Patch #2240: Implement signal.setitimer and signal.getitimer.

This commit is contained in:
Martin v. Löwis 2008-03-24 13:31:16 +00:00
parent cdbc977c03
commit aef18b1c67
8 changed files with 313 additions and 16 deletions

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@ -39,12 +39,13 @@ rules for working with signals and their handlers:
* Some care must be taken if both signals and threads are used in the same
program. The fundamental thing to remember in using signals and threads
simultaneously is: always perform :func:`signal` operations in the main thread
of execution. Any thread can perform an :func:`alarm`, :func:`getsignal`, or
:func:`pause`; only the main thread can set a new signal handler, and the main
thread will be the only one to receive signals (this is enforced by the Python
:mod:`signal` module, even if the underlying thread implementation supports
sending signals to individual threads). This means that signals can't be used
as a means of inter-thread communication. Use locks instead.
of execution. Any thread can perform an :func:`alarm`, :func:`getsignal`,
:func:`pause`, :func:`setitimer` or :func:`getitimer`; only the main thread
can set a new signal handler, and the main thread will be the only one to
receive signals (this is enforced by the Python :mod:`signal` module, even
if the underlying thread implementation supports sending signals to
individual threads). This means that signals can't be used as a means of
inter-thread communication. Use locks instead.
The variables defined in the :mod:`signal` module are:
@ -78,6 +79,36 @@ The variables defined in the :mod:`signal` module are:
One more than the number of the highest signal number.
.. data:: ITIMER_REAL
Decrements interval timer in real time, and delivers SIGALRM upon expiration.
.. data:: ITIMER_VIRTUAL
Decrements interval timer only when the process is executing, and delivers
SIGVTALRM upon expiration.
.. data:: ITIMER_PROF
Decrements interval timer both when the process executes and when the
system is executing on behalf of the process. Coupled with ITIMER_VIRTUAL,
this timer is usually used to profile the time spent by the application
in user and kernel space. SIGPROF is delivered upon expiration.
The :mod:`signal` module defines one exception:
.. exception:: ItimerError
Raised to signal an error from the underlying :func:`setitimer` or
:func:`getitimer` implementation. Expect this error if an invalid
interval timer or a negative time is passed to :func:`setitimer`.
This error is a subtype of :exc:`IOError`.
The :mod:`signal` module defines the following functions:
@ -110,6 +141,29 @@ The :mod:`signal` module defines the following functions:
:manpage:`signal(2)`.)
.. function:: setitimer(which, seconds[, interval])
Sets given itimer (one of :const:`signal.ITIMER_REAL`,
:const:`signal.ITIMER_VIRTUAL` or :const:`signal.ITIMER_PROF`) especified
by *which* to fire after *seconds* (float is accepted, different from
:func:`alarm`) and after that every *interval* seconds. The interval
timer specified by *which* can be cleared by setting seconds to zero.
The old values are returned as a tuple: (delay, interval).
Attempting to pass an invalid interval timer will cause a
:exc:`ItimerError`.
.. versionadded:: 2.6
.. function:: getitimer(which)
Returns current value of a given itimer especified by *which*.
.. versionadded:: 2.6
.. function:: set_wakeup_fd(fd)
Set the wakeup fd to *fd*. When a signal is received, a ``'\0'`` byte is
@ -124,7 +178,6 @@ The :mod:`signal` module defines the following functions:
exception to be raised.
.. function:: siginterrupt(signalnum, flag)
Change system call restart behaviour: if *flag* is :const:`False`, system calls

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@ -258,9 +258,93 @@ class SiginterruptTest(unittest.TestCase):
i=self.readpipe_interrupted(lambda: signal.siginterrupt(self.signum, 0))
self.assertEquals(i, False)
class ItimerTest(unittest.TestCase):
def setUp(self):
self.hndl_called = False
self.hndl_count = 0
self.itimer = None
def tearDown(self):
if self.itimer is not None: # test_itimer_exc doesn't change this attr
# just ensure that itimer is stopped
signal.setitimer(self.itimer, 0)
def sig_alrm(self, *args):
self.hndl_called = True
if test_support.verbose:
print("SIGALRM handler invoked", args)
def sig_vtalrm(self, *args):
self.hndl_called = True
if self.hndl_count > 3:
# it shouldn't be here, because it should have been disabled.
raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL "
"timer.")
elif self.hndl_count == 3:
# disable ITIMER_VIRTUAL, this function shouldn't be called anymore
signal.setitimer(signal.ITIMER_VIRTUAL, 0)
if test_support.verbose:
print("last SIGVTALRM handler call")
self.hndl_count += 1
if test_support.verbose:
print("SIGVTALRM handler invoked", args)
def sig_prof(self, *args):
self.hndl_called = True
signal.setitimer(signal.ITIMER_PROF, 0)
if test_support.verbose:
print("SIGPROF handler invoked", args)
def test_itimer_exc(self):
# XXX I'm assuming -1 is an invalid itimer, but maybe some platform
# defines it ?
self.assertRaises(signal.ItimerError, signal.setitimer, -1, 0)
# negative time
self.assertRaises(signal.ItimerError, signal.setitimer,
signal.ITIMER_REAL, -1)
def test_itimer_real(self):
self.itimer = signal.ITIMER_REAL
signal.signal(signal.SIGALRM, self.sig_alrm)
signal.setitimer(self.itimer, 1.0)
if test_support.verbose:
print("\ncall pause()...")
signal.pause()
self.assertEqual(self.hndl_called, True)
def test_itimer_virtual(self):
self.itimer = signal.ITIMER_VIRTUAL
signal.signal(signal.SIGVTALRM, self.sig_vtalrm)
signal.setitimer(self.itimer, 0.3, 0.2)
for i in xrange(100000000):
if signal.getitimer(self.itimer) == (0.0, 0.0):
break # sig_vtalrm handler stopped this itimer
# virtual itimer should be (0.0, 0.0) now
self.assertEquals(signal.getitimer(self.itimer), (0.0, 0.0))
# and the handler should have been called
self.assertEquals(self.hndl_called, True)
def test_itimer_prof(self):
self.itimer = signal.ITIMER_PROF
signal.signal(signal.SIGPROF, self.sig_prof)
signal.setitimer(self.itimer, 0.2)
for i in xrange(100000000):
if signal.getitimer(self.itimer) == (0.0, 0.0):
break # sig_prof handler stopped this itimer
self.assertEqual(self.hndl_called, True)
def test_main():
test_support.run_unittest(BasicSignalTests, InterProcessSignalTests,
WakeupSignalTests, SiginterruptTest)
WakeupSignalTests, SiginterruptTest, ItimerTest)
if __name__ == "__main__":

