Changeset a7fac14 for owl.c

Timestamp:

Jul 23, 2011, 7:30:51 PM (13 years ago)

Author:

David Benjamin <davidben@mit.edu>

Branches:

master, release-1.10, release-1.9

Children:

4ebbfbc, 85bb19b, d933c3ca

Parents:

f661cee

git-author:

David Benjamin <davidben@mit.edu> (07/20/11 02:03:42)

git-committer:

David Benjamin <davidben@mit.edu> (07/23/11 19:30:51)

Message:

Assign all watched signals to a dummy no-op disposition

Otherwise some (namely SIGWINCH) may have SIG_DFL = SIG_IGN. This means
that the signal is ignored if the signal thread is in the middle of
processing another signal (a race condition), and on Solaris it's not
delivered at all.

Also more consistently consider errors in setup here fatal. And rename
CHECK_RESULT to OR_DIE.

Reported-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Adam Glasgall <adam@crossproduct.net>

File:

• owl.c (modified) (2 diffs)

owl.c

@@ -389 +389 @@
 }
 
-#define CHECK_RESULT(s, syscall) \
+#define OR_DIE(s, syscall)       \
   G_STMT_START {                 \
-    if ((syscall) != 0) {        \
+    if ((syscall) == -1) {       \
       perror((s));               \
       exit(1);                   \
@@ -402 +402 @@
   sigset_t sigset;
   int ret, i;
-  const int signals[] = { SIGABRT, SIGBUS, SIGCHLD, SIGFPE, SIGHUP, SIGILL,
-                          SIGINT, SIGQUIT, SIGSEGV, SIGTERM, SIGWINCH };
+  const int reset_signals[] = { SIGABRT, SIGBUS, SIGCHLD, SIGFPE, SIGILL,
+                                SIGQUIT, SIGSEGV, };
+  /* Don't bother resetting watched ones because owl_signal_init will. */
+  const int watch_signals[] = { SIGWINCH, SIGTERM, SIGHUP, SIGINT, };
 
   /* Sanitize our signals; the mask and dispositions from our parent
    * aren't really useful. Signal list taken from equivalent code in
    * Chromium. */
-  CHECK_RESULT("sigemptyset", sigemptyset(&sigset));
+  OR_DIE("sigemptyset", sigemptyset(&sigset));
   if ((ret = pthread_sigmask(SIG_SETMASK, &sigset, NULL)) != 0) {
     errno = ret;
     perror("pthread_sigmask");
-  }
-  for (i = 0; i < G_N_ELEMENTS(signals); i++) {
-    CHECK_RESULT("sigaction", sigaction(signals[i], &sig_default, NULL));
+    exit(1);
+  }
+  for (i = 0; i < G_N_ELEMENTS(reset_signals); i++) {
+    OR_DIE("sigaction", sigaction(reset_signals[i], &sig_default, NULL));
   }
 
   /* Turn off SIGPIPE; we check the return value of write. */
-  CHECK_RESULT("sigaction", sigaction(SIGPIPE, &sig_ignore, NULL));
+  OR_DIE("sigaction", sigaction(SIGPIPE, &sig_ignore, NULL));
 
   /* Register some signals with the signal thread. */
-  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGWINCH));
-  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGTERM));
-  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGHUP));
-  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGINT));
-  owl_signal_init(&sigset, sig_handler, NULL);
+  owl_signal_init(watch_signals, G_N_ELEMENTS(watch_signals),
+                  sig_handler, NULL);
 }