gcc/libgo/runtime/go-signal.c

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/* go-signal.c -- signal handling for Go.
Copyright 2009 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
#include <signal.h>
#include <stdlib.h>
#include <sys/time.h>
#include "go-assert.h"
#include "go-panic.h"
#include "go-signal.h"
#include "runtime.h"
#ifndef SA_RESTART
#define SA_RESTART 0
#endif
/* What to do for a signal. */
struct sigtab
{
/* Signal number. */
int sig;
/* Nonzero if the signal should be ignored. */
_Bool ignore;
/* Nonzero if we should restart system calls. */
_Bool restart;
};
/* What to do for signals. */
static struct sigtab signals[] =
{
{ SIGHUP, 0, 1 },
{ SIGINT, 0, 1 },
{ SIGALRM, 1, 1 },
{ SIGTERM, 0, 1 },
#ifdef SIGBUS
{ SIGBUS, 0, 0 },
#endif
#ifdef SIGFPE
{ SIGFPE, 0, 0 },
#endif
#ifdef SIGUSR1
{ SIGUSR1, 1, 1 },
#endif
#ifdef SIGSEGV
{ SIGSEGV, 0, 0 },
#endif
#ifdef SIGUSR2
{ SIGUSR2, 1, 1 },
#endif
#ifdef SIGPIPE
{ SIGPIPE, 1, 0 },
#endif
#ifdef SIGCHLD
{ SIGCHLD, 1, 1 },
#endif
#ifdef SIGTSTP
{ SIGTSTP, 1, 1 },
#endif
#ifdef SIGTTIN
{ SIGTTIN, 1, 1 },
#endif
#ifdef SIGTTOU
{ SIGTTOU, 1, 1 },
#endif
#ifdef SIGURG
{ SIGURG, 1, 1 },
#endif
#ifdef SIGXCPU
{ SIGXCPU, 1, 1 },
#endif
#ifdef SIGXFSZ
{ SIGXFSZ, 1, 1 },
#endif
#ifdef SIGVTARLM
{ SIGVTALRM, 1, 1 },
#endif
#ifdef SIGWINCH
{ SIGWINCH, 1, 1 },
#endif
#ifdef SIGIO
{ SIGIO, 1, 1 },
#endif
#ifdef SIGPWR
{ SIGPWR, 1, 1 },
#endif
{ -1, 0, 0 }
};
/* The Go signal handler. */
static void
sighandler (int sig)
{
const char *msg;
int i;
if (sig == SIGPROF)
{
/* FIXME. */
runtime_sigprof (0, 0, nil);
return;
}
/* FIXME: Should check siginfo for more information when
available. */
msg = NULL;
switch (sig)
{
#ifdef SIGBUS
case SIGBUS:
msg = "invalid memory address or nil pointer dereference";
break;
#endif
#ifdef SIGFPE
case SIGFPE:
msg = "integer divide by zero or floating point error";
break;
#endif
#ifdef SIGSEGV
case SIGSEGV:
msg = "invalid memory address or nil pointer dereference";
break;
#endif
default:
break;
}
if (msg != NULL)
{
sigset_t clear;
if (__sync_bool_compare_and_swap (&m->mallocing, 1, 1))
{
fprintf (stderr, "caught signal while mallocing: %s\n", msg);
__go_assert (0);
}
/* The signal handler blocked signals; unblock them. */
i = sigfillset (&clear);
__go_assert (i == 0);
i = sigprocmask (SIG_UNBLOCK, &clear, NULL);
__go_assert (i == 0);
__go_panic_msg (msg);
}
if (__go_sigsend (sig))
return;
for (i = 0; signals[i].sig != -1; ++i)
{
if (signals[i].sig == sig)
{
struct sigaction sa;
if (signals[i].ignore)
return;
memset (&sa, 0, sizeof sa);
sa.sa_handler = SIG_DFL;
i = sigemptyset (&sa.sa_mask);
__go_assert (i == 0);
if (sigaction (sig, &sa, NULL) != 0)
abort ();
raise (sig);
exit (2);
}
}
abort ();
}
/* Initialize signal handling for Go. This is called when the program
starts. */
void
__initsig ()
{
struct sigaction sa;
int i;
siginit ();
memset (&sa, 0, sizeof sa);
sa.sa_handler = sighandler;
i = sigfillset (&sa.sa_mask);
__go_assert (i == 0);
for (i = 0; signals[i].sig != -1; ++i)
{
sa.sa_flags = signals[i].restart ? SA_RESTART : 0;
if (sigaction (signals[i].sig, &sa, NULL) != 0)
__go_assert (0);
}
}
void
runtime_resetcpuprofiler(int32 hz)
{
struct itimerval it;
struct sigaction sa;
int i;
memset (&it, 0, sizeof it);
memset (&sa, 0, sizeof sa);
i = sigfillset (&sa.sa_mask);
__go_assert (i == 0);
if (hz == 0)
{
i = setitimer (ITIMER_PROF, &it, NULL);
__go_assert (i == 0);
sa.sa_handler = SIG_IGN;
i = sigaction (SIGPROF, &sa, NULL);
__go_assert (i == 0);
}
else
{
sa.sa_handler = sighandler;
sa.sa_flags = SA_RESTART;
i = sigaction (SIGPROF, &sa, NULL);
__go_assert (i == 0);
it.it_interval.tv_sec = 0;
it.it_interval.tv_usec = 1000000 / hz;
it.it_value = it.it_interval;
i = setitimer (ITIMER_PROF, &it, NULL);
__go_assert (i == 0);
}
m->profilehz = hz;
}