catch slow sigcont

rts.tests/supervise-stop.exp

@@ -2,6 +2,6 @@
 in stop
 
 --- supervise stops log after main
-Caught CONT
 Caught TERM
+Caught CONT
 

rts.tests/svc.exp

@@ -8,5 +8,5 @@ Caught QUIT
 Caught USR1
 Caught USR2
 Caught WINCH
-Caught CONT
 Caught TERM
+Caught CONT

sleeper.c

@@ -4,6 +4,9 @@
 #include "str.h"
 #include <unistd.h>
 
+int flag_cont = 0;
+int flag_term = 0;
+
 static void catch_sig(int sig)
 {
   char buf[7+14+2] = "Caught ";
@@ -12,11 +15,11 @@ static void catch_sig(int sig)
   int i;
   switch (sig) {
   case SIGALRM: name = "ALRM"; break;
-  case SIGCONT: name = "CONT"; break;
+  case SIGCONT: flag_cont = 1; return;
   case SIGHUP: name = "HUP"; break;
   case SIGINT: name = "INT"; break;
   case SIGQUIT: name = "QUIT"; break;
-  case SIGTERM: name = "TERM"; break;
+  case SIGTERM: flag_term = 1; return;
   case SIGUSR1: name = "USR1"; break;
   case SIGUSR2: name = "USR2"; break;
   case SIGWINCH: name = "WINCH"; break;
@@ -27,12 +30,13 @@ static void catch_sig(int sig)
   i += 7;
   buf[i++] = '\n';
   ignored = write(1,buf,i);
-  if (sig != SIGCONT)
-    _exit(1);
+  _exit(1);
 }
 
 int main(void)
 {
+  int i, ignored;
+
   sig_catch(SIGALRM,catch_sig);
   sig_catch(SIGCONT,catch_sig);
   sig_catch(SIGHUP,catch_sig);
@@ -42,6 +46,48 @@ int main(void)
   sig_catch(SIGUSR1,catch_sig);
   sig_catch(SIGUSR2,catch_sig);
   sig_catch(SIGWINCH,catch_sig);
-  sleep(9999);
+
+  for (i = 0; i < 9999; ++i) {
+    if (!flag_cont && !flag_term) sleep(1);
+    /*
+     * here we have some combination of flag_cont and flag_term.
+     *
+     * if neither, nothing happened. continue.
+     *
+     * if both, then sig_term was interrupted by sig_cont, so we know
+     * we've handled svc -d. print both and exit.
+     *
+     * if only flag_cont set, we know we're handling svc -c since svc -d
+     * would've either set both (as above) or only set flag_term (below).
+     * print the cont message and exit.
+     *
+     * if only flag_term set, we might be handling svc -t by itself, or
+     * maybe svc -d has returned from the sig_term handler before sig_cont
+     * arrived. in either case, reset flag_term, print the term message,
+     * and continue.
+     *
+     * as a special case, if only flag_cont set, we might be handling
+     * the second half of svc -d where sig_cont arrived so late we already
+     * looped around here once and handled the sig_term. print the cont
+     * message and exit.
+     *
+     * one hidden gotcha here is that any test following a sig_term will
+     * be handled by the same sleeper instance as sig_term itself. don't
+     * schedule a svc -t test last.
+     *
+     * another gotcha is the race condition between the flag test above
+     * and sleep(). if a cont/term signal arrives at that point, we incur
+     * additional delay which could muck up the tests. don't test svc -c
+     * immediately after svc -t, and schedule svc -dx test last.
+     */
+    if (flag_term) {
+      flag_term = 0;
+      ignored = write(1, "Caught TERM\n", 12);
+    }
+    if (flag_cont) {
+      ignored = write(1, "Caught CONT\n", 12);
+      _exit(1);
+    }
+  }
   return 0;
 }