static PyObject *DefaultHandler;
|
||
static PyObject *IgnoreHandler;
|
||
static PyObject *IntHandler;
|
||
|
||
|
||
|
||
static PyObject *
|
||
signal_default_int_handler(self, arg)
|
||
PyObject *self;
|
||
PyObject *arg;
|
||
{
|
||
PyErr_SetNone(PyExc_KeyboardInterrupt);
|
||
return NULL;
|
||
}
|
||
|
||
|
||
static RETSIGTYPE
|
||
signal_handler(sig_num)
|
||
int sig_num;
|
||
{
|
||
#ifdef WITH_THREAD
|
||
/* See NOTES section above */
|
||
if (getpid() == main_pid) {
|
||
#endif
|
||
is_tripped++;
|
||
Handlers[sig_num].tripped = 1;
|
||
Py_AddPendingCall((int (*) Py_PROTO((ANY *)))PyErr_CheckSignals, NULL);
|
||
#ifdef WITH_THREAD
|
||
}
|
||
#endif
|
||
#ifdef SIGCHLD
|
||
if (sig_num == SIGCHLD) {
|
||
/* To avoid infinite recursion, this signal remains
|
||
reset until explicit re-instated.
|
||
Don't clear the 'func' field as it is our pointer
|
||
to the Python handler... */
|
||
return;
|
||
}
|
||
#endif
|
||
(void *)signal(sig_num, &signal_handler);
|
||
}
|
||
|
||
|
||
|
||
#ifndef DONT_HAVE_SIG_ALARM
|
||
static PyObject *
|
||
signal_alarm(self, args)
|
||
PyObject *self; /* Not used */
|
||
PyObject *args;
|
||
{
|
||
int t;
|
||
if (!PyArg_Parse(args, "i", &t))
|
||
return NULL;
|
||
/* alarm() returns the number of seconds remaining */
|
||
return PyInt_FromLong(alarm(t));
|
||
}
|
||
#endif
|
||
|
||
#ifndef DONT_HAVE_SIG_PAUSE
|
||
static PyObject *
|
||
signal_pause(self, args)
|
||
PyObject *self; /* Not used */
|
||
PyObject *args;
|
||
{
|
||
if (!PyArg_NoArgs(args))
|
||
return NULL;
|
||
|
||
Py_BEGIN_ALLOW_THREADS
|
||
(void)pause();
|
||
Py_END_ALLOW_THREADS
|
||
/* make sure that any exceptions that got raised are propagated
|
||
* back into Python
|
||
*/
|
||
if (PyErr_CheckSignals())
|
||
return NULL;
|
||
|
||
Py_INCREF(Py_None);
|
||
return Py_None;
|
||
}
|
||
#endif
|
||
|
||
|
||
static PyObject *
|
||
signal_signal(self, args)
|
||
PyObject *self; /* Not used */
|
||
PyObject *args;
|
||
{
|
||
PyObject *obj;
|
||
int sig_num;
|
||
PyObject *old_handler;
|
||
RETSIGTYPE (*func)();
|
||
if (!PyArg_Parse(args, "(iO)", &sig_num, &obj))
|
||
return NULL;
|
||
#ifdef WITH_THREAD
|
||
if (get_thread_ident() != main_thread) {
|
||
PyErr_SetString(PyExc_ValueError,
|
||
"signal only works in main thread");
|
||
return NULL;
|
||
}
|
||
#endif
|
||
if (sig_num < 1 || sig_num >= NSIG) {
|
||
PyErr_SetString(PyExc_ValueError,
|
||
"signal number out of range");
|
||
return NULL;
|
||
}
|
||
if (obj == IgnoreHandler)
|
||
func = SIG_IGN;
|
||
else if (obj == DefaultHandler)
|
||
func = SIG_DFL;
|
||
else if (!PyCallable_Check(obj)) {
|
||
PyErr_SetString(PyExc_TypeError,
|
||
"signal handler must be signal.SIG_IGN, signal.SIG_DFL, or a callable object");
|
||
return NULL;
|
||
}
|
||
else
|
||
func = signal_handler;
|
||
if (signal(sig_num, func) == SIG_ERR) {
|
||
PyErr_SetFromErrno(PyExc_RuntimeError);
|
||
return NULL;
|
||
}
|
||
