Merge pull request #4788 from grondo/taskmap-unknown

libtaskmap: support RFC 34 unknown task maps

src/common/libtaskmap/taskmap.c

@@ -135,6 +135,12 @@ struct taskmap *taskmap_create (void)
     return NULL;
 }
 
+bool taskmap_unknown (const struct taskmap *map)
+{
+    /*  A zero-length mapping indicates that the task map is unknown */
+    return zlistx_size (map->blocklist) == 0;
+}
+
 static char *to_string (int n, char *buf, int len)
 {
     (void) snprintf (buf, len, "%d", n);
@@ -350,7 +356,7 @@ const struct idset *taskmap_taskids (const struct taskmap *map, int nodeid)
     struct taskmap_block *block;
     struct idset *taskids;
 
-    if (!map || nodeid < 0) {
+    if (!map || nodeid < 0 || taskmap_unknown (map)) {
         errno = EINVAL;
         return NULL;
     }
@@ -391,7 +397,7 @@ int taskmap_nodeid (const struct taskmap *map, int taskid)
     struct taskmap_block *block;
     int current = 0;
 
-    if (!map || taskid < 0) {
+    if (!map || taskid < 0 || taskmap_unknown (map)) {
         errno = EINVAL;
         return -1;
     }
@@ -425,7 +431,7 @@ int taskmap_nnodes (const struct taskmap *map)
     struct taskmap_block *block;
     int n;
 
-    if (!map) {
+    if (!map || taskmap_unknown (map)) {
         errno = EINVAL;
         return -1;
     }
@@ -446,7 +452,7 @@ int taskmap_total_ntasks (const struct taskmap *map)
     struct taskmap_block *block;
     int n;
 
-    if (!map) {
+    if (!map || taskmap_unknown (map)) {
         errno = EINVAL;
         return -1;
     }
@@ -612,6 +618,9 @@ static char *taskmap_encode_pmi (const struct taskmap *map)
     zlistx_t *l;
     int saved_errno;
 
+    if (taskmap_unknown (map))
+        return strdup ("");
+
     if (!(l = zlistx_new ())) {
         errno = ENOMEM;
         return NULL;

src/common/libtaskmap/taskmap.h

@@ -55,6 +55,10 @@ struct taskmap *taskmap_decode (const char *map, flux_error_t *errp);
  */
 char *taskmap_encode (const struct taskmap *map, int flags);
 
+/*  Return true if the task mapping is uknown.
+ */
+bool taskmap_unknown (const struct taskmap *map);
+
 /*  Return an idset of taskids encoded in 'map' for nodeid 'nodeid'.
  *  Returns an idset on success, which may only be vaild until the next
  *   call to taskmap_taskids(), caller should use idset_copy() if necessary.

src/common/libtaskmap/test/taskmap.c

@@ -80,12 +80,16 @@ static void rfc34_tests ()
         is (s, t->expected,
             "taskmap raw=%s",
             s);
+        if (strlen (s))
+            ok (taskmap_unknown (map) == false,
+                "taskmap is known");
         taskmap_destroy (map);
         free (s);
     }
 }
 
 struct test_vector pmi_tests[] = {
+    { "[]", "" },
     { "[[0,4,4,1]]", "(vector,(0,4,4))" },
     { "[[0,4,2,1],[4,2,4,1]]", "(vector,(0,4,2),(4,2,4))" },
     { "[[0,4,1,4]]", "(vector,(0,4,1),(0,4,1),(0,4,1),(0,4,1))" },
@@ -225,6 +229,22 @@ static void error_tests ()
     if (!(map = taskmap_create ()))
         BAIL_OUT ("taskmap_create");
 
+    /* Test "unknown" task map errors */
+    ok (taskmap_unknown (map),
+        "taskmap_unknown returns true for empty task map");
+    ok (taskmap_nnodes (map) < 0 && errno == EINVAL,
+        "taskmap_nnodes on unknown taskmap returns EINVAL");
+    ok (taskmap_total_ntasks (map) < 0 && errno == EINVAL,
+        "taskmap_nnodes on unknown taskmap returns EINVAL");
+    ok (taskmap_nodeid (map, 0) < 0 && errno == EINVAL,
+        "taskmap_nodeid on unknown taskmap returns EINVAL");
+    ok (taskmap_taskids (map, 0) == NULL && errno == EINVAL,
+        "taskmap_taskids on unknown taskmap returns EINVAL");
+
+    /* Add one task to taskmap so it is no longer unknown */
+    ok (taskmap_append (map, 0, 1, 1) == 0,
+        "add one task to taskmap so it is no longer unknown");
+
     ok (taskmap_encode (NULL, 0) == NULL && errno == EINVAL,
         "taskmap_encode (NULL) returns EINVAL");
     ok (taskmap_encode (map, 0xff) == NULL && errno == EINVAL,

src/shell/info.c

@@ -273,6 +273,10 @@ int shell_info_set_taskmap (struct shell_info *info,
         errno = EINVAL;
         return -1;
     }
+    if (taskmap_unknown (map)) {
+        shell_log_error ("invalid taskmap: mapping is unknown");
+        return -1;
+    }
     if (info->taskmap
         && taskmap_check (info->taskmap, map, &error) < 0) {
         shell_log_error ("invalid taskmap: %s", error.text);

t/t2616-job-shell-taskmap.t

@@ -122,6 +122,10 @@ test_expect_success 'taskmap=manual works' '
 		| jq -e ".context.taskmap.map == [[1,3,4,1],[0,1,4,1]]" &&
 	test_check_taskmap $id
 '
+test_expect_success 'taskmap=manual with unknown taskmap fails' '
+	test_must_fail_or_be_terminated \
+		flux mini run --taskmap="manual:[]" true
+'
 test_expect_success 'invalid taskmap causes job failure' '
 	test_must_fail_or_be_terminated \
 		flux mini run -vvv --taskmap=foo true