#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <errno.h>
#ifdef HAVE_PROCESS_H
#include <process.h>
#endif
#include <unistd.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <full-write.h>
#include "libguile/_scm.h"
#include "libguile/async.h"
#include "libguile/eval.h"
#include "libguile/root.h"
#include "libguile/vectors.h"
#include "libguile/threads.h"
#include "libguile/validate.h"
#include "libguile/scmsigs.h"
#ifdef RETSIGTYPE
# define SIGRETTYPE RETSIGTYPE
#else
# ifdef STDC_HEADERS
# define SIGRETTYPE void
# else
# define SIGRETTYPE int
# endif
#endif
static SCM *signal_handlers;
static SCM signal_handler_asyncs;
static SCM signal_handler_threads;
scm_i_thread *scm_i_signal_delivery_thread = NULL;
static scm_i_pthread_mutex_t signal_delivery_thread_mutex =
SCM_I_PTHREAD_MUTEX_INITIALIZER;
#ifdef HAVE_SIGACTION
static struct sigaction orig_handlers[NSIG];
#else
static SIGRETTYPE (*orig_handlers[NSIG])(int);
#endif
static SCM
close_1 (SCM proc, SCM arg)
{
return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda, SCM_EOL,
scm_list_2 (proc, arg)));
}
#if SCM_USE_PTHREAD_THREADS
static int signal_pipe[2];
static SIGRETTYPE
take_signal (int signum)
{
char sigbyte = signum;
full_write (signal_pipe[1], &sigbyte, 1);
#ifndef HAVE_SIGACTION
signal (signum, take_signal);
#endif
}
struct signal_pipe_data
{
char sigbyte;
ssize_t n;
int err;
};
static void*
read_signal_pipe_data (void * data)
{
struct signal_pipe_data *sdata = data;
sdata->n = read (signal_pipe[0], &sdata->sigbyte, 1);
sdata->err = errno;
return NULL;
}
static SCM
signal_delivery_thread (void *data)
{
int sig;
#if HAVE_PTHREAD_SIGMASK
sigset_t all_sigs;
sigfillset (&all_sigs);
scm_i_pthread_sigmask (SIG_SETMASK, &all_sigs, NULL);
#endif
while (1)
{
struct signal_pipe_data sigdata;
scm_without_guile (read_signal_pipe_data, &sigdata);
sig = sigdata.sigbyte;
if (sigdata.n == 1 && sig >= 0 && sig < NSIG)
{
SCM h, t;
h = SCM_SIMPLE_VECTOR_REF (signal_handler_asyncs, sig);
t = SCM_SIMPLE_VECTOR_REF (signal_handler_threads, sig);
if (scm_is_true (h))
scm_system_async_mark_for_thread (h, t);
}
else if (sigdata.n == 0)
break;
else if (sigdata.n < 0 && sigdata.err != EINTR)
perror ("error in signal delivery thread");
}
return SCM_UNSPECIFIED;
}
static void
start_signal_delivery_thread (void)
{
SCM signal_thread;
scm_i_pthread_mutex_lock (&signal_delivery_thread_mutex);
if (pipe2 (signal_pipe, O_CLOEXEC) != 0)
scm_syserror (NULL);
signal_thread = scm_spawn_thread (signal_delivery_thread, NULL,
scm_handle_by_message,
"signal delivery thread");
scm_i_signal_delivery_thread = SCM_I_THREAD_DATA (signal_thread);
scm_i_pthread_mutex_unlock (&signal_delivery_thread_mutex);
}
void
scm_i_ensure_signal_delivery_thread ()
{
static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
scm_i_pthread_once (&once, start_signal_delivery_thread);
}
#else
static SIGRETTYPE
take_signal (int signum)
{
SCM cell = SCM_SIMPLE_VECTOR_REF (signal_handler_asyncs, signum);
scm_i_thread *t = SCM_I_CURRENT_THREAD;
if (scm_is_false (SCM_CDR (cell)))
{
SCM_SETCDR (cell, t->active_asyncs);
t->active_asyncs = cell;
t->pending_asyncs = 1;
}
#ifndef HAVE_SIGACTION
signal (signum, take_signal);
#endif
}
void
scm_i_ensure_signal_delivery_thread ()
{
return;
}
#endif
static void
install_handler (int signum, SCM thread, SCM handler)
{
if (scm_is_false (handler))
{
SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, SCM_BOOL_F);
SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, SCM_BOOL_F);
}
else
{
SCM async = close_1 (handler, scm_from_int (signum));
#if !SCM_USE_PTHREAD_THREADS
async = scm_cons (async, SCM_BOOL_F);
#endif
SCM_SIMPLE_VECTOR_SET (*signal_handlers, signum, handler);
SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs, signum, async);
}
SCM_SIMPLE_VECTOR_SET (signal_handler_threads, signum, thread);
}
SCM
scm_sigaction (SCM signum, SCM handler, SCM flags)
{
return scm_sigaction_for_thread (signum, handler, flags, SCM_UNDEFINED);
}
SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0,
(SCM signum, SCM handler, SCM flags, SCM thread),
"Install or report the signal handler for a specified signal.\n\n"
"@var{signum} is the signal number, which can be specified using the value\n"
"of variables such as @code{SIGINT}.\n\n"
"If @var{handler} is omitted, @code{sigaction} returns a pair: the\n"
"CAR is the current\n"
"signal hander, which will be either an integer with the value @code{SIG_DFL}\n"
"(default action) or @code{SIG_IGN} (ignore), or the Scheme procedure which\n"
"handles the signal, or @code{#f} if a non-Scheme procedure handles the\n"
"signal. The CDR contains the current @code{sigaction} flags for the handler.\n\n"
"If @var{handler} is provided, it is installed as the new handler for\n"
"@var{signum}. @var{handler} can be a Scheme procedure taking one\n"
"argument, or the value of @code{SIG_DFL} (default action) or\n"
"@code{SIG_IGN} (ignore), or @code{#f} to restore whatever signal handler\n"
"was installed before @code{sigaction} was first used. When\n"
"a scheme procedure has been specified, that procedure will run\n"
"in the given @var{thread}. When no thread has been given, the\n"
"thread that made this call to @code{sigaction} is used.\n"
"Flags can optionally be specified for the new handler.\n"
"The return value is a pair with information about the\n"
"old handler as described above.\n\n"
"This interface does not provide access to the \"signal blocking\"\n"
"facility. Maybe this is not needed, since the thread support may\n"
"provide solutions to the problem of consistent access to data\n"
"structures.")
#define FUNC_NAME s_scm_sigaction_for_thread
{
int csig;
#ifdef HAVE_SIGACTION
struct sigaction action;
struct sigaction old_action;
#else
SIGRETTYPE (* chandler) (int) = SIG_DFL;
SIGRETTYPE (* old_chandler) (int);
#endif
int query_only = 0;
int save_handler = 0;
SCM old_handler;
csig = scm_to_signed_integer (signum, 0, NSIG-1);
#if defined(HAVE_SIGACTION)
action.sa_flags = 0;
if (!SCM_UNBNDP (flags))
action.sa_flags |= scm_to_int (flags);
sigemptyset (&action.sa_mask);
#endif
if (SCM_UNBNDP (thread))
thread = scm_current_thread ();
else
{
SCM_VALIDATE_THREAD (4, thread);
if (scm_c_thread_exited_p (thread))
SCM_MISC_ERROR ("thread has already exited", SCM_EOL);
}
scm_i_ensure_signal_delivery_thread ();
SCM_CRITICAL_SECTION_START;
old_handler = SCM_SIMPLE_VECTOR_REF (*signal_handlers, csig);
if (SCM_UNBNDP (handler))
query_only = 1;
else if (scm_is_integer (handler))
{
long handler_int = scm_to_long (handler);
if (handler_int == (long) SIG_DFL || handler_int == (long) SIG_IGN)
{
#ifdef HAVE_SIGACTION
action.sa_handler = (SIGRETTYPE (*) (int)) handler_int;
#else
chandler = (SIGRETTYPE (*) (int)) handler_int;
#endif