old_handler = Handlers[sig_num].func;
|
||
Handlers[sig_num].tripped = 0;
|
||
Py_INCREF(obj);
|
||
Handlers[sig_num].func = obj;
|
||
return old_handler;
|
||
}
|
||
|
||
|
||
static PyObject *
|
||
signal_get_signal(self, args)
|
||
PyObject *self; /* Not used */
|
||
PyObject *args;
|
||
{
|
||
int sig_num;
|
||
PyObject *old_handler;
|
||
if (!PyArg_Parse(args, "i", &sig_num))
|
||
return NULL;
|
||
if (sig_num < 1 || sig_num >= NSIG) {
|
||
PyErr_SetString(PyExc_ValueError,
|
||
"signal number out of range");
|
||
return NULL;
|
||
}
|
||
old_handler = Handlers[sig_num].func;
|
||
Py_INCREF(old_handler);
|
||
return old_handler;
|
||
}
|
||
|
||
|
||
|
||
/* List of functions defined in the module */
|
||
static PyMethodDef signal_methods[] = {
|
||
#ifndef DONT_HAVE_SIG_ALARM
|
||
{"alarm", signal_alarm},
|
||
#endif
|
||
{"signal", signal_signal},
|
||
{"getsignal", signal_get_signal},
|
||
#ifndef DONT_HAVE_SIG_PAUSE
|
||
{"pause", signal_pause},
|
||
#endif
|
||
{"default_int_handler", signal_default_int_handler},
|
||
{NULL, NULL} /* sentinel */
|
||
};
|
||
|
||
|
||
|
||
void
|
||
initsignal()
|
||
{
|
||
PyObject *m, *d, *x;
|
||
int i;
|
||
|
||
#ifdef WITH_THREAD
|
||
main_thread = get_thread_ident();
|
||
main_pid = getpid();
|
||
#endif
|
||
|
||
/* Create the module and add the functions */
|
||
m = Py_InitModule("signal", signal_methods);
|
||
|
||
/* Add some symbolic constants to the module */
|
||
d = PyModule_GetDict(m);
|
||
|
||
x = DefaultHandler = PyInt_FromLong((long)SIG_DFL);
|
||
if (!x || PyDict_SetItemString(d, "SIG_DFL", x) < 0)
|
||
goto finally;
|
||
Py_DECREF(x);
|
||
|
||
x = IgnoreHandler = PyInt_FromLong((long)SIG_IGN);
|
||
if (!x || PyDict_SetItemString(d, "SIG_IGN", x) < 0)
|
||
goto finally;
|
||
|
||
x = PyInt_FromLong((long)NSIG);
|
||
if (!x || PyDict_SetItemString(d, "NSIG", x) < 0)
|
||
goto finally;
|
||
|
||
x = IntHandler = PyDict_GetItemString(d, "default_int_handler");
|
||
if (!x)
|
||
goto finally;
|
||
|
||
Handlers[0].tripped = 0;
|
||
for (i = 1; i < NSIG; i++) {
|
||
RETSIGTYPE (*t)();
|
||
#ifdef HAVE_SIGACTION
|
||
struct sigaction act;
|
||
sigaction(i, 0, &act);
|
||
t = act.sa_handler;
|
||
#else
|
||
t = signal(i, SIG_IGN);
|
||
signal(i, t);
|
||
#endif
|
||
Handlers[i].tripped = 0;
|
||
if (t == SIG_DFL)
|
||
Handlers[i].func = DefaultHandler;
|
||
else if (t == SIG_IGN)
|
||
Handlers[i].func = IgnoreHandler;
|
||
else
|
||
Handlers[i].func = Py_None; /* None of our business */
|
||
Py_INCREF(Handlers[i].func);
|
||
}
|
||
if (Handlers[SIGINT].func == DefaultHandler) {
|
||
/* Install default int handler */
|
||
Py_DECREF(Handlers[SIGINT].func);
|
||
Handlers[SIGINT].func = IntHandler;
|
||
Py_INCREF(IntHandler);
|
||
signal(SIGINT, &signal_handler);
|
||
}
|
||
|
||
#ifdef SIGHUP
|
||
x = PyInt_FromLong(SIGHUP);
|
||
PyDict_SetItemString(d, "SIGHUP", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGINT
