Signal when shutting down
diff --git a/src/core/iomgr/iomgr.c b/src/core/iomgr/iomgr.c
index 9bbff41..ec31de2 100644
--- a/src/core/iomgr/iomgr.c
+++ b/src/core/iomgr/iomgr.c
@@ -186,6 +186,9 @@
     g_cbs_tail->next = dcb;
     g_cbs_tail = dcb;
   }
+  if (g_shutdown) {
+    gpr_cv_signal(&g_rcv);
+  }
   gpr_mu_unlock(&g_mu);
 }