install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
}
else
{
SCM_CRITICAL_SECTION_END;
SCM_OUT_OF_RANGE (2, handler);
}
}
else if (scm_is_false (handler))
{
#ifdef HAVE_SIGACTION
if (orig_handlers[csig].sa_handler == SIG_ERR)
query_only = 1;
else
{
action = orig_handlers[csig];
orig_handlers[csig].sa_handler = SIG_ERR;
install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
}
#else
if (orig_handlers[csig] == SIG_ERR)
query_only = 1;
else
{
chandler = orig_handlers[csig];
orig_handlers[csig] = SIG_ERR;
install_handler (csig, SCM_BOOL_F, SCM_BOOL_F);
}
#endif
}
else
{
SCM_VALIDATE_PROC (2, handler);
#ifdef HAVE_SIGACTION
action.sa_handler = take_signal;
if (orig_handlers[csig].sa_handler == SIG_ERR)
save_handler = 1;
#else
chandler = take_signal;
if (orig_handlers[csig] == SIG_ERR)
save_handler = 1;
#endif
install_handler (csig, thread, handler);
}
switch (csig)
{
case SIGFPE:
case SIGILL:
case SIGSEGV:
#ifdef SIGBUS
case SIGBUS:
#endif
case SIGABRT:
#if defined(SIGIOT) && (SIGIOT != SIGABRT)
case SIGIOT:
#endif
#ifdef SIGTRAP
case SIGTRAP:
#endif
#ifdef SIGEMT
case SIGEMT:
#endif
#ifdef SIGSYS
case SIGSYS:
#endif
query_only = 1;
}
#ifdef HAVE_SIGACTION
if (query_only)
{
if (sigaction (csig, 0, &old_action) == -1)
SCM_SYSERROR;
}
else
{
if (sigaction (csig, &action , &old_action) == -1)
SCM_SYSERROR;
if (save_handler)
orig_handlers[csig] = old_action;
}
if (old_action.sa_handler == SIG_DFL || old_action.sa_handler == SIG_IGN)
old_handler = scm_from_long ((long) old_action.sa_handler);
SCM_CRITICAL_SECTION_END;
return scm_cons (old_handler, scm_from_int (old_action.sa_flags));
#else
if (query_only)
{
if ((old_chandler = signal (csig, SIG_IGN)) == SIG_ERR)
SCM_SYSERROR;
if (signal (csig, old_chandler) == SIG_ERR)
SCM_SYSERROR;
}
else
{
if ((old_chandler = signal (csig, chandler)) == SIG_ERR)
SCM_SYSERROR;
if (save_handler)
orig_handlers[csig] = old_chandler;
}
if (old_chandler == SIG_DFL || old_chandler == SIG_IGN)
old_handler = scm_from_long ((long) old_chandler);
SCM_CRITICAL_SECTION_END;
return scm_cons (old_handler, scm_from_int (0));
#endif
}
#undef FUNC_NAME
SCM_DEFINE (scm_restore_signals, "restore-signals", 0, 0, 0,
(void),
"Return all signal handlers to the values they had before any call to\n"
"@code{sigaction} was made. The return value is unspecified.")
#define FUNC_NAME s_scm_restore_signals
{
int i;
for (i = 0; i < NSIG; i++)
{
#ifdef HAVE_SIGACTION
if (orig_handlers[i].sa_handler != SIG_ERR)
{
if (sigaction (i, &orig_handlers[i], NULL) == -1)
SCM_SYSERROR;
orig_handlers[i].sa_handler = SIG_ERR;
SCM_SIMPLE_VECTOR_SET (*signal_handlers, i, SCM_BOOL_F);
}
#else
if (orig_handlers[i] != SIG_ERR)
{
if (signal (i, orig_handlers[i]) == SIG_ERR)
SCM_SYSERROR;
orig_handlers[i] = SIG_ERR;
SCM_SIMPLE_VECTOR_SET (*signal_handlers, i, SCM_BOOL_F);
}
#endif
}
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
#if HAVE_DECL_ALARM
SCM_DEFINE (scm_alarm, "alarm", 1, 0, 0,
(SCM i),
"Set a timer to raise a @code{SIGALRM} signal after the specified\n"
"number of seconds (an integer). It's advisable to install a signal\n"
"handler for\n"
"@code{SIGALRM} beforehand, since the default action is to terminate\n"
"the process.\n\n"
"The return value indicates the time remaining for the previous alarm,\n"
"if any. The new value replaces the previous alarm. If there was\n"
"no previous alarm, the return value is zero.")