|
||
x = PyInt_FromLong(SIGINT);
|
||
PyDict_SetItemString(d, "SIGINT", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGQUIT
|
||
x = PyInt_FromLong(SIGQUIT);
|
||
PyDict_SetItemString(d, "SIGQUIT", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGILL
|
||
x = PyInt_FromLong(SIGILL);
|
||
PyDict_SetItemString(d, "SIGILL", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGTRAP
|
||
x = PyInt_FromLong(SIGTRAP);
|
||
PyDict_SetItemString(d, "SIGTRAP", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGIOT
|
||
x = PyInt_FromLong(SIGIOT);
|
||
PyDict_SetItemString(d, "SIGIOT", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGABRT
|
||
x = PyInt_FromLong(SIGABRT);
|
||
PyDict_SetItemString(d, "SIGABRT", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGEMT
|
||
x = PyInt_FromLong(SIGEMT);
|
||
PyDict_SetItemString(d, "SIGEMT", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGFPE
|
||
x = PyInt_FromLong(SIGFPE);
|
||
PyDict_SetItemString(d, "SIGFPE", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGKILL
|
||
x = PyInt_FromLong(SIGKILL);
|
||
PyDict_SetItemString(d, "SIGKILL", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGBUS
|
||
x = PyInt_FromLong(SIGBUS);
|
||
PyDict_SetItemString(d, "SIGBUS", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGSEGV
|
||
x = PyInt_FromLong(SIGSEGV);
|
||
PyDict_SetItemString(d, "SIGSEGV", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGSYS
|
||
x = PyInt_FromLong(SIGSYS);
|
||
PyDict_SetItemString(d, "SIGSYS", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGPIPE
|
||
x = PyInt_FromLong(SIGPIPE);
|
||
PyDict_SetItemString(d, "SIGPIPE", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGALRM
|
||
x = PyInt_FromLong(SIGALRM);
|
||
PyDict_SetItemString(d, "SIGALRM", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGTERM
|
||
x = PyInt_FromLong(SIGTERM);
|
||
PyDict_SetItemString(d, "SIGTERM", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGUSR1
|
||
x = PyInt_FromLong(SIGUSR1);
|
||
PyDict_SetItemString(d, "SIGUSR1", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGUSR2
|
||
x = PyInt_FromLong(SIGUSR2);
|
||
PyDict_SetItemString(d, "SIGUSR2", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGCLD
|
||
x = PyInt_FromLong(SIGCLD);
|
||
PyDict_SetItemString(d, "SIGCLD", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGCHLD
|
||
x = PyInt_FromLong(SIGCHLD);
|
||
PyDict_SetItemString(d, "SIGCHLD", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGPWR
|
||
x = PyInt_FromLong(SIGPWR);
|
||
PyDict_SetItemString(d, "SIGPWR", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGIO
|
||
x = PyInt_FromLong(SIGIO);
|
||
PyDict_SetItemString(d, "SIGIO", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGURG
|
||
x = PyInt_FromLong(SIGURG);
|
||
PyDict_SetItemString(d, "SIGURG", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGWINCH
|
||
x = PyInt_FromLong(SIGWINCH);
|
||
PyDict_SetItemString(d, "SIGWINCH", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGPOLL
|
||
x = PyInt_FromLong(SIGPOLL);
|
||
PyDict_SetItemString(d, "SIGPOLL", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGSTOP
|
||
x = PyInt_FromLong(SIGSTOP);
|
||
PyDict_SetItemString(d, "SIGSTOP", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGTSTP
|
||
x = PyInt_FromLong(SIGTSTP);
|
||
PyDict_SetItemString(d, "SIGTSTP", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGCONT
|
||
x = PyInt_FromLong(SIGCONT);
|
||
PyDict_SetItemString(d, "SIGCONT", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGTTIN
|
||
x = PyInt_FromLong(SIGTTIN);
|
||
PyDict_SetItemString(d, "SIGTTIN", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGTTOU
|
||
x = PyInt_FromLong(SIGTTOU);
|
||
PyDict_SetItemString(d, "SIGTTOU", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGVTALRM
|
||
x = PyInt_FromLong(SIGVTALRM);
|
||
PyDict_SetItemString(d, "SIGVTALRM", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGPROF
|
||
x = PyInt_FromLong(SIGPROF);
|
||
PyDict_SetItemString(d, "SIGPROF", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGXCPU
|
||
x = PyInt_FromLong(SIGXCPU);
|
||
PyDict_SetItemString(d, "SIGXCPU", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
#ifdef SIGXFSZ
|
||
x = PyInt_FromLong(SIGXFSZ);
|
||
PyDict_SetItemString(d, "SIGXFSZ", x);
|
||
Py_XDECREF(x);
|
||
#endif
|
||
if (!PyErr_Occurred())
|
||
return;
|
||
|
||
/* Check for errors */
|
||
finally:
|
||
Py_FatalError("can't initialize module signal");
|
||
}
|
||
|
||
|
||
|
||
/* Declared in pyerrors.h */
|
||
int
|
||
PyErr_CheckSignals()
|
||
{
|
||
int i;
|
||
PyObject *f;
|
||
|
||
if (!is_tripped)
|
||
return 0;
|
||
#ifdef WITH_THREAD
|
||
if (get_thread_ident() != main_thread)
|
||
return 0;
|
||
#endif
|
||
if (!(f = PyEval_GetFrame()))
|
||
f = Py_None;
|
||
|
||
for (i = 1; i < NSIG; i++) {
|
||
if (Handlers[i].tripped) {
|
||
PyObject *result = NULL;
|
||
PyObject *arglist = Py_BuildValue("(iO)", i, f);
|
||
Handlers[i].tripped = 0;
|
||
|
||
if (arglist) {
|
||
result = PyEval_CallObject(Handlers[i].func,
|
||
arglist);
|
||
Py_DECREF(arglist);
|
||
}
|
||
if (!result)
|
||
return -1;
|
||
|
||
Py_DECREF(result);
|
||
}
|
||
}
|
||
is_tripped = 0;
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Replacements for intrcheck.c functionality
|
||
* Declared in pyerrors.h
|
||
*/
|
||
void
|
||
PyErr_SetInterrupt()
|
||
{
|
||
is_tripped++;
|
||
Handlers[SIGINT].tripped = 1;
|
||
Py_AddPendingCall((int (*) Py_PROTO((ANY *)))PyErr_CheckSignals, NULL);
|
||
}
|
||
|
||
void
|
||
PyOS_InitInterrupts()
|
||
{
|
||
initsignal();
|
||
}
|
||
|
||
int
|
||
PyOS_InterruptOccurred()
|
||
{
|
||
if (Handlers[SIGINT].tripped) {
|
||
#ifdef WITH_THREAD
|
||
if (get_thread_ident() != main_thread)
|
||
return 0;
|
||
#endif
|
||
Handlers[SIGINT].tripped = 0;
|
||
return 1;
|
||
}
|
||
return 0;
|
||
}
|