spidermonkey 1.8.5 crashes in debug mode - c++

Question

I am using Spidermonkey 1.8.5 in my application.
My application crashes when I use the debug JS library. I am building the library with the following options:
--enable-debug --disable-optimize --enable-threadsafe
crash is pointing here:
Assertion failure: (cx)->thread->data.requestDepth || (cx)->thread == (cx)->runtime->gcThread, at ../../src/jsapi.cpp
Here is the sample program
/* 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;
}
If I am building in release mode the program works fine. this problem is only with the debug mode. What am I missing here?

Answer 1

Insert JS_BeginRequest(cx); just before the JS_NewCompartmentAndGlobalObject call.
Insert JS_EndRequest(cx); just before the call to JS_DestroyContext.
Most JSAPI functions require a request. (I'm not sure why. The original reason for threads had to do with multithreading, but each JSRuntime is single-threaded now.)
The debug build of SpiderMonkey includes assertions that check API usage in ways that release mode can't. So you will likely see debug-only assertions again. I strongly recommend developing against a debug build, because those assertions almost always indicate real problems.
The next SpiderMonkey release is coming soon: https://bugzilla.mozilla.org/show_bug.cgi?id=735599#c54