From d9628b27abfb090d854f77073bc9a1870d804164 Mon Sep 17 00:00:00 2001
From: Ben Longbons <b.r.longbons@gmail.com>
Date: Thu, 19 Jul 2012 15:27:18 -0700
Subject: Hopefully make shutdown more clean.

---
 src/common/core.c | 49 ++++++++++++++++++++++++++++++++++---------------
 src/common/core.h |  2 +-
 2 files changed, 35 insertions(+), 16 deletions(-)

(limited to 'src/common')

diff --git a/src/common/core.c b/src/common/core.c
index 2b1b67c..b08276c 100644
--- a/src/common/core.c
+++ b/src/common/core.c
@@ -15,19 +15,6 @@
 extern int  do_init (int, char **);
 extern void term_func (void);
 
-static void chld_proc (int UNUSED)
-{
-    wait(NULL);
-}
-static void sig_proc (int UNUSED)
-{
-    term_func ();
-    for (int i = 0; i < fd_max; i++)
-        if (session[i])
-            close (i);
-    exit (0);
-}
-
 // Added by Gabuzomeu
 //
 // This is an implementation of signal() using sigaction() for portability.
@@ -40,7 +27,12 @@ sigfunc compat_signal (int signo, sigfunc func)
     struct sigaction sact, oact;
 
     sact.sa_handler = func;
-    sigemptyset (&sact.sa_mask);
+    sigfillset (&sact.sa_mask);
+    sigdelset(&sact.sa_mask, SIGSEGV);
+    sigdelset(&sact.sa_mask, SIGBUS);
+    sigdelset(&sact.sa_mask, SIGTRAP);
+    sigdelset(&sact.sa_mask, SIGILL);
+    sigdelset(&sact.sa_mask, SIGFPE);
     sact.sa_flags = 0;
 
     if (sigaction (signo, &sact, &oact) < 0)
@@ -49,8 +41,29 @@ sigfunc compat_signal (int signo, sigfunc func)
     return oact.sa_handler;
 }
 
+static void chld_proc (int UNUSED)
+{
+    wait(NULL);
+}
+static void sig_proc (int UNUSED)
+{
+    for (int i = 1; i < 31; ++i)
+        compat_signal(i, SIG_IGN);
+    term_func ();
+    _exit (0);
+}
+
 bool runflag = true;
 
+/*
+    Note about fatal signals:
+
+    Under certain circumstances,
+    the following signals MUST not be ignored:
+    SIGFPE, SIGSEGV, SIGILL
+    Unless you use SA_SIGINFO and *carefully* check the origin,
+    that means they must be SIG_DFL.
+ */
 int main (int argc, char **argv)
 {
     /// Note that getpid() and getppid() may be very close
@@ -58,6 +71,10 @@ int main (int argc, char **argv)
 
     do_socket ();
 
+    do_init (argc, argv);
+    // set up exit handlers *after* the initialization has happened.
+    // This is because term_func is likely to depend on successful init.
+
     compat_signal (SIGPIPE, SIG_IGN);
     compat_signal (SIGTERM, sig_proc);
     compat_signal (SIGINT, sig_proc);
@@ -68,8 +85,10 @@ int main (int argc, char **argv)
     compat_signal (SIGBUS, SIG_DFL);
     compat_signal (SIGTRAP, SIG_DFL);
     compat_signal (SIGILL, SIG_DFL);
+    compat_signal (SIGFPE, SIG_DFL);
+
+    atexit (term_func);
 
-    do_init (argc, argv);
     while (runflag)
     {
         do_sendrecv (do_timer (gettick_nocache ()));
diff --git a/src/common/core.h b/src/common/core.h
index 6722ca2..44473e9 100644
--- a/src/common/core.h
+++ b/src/common/core.h
@@ -13,7 +13,7 @@ extern bool runflag;
 extern int  do_init (int, char **);
 
 /// Cleanup function called whenever a signal kills us
-/// NOT currently called when exit() is called
+/// or when if we manage to exit() gracefully.
 extern void term_func (void);
 
 #endif // CORE_H
-- 
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