Hello Steve, thank you for your reply.
Am 09.01.2014 21:47, schrieb Steve Fink: > On 01/06/2014 09:25 AM, Andreas Schlegel wrote: >> Hello, >> >> I need the JSContext to declare JS::RootedObjects or Values. >> Especially for the case of WeakMap/Map/Set-Hasher I don't have the >> JSContext. >> >> At the moment I use the following implementation to get the JSContext >> (this is a code snipped of a hash-function): >> >> JSRuntime * rt = JS_GetObjectRuntime(&value.toObject()); >> JSContext *cx = DefaultJSContext(rt); >> return DefaultHasher<JSObject >> *>::hash(value.toObject().GetIdentityObject(cx)); >> >> If I want to change the operator== of Value.h, I cannot use the first >> two functions, because they aren't known and I cannot include jsapi.h >> because of circle include errors. >> >> Is there a better way to retrieve the JSContext from JS::Value or JSObject? > No, since Values and JSObjects are not associated with JSContexts. > JSContexts relate to control flow, and are independent of the data. > > One way to solve this would be to reimplement the JSRuntime rooters, and > automatically fetch the runtime from TLS. We had that before, but > removed it because it was such a large perf footgun. It sounds like > Gecko has places where it would be properly used, though, so we should > perhaps add it back in some form. > > AIUI, you're doing experimental work on transparent proxies. I assume > perf doesn't matter too much? (Must not, if you're willing to make '==' > way way more complex!) Then why not make operator== out of line and > define it in jsapi.cpp or somewhere? Yes I'm doing experimental work on transparent proxies, but I hope this gives not a really bad perf. I will evaluate it later. I try to change as few as possible on the program structure to increase the acceptance for this thematic. But I think you're correct and I can only define the operator outside JS::Value to get it to work. Is it really possible to create it in jsapi.cpp, because Value.h is an include in jsapi.h(-->Circle include)? If I understand it correct with "JS_GetObjectRuntime" I get the Runtime and there is only one. With "DefaultJSContext(rt)" I get the correct Context if only one is available or the default in an multi-threading application. If I have a multi-threaded application and the object has an other Context as the default is this correct or not? If not how can I get the correct? >> My sencond question is: >> Where is the best place for the GetIdentityObject-function? Because >> JSObject and most other files are also not known to Value.h. I've tried >> to include jsproxy.h with my function, which leads also to a circle include. > What types does it require? I'd kind of expect it to be declared in > Value.h and defined somewhere like jsproxy.cpp. You mean I should declarate it as extern in Value.h and implement it in jsproxy.cpp? > Thanks Andreas _______________________________________________ dev-tech-js-engine-internals mailing list dev-tech-js-engine-internals@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals
