Fix push_complex_descriptor to avoid unlimited global mark stack growth

(Cherry-pick commits c18ff9a, 4781c6d from 'release-7_4' branch.)

Global mark stack should not grow in parallel marker mode (as
fixed-size local_mark_stack is used instead).

* typd_mlc.c [PARALLEL_MARK] (GC_array_mark_proc): Do not set
GC_mark_stack_too_small if GC_parallel (and new_mark_stack_ptr is
null) unless mark_stack_limit belongs to the global mark stack; add
comment.

diff --git a/typd_mlc.c b/typd_mlc.c
index e3b267251ba10686484a9730e825173f002356c9..e08f5a9972dc087b4b517754db636c1d1dcc1ded 100644 (file)
--- a/typd_mlc.c
+++ b/typd_mlc.c
@@ -520,7 +520,13 @@ STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
         /* and request a mark stack expansion.                          */
         /* This cannot cause a mark stack overflow, since it replaces   */
         /* the original array entry.                                    */
-        GC_mark_stack_too_small = TRUE;
+#       ifdef PARALLEL_MARK
+            /* We might be using a local_mark_stack in parallel mode.   */
+            if (GC_mark_stack + GC_mark_stack_size == mark_stack_limit)
+#       endif
+        {
+            GC_mark_stack_too_small = TRUE;
+        }
         new_mark_stack_ptr = orig_mark_stack_ptr + 1;
         new_mark_stack_ptr -> mse_start = (ptr_t)addr;
         new_mark_stack_ptr -> mse_descr = sz | GC_DS_LENGTH;