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/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy and Damien Doligez, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../LICENSE. */
/* */
/***********************************************************************/
/* $Id$ */
#include <signal.h>
#include "alloc.h"
#include "callback.h"
#include "config.h"
#include "fail.h"
#include "memory.h"
#include "misc.h"
#include "mlvalues.h"
#include "roots.h"
#include "signals.h"
#include "sys.h"
#if macintosh
#include "rotatecursor.h"
#endif /* macintosh */
#ifdef _WIN32
typedef void (*sighandler)(int sig);
extern sighandler win32_signal(int sig, sighandler action);
#define signal(sig,act) win32_signal(sig,act)
#endif
int volatile async_signal_mode = 0;
int volatile pending_signal = 0;
int volatile something_to_do = 0;
int volatile force_major_slice = 0;
value signal_handlers = 0;
void (*enter_blocking_section_hook)(void) = NULL;
void (*leave_blocking_section_hook)(void) = NULL;
void (* volatile async_action_hook)(void) = NULL;
void process_event(void)
{
int signal_number;
void (*async_action)(void);
if (force_major_slice) minor_collection (); /* FIXME should be check_urgent_gc */
/* If a signal arrives between the following two instructions,
it will be lost. To do: use atomic swap or atomic read-and-clear
for processors that support it? */
signal_number = pending_signal;
pending_signal = 0;
if (signal_number) execute_signal(signal_number, 0);
/* If an async action is scheduled between the following two instructions,
it will be lost. */
async_action = async_action_hook;
async_action_hook = NULL;
if (async_action != NULL) (*async_action)();
#if macintosh
ROTATECURSOR_MAGIC ();
#endif
}
static int rev_convert_signal_number(int signo);
void execute_signal(int signal_number, int in_signal_handler)
{
value res;
#ifdef POSIX_SIGNALS
sigset_t sigs;
/* Block the signal before executing the handler, and record in sigs
the original signal mask */
sigemptyset(&sigs);
sigaddset(&sigs, signal_number);
sigprocmask(SIG_BLOCK, &sigs, &sigs);
#endif
res = callback_exn(Field(signal_handlers, signal_number),
Val_int(rev_convert_signal_number(signal_number)));
#ifdef POSIX_SIGNALS
if (! in_signal_handler) {
/* Restore the original signal mask */
sigprocmask(SIG_SETMASK, &sigs, NULL);
} else if (Is_exception_result(res)) {
/* Restore the original signal mask and unblock the signal itself */
sigdelset(&sigs, signal_number);
sigprocmask(SIG_SETMASK, &sigs, NULL);
}
#endif
if (Is_exception_result(res)) mlraise(Extract_exception(res));
}
void handle_signal(int signal_number)
{
#if !defined(POSIX_SIGNALS) && !defined(BSD_SIGNALS)
signal(signal_number, handle_signal);
#endif
if (async_signal_mode){
leave_blocking_section ();
execute_signal(signal_number, 1);
enter_blocking_section ();
}else{
pending_signal = signal_number;
something_to_do = 1;
}
}
void urge_major_slice (void)
{
force_major_slice = 1;
something_to_do = 1;
}
CAMLexport void enter_blocking_section(void)
{
int temp;
while (1){
Assert (!async_signal_mode);
/* If a signal arrives between the next two instructions,
it will be lost. */
temp = pending_signal; pending_signal = 0;
if (temp) execute_signal(temp, 0);
async_signal_mode = 1;
if (!pending_signal) break;
async_signal_mode = 0;
}
if (enter_blocking_section_hook != NULL) enter_blocking_section_hook();
}
CAMLexport void leave_blocking_section(void)
{
#ifdef _WIN32
int signal_number;
#endif
if (leave_blocking_section_hook != NULL) leave_blocking_section_hook();
#ifdef _WIN32
/* Under Win32, asynchronous signals such as ctrl-C are not processed
immediately (see ctrl_handler in win32.c), but simply set
pending_signal and let the system call run to completion.
