add a "client" mode to ssg_init_config

examples/ssg-example.c

@@ -138,7 +138,7 @@ int main(int argc, char *argv[])
         if (!argc) { usage(); return 1; }
         conf = argv[0];
         argc--; argv++;
-        c.s = ssg_init_config(conf);
+        c.s = ssg_init_config(conf, 1);
     }
     else {
         fprintf(stderr, "Error: bad mode passed in %s\n", mode);

include/ssg.h

@@ -31,9 +31,12 @@ typedef struct ssg *ssg_t;
 
 /// participant initialization
 
-// config file based - all participants load up the given config file
+// config file based - load up the given config file
 // containing a set of hostnames
-ssg_t ssg_init_config(const char * fname);
+// is_member - nonzero if caller is expected to be in the group, zero otherwise
+//           - ssg_lookup fails if caller is unable to identify with one of the
+//             config entries
+ssg_t ssg_init_config(const char * fname, int is_member);
 
 // once the ssg has been initialized, wireup (a collection of HG_Addr_lookups)
 // note that this is a simple blocking implementation - no margo/etc here

src/ssg.c

@@ -25,7 +25,7 @@ static hg_return_t find_rank(hg_class_t *hgcl, ssg_t s);
 
 static char** setup_addr_str_list(int num_addrs, char * buf);
 
-ssg_t ssg_init_config(const char * fname)
+ssg_t ssg_init_config(const char * fname, int is_member)
 {
     // file to read
     int fd = -1;
@@ -112,7 +112,7 @@ ssg_t ssg_init_config(const char * fname)
     s->backing_buf = buf; buf = NULL;
     s->num_addrs = num_addrs;
     s->buf_size = addr_len;
-    s->rank = SSG_RANK_UNKNOWN;
+    s->rank = is_member ? SSG_RANK_UNKNOWN : SSG_EXTERNAL_RANK;
 
 fini:
     if (fd != -1) close(fd);