feat: drive GC from sched_end_session — live_jobs mark, seq_cst fence, gc_sweep (6-8, 6-12)

src/scheduler/testsuite/test.c

@@ -196,6 +196,30 @@ test_meet_host_selection_always_false_fails(void)
     sel_optimize_test_reset();
 }
 
+static void
+test_gc_predicates_idle_invariant(void)
+{
+    xce_scheduler_t sched;
+    memset(&sched, 0, sizeof(sched));
+    /* staging_merge_complete=1 means GC is safe to run */
+    atomic_store(&sched.staging_merge_complete, 1);
+
+    sel_optimize_set(1);
+    sel_node_table_init();
+
+    /* Verify the atomic fields are readable — testing the predicate contract */
+    TEST_ASSERT_EQUAL_INT(0, atomic_load(&sched.session_active));
+    TEST_ASSERT_EQUAL_INT(0, atomic_load(&sched.eval_in_progress));
+    TEST_ASSERT_EQUAL_INT(1, atomic_load(&sched.staging_merge_complete));
+
+    /* GC operations on an empty node table must not crash */
+    gc_clear_marks();
+    gc_sweep_select_nodes(NULL, 0);
+
+    sel_node_table_fini();
+    sel_optimize_test_reset();
+}
+
 #define TEST(x)                                                                \
     do {                                                                       \
         if (check_test(&arguments, #x)) {                                      \
@@ -215,6 +239,7 @@ int main(int argc, char* argv[])
     TEST(test_meet_host_selection_null_select_passes);
     TEST(test_meet_host_selection_always_true_passes);
     TEST(test_meet_host_selection_always_false_fails);
+    TEST(test_gc_predicates_idle_invariant);
 
     return UNITY_END();
 }