Lazily move units from active_units to stale_units

to avoid SEGV like
http://ci.rvm.jp/results/trunk-mjit@phosphorus-docker/3289588
by a race condition between mjit_recompile and compation around active_units

1 files changed, 4 insertions, 3 deletions

diff --git a/mjit.c b/mjit.c
index 34f83a4633..2b6ceba2d3 100644
--- a/mjit.c
+++ b/mjit.c
@@ -333,12 +333,13 @@ mjit_recompile(const rb_iseq_t *iseq)
     verbose(1, "JIT recompile: %s@%s:%d", RSTRING_PTR(iseq->body->location.label),
             RSTRING_PTR(rb_iseq_path(iseq)), FIX2INT(iseq->body->location.first_lineno));
 
+    // Lazily move active_units to stale_units to avoid race conditions around active_units with compaction
     CRITICAL_SECTION_START(3, "in rb_mjit_recompile_iseq");
-    remove_from_list(iseq->body->jit_unit, &active_units);
-    iseq->body->jit_func = (mjit_func_t)NOT_ADDED_JIT_ISEQ_FUNC;
-    add_to_list(iseq->body->jit_unit, &stale_units);
+    iseq->body->jit_unit->stale_p = true;
+    pending_stale_p = true;
     CRITICAL_SECTION_FINISH(3, "in rb_mjit_recompile_iseq");
 
+    iseq->body->jit_func = (mjit_func_t)NOT_ADDED_JIT_ISEQ_FUNC;
     mjit_add_iseq_to_process(iseq, &iseq->body->jit_unit->compile_info);
     if (UNLIKELY(mjit_opts.wait)) {
         mjit_wait(iseq->body);