Require non-NULL exec_ctx to unref.

src/core/lib/iomgr/tcp_server.h

@@ -101,8 +101,8 @@ grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s);
 void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
                                            grpc_closure *shutdown_starting);
 
-/* If the refcount drops to zero, delete s, and call (exec_ctx==NULL) or enqueue
-   a call (exec_ctx!=NULL) to shutdown_complete. */
+/* If the refcount drops to zero, enqueue calls on exec_ctx to
+   shutdown_listeners and delete s. */
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s);
 
 /* Shutdown the fds of listeners. */

src/core/lib/iomgr/tcp_server_posix.c

@@ -745,22 +745,11 @@ void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
 
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
   if (gpr_unref(&s->refs)) {
-    grpc_exec_ctx local_exec_ctx = GRPC_EXEC_CTX_INIT;
-    bool finish_ctx = false;
-    /* FIXME: API allows a NULL exec_ctx, although this might cause us to delete
-       ourself before some enqueued work in some other exec_ctx runs. */
-    if (exec_ctx == NULL) {
-      exec_ctx = &local_exec_ctx;
-      finish_ctx = true;
-    }
     grpc_tcp_server_shutdown_listeners(exec_ctx, s);
     gpr_mu_lock(&s->mu);
     grpc_exec_ctx_enqueue_list(exec_ctx, &s->shutdown_starting, NULL);
     gpr_mu_unlock(&s->mu);
     tcp_server_destroy(exec_ctx, s);
-    if (finish_ctx) {
-      grpc_exec_ctx_finish(exec_ctx);
-    }
   }
 }
 

src/core/lib/iomgr/tcp_server_windows.c

@@ -121,6 +121,9 @@ grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
 }
 
 static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
+  gpr_mu_lock(&s->mu);
+  GPR_ASSERT(s->shutdown);
+  gpr_mu_unlock(&s->mu);
   if (s->shutdown_complete != NULL) {
     grpc_exec_ctx_sched(exec_ctx, s->shutdown_complete, GRPC_ERROR_NONE, NULL);
   }
@@ -139,7 +142,7 @@ static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 }
 
 grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s) {
-  gpr_ref(&s->refs);
+  gpr_ref_non_zero(&s->refs);
   return s;
 }
 
@@ -174,19 +177,11 @@ static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
 
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
   if (gpr_unref(&s->refs)) {
-    /* Complete shutdown_starting work before destroying. */
-    grpc_exec_ctx local_exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_tcp_server_shutdown_listeners(exec_ctx, s);
     gpr_mu_lock(&s->mu);
-    grpc_exec_ctx_enqueue_list(&local_exec_ctx, &s->shutdown_starting, NULL);
+    grpc_exec_ctx_enqueue_list(exec_ctx, &s->shutdown_starting, NULL);
     gpr_mu_unlock(&s->mu);
-    if (exec_ctx == NULL) {
-      grpc_exec_ctx_flush(&local_exec_ctx);
-      tcp_server_destroy(&local_exec_ctx, s);
-      grpc_exec_ctx_finish(&local_exec_ctx);
-    } else {
-      grpc_exec_ctx_finish(&local_exec_ctx);
-      tcp_server_destroy(exec_ctx, s);
-    }
+    tcp_server_destroy(exec_ctx, s);
   }
 }