starter: Only handle SIGCHLD asynchronously and the rest in pselect(2).

diff --git a/src/starter/starter.c b/src/starter/starter.c
index 0cec936c3462ed74d40653133752a754968688b4..5322d271ee0407f257bf686e3bf65e6b9a2a8e16 100644 (file)
--- a/src/starter/starter.c
+++ b/src/starter/starter.c
@@ -12,6 +12,7 @@
  * for more details.
  */
 
+#include <sys/select.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
@@ -292,7 +293,7 @@ int main (int argc, char **argv)
 
        int i;
        int id = 1;
-       struct timeval tv;
+       struct timespec ts;
        unsigned long auto_update = 0;
        time_t last_reload;
        bool no_fork = FALSE;
@@ -494,7 +495,7 @@ int main (int argc, char **argv)
        }
 
        /* we handle these signals in the main thread, so we don't want any
-        * of the others to catch them. install a handler for fatal signals. */
+        * of the others to catch them */
        memset(&action, 0, sizeof(action));
        sigemptyset(&action.sa_mask);
        sigaddset(&action.sa_mask, SIGHUP);
@@ -506,6 +507,7 @@ int main (int argc, char **argv)
        sigaddset(&action.sa_mask, SIGUSR1);
        pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 
+       /* install a handler for fatal signals */
        action.sa_handler = fatal_signal_handler;
        sigaction(SIGSEGV, &action, NULL);
        sigaction(SIGILL, &action, NULL);
@@ -518,8 +520,7 @@ int main (int argc, char **argv)
                        lib->settings->get_int(lib->settings, "starter.threads",
                                                                   DEFAULT_THREADS));
 
-       /* enable signals for main thread and install signal handler */
-       pthread_sigmask(SIG_UNBLOCK, &action.sa_mask, NULL);
+       /* install signal handler for main thread */
        action.sa_handler = signal_handler;
        sigaction(SIGHUP, &action, NULL);
        sigaction(SIGINT, &action, NULL);
@@ -529,6 +530,13 @@ int main (int argc, char **argv)
        sigaction(SIGCHLD, &action, NULL);
        sigaction(SIGUSR1, &action, NULL);
 
+       /* the only signal we want to receive asynchronously is SIGCHLD */
+       sigemptyset(&action.sa_mask);
+       sigaddset(&action.sa_mask, SIGCHLD);
+       pthread_sigmask(SIG_UNBLOCK, &action.sa_mask, NULL);
+       /* the rest is unblocked in pselect() below */
+       sigemptyset(&action.sa_mask);
+
        for (;;)
        {
                /*
@@ -854,15 +862,16 @@ int main (int argc, char **argv)
                {
                        time_t now = time_monotonic(NULL);
 
-                       tv.tv_sec = (now < last_reload + auto_update)
-                                       ? (last_reload + auto_update-now) : 0;
-                       tv.tv_usec = 0;
+                       ts.tv_sec = (now < last_reload + auto_update) ?
+                                               (last_reload + auto_update - now) : 0;
+                       ts.tv_nsec = 0;
                }
 
                /*
                 * Wait for something to happen
                 */
-               if (select(0, NULL, NULL, NULL, auto_update ? &tv : NULL) == 0)
+               if (pselect(0, NULL, NULL, NULL, auto_update ? &ts : NULL,
+                                       &action.sa_mask) == 0)
                {
                        /* timeout -> auto_update */
                        _action_ |= FLAG_ACTION_UPDATE;