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from __future__ import with_statement
import signal as cpy_signal
import sys
import os
import errno
from pypy.interpreter.error import (
OperationError, exception_from_saved_errno, oefmt)
from pypy.interpreter.executioncontext import (AsyncAction, AbstractActionFlag,
PeriodicAsyncAction)
from pypy.interpreter.gateway import unwrap_spec
from rpython.rlib import jit, rposix, rgc
from rpython.rlib.objectmodel import we_are_translated
from rpython.rlib.rarithmetic import intmask
from rpython.rlib.rsignal import *
from rpython.rtyper.lltypesystem import lltype, rffi
WIN32 = sys.platform == 'win32'
class SignalActionFlag(AbstractActionFlag):
# This class uses the C-level pypysig_counter variable as the tick
# counter. The C-level signal handler will reset it to -1 whenever
# a signal is received. This causes CheckSignalAction.perform() to
# be called.
def get_ticker(self):
p = pypysig_getaddr_occurred()
return p.c_value
def reset_ticker(self, value):
p = pypysig_getaddr_occurred()
p.c_value = value
def rearm_ticker(self):
p = pypysig_getaddr_occurred()
p.c_value = -1
def decrement_ticker(self, by):
p = pypysig_getaddr_occurred()
value = p.c_value
if self.has_bytecode_counter: # this 'if' is constant-folded
if jit.isconstant(by) and by == 0:
pass # normally constant-folded too
else:
value -= by
p.c_value = value
return value
class CheckSignalAction(PeriodicAsyncAction):
"""An action that is automatically invoked when a signal is received."""
# Note that this is a PeriodicAsyncAction: it means more precisely
# that it is called whenever the C-level ticker becomes < 0.
# Without threads, it is only ever set to -1 when we receive a
# signal. With threads, it also decrements steadily (but slowly).
def __init__(self, space):
"NOT_RPYTHON"
AsyncAction.__init__(self, space)
self.pending_signal = -1
self.fire_in_another_thread = False
@rgc.no_collect
def _after_thread_switch():
if self.fire_in_another_thread:
if self.space.threadlocals.signals_enabled():
self.fire_in_another_thread = False
self.space.actionflag.rearm_ticker()
# this occurs when we just switched to the main thread
# and there is a signal pending: we force the ticker to
# -1, which should ensure perform() is called quickly.
self._after_thread_switch = _after_thread_switch
# ^^^ so that 'self._after_thread_switch' can be annotated as a
# constant
def startup(self, space):
# this is translated
if space.config.objspace.usemodules.thread:
from rpython.rlib import rgil
rgil.invoke_after_thread_switch(self._after_thread_switch)
def perform(self, executioncontext, frame):
self._poll_for_signals()
@jit.dont_look_inside
def _poll_for_signals(self):
# Poll for the next signal, if any
n = self.pending_signal
if n < 0:
n = pypysig_poll()
while n >= 0:
if self.space.threadlocals.signals_enabled():
# If we are in the main thread, report the signal now,
# and poll more
self.pending_signal = -1
report_signal(self.space, n)
n = self.pending_signal
if n < 0:
n = pypysig_poll()
else:
# Otherwise, arrange for perform() to be called again
# after we switch to the main thread.
self.pending_signal = n
self.fire_in_another_thread = True
break
def set_interrupt(self):
"Simulates the effect of a SIGINT signal arriving"
if not we_are_translated():
self.pending_signal = cpy_signal.SIGINT
# ^^^ may override another signal, but it's just for testing
self.fire_in_another_thread = True
else:
pypysig_pushback(cpy_signal.SIGINT)
# ____________________________________________________________
class Handlers:
def __init__(self, space):
self.handlers_w = {}
for signum in range(1, NSIG):
if WIN32 and signum not in signal_values:
self.handlers_w[signum] = space.w_None
else:
self.handlers_w[signum] = space.newint(SIG_DFL)
def _get_handlers(space):
return space.fromcache(Handlers).handlers_w
def report_signal(space, n):
handlers_w = _get_handlers(space)
try:
w_handler = handlers_w[n]
except KeyError:
return # no handler, ignore signal
if not space.is_true(space.callable(w_handler)):
return # w_handler is SIG_IGN or SIG_DFL?
# re-install signal handler, for OSes that clear it
pypysig_reinstall(n)
# invoke the app-level handler
ec = space.getexecutioncontext()
w_frame = ec.gettopframe_nohidden()
space.call_function(w_handler, space.newint(n), w_frame)
@unwrap_spec(signum=int)
def getsignal(space, signum):
"""
getsignal(sig) -> action
Return the current action for the given signal. The return value can be:
SIG_IGN -- if the signal is being ignored
SIG_DFL -- if the default action for the signal is in effect
None -- if an unknown handler is in effect
anything else -- the callable Python object used as a handler
"""
check_signum_in_range(space, signum)
handlers_w = _get_handlers(space)
return handlers_w[signum]
def default_int_handler(space, w_signum, w_frame):
"""
default_int_handler(...)
The default handler for SIGINT installed by Python.
It raises KeyboardInterrupt.
