ocaml/asmrun/signals.c

338 lines
8.0 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* Automatique. Distributed only by permission. */
/* */
/***********************************************************************/
/* $Id$ */
#include <signal.h>
#include <stdio.h>
#if defined(__linux) && defined(TARGET_power)
#include <asm/sigcontext.h>
#endif
#include "alloc.h"
#include "callback.h"
#include "memory.h"
#include "minor_gc.h"
#include "misc.h"
#include "mlvalues.h"
#include "fail.h"
#include "signals.h"
Volatile int async_signal_mode = 0;
Volatile int pending_signal = 0;
Volatile int force_major_slice = 0;
value signal_handlers = 0;
extern unsigned long caml_last_return_address;
/* Call the handler for the given signal */
static void execute_signal(signal_number)
int signal_number;
{
Assert (!async_signal_mode);
callback(Field(signal_handlers, signal_number), Val_int(signal_number));
}
/* This routine is the common entry point for garbage collection
and signal handling */
void garbage_collection()
{
int sig;
if (young_ptr < young_start || force_major_slice) minor_collection();
/* If a signal arrives between the following two instructions,
it will be lost. */
sig = pending_signal;
pending_signal = 0;
if (sig) execute_signal(sig);
young_limit = young_start;
}
/* Trigger a garbage collection as soon as possible */
void urge_major_slice ()
{
force_major_slice = 1;
young_limit = young_end;
/* This is only moderately effective on ports that cache young_limit
in a register, since modify() is called directly, not through
caml_c_call, so it may take a while before the register is reloaded
from young_limit. */
}
void enter_blocking_section()
{
int sig;
while (1){
Assert (!async_signal_mode);
/* If a signal arrives between the next two instructions,
it will be lost. */
sig = pending_signal;
pending_signal = 0;
if (sig) execute_signal(sig);
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;
}
#if defined(TARGET_alpha) || defined(TARGET_mips) || \
(defined(TARGET_power) && defined(_AIX))
void handle_signal(sig, code, context)
int sig, code;
struct sigcontext * context;
#elif defined(TARGET_power) && defined(__linux)
void handle_signal(sig, context)
int sig;
struct pt_regs * context;
#else
void handle_signal(sig)
int sig;
#endif
{
#ifndef POSIX_SIGNALS
#ifndef BSD_SIGNALS
signal(sig, handle_signal);
#endif
#endif
if (async_signal_mode) {
/* We are interrupting a C function blocked on I/O.
Callback the Caml code immediately. */
leave_blocking_section();
callback(Field(signal_handlers, sig), Val_int(sig));
enter_blocking_section();
} else {
/* We can't execute the signal code immediately.
Instead, we remember the signal and play with the allocation limit
so that the next allocation will trigger a garbage collection. */
pending_signal = sig;
young_limit = young_end;
/* Some ports cache young_limit in a register.
Use the signal context to modify that register too, but not if
we are inside C code (i.e. caml_last_return_address != 0). */
#ifdef TARGET_alpha
/* Cached in register $14 */
if (caml_last_return_address == 0)
context->sc_regs[14] = (long) young_limit;
#endif
#ifdef TARGET_mips
/* Cached in register $23 */
if (caml_last_return_address == 0)
context->sc_regs[23] = (int) young_limit;
#endif
#ifdef TARGET_power
/* Cached in register 31 */
#ifdef _AIX
if (caml_last_return_address == 0)
context->sc_jmpbuf.jmp_context.gpr[31] = (ulong_t) young_limit;
#endif
#ifdef __linux
if (caml_last_return_address == 0)
context->gpr[31] = (unsigned long) young_limit;
#endif
#endif
}
}
#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
int posix_signals[] = {
SIGABRT, SIGALRM, SIGFPE, SIGHUP, SIGILL, SIGINT, SIGKILL, SIGPIPE,
SIGQUIT, SIGSEGV, SIGTERM, SIGUSR1, SIGUSR2, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGVTALRM, SIGPROF
};
#ifndef NSIG
#define NSIG 32
#endif
value install_signal_handler(signal_number, action) /* ML */
value signal_number, action;
{
int sig;
void (*act)();
#ifdef POSIX_SIGNALS
struct sigaction sigact;
#endif
sig = Int_val(signal_number);
if (sig < 0) sig = posix_signals[-sig-1];
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 */
if (signal_handlers == 0) {
int i;
Begin_root (action);
signal_handlers = alloc_tuple(NSIG);
End_roots();
for (i = 0; i < NSIG; i++) Field(signal_handlers, i) = Val_int(0);
register_global_root(&signal_handlers);
}
modify(&Field(signal_handlers, sig), Field(action, 0));
act = handle_signal;
break;
}
#ifndef POSIX_SIGNALS
signal(sig, act);
#else
sigact.sa_handler = act;
sigact.sa_flags = 0;
sigemptyset(&sigact.sa_mask);
sigaction(sig, &sigact, NULL);
#endif
return Val_unit;
}
/* Machine- and OS-dependent handling of bound check trap */
#if defined(TARGET_sparc) && defined(SYS_sunos)
static void trap_handler(sig, code, context, address)
int sig, code;
struct sigcontext * context;
char * address;
{
if (code == ILL_TRAP_FAULT(5)) {
array_bound_error();
} else {
fprintf(stderr, "Fatal error: illegal instruction, code 0x%x\n", code);
exit(100);
}
}
#endif
#if defined(TARGET_sparc) && defined(SYS_solaris)
static void trap_handler(sig, info, context)
int sig;
siginfo_t * info;
struct ucontext_t * context;
{
if (info->si_code == ILL_ILLTRP) {
array_bound_error();
} else {
fprintf(stderr, "Fatal error: illegal instruction, code 0x%x\n",
info->si_code);
exit(100);
}
}
#endif
#if defined(TARGET_sparc) && defined(SYS_bsd)
static void trap_handler(sig)
int sig;
{
array_bound_error();
}
#endif
#if defined(TARGET_power)
static void trap_handler(sig)
int sig;
{
array_bound_error();
}
#endif
/* Initialization of signal stuff */
void init_signals()
{
#if defined(TARGET_sparc) && (defined(SYS_sunos) || defined(SYS_bsd))
signal(SIGILL, trap_handler);
#endif
#if defined(TARGET_sparc) && defined(SYS_solaris)
struct sigaction act;
act.sa_sigaction = trap_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
sigaction(SIGILL, &act, NULL);
#endif
#if defined(TARGET_power)
signal(SIGTRAP, trap_handler);
#endif
}