Document assumption about GC lock for GC_clear_exclusion_table

* include/gc/gc.h (GC_clear_exclusion_table): Add comment about GC
lock.
* mark_rts.c (GC_clear_exclusion_table): Likewise.
* mark_rts.c (GC_clear_exclusion_table): Copy comment from gc.h.

1 files changed, 3 insertions, 0 deletions

diff --git a/mark_rts.c b/mark_rts.c
index 8e61fd31..5caff4af 100644
--- a/mark_rts.c
+++ b/mark_rts.c
@@ -525,6 +525,9 @@ struct exclusion GC_excl_table[MAX_EXCLUSIONS];
                                         -- address order.
 */
 
+/* Clear the number of entries in the exclusion table.  The caller  */
+/* should acquire the GC lock (to avoid data race) but no assertion */
+/* about it by design.                                              */
 GC_API void GC_CALL GC_clear_exclusion_table(void)
 {
     GC_excl_table_entries = 0;