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try to avoid calling notify on the "dumb" signals

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This commit is contained in:
rsc 2004-10-22 17:12:11 +00:00
parent 99834d136f
commit aa200fe309
1 changed files with 92 additions and 53 deletions
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145
src/lib9/notify.c
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@ -8,35 +8,36 @@ extern char *_p9sigstr(int, char*);
static struct {
int sig;
int restart;
int dumb;
} sigs[] = {
SIGHUP, 0,
SIGINT, 0,
SIGQUIT, 0,
SIGILL, 0,
SIGTRAP, 0,
SIGHUP, 0, 0,
SIGINT, 0, 0,
SIGQUIT, 0, 0,
SIGILL, 0, 0,
SIGTRAP, 0, 0,
/* SIGABRT, */
#ifdef SIGEMT
SIGEMT, 0,
SIGEMT, 0, 0,
#endif
SIGFPE, 0,
SIGBUS, 0,
SIGFPE, 0, 0,
SIGBUS, 0, 0,
/* SIGSEGV, */
SIGCHLD, 1,
SIGSYS, 0,
SIGPIPE, 0,
SIGALRM, 0,
SIGTERM, 0,
SIGTSTP, 1,
SIGTTIN, 1,
SIGTTOU, 1,
SIGXCPU, 0,
SIGXFSZ, 0,
SIGVTALRM, 0,
SIGUSR1, 0,
SIGUSR2, 0,
SIGWINCH, 1,
SIGCHLD, 1, 1,
SIGSYS, 0, 0,
SIGPIPE, 0, 1,
SIGALRM, 0, 0,
SIGTERM, 0, 0,
SIGTSTP, 1, 1,
SIGTTIN, 1, 1,
SIGTTOU, 1, 1,
SIGXCPU, 0, 0,
SIGXFSZ, 0, 0,
SIGVTALRM, 0, 0,
SIGUSR1, 0, 0,
SIGUSR2, 0, 0,
SIGWINCH, 1, 1,
#ifdef SIGINFO
SIGINFO, 0,
SIGINFO, 0, 0,
#endif
};
@ -56,6 +57,13 @@ getonejmp(void)
Jmp *(*_notejmpbuf)(void) = getonejmp;
static void (*notifyf)(void*, char*);
static int alldumb;
static void
nop(int sig)
{
USED(sig);
}
static void
notifysigf(int sig)
@ -85,40 +93,71 @@ noted(int v)
return 0;
}
static void
handlesig(int s, int r, int skip)
{
struct sigaction sa, osa;
/*
* If someone has already installed a handler,
* It's probably some ld preload nonsense,
* like pct (a SIGVTALRM-based profiler).
* Leave it alone.
*/
sigaction(s, nil, &osa);
if(osa.sa_handler != SIG_DFL && osa.sa_handler != notifysigf && osa.sa_handler != nop)
return;
memset(&sa, 0, sizeof sa);
if(skip)
sa.sa_handler = nop;
else if(notifyf == 0)
sa.sa_handler = SIG_DFL;
else
sa.sa_handler = notifysigf;
/*
* We assume that one jump buffer per thread
* is okay, which means that we can't deal with
* signal handlers called during signal handlers.
*/
sigfillset(&sa.sa_mask);
if(r)
sa.sa_flags |= SA_RESTART;
else
sa.sa_flags &= ~SA_RESTART;
sigaction(s, &sa, nil);
}
int
notify(void (*f)(void*, char*))
{
int i;
struct sigaction sa, osa;
memset(&sa, 0, sizeof sa);
if(f == 0)
sa.sa_handler = SIG_DFL;
else{
notifyf = f;
sa.sa_handler = notifysigf;
}
for(i=0; i<nelem(sigs); i++){
/*
* If someone has already installed a handler,
* It's probably some ld preload nonsense,
* like pct (a SIGVTALRM-based profiler).
* Leave it alone.
*/
sigaction(sigs[i].sig, nil, &osa);
if(osa.sa_handler != SIG_DFL)
continue;
/*
* We assume that one jump buffer per thread
* is okay, which means that we can't deal with
* signal handlers called during signal handlers.
*/
sigfillset(&sa.sa_mask);
if(sigs[i].restart)
sa.sa_flags |= SA_RESTART;
else
sa.sa_flags &= ~SA_RESTART;
sigaction(sigs[i].sig, &sa, nil);
}
notifyf = f;
for(i=0; i<nelem(sigs); i++)
handlesig(sigs[i].sig, sigs[i].restart, sigs[i].dumb && !alldumb);
return 0;
}
void
notifyall(int all)
{
int i;
alldumb = all;
for(i=0; i<nelem(sigs); i++)
if(sigs[i].dumb)
handlesig(sigs[i].sig, sigs[i].restart, !all);
}
void
notifyatsig(int sig, int use)
{
int i;
for(i=0; i<nelem(sigs); i++)
if(sigs[i].sig == sig)
handlesig(sigs[i].sig, sigs[i].restart, 0);
}