tplay nicer with others w.r.t. signal masks - plan9port - [fork] Plan 9 from user space
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---
(DIR) commit f3ecd8ae845e35bc0d5576d4fb3a4ba5ed097a37
(DIR) parent 76164c00c364039613d03f1f5f1c3e2c29ae5ac2
(HTM) Author: rsc <devnull@localhost>
Date: Tue, 8 Feb 2005 19:08:47 +0000
play nicer with others w.r.t. signal masks
Diffstat:
M src/lib9/notify.c | 80 ++++++++++++++-----------------
1 file changed, 37 insertions(+), 43 deletions(-)
---
(DIR) diff --git a/src/lib9/notify.c b/src/lib9/notify.c
t@@ -31,48 +31,44 @@ typedef struct Sig Sig;
struct Sig
{
int sig; /* signal number */
- int restart; /* do we restart the system call after this signal is handled? */
- int enabled; /* is this signal enabled (not masked)? */
- int notified; /* do we call the notify function for this signal? */
+ int flags;
};
-/*
- * Bug. It is profoundly anti-social to play with the masks like this.
- * For example, even though we don't want to see SIGTSTP, others do.
- * Running bash inside a 9term that has disabled SIGTSTP makes ^Z not work.
- * Instead we need to leave the signals enabled but notifyoff them.
- */
+enum
+{
+ Restart = 1<<0,
+ Ignore = 1<<1,
+};
-/* initial settings; for current status, ask the kernel */
static Sig sigs[] = {
- SIGHUP, 0, 1, 1,
- SIGINT, 0, 1, 1,
- SIGQUIT, 0, 1, 1,
- SIGILL, 0, 1, 1,
- SIGTRAP, 0, 1, 1,
-/* SIGABRT, 0, 1, 1, */
+ SIGHUP, 0,
+ SIGINT, 0,
+ SIGQUIT, 0,
+ SIGILL, 0,
+ SIGTRAP, 0,
+/* SIGABRT, 0, */
#ifdef SIGEMT
- SIGEMT, 0, 1, 1,
+ SIGEMT, 0,
#endif
- SIGFPE, 0, 1, 1,
- SIGBUS, 0, 1, 1,
-/* SIGSEGV, 0, 1, 1, */
- SIGCHLD, 1, 0, 1,
- SIGSYS, 0, 1, 1,
- SIGPIPE, 0, 0, 1,
- SIGALRM, 0, 1, 1,
- SIGTERM, 0, 1, 1,
- SIGTSTP, 1, 0, 1,
- SIGTTIN, 1, 0, 1,
- SIGTTOU, 1, 0, 1,
- SIGXCPU, 0, 1, 1,
- SIGXFSZ, 0, 1, 1,
- SIGVTALRM, 0, 1, 1,
- SIGUSR1, 0, 1, 1,
- SIGUSR2, 0, 1, 1,
- SIGWINCH, 1, 0, 1,
+ SIGFPE, 0,
+ SIGBUS, 0,
+/* SIGSEGV, 0, */
+ SIGCHLD, Restart|Ignore,
+ SIGSYS, 0,
+ SIGPIPE, Ignore,
+ SIGALRM, 0,
+ SIGTERM, 0,
+ SIGTSTP, Restart|Ignore,
+ SIGTTIN, Restart|Ignore,
+ SIGTTOU, Restart|Ignore,
+ SIGXCPU, 0,
+ SIGXFSZ, 0,
+ SIGVTALRM, 0,
+ SIGUSR1, 0,
+ SIGUSR2, 0,
+ SIGWINCH, Restart|Ignore,
#ifdef SIGINFO
- SIGINFO, 1, 1, 1,
+ SIGINFO, Restart|Ignore,
#endif
};
t@@ -121,6 +117,7 @@ signotify(int sig)
{
char tmp[64];
Jmp *j;
+ Sig *s;
j = (*_notejmpbuf)();
switch(p9setjmp(j->b)){
t@@ -130,6 +127,9 @@ signotify(int sig)
/* fall through */
case 1: /* noted(NDFLT) */
if(0)print("DEFAULT %d\n", sig);
+ s = findsig(sig);
+ if(s && (s->flags&Ignore))
+ return;
signal(sig, SIG_DFL);
raise(sig);
_exit(1);
t@@ -216,7 +216,7 @@ notifyseton(int s, int on)
return -1;
memset(&sa, 0, sizeof sa);
sa.sa_handler = on ? signotify : signonotify;
- if(sig->restart)
+ if(sig->flags&Restart)
sa.sa_flags |= SA_RESTART;
/*
t@@ -264,13 +264,7 @@ noteinit(void)
*/
if(handler(sig->sig) != SIG_DFL)
continue;
- /*
- * Should we only disable and not enable signals?
- * (I.e. if parent has disabled for us, should we still enable?)
- * Right now we always initialize to the state we want.
- */
- notesetenable(sig->sig, sig->enabled);
- notifyseton(sig->sig, sig->notified);
+ notifyseton(sig->sig, 1);
}
}