c++ - spidermonkey 1.8.5 在 Debug模式下崩溃

Question

我在我的应用程序中使用 Spidermonkey 1.8.5。当我使用调试 JS 库时，我的应用程序崩溃了。我正在使用以下选项构建库:--enable-debug --disable-optimize --enable-threadsafe

崩溃指向这里:断言失败:(cx)->thread->data.requestDepth || (cx)->thread == (cx)->runtime->gcThread, at ../../src/jsapi.cpp

这是示例程序

/* Include the JSAPI header file to get access to SpiderMonkey. */
#include "jsapi.h"



/* The class of the global object. */
static JSClass global_class = {
    "global", JSCLASS_GLOBAL_FLAGS,
    JS_PropertyStub, JS_PropertyStub, JS_PropertyStub, JS_StrictPropertyStub,
    JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub,
    JSCLASS_NO_OPTIONAL_MEMBERS
};

/* The error reporter callback. */
void reportError(JSContext *cx, const char *message, JSErrorReport *report)
{
    fprintf(stderr, "%s:%u:%s\n",
            report->filename ? report->filename : "<no filename=\"filename\">",
            (unsigned int) report->lineno,
            message);
}

int main(int argc, const char *argv[])
{
    /* JSAPI variables. */
    JSRuntime *rt;
    JSContext *cx;
    JSObject  *global;
    printf("Started\n");
    /* Create a JS runtime. You always need at least one runtime per process. */
    rt = JS_NewRuntime(8 * 1024 * 1024);

    if (rt == NULL)
        return 1;

    /*
     * Create a context. You always need a context per thread.
     * Note that this program is not multi-threaded.
     */
    cx = JS_NewContext(rt, 8192);
    if (cx == NULL)
        return 1;

    JS_SetErrorReporter(cx, reportError);

    /*
     * Create the global object in a new compartment.
     * You always need a global object per context.
     */
    global = JS_NewCompartmentAndGlobalObject(cx, &global_class, NULL);
    if (global == NULL)
        return 1;

    /*
     * Populate the global object with the standard JavaScript
     * function and object classes, such as Object, Array, Date.
     */
    if (!JS_InitStandardClasses(cx, global))
        return 1;

    /* Your application code here. This may include JSAPI calls
     * to create your own custom JavaScript objects and to run scripts.
     *
     * The following example code creates a literal JavaScript script,
     * evaluates it, and prints the result to stdout.
     *
     * Errors are conventionally saved in a JSBool variable named ok.
     */
    char *script = "'Hello ' + 'World!'";
    jsval rval;
    JSString *str;
    JSBool ok;
    const char *filename = "noname";
    uintN lineno = 0;

    ok = JS_EvaluateScript(cx, global, script, strlen(script),
                           filename, lineno, &rval);
    if (rval == NULL | rval == JS_FALSE)
        return 1;

    str = JS_ValueToString(cx, rval);
    printf("%s\n", JS_EncodeString(cx, str));

    /* End of your application code */

    /* Clean things up and shut down SpiderMonkey. */
    JS_DestroyContext(cx);
    JS_DestroyRuntime(rt);
    JS_ShutDown();
    return 0;
}

如果我在 Release模式下构建，程序运行良好。此问题仅与 Debug模式有关。我在这里缺少什么？

Answer 1

在 JS_NewCompartmentAndGlobalObject 调用之前插入 JS_BeginRequest(cx);。

在调用 JS_DestroyContext 之前插入 JS_EndRequest(cx);。

大多数 JSAPI 函数都需要一个请求。 (我不确定为什么。线程的最初原因与多线程有关，但现在每个 JSRuntime 都是单线程的。)

SpiderMonkey 的调试版本包括以 Release模式无法做到的方式检查 API 使用情况的断言。因此，您可能会再次看到仅调试断言。我强烈建议针对调试版本进行开发，因为这些断言几乎总是表明真正的问题。

下一个 SpiderMonkey 版本即将发布:https://bugzilla.mozilla.org/show_bug.cgi?id=735599#c54