util: Don't set thread name to empty

In monitor_daemon(), it set subprogram_name to "" which causes system crash
in some platform when trying to set the thread name to "".  This change set
thread name to program name in this case.

Signed-off-by: Guolin Yang <gyang@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/lib/util.c b/lib/util.c
index 3cada4a..b800455 100644 (file)
--- a/lib/util.c
+++ b/lib/util.c
@@ -405,13 +405,14 @@ get_subprogram_name(void)
 void
 set_subprogram_name(const char *name)
 {
+    const char *pname = name[0] ? name : program_name;
     free(subprogram_name_set(xstrdup(name)));
 #if HAVE_GLIBC_PTHREAD_SETNAME_NP
-    pthread_setname_np(pthread_self(), name);
+    pthread_setname_np(pthread_self(), pname);
 #elif HAVE_NETBSD_PTHREAD_SETNAME_NP
-    pthread_setname_np(pthread_self(), "%s", name);
+    pthread_setname_np(pthread_self(), "%s", pname);
 #elif HAVE_PTHREAD_SET_NAME_NP
-    pthread_set_name_np(pthread_self(), name);
+    pthread_set_name_np(pthread_self(), pname);
 #endif
 }