garbage collect context (fiber) properly

3 files changed, 8 insertions, 3 deletions

diff --git a/include/mruby.h b/include/mruby.h
index 73c38cf1d..925344502 100644
--- a/include/mruby.h
+++ b/include/mruby.h
@@ -74,6 +74,8 @@ struct mrb_context {
   int rsize;
   struct RProc **ensure;
   int esize;
+
+  struct RFiber *fib;
 };
 
 enum gc_state {
diff --git a/mrbgems/mruby-fiber/src/fiber.c b/mrbgems/mruby-fiber/src/fiber.c
index e46e3cb02..c338b8b95 100644
--- a/mrbgems/mruby-fiber/src/fiber.c
+++ b/mrbgems/mruby-fiber/src/fiber.c
@@ -80,9 +80,9 @@ fiber_init(mrb_state *mrb, mrb_value self)
 
   f->cxt = (struct mrb_context*)mrb_malloc(mrb, sizeof(struct mrb_context));
   *f->cxt = mrb_context_zero;
+  c = f->cxt;
 
   /* initialize VM stack */
-  c = f->cxt;
   c->stbase = (mrb_value *)mrb_calloc(mrb, FIBER_STACK_INIT_SIZE, sizeof(mrb_value));
   c->stend = c->stbase + FIBER_STACK_INIT_SIZE;
   c->stack = c->stbase;
@@ -104,6 +104,8 @@ fiber_init(mrb_state *mrb, mrb_value self)
   ci[1] = ci[0];
   c->ci++;                      /* push dummy callinfo */
 
+  c->fib = f;
+
   return self;
 }
 
diff --git a/src/gc.c b/src/gc.c
index 4837d5207..4d0ba8a16 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -412,7 +412,9 @@ mark_context(mrb_state *mrb, struct mrb_context *c)
     mrb_gc_mark(mrb, (struct RBasic*)ci->proc);
     mrb_gc_mark(mrb, (struct RBasic*)ci->target_class);
   }
-  if (c->prev) mark_context(mrb, c->prev);
+  if (c->prev && c->prev->fib) {
+    mrb_gc_mark(mrb, (struct RBasic*)c->prev->fib);
+  }
 }
 
 static void
@@ -472,7 +474,6 @@ gc_mark_children(mrb_state *mrb, struct RBasic *obj)
       struct mrb_context *c = ((struct RFiber*)obj)->cxt;
 
       mark_context(mrb, c);
-      ((struct RFiber*)obj)->cxt = NULL;
     }
     break;