ocaml/byterun/signals.c

159 lines
3.2 KiB
C

#include <signal.h>
#include "alloc.h"
#include "config.h"
#include "fail.h"
#include "interp.h"
#include "memory.h"
#include "misc.h"
#include "mlvalues.h"
#include "roots.h"
#include "signals.h"
static Volatile int async_signal_mode = 0;
Volatile int pending_signal = 0;
value signal_handlers = 0;
static void execute_signal(signal_number)
int signal_number;
{
Assert (!async_signal_mode);
callback(Field(signal_handlers, signal_number), Val_int(signal_number));
}
void handle_signal(signal_number)
int signal_number;
{
#ifndef BSD_SIGNALS
signal(signal_number, handle_signal);
#endif
if (async_signal_mode){
leave_blocking_section ();
execute_signal(signal_number);
enter_blocking_section ();
}else{
pending_signal = signal_number;
something_to_do = 1;
}
}
void enter_blocking_section()
{
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);
async_signal_mode = 1;
if (!pending_signal) break;
async_signal_mode = 0;
}
}
/* This function may be called from outside a blocking section. */
void leave_blocking_section()
{
async_signal_mode = 0;
}
#ifndef SIGABRT
#define SIGABRT 0
#endif
#ifndef SIGALRM
#define SIGALRM 0
#endif
#ifndef SIGFPE
#define SIGFPE 0
#endif
#ifndef SIGHUP
#define SIGHUP 0
#endif
#ifndef SIGILL
#define SIGILL 0
#endif
#ifndef SIGINT
#define SIGINT 0
#endif
#ifndef SIGKILL
#define SIGKILL 0
#endif
#ifndef SIGPIPE
#define SIGPIPE 0
#endif
#ifndef SIGQUIT
#define SIGQUIT 0
#endif
#ifndef SIGSEGV
#define SIGSEGV 0
#endif
#ifndef SIGTERM
#define SIGTERM 0
#endif
#ifndef SIGUSR1
#define SIGUSR1 0
#endif
#ifndef SIGUSR2
#define SIGUSR2 0
#endif
#ifndef SIGCHLD
#define SIGCHLD 0
#endif
#ifndef SIGCONT
#define SIGCONT 0
#endif
#ifndef SIGSTOP
#define SIGSTOP 0
#endif
#ifndef SIGTSTP
#define SIGTSTP 0
#endif
#ifndef SIGTTIN
#define SIGTTIN 0
#endif
#ifndef SIGTTOU
#define SIGTTOU 0
#endif
int posix_signals[] = {
SIGABRT, SIGALRM, SIGFPE, SIGHUP, SIGILL, SIGINT, SIGKILL, SIGPIPE,
SIGQUIT, SIGSEGV, SIGTERM, SIGUSR1, SIGUSR2, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU
};
value install_signal_handler(signal_number, action) /* ML */
value signal_number, action;
{
int sig = Int_val(signal_number);
if (sig < 0) {
sig = posix_signals[-sig-1];
if (sig == 0) invalid_argument("Sys.signal: unavailable signal");
}
switch(Tag_val(action)) {
case 0: /* Signal_default */
signal(sig, SIG_DFL);
break;
case 1: /* Signal_ignore */
signal(sig, SIG_IGN);
break;
case 2: /* Signal_handle */
if (signal_handlers == 0) {
int i;
Push_roots(r, 1);
r[0] = action;
signal_handlers = alloc_tuple(32);
action = r[0];
Pop_roots();
for (i = 0; i < 32; i++) Field(signal_handlers, i) = Val_int(0);
register_global_root(&signal_handlers);
}
modify(&Field(signal_handlers, sig), Field(action, 0));
signal(sig, handle_signal);
break;
default:
Assert(0);
}
return Val_unit;
}