Thank you very much On Friday, 24 March 2023 at 23:27:13 UTC+7 s...@google.com wrote:
> On Thu, Mar 23, 2023 at 6:50 PM Thaina Yu <thai...@gmail.com> wrote: > >> I am not sure how limited it is but there are many situation that we just >> need a value to pass object from one function to another immediately in the >> same flow >> >> By the way, which the handle would be returned as EM_ASM_INT or >> EM_ASM_PTR ? >> > > EM_ASM_INT is probably what you want if you want to return an integer > handle to JS object. e.g. Something like an EM_VAL or a handle to JS > promise. > > In emscripten we use this thing called a HandleAllocator to map integers > to JS objects: > https://github.com/emscripten-core/emscripten/blob/3cf83fdc4711e9bf3b01cf9821e717311a13c1b5/src/library.js#L3714-L3715 > > Because native code wants to deal with integers whenever we want to pass a > JS object to native code we go through this handle allocator. When JS > receives an integer handle from native code it can turn it back into a JS > object by looking it up in a given handle allocator. In theory being able > to pass externref directly looks like a way to remove the need for the > extra mapping, but in practice C/C++ needs to be able to store handles in > memory (and in data structures that live in memory) so using > externref instead of `int` for EM_VAL doesn't work (at least not today). > > > >> On Friday, 24 March 2023 at 01:47:20 UTC+7 s...@google.com wrote: >> >>> On Thu, Mar 23, 2023 at 10:12 AM Thaina Yu <thai...@gmail.com> wrote: >>> >>>> I don't actually know which things unity would use to hold the value of >>>> externref, just guessing it would be IntPtr. But by anything it require >>>> that emscripten can officially define externref first anyway >>>> >>> >>> The problem is that externref can't live in memory, so it can't live >>> inside a struct or class or array or any C#/C++/C data type. So it's not >>> going to be very usable IIUC. We already have `EM_VAL` in emscripten >>> which is a way to refer to a JS object via an integer handle. I don't >>> think we can build anything better than EM_VAL any time soon, at least >>> nothing that can work well with C/C++/C#, but perhaps I'm missing something? >>> >>> >>> >>> >>>> On Friday, 24 March 2023 at 00:03:02 UTC+7 s...@google.com wrote: >>>> >>>>> On Thu, Mar 23, 2023 at 9:51 AM Thaina Yu <thai...@gmail.com> wrote: >>>>> >>>>>> I am actually using emscripten from unity and I mainly use C# code >>>>>> from unity side. But there are tons of 3rd party library and SDK that >>>>>> written with assumption that we will only use JavaScript. It then need >>>>>> us >>>>>> to construct javascript object in javascript and pass javascript object >>>>>> reference all over the places. For example, the google's firebase SDK >>>>>> that >>>>>> we need to construct it special object type to work with its complex >>>>>> services >>>>>> >>>>>> It then become very frustrating to wrap everything in an API with >>>>>> mergeInto library that kept growing for everythings related to js object >>>>>> >>>>>> With just the ability to pass externref into C# as IntPtr or int64 >>>>>> and so C# can pass it to another js API after it was done everything in >>>>>> C# >>>>>> is just what we really need, everything would come together as a flow of >>>>>> reference. The chain of bottleneck is that unity rely on emscripten to >>>>>> fully support externref first then it could start support it in some >>>>>> future. So the sluggish are stacking up >>>>>> >>>>> >>>>> But `IntPtr` and `int64` are fundamentally not externref, right? Or >>>>> are you imagining those being indexes into a table of externref perhaps? >>>>> That would work, but then the tricky part becoming managing that table. >>>>> This is mind what embind does when it refers to JS object from native >>>>> code >>>>> I believe. >>>>> >>>>> >>>>>> On Thursday, 23 March 2023 at 23:34:43 UTC+7 s...@google.com wrote: >>>>>> >>>>>>> On Thu, Mar 23, 2023 at 9:20 AM Thaina Yu <thai...@gmail.com> wrote: >>>>>>> >>>>>>>> Thank you very much. Are there any public discussion or roadmap to >>>>>>>> add EM_ASM_REF into emscripten? >>>>>>>> >>>>>>> >>>>>>> You are the first person that I know of to suggest it. >>>>>>> >>>>>>> Be aware that using externref directly in C/C++ is very limited, >>>>>>> even after the recent changes. For example you can't store them in >>>>>>> structs >>>>>>> or class or store them to memory. All you can really do with them is >>>>>>> pass >>>>>>> them around and (maybe) put them in tables. So in practice I'm not >>>>>>> sure >>>>>>> how useful this stuff is yet, but I could be wrong? >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> On Thursday, 23 March 2023 at 23:17:52 UTC+7 s...@google.com wrote: >>>>>>>> >>>>>>>>> On Thu, Mar 23, 2023 at 6:52 AM Thaina Yu <thai...@gmail.