fix(js): tighten task cleanup guards

Author: ithewei

docs/cn/HttpJsHandler.md

@@ -94,7 +94,7 @@ options.stack_size = 1024 * 1024;        // QuickJS 栈上限，0 表示不限
 router.GET("/hello", HttpJsHandler("scripts/hello.js", options));
 ```
 
-`memory_limit` 和 `stack_size` 作用在每个 event loop 复用的 QuickJS runtime 上；同一个 loop 上第一次创建 JS runtime 时生效。
+`memory_limit` 和 `stack_size` 作用在每个 event loop 复用的 QuickJS runtime 上；同一个 loop 上第一次创建 JS runtime 时生效。后续同一 loop 上再创建 `HttpJsHandler` 时会复用已有 runtime；如果传入不同限制，会记录 warning，但不会重建 runtime。
 
 ## 目录映射
 

js/hvjs.cpp

@@ -362,7 +362,13 @@ void HvJsPromiseOp::cancel(const char* reason) {
 HvJsRuntime* hvjs_runtime(hloop_t* loop, const HvJsRuntimeOptions& options) {
     if (loop == NULL) return NULL;
     HvJsRuntime* runtime = (HvJsRuntime*)hloop_js_runtime(loop);
-    if (runtime) return runtime;
+    if (runtime) {
+        if (runtime->options.memory_limit != options.memory_limit || runtime->options.stack_size != options.stack_size) {
+            hlogw("[js] QuickJS runtime already exists on this hloop; ignoring new memory_limit=%llu stack_size=%llu",
+                  (unsigned long long)options.memory_limit, (unsigned long long)options.stack_size);
+        }
+        return runtime;
+    }
 
     runtime = new HvJsRuntime();
     runtime->options = options;
@@ -402,11 +408,11 @@ void hvjs_task_unref(HvJsTask* task) {
         }
     }
     finish_deferred_ops(task);
-    if (!JS_IsUndefined(task->promise_result)) {
+    if (task->js && !JS_IsUndefined(task->promise_result)) {
         JS_FreeValue(task->js, task->promise_result);
         task->promise_result = JS_UNDEFINED;
     }
-    if (!JS_IsUndefined(task->promise)) {
+    if (task->js && !JS_IsUndefined(task->promise)) {
         JS_FreeValue(task->js, task->promise);
         task->promise = JS_UNDEFINED;
     }
@@ -469,9 +475,7 @@ bool hvjs_task_start_timeout(HvJsTask* task, int timeout_ms) {
 void hvjs_task_cancel_timeout(HvJsTask* task) {
     if (task == NULL) return;
     if (task->timeout_timer_id != INVALID_TIMER_ID && task->loop_ptr) {
-        if (task->loop_ptr->isRunning()) {
-            task->loop_ptr->killTimer(task->timeout_timer_id);
-        }
+        task->loop_ptr->killTimer(task->timeout_timer_id);
         task->timeout_timer_id = INVALID_TIMER_ID;
         hvjs_task_unref(task);
     }