Hence, test pending_signal here and act upon it, before we get
a chance to process the result of the system call. */
signal_number = pending_signal;
pending_signal = 0;
if (signal_number) execute_signal(signal_number, 1);
#endif
Assert(async_signal_mode);
async_signal_mode = 0;
}
#ifndef SIGABRT
#define SIGABRT -1
#endif
#ifndef SIGALRM
#define SIGALRM -1
#endif
#ifndef SIGFPE
#define SIGFPE -1
#endif
#ifndef SIGHUP
#define SIGHUP -1
#endif
#ifndef SIGILL
#define SIGILL -1
#endif
#ifndef SIGINT
#define SIGINT -1
#endif
#ifndef SIGKILL
#define SIGKILL -1
#endif
#ifndef SIGPIPE
#define SIGPIPE -1
#endif
#ifndef SIGQUIT
#define SIGQUIT -1
#endif
#ifndef SIGSEGV
#define SIGSEGV -1
#endif
#ifndef SIGTERM
#define SIGTERM -1
#endif
#ifndef SIGUSR1
#define SIGUSR1 -1
#endif
#ifndef SIGUSR2
#define SIGUSR2 -1
#endif
#ifndef SIGCHLD
#define SIGCHLD -1
#endif
#ifndef SIGCONT
#define SIGCONT -1
#endif
#ifndef SIGSTOP
#define SIGSTOP -1
#endif
#ifndef SIGTSTP
#define SIGTSTP -1
#endif
#ifndef SIGTTIN
#define SIGTTIN -1
#endif
#ifndef SIGTTOU
#define SIGTTOU -1
#endif
#ifndef SIGVTALRM
#define SIGVTALRM -1
#endif
#ifndef SIGPROF
#define SIGPROF -1
#endif
static int posix_signals[] = {
SIGABRT, SIGALRM, SIGFPE, SIGHUP, SIGILL, SIGINT, SIGKILL, SIGPIPE,
SIGQUIT, SIGSEGV, SIGTERM, SIGUSR1, SIGUSR2, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGVTALRM, SIGPROF
};
CAMLexport int convert_signal_number(int signo)
{
if (signo < 0 && signo >= -(sizeof(posix_signals) / sizeof(int)))
return posix_signals[-signo-1];
else
return signo;
}
static int rev_convert_signal_number(int signo)
{
int i;
for (i = 0; i < sizeof(posix_signals) / sizeof(int); i++)
if (signo == posix_signals[i]) return -i - 1;
return signo;
}
#ifndef NSIG
#define NSIG 64
#endif
CAMLprim value install_signal_handler(value signal_number, value action)
{
CAMLparam2 (signal_number, action);
int sig;
void (*act)(int signo), (*oldact)(int signo);
#ifdef POSIX_SIGNALS
struct sigaction sigact, oldsigact;
#endif
CAMLlocal1 (res);
sig = convert_signal_number(Int_val(signal_number));
if (sig < 0 || sig >= NSIG)
invalid_argument("Sys.signal: unavailable signal");
switch(action) {
case Val_int(0): /* Signal_default */
act = SIG_DFL;
break;
case Val_int(1): /* Signal_ignore */
act = SIG_IGN;
break;
default: /* Signal_handle */
act = handle_signal;
break;
}
#ifdef POSIX_SIGNALS
sigact.sa_handler = act;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0;
if (sigaction(sig, &sigact, &oldsigact) == -1) caml_sys_error(NO_ARG);
oldact = oldsigact.sa_handler;
#else
oldact = signal(sig, act);
if (oldact == SIG_ERR) caml_sys_error(NO_ARG);
#endif
if (oldact == handle_signal) {
res = alloc_small (1, 0); /* Signal_handle */
Field(res, 0) = Field(signal_handlers, sig);
}
else if (oldact == SIG_IGN)
res = Val_int(1); /* Signal_ignore */
else
res = Val_int(0); /* Signal_default */
if (Is_block(action)) {
if (signal_handlers == 0) {
signal_handlers = alloc(NSIG, 0);
register_global_root(&signal_handlers);
}
modify(&Field(signal_handlers, sig), Field(action, 0));
}
CAMLreturn (res);
}
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