"""
raise OperationError(space.w_KeyboardInterrupt, space.w_None)
@jit.dont_look_inside
@unwrap_spec(timeout=int)
def alarm(space, timeout):
"""alarm(seconds)
Arrange for SIGALRM to arrive after the given number of seconds.
"""
return space.newint(c_alarm(timeout))
@jit.dont_look_inside
def pause(space):
"""pause()
Wait until a signal arrives.
"""
c_pause()
return space.w_None
def check_signum_in_range(space, signum):
if 1 <= signum < NSIG:
return
raise oefmt(space.w_ValueError, "signal number out of range")
@jit.dont_look_inside
@unwrap_spec(signum=int)
def signal(space, signum, w_handler):
"""
signal(sig, action) -> action
Set the action for the given signal. The action can be SIG_DFL,
SIG_IGN, or a callable Python object. The previous action is
returned. See getsignal() for possible return values.
*** IMPORTANT NOTICE ***
A signal handler function is called with two arguments:
the first is the signal number, the second is the interrupted stack frame.
"""
if WIN32 and signum not in signal_values:
raise oefmt(space.w_ValueError, "invalid signal value")
if not space.threadlocals.signals_enabled():
raise oefmt(space.w_ValueError,
"signal only works in main thread or with "
"__pypy__.thread.enable_signals()")
check_signum_in_range(space, signum)
if space.eq_w(w_handler, space.newint(SIG_DFL)):
pypysig_default(signum)
elif space.eq_w(w_handler, space.newint(SIG_IGN)):
pypysig_ignore(signum)
else:
if not space.is_true(space.callable(w_handler)):
raise oefmt(space.w_TypeError,
"'handler' must be a callable or SIG_DFL or SIG_IGN")
pypysig_setflag(signum)
handlers_w = _get_handlers(space)
old_handler = handlers_w[signum]
handlers_w[signum] = w_handler
return old_handler
@jit.dont_look_inside
@unwrap_spec(fd=int)
def set_wakeup_fd(space, fd):
"""Sets the fd to be written to (with '\0') when a signal
comes in. Returns the old fd. A library can use this to
wakeup select or poll. The previous fd is returned.
The fd must be non-blocking.
"""
if not space.threadlocals.signals_enabled():
raise oefmt(space.w_ValueError,
"set_wakeup_fd only works in main thread or with "
"__pypy__.thread.enable_signals()")
if fd != -1:
try:
os.fstat(fd)
except OSError as e:
if e.errno == errno.EBADF:
raise oefmt(space.w_ValueError, "invalid fd")
old_fd = pypysig_set_wakeup_fd(fd, True)
return space.newint(intmask(old_fd))
@jit.dont_look_inside
@unwrap_spec(signum=int, flag=int)
def siginterrupt(space, signum, flag):
"""siginterrupt(sig, flag) -> None
change system call restart behaviour: if flag is False, system calls
will be restarted when interrupted by signal sig, else system calls
will be interrupted.
"""
check_signum_in_range(space, signum)
if rffi.cast(lltype.Signed, c_siginterrupt(signum, flag)) < 0:
errno = rposix.get_saved_errno()
raise OperationError(space.w_RuntimeError, space.newint(errno))
#__________________________________________________________
def timeval_from_double(d, timeval):
rffi.setintfield(timeval, 'c_tv_sec', int(d))
rffi.setintfield(timeval, 'c_tv_usec', int((d - int(d)) * 1000000))
def double_from_timeval(tv):
return rffi.getintfield(tv, 'c_tv_sec') + (
rffi.getintfield(tv, 'c_tv_usec') / 1000000.0)
def itimer_retval(space, val):
w_value = space.newfloat(double_from_timeval(val.c_it_value))
w_interval = space.newfloat(double_from_timeval(val.c_it_interval))
return space.newtuple([w_value, w_interval])
class Cache:
def __init__(self, space):
self.w_itimererror = space.new_exception_class("signal.ItimerError",
space.w_IOError)
def get_itimer_error(space):
return space.fromcache(Cache).w_itimererror
@jit.dont_look_inside
@unwrap_spec(which=int, first=float, interval=float)
def setitimer(space, which, first, interval=0):
"""setitimer(which, seconds[, interval])
Sets given itimer (one of ITIMER_REAL, ITIMER_VIRTUAL
or ITIMER_PROF) to fire after value seconds and after
that every interval seconds.
The itimer can be cleared by setting seconds to zero.
Returns old values as a tuple: (delay, interval).
"""
with lltype.scoped_alloc(itimervalP.TO, 1) as new:
timeval_from_double(first, new[0].c_it_value)
timeval_from_double(interval, new[0].c_it_interval)
with lltype.scoped_alloc(itimervalP.TO, 1) as old:
ret = c_setitimer(which, new, old)
if ret != 0:
raise exception_from_saved_errno(space, get_itimer_error(space))
return itimer_retval(space, old[0])
@jit.dont_look_inside
@unwrap_spec(which=int)
def getitimer(space, which):
"""getitimer(which)
Returns current value of given itimer.
"""
with lltype.scoped_alloc(itimervalP.TO, 1) as old:
c_getitimer(which, old)
return itimer_retval(space, old[0])
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