#define FUNC_NAME s_scm_alarm
{
return scm_from_uint (alarm (scm_to_uint (i)));
}
#undef FUNC_NAME
#endif
#ifdef HAVE_SETITIMER
SCM_DEFINE (scm_setitimer, "setitimer", 5, 0, 0,
(SCM which_timer,
SCM interval_seconds, SCM interval_microseconds,
SCM value_seconds, SCM value_microseconds),
"Set the timer specified by @var{which_timer} according to the given\n"
"@var{interval_seconds}, @var{interval_microseconds},\n"
"@var{value_seconds}, and @var{value_microseconds} values.\n"
"\n"
"Return information about the timer's previous setting."
"\n"
"Errors are handled as described in the guile info pages under ``POSIX\n"
"Interface Conventions''.\n"
"\n"
"The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
"and @code{ITIMER_PROF}.\n"
"\n"
"The return value will be a list of two cons pairs representing the\n"
"current state of the given timer. The first pair is the seconds and\n"
"microseconds of the timer @code{it_interval}, and the second pair is\n"
"the seconds and microseconds of the timer @code{it_value}.")
#define FUNC_NAME s_scm_setitimer
{
int rv;
int c_which_timer;
struct itimerval new_timer;
struct itimerval old_timer;
c_which_timer = SCM_NUM2INT(1, which_timer);
new_timer.it_interval.tv_sec = SCM_NUM2LONG(2, interval_seconds);
new_timer.it_interval.tv_usec = SCM_NUM2LONG(3, interval_microseconds);
new_timer.it_value.tv_sec = SCM_NUM2LONG(4, value_seconds);
new_timer.it_value.tv_usec = SCM_NUM2LONG(5, value_microseconds);
SCM_SYSCALL(rv = setitimer(c_which_timer, &new_timer, &old_timer));
if(rv != 0)
SCM_SYSERROR;
return scm_list_2 (scm_cons (scm_from_long (old_timer.it_interval.tv_sec),
scm_from_long (old_timer.it_interval.tv_usec)),
scm_cons (scm_from_long (old_timer.it_value.tv_sec),
scm_from_long (old_timer.it_value.tv_usec)));
}
#undef FUNC_NAME
#endif
#ifdef HAVE_GETITIMER
SCM_DEFINE (scm_getitimer, "getitimer", 1, 0, 0,
(SCM which_timer),
"Return information about the timer specified by @var{which_timer}"
"\n"
"Errors are handled as described in the guile info pages under ``POSIX\n"
"Interface Conventions''.\n"
"\n"
"The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
"and @code{ITIMER_PROF}.\n"
"\n"
"The return value will be a list of two cons pairs representing the\n"
"current state of the given timer. The first pair is the seconds and\n"
"microseconds of the timer @code{it_interval}, and the second pair is\n"
"the seconds and microseconds of the timer @code{it_value}.")
#define FUNC_NAME s_scm_getitimer
{
int rv;
int c_which_timer;
struct itimerval old_timer;
c_which_timer = SCM_NUM2INT(1, which_timer);
SCM_SYSCALL(rv = getitimer(c_which_timer, &old_timer));
if(rv != 0)
SCM_SYSERROR;
return scm_list_2 (scm_cons (scm_from_long (old_timer.it_interval.tv_sec),
scm_from_long (old_timer.it_interval.tv_usec)),
scm_cons (scm_from_long (old_timer.it_value.tv_sec),
scm_from_long (old_timer.it_value.tv_usec)));
}
#undef FUNC_NAME
#endif
#ifdef HAVE_PAUSE
SCM_DEFINE (scm_pause, "pause", 0, 0, 0,
(),
"Pause the current process (thread?) until a signal arrives whose\n"
"action is to either terminate the current process or invoke a\n"
"handler procedure. The return value is unspecified.")
#define FUNC_NAME s_scm_pause
{
pause ();
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
#endif
SCM_DEFINE (scm_sleep, "sleep", 1, 0, 0,
(SCM i),
"Wait for the given number of seconds (an integer) or until a signal\n"
"arrives. The return value is zero if the time elapses or the number\n"
"of seconds remaining otherwise.\n"
"\n"
"See also @code{usleep}.")
#define FUNC_NAME s_scm_sleep
{
return scm_from_uint (scm_std_sleep (scm_to_uint (i)));
}
#undef FUNC_NAME
SCM_DEFINE (scm_usleep, "usleep", 1, 0, 0,
(SCM i),
"Wait the given period @var{usecs} microseconds (an integer).\n"
"If a signal arrives the wait stops and the return value is the\n"
"time remaining, in microseconds. If the period elapses with no\n"
"signal the return is zero.\n"
"\n"
"On most systems the process scheduler is not microsecond accurate and\n"
"the actual period slept by @code{usleep} may be rounded to a system\n"
"clock tick boundary. Traditionally such ticks were 10 milliseconds\n"
"apart, and that interval is often still used.\n"
"\n"
"See also @code{sleep}.")
#define FUNC_NAME s_scm_usleep
{
return scm_from_ulong (scm_std_usleep (scm_to_ulong (i)));
}
#undef FUNC_NAME
SCM_DEFINE (scm_raise, "raise", 1, 0, 0,
(SCM sig),
"Sends a specified signal @var{sig} to the current process, where\n"
"@var{sig} is as described for the kill procedure.")
#define FUNC_NAME s_scm_raise
{
if (raise (scm_to_int (sig)) != 0)
SCM_SYSERROR;
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
void
scm_i_close_signal_pipe()
{
scm_i_pthread_mutex_lock (&signal_delivery_thread_mutex);
#if SCM_USE_PTHREAD_THREADS
if (scm_i_signal_delivery_thread != NULL)
close (signal_pipe[1]);
#endif
scm_i_pthread_mutex_unlock (&signal_delivery_thread_mutex);
}
void
scm_init_scmsigs ()
{
int i;
signal_handlers =
SCM_VARIABLE_LOC (scm_c_define ("signal-handlers",
scm_c_make_vector (NSIG, SCM_BOOL_F)));
signal_handler_asyncs = scm_c_make_vector (NSIG, SCM_BOOL_F);
signal_handler_threads = scm_c_make_vector (NSIG, SCM_BOOL_F);
for (i = 0; i < NSIG; i++)
{
#ifdef HAVE_SIGACTION
orig_handlers[i].sa_handler = SIG_ERR;
#else
orig_handlers[i] = SIG_ERR;
#endif
}
scm_c_define ("NSIG", scm_from_long (NSIG));
scm_c_define ("SIG_IGN", scm_from_long ((long) SIG_IGN));
scm_c_define ("SIG_DFL", scm_from_long ((long) SIG_DFL));
#ifdef SA_NOCLDSTOP
scm_c_define ("SA_NOCLDSTOP", scm_from_long (SA_NOCLDSTOP));
#endif
#ifdef SA_RESTART
scm_c_define ("SA_RESTART", scm_from_long (SA_RESTART));
#endif
#if defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER)
scm_c_define ("ITIMER_REAL", scm_from_int (ITIMER_REAL));
scm_c_define ("ITIMER_VIRTUAL", scm_from_int (ITIMER_VIRTUAL));
scm_c_define ("ITIMER_PROF", scm_from_int (ITIMER_PROF));
#endif
#include "libguile/scmsigs.x"
}