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@ -528,6 +528,7 @@ Fran
Zach Pincus
Michael Piotrowski
Antoine Pitrou
Guilherme Polo
Michael Pomraning
Iustin Pop
John Popplewell

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@ -60,6 +60,11 @@ Core and builtins
- Issue #2143: Fix embedded readline() hang on SSL socket EOF.
Extensions Modules
------------------
- Patch #2240: Implement signal.setitimer and signal.getitimer.
Library
-------

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@ -13,6 +13,7 @@
#include <signal.h>
#include <sys/stat.h>
#include <sys/time.h>
#ifndef SIG_ERR
#define SIG_ERR ((PyOS_sighandler_t)(-1))
@ -93,6 +94,49 @@ static PyObject *IntHandler;
static PyOS_sighandler_t old_siginthandler = SIG_DFL;
#ifdef HAVE_GETITIMER
static PyObject *ItimerError;
/* auxiliary functions for setitimer/getitimer */
static void
timeval_from_double(double d, struct timeval *tv)
{
tv->tv_sec = floor(d);
tv->tv_usec = fmod(d, 1.0) * 1000000.0;
}
static inline double
double_from_timeval(struct timeval *tv)
{
return tv->tv_sec + (double)(tv->tv_usec / 1000000.0);
}
static PyObject *
itimer_retval(struct itimerval *iv)
{
PyObject *r, *v;
r = PyTuple_New(2);
if (r == NULL)
return NULL;
if(!(v = PyFloat_FromDouble(double_from_timeval(&iv->it_value)))) {
Py_DECREF(r);
return NULL;
}
PyTuple_SET_ITEM(r, 0, v);
if(!(v = PyFloat_FromDouble(double_from_timeval(&iv->it_interval)))) {
Py_DECREF(r);
return NULL;
}
PyTuple_SET_ITEM(r, 1, v);
return r;
}
#endif
static PyObject *
signal_default_int_handler(PyObject *self, PyObject *args)
@ -347,10 +391,76 @@ PySignal_SetWakeupFd(int fd)
}
#ifdef HAVE_SETITIMER
static PyObject *
signal_setitimer(PyObject *self, PyObject *args)
{
double first;
double interval = 0;
int which;
struct itimerval new, old;
if(!PyArg_ParseTuple(args, "id|d:setitimer", &which, &first, &interval))
return NULL;
timeval_from_double(first, &new.it_value);
timeval_from_double(interval, &new.it_interval);
/* Let OS check "which" value */
if (setitimer(which, &new, &old) != 0) {
PyErr_SetFromErrno(ItimerError);
return NULL;
}
return itimer_retval(&old);
}
PyDoc_STRVAR(setitimer_doc,
"setitimer(which, seconds[, interval])\n\
\n\
Sets given itimer (one of ITIMER_REAL, ITIMER_VIRTUAL\n\
or ITIMER_PROF) to fire after value seconds and after\n\
that every interval seconds.\n\
The itimer can be cleared by setting seconds to zero.\n\
\n\
Returns old values as a tuple: (delay, interval).");
#endif
#ifdef HAVE_GETITIMER
static PyObject *
signal_getitimer(PyObject *self, PyObject *args)
{
int which;
struct itimerval old;
if (!PyArg_ParseTuple(args, "i:getitimer", &which))
return NULL;
if (getitimer(which, &old) != 0) {
PyErr_SetFromErrno(ItimerError);
return NULL;
}
return itimer_retval(&old);
}
PyDoc_STRVAR(getitimer_doc,
"getitimer(which)\n\
\n\
Returns current value of given itimer.");
#endif
/* List of functions defined in the module */
static PyMethodDef signal_methods[] = {
#ifdef HAVE_ALARM
{"alarm", signal_alarm, METH_VARARGS, alarm_doc},
#endif
#ifdef HAVE_SETITIMER
{"setitimer", signal_setitimer, METH_VARARGS, setitimer_doc},
#endif
#ifdef HAVE_GETITIMER
{"getitimer", signal_getitimer, METH_VARARGS, getitimer_doc},
#endif
{"signal", signal_signal, METH_VARARGS, signal_doc},
{"getsignal", signal_getsignal, METH_VARARGS, getsignal_doc},
@ -374,19 +484,32 @@ PyDoc_STRVAR(module_doc,
Functions:\n\
\n\
alarm() -- cause SIGALRM after a specified time [Unix only]\n\
setitimer() -- cause a signal (described below) after a specified\n\
float time and the timer may restart then [Unix only]\n\