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Do we have anyway to write hand-written assembly code along with >>>>>>>>>> emscripten? And is it possible to return that externref from wasm >>>>>>>>>> code into >>>>>>>>>> emscripten world? >>>>>>>>> >>>>>>>>> >>>>>>>>> Here is the example how to use externref in assembly: >>>>>>>>> https://github.com/emscripten-core/emscripten/blob/main/test/core/test_externref.s >>>>>>>>> >>>>>>>>> Until recently there was no way to communicate those references >>>>>>>>> directly to C++ but it maybe possible now that upstream clan support >>>>>>>>> has >>>>>>>>> landed. >>>>>>>>> >>>>>>>>> There is no current support for externref in EM_ASM. We could >>>>>>>>> potentially add EM_ASM_REF which returns a ref to C/C++ but until >>>>>>>>> recently >>>>>>>>> that would have been impossible. >>>>>>>>> >>>>>>>>> >>>>>>>>>> I am actually using unity which use emscripten to build webgl. >>>>>>>>>> Would it possible to use EM_ASM_PTR to write wasm code to return as >>>>>>>>>> pointer >>>>>>>>>> (externref ? (an so I might return pointer as IntPtr in C#)) ? >>>>>>>>>> >>>>>>>>>> On Friday, 17 March 2023 at 22:35:55 UTC+7 tli...@google.com >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Yes, but note that the usage in that commit is only in >>>>>>>>>>> hand-written assembly code, not in C/C++. >>>>>>>>>>> >>>>>>>>>>> More recently, support for externref landed upstream in clang: >>>>>>>>>>> https://github.com/llvm/llvm-project/blob/main/clang/test/CodeGen/WebAssembly/wasm-externref.c. >>>>>>>>>>> >>>>>>>>>>> AFAIK we haven't yet experimented with it in Emscripten, but in >>>>>>>>>>> principle >>>>>>>>>>> it should work. >>>>>>>>>>> >>>>>>>>>>> On Fri, Mar 17, 2023 at 10:23 AM Thaina Yu <thai...@gmail.com> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>> Is this mean externref already usable? >>>>>>>>>>>> >>>>>>>>>>>> https://github.com/emscripten-core/emscripten/pull/15913 >>>>>>>>>>>> >>>>>>>>>>>> On Monday, 10 October 2022 at 22:56:34 UTC+7 >>>>>>>>>>>> karl.we...@gmail.com wrote: >>>>>>>>>>>> >>>>>>>>>>>>> Does anyone have news on this topic? >>>>>>>>>>>>> >>>>>>>>>>>>> tli...@google.com schrieb am Montag, 25. Januar 2021 um >>>>>>>>>>>>> 19:51:36 UTC+1: >>>>>>>>>>>>> >>>>>>>>>>>>>> I don't think so, but you can keep an eye on commits from >>>>>>>>>>>>>> "wingo" and "pmatos" on reviews.llvm.org to keep track of >>>>>>>>>>>>>> the progress. >>>>>>>>>>>>>> >>>>>>>>>>>>>> On Mon, Jan 25, 2021 at 12:55 AM ben layet <lay...@gmail.com> >>>>>>>>>>>>>> wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>>> Thanks! >>>>>>>>>>>>>>> Is there a feature ticket in a publicly visible ticket >>>>>>>>>>>>>>> tracker that I can keep an eye on? >>>>>>>>>>>>>>> cheers >>>>>>>>>>>>>>> ben >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> On Saturday, 23 January 2021 at 17:54:25 UTC >>>>>>>>>>>>>>> tli...@google.com wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Not yet, but there are some folks working on this. Perhaps >>>>>>>>>>>>>>>> it will be ready to use in a few months? It’s hard to say for >>>>>>>>>>>>>>>> sure. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> On Sat, Jan 23, 2021 at 03:49 ben layet <lay...@gmail.com> >>>>>>>>>>>>>>>> wrote: >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Does emscripten support externref reference types for >>>>>>>>>>>>>>>>> holding opaque handles to JS objects in C++? If not, any idea >>>>>>>>>>>>>>>>> when? >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> -- >>>>>>>>>>>>>>>>> You received this message because you are subscribed to >>>>>>>>>>>>>>>>> the Google Groups "emscripten-discuss" group. >>>>>>>>>>>>>>>>> To unsubscribe from this group and stop receiving emails >>>>>>>>>>>>>>>>> from it, send an email to >>>>>>>>>>>>>>>>> emscripten-disc...@googlegroups.com. >>>>>>>>>>>>>>>>> To view this discussion on the web visit >>>>>>>>>>>>>>>>> https://groups.google.com/d/msgid/emscripten-discuss/7f6178fa-bd05-4f65-aa7c-9e5a405bf851n%40googlegroups.com >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> <https://groups.google.com/d/msgid/emscripten-discuss/7f6178fa-bd05-4f65-aa7c-9e5a405bf851n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>>>>>>>>>>>> . >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> -- >>>>>>>>>>>>>>> You received this message because you are subscribed to the >>>>>>>>>>>>>>> Google Groups "emscripten-discuss" group. >>>>>>>>>>>>>>> To unsubscribe from this group 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https://groups.google.com/d/msgid/emscripten-discuss/57b1491a-7025-4967-a66e-ebcbf10f5e2bn%40googlegroups.com >>>>>>>>>>>> >>>>>>>>>>>> <https://groups.google.com/d/msgid/emscripten-discuss/57b1491a-7025-4967-a66e-ebcbf10f5e2bn%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>>>>>>> . >>>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>> You received this message because you are subscribed to the >>>>>>>>>> Google Groups "emscripten-discuss" group. >>>>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>>>> send an email to emscripten-disc...@googlegroups.com. >>>>>>>>>> >>>>>>>>> To view this discussion on the web visit >>>>>>>>>> https://groups.google.com/d/msgid/emscripten-discuss/ed80516b-e1ac-4ba1-a535-acd1f632a2f5n%40googlegroups.com >>>>>>>>>> >>>>>>>>>> <https://groups.google.com/d/msgid/emscripten-discuss/ed80516b-e1ac-4ba1-a535-acd1f632a2f5n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>>>>> . >>>>>>>>>> >>>>>>>>> -- >>>>>>>> You 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