Right, Handle<> (and Local<>) can only be stack allocated and have to live
within a HandleScope. If you want to store a reference to a V8 object, you
need a Persistent<>, see esp. https://developers.google.com/v8/embed#handles
best
-jochen
On Sat, Jan 25, 2014 at 8:52 PM, Kevin Ingwersen
<ingwie2...@googlemail.com>wrote:
> To really store something:
>
> Persistent<Value> MyVal = Persistent<Value>::New( Value::New() );
>
> Replace Value with something like Array, for example. That will give you
> an ever-existing value, not devoured by the GC. That, at least, works in my
> case o.o;
> Am Sa. Jan. 25 2014 19:07:14 schrieb mh:
>
> Hi.
>
> A cursory look at the code tells me you aren't quite aware of the
> existence of the "monster" called GC in v8. You can't just
> store the return value of a call for later use, there ain't any guarantee
> the monster won't devour it before you get to it :-).
> Search for the term Persistent in this group, and maybe you will find the
> answer. Hope it helps.
>
>
>
> On Friday, January 24, 2014 2:23:06 PM UTC-6, Pierre Saunier wrote:
>>
>> Hi,
>>
>> I want to use V8 as the scripting engine of my 3D modeler... but for the
>> moment, I have some troubles...
>>
>> basicaly, I have a structre like this:
>> typedef struct
>> {
>> v8::Isolate* isolate;
>> v8::Handle<v8::ObjectTemplate> global;
>> v8::Handle<v8::Context> context;
>> v8::Handle<v8::Script> script;
>> }v8ScriptEngineDef;
>>
>>
>> a function to compile a script:
>> int scriptCompile(char *fileName, char *code, v8ScriptEngineDef
>> *v8Engine,
>> scriptExternalFuncDef *externalFunc)
>> {
>>
>> v8::HandleScope handle_scope(v8Engine->isolate);
>> v8Engine->global = v8::ObjectTemplate::New();
>> v8_create_file_obj(v8Engine->isolate, v8Engine->global);
>> v8_create_color_obj(v8Engine->isolate, v8Engine->global);
>> v8_create_image_obj(v8Engine->isolate, v8Engine->global);
>> v8_create_gui_obj(v8Engine->isolate, v8Engine->global);
>>
>> v8Engine->global->Set(v8::String::NewFromUtf8(v8Engine->isolate,
>> "console"),
>> v8::FunctionTemplate::New(v8Engine->isolate,
>> v8_console));
>>
>> v8Engine->context = v8::Context::New(v8Engine->isolate, NULL,
>> v8Engine->global);
>> if(v8Engine->context.IsEmpty()) {
>> scriptEngineAddToConsole(v8Engine, "Error creating context\n");
>> return FALSE;
>> }
>> v8Engine->context->Enter();
>>
>> v8::TryCatch try_catch;
>> v8::Handle<v8::String> v8fileName =
>> v8::String::NewFromUtf8(v8Engine->isolate,
>> fileName);
>> v8::Handle<v8::String> v8code = v8::String::NewFromUtf8(v8Engine->isolate,
>> code);
>> v8Engine->script = v8::Script::Compile(v8code, v8fileName);
>> if(v8Engine->script.IsEmpty())
>> {
>> // Print errors that happened during compilation.
>> ReportException(v8Engine, v8Engine->isolate, &try_catch);
>> return false;
>> }
>> v8Engine->context->Exit();
>> // scriptRun(engine);
>>
>>
>> return TRUE;
>> }
>>
>> and a running function:
>> int scriptRun(v8ScriptEngineDef *v8Engine)
>> {
>> v8::HandleScope handle_scope(v8Engine->isolate);
>> v8::TryCatch try_catch;
>> v8Engine->context->Enter();
>> v8::Handle<v8::Value> result = v8Engine->script->Run();
>> if (result.IsEmpty())
>> {
>> assert(try_catch.HasCaught());
>> // Print errors that happened during execution.
>> ReportException(v8Engine, v8Engine->isolate, &try_catch);
>> return false;
>> }
>> assert(!try_catch.HasCaught());
>> if (!result->IsUndefined())
>> {
>> // If all went well and the result wasn't undefined then print
>> // the returned value.
>> v8::String::Utf8Value str(result);
>> const char* cstr = *str;
>> scriptEngineAddToConsole(v8Engine, (char *)cstr);
>> }
>> v8Engine->context->Exit();
>> return true;
>> }
>>
>> The problem is if I call the running function from the Compile function
>> (in comment), everythink is working fine.
>> But, If I call the compile fonction, then the run function... crash!!!
>>
>>
>> Can somebody explain me what I am doing wrong?
>>
>>
>> thanks,
>>
>> Pierre
>>
>
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