Hi Clemens, thanks a lot for your help. You are brilliant! Your solution works out of the box ;)
[image: wasm_memory.png] Now I can finally tackle those bugs in the Wasm code. Kind regards, Immanuel Am Dienstag, 22. September 2020 12:30:43 UTC+2 schrieb Clemens Backes: > > Hi Immanuel, > > the problem is probably related to your manipulation of the raw memory > pointer <https://groups.google.com/g/v8-dev/c/jQMLH3EkCoM/m/gHw9elpKDwAJ>. > For debugging, we are not using this pointer, but the WasmMemoryObject > <https://source.chromium.org/chromium/chromium/src/+/master:v8/src/wasm/wasm-objects.h;l=289;drc=69ca751bc8aace8c15a6a2d2e22d1658914e4145> > > which is attached to the WasmInstanceObject > <https://source.chromium.org/chromium/chromium/src/+/master:v8/src/wasm/wasm-objects.h;l=370;drc=ee9e7e404e5a3f75a3ca0489aaf80490f625ca27>. > > This one is still pointing to the original memory, not the one you set via > your added "SetWasmInstanceRawMemory" function. > > The WasmMemoryObject has an attached JSArrayBuffer. Maybe you can set the > backing store of that array buffer to point to your external memory? > It should be clear that this is totally unsupported territory, so you will > have to try if that hack works. > > I am thinking something along the lines of (extending > your SetWasmInstanceRawMemory function): > void SetWasmInstanceRawMemory(Local<Object> wasmInstance, uint8_t* > mem_start, > size_t mem_size) { > auto instance = > > i::Handle<i::WasmInstanceObject>::cast(Utils::OpenHandle(*wasmInstance)); > auto* i_isolate = > reinterpret_cast<i::Isolate*>(wasmInstance->GetIsolate()); > instance->SetRawMemory(mem_start, mem_size); > std::unique_ptr<i::BackingStore> backing_store = > i::BackingStore::WrapAllocation(i_isolate, mem_start, mem_size, > i::SharedFlag::kNotShared, false); > > instance->memory_object().array_buffer().Attach(std::move(backing_store)); > } > > This code comes without any guarantees, it might or might not work, but > maybe it helps you understand the problem and develop a working solution > from there. > > Cheers, > Clemens > > > On Tue, Sep 22, 2020 at 11:46 AM Immanuel Haffner <haffner...@gmail.com > <javascript:>> wrote: > >> I upgraded V8 to v8.6.405 and Chromium to 85. Still the problem persists >> that the Wasm linear memory appears "all zeroes" although the Wasm code >> reads the correct data. Could anybody please provide some help? >> >> Immanuel Haffner schrieb am Montag, 14. September 2020 um 14:21:28 UTC+2: >> >>> Hi all, >>> >>> I am trying to debug Wasm code that manipulates its linear memory. I am >>> running the code in embedded V8 and I am using the V8 inspector API to >>> connect with CDT. Although I can verify on the embedder's side that the >>> linear memory was manipulated, all I see in CDT is zeroes. The attached >>> image shows what I mean. >>> >>> [image: Screenshot_20200914_141705.png] >>> The memory of the Wasm instance is "all zeroes". What am I doing wrong? >>> Using the V8 API from the embedder I can verify that the linear memory was >>> written and contains some data I'd expect to see in CDT. >>> >>> Do you have any ideas what I am doing wrong? >>> >>> Thanks & regards, >>> Immanuel >>> >> -- >> -- >> v8-users mailing list >> v8-u...@googlegroups.com <javascript:> >> http://groups.google.com/group/v8-users >> --- >> You received this message because you are subscribed to the Google Groups >> "v8-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to v8-u...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/v8-users/13c9e3ab-3cfc-46be-b485-69f8292a73c9n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/v8-users/13c9e3ab-3cfc-46be-b485-69f8292a73c9n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > > Clemens Backes > > Software Engineer > > clem...@google.com <javascript:> > > Google Germany GmbH > > Erika-Mann-Straße 33 > > 80636 München > > Geschäftsführer: Paul Manicle, Halimah DeLaine Prado > > Registergericht und -nummer: Hamburg, HRB 86891 > > Sitz der Gesellschaft: Hamburg > > Diese E-Mail ist vertraulich. Falls sie diese fälschlicherweise erhalten > haben sollten, leiten Sie diese bitte nicht an jemand anderes weiter, > löschen Sie alle Kopien und Anhänge davon und lassen Sie mich bitte wissen, > dass die E-Mail an die falsche Person gesendet wurde. > > > This e-mail is confidential. If you received this communication by > mistake, please don't forward it to anyone else, please erase all copies > and attachments, and please let me know that it has gone to the wrong > person. > > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-users/d15d517b-22b2-42fd-b499-f55fa6cf4c2eo%40googlegroups.com.