getitimer() -- get current value of timer [Unix only]\n\
signal() -- set the action for a given signal\n\
getsignal() -- get the signal action for a given signal\n\
pause() -- wait until a signal arrives [Unix only]\n\
default_int_handler() -- default SIGINT handler\n\
\n\
Constants:\n\
\n\
signal constants:\n\
SIG_DFL -- used to refer to the system default handler\n\
SIG_IGN -- used to ignore the signal\n\
NSIG -- number of defined signals\n\
\n\
SIGINT, SIGTERM, etc. -- signal numbers\n\
\n\
itimer constants:\n\
ITIMER_REAL -- decrements in real time, and delivers SIGALRM upon\n\
expiration\n\
ITIMER_VIRTUAL -- decrements only when the process is executing,\n\
and delivers SIGVTALRM upon expiration\n\
ITIMER_PROF -- decrements both when the process is executing and\n\
when the system is executing on behalf of the process.\n\
Coupled with ITIMER_VIRTUAL, this timer is usually\n\
used to profile the time spent by the application\n\
in user and kernel space. SIGPROF is delivered upon\n\
expiration.\n\
\n\n\
*** IMPORTANT NOTICE ***\n\
A signal handler function is called with two arguments:\n\
the first is the signal number, the second is the interrupted stack frame.");
@ -639,6 +762,29 @@ initsignal(void)
PyDict_SetItemString(d, "SIGINFO", x);
Py_XDECREF(x);
#endif
#ifdef ITIMER_REAL
x = PyLong_FromLong(ITIMER_REAL);
PyDict_SetItemString(d, "ITIMER_REAL", x);
Py_DECREF(x);
#endif
#ifdef ITIMER_VIRTUAL
x = PyLong_FromLong(ITIMER_VIRTUAL);
PyDict_SetItemString(d, "ITIMER_VIRTUAL", x);
Py_DECREF(x);
#endif
#ifdef ITIMER_PROF
x = PyLong_FromLong(ITIMER_PROF);
PyDict_SetItemString(d, "ITIMER_PROF", x);
Py_DECREF(x);
#endif
#if defined (HAVE_SETITIMER) || defined (HAVE_GETITIMER)
ItimerError = PyErr_NewException("signal.ItimerError",
PyExc_IOError, NULL);
PyDict_SetItemString(d, "ItimerError", ItimerError);
#endif
if (!PyErr_Occurred())
return;

8
configure vendored
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@ -1,5 +1,5 @@
#! /bin/sh
# From configure.in Revision: 61436 .
# From configure.in Revision: 61722 .
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.61 for python 2.6.
#
@ -15506,8 +15506,10 @@ echo "${ECHO_T}MACHDEP_OBJS" >&6; }
for ac_func in alarm bind_textdomain_codeset chown clock confstr \
ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
for ac_func in alarm setitimer getitimer bind_textdomain_codeset chown \
clock confstr ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getpwent getspnam getspent getsid getwd \
kill killpg lchmod lchown lstat mkfifo mknod mktime \

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@ -2303,8 +2303,8 @@ fi
AC_MSG_RESULT(MACHDEP_OBJS)
# checks for library functions
AC_CHECK_FUNCS(alarm bind_textdomain_codeset chown clock confstr \
ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
AC_CHECK_FUNCS(alarm setitimer getitimer bind_textdomain_codeset chown \
clock confstr ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getpwent getspnam getspent getsid getwd \
kill killpg lchmod lchown lstat mkfifo mknod mktime \

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@ -243,6 +243,9 @@
/* Define this if you have the 6-arg version of gethostbyname_r(). */
#undef HAVE_GETHOSTBYNAME_R_6_ARG
/* Define to 1 if you have the `getitimer' function. */
#undef HAVE_GETITIMER
/* Define to 1 if you have the `getloadavg' function. */
#undef HAVE_GETLOADAVG
@ -501,6 +504,9 @@
/* Define if you have the 'setgroups' function. */
#undef HAVE_SETGROUPS
/* Define to 1 if you have the `setitimer' function. */
#undef HAVE_SETITIMER
/* Define to 1 if you have the `setlocale' function. */
#undef HAVE_SETLOCALE