Async/await and webgl builds

Hello,
I'm not sure if this fits to here but im writing anyway
I have just started to test new 2017.1 builds to see how goes the new scripting stuff. I have tried to make some async methods which works fine on standalone builds. But when i try to build it using webgl, async methods doesnt seems to continue after awaited task finishes. Is this a known issue or am i making something wrong?

 

Here is a code piece that works on standalone players but not on webgl.

Code (CSharp):

1. using System.Threading.Tasks;
2. using UnityEngine;
3.  
4. class ExampleAsyncAwait : MonoBehaviour
5. {
6.     void Start()
7.     {
8.         Task testTask = TestMethod();
9.     }
10.  
11.     async Task TestMethod()
12.     {
13.         Debug.Log("First hello");
14.         await Task.Delay(1000);
15.  
16.         Debug.Log("Second hello");
17.         await Task.Delay(1000);
18.  
19.         Debug.Log("Third hello");
20.         await Task.Delay(1000);
21.  
22.         Debug.Log("Yet another hello");
23.         await Task.Delay(1000);
24.  
25.         Debug.Log("Finished");
26.     }
27. }
28.  

Actually it must be no different then coroutines but with nice syntax using the synchronization context provided by unity itself.

 

I have replaced delays with yields and it seemed to work. It could be possible that those delay tasks are not implemented on webgl.

 

Thanks for your time. I have just implemented a custom task to make delayed yields. It would be nice if unity provides these by itself like the ones(WaitForSeconds etc...) we use for coroutines.

Anyway i have a second question Here is a simple code that shows the problem...

Code (CSharp):

1. using System.Threading.Tasks;
2. using UnityEngine;
3.  
4. class ExampleAsyncAwait : MonoBehaviour
5. {
6.     void Start()
7.     {
8.         Task testTask = TestMethod();
9.     }
10.  
11.     async Task TestMethod()
12.     {
13.         Dummy testObject = await TestSubMethod<Dummy>();
14.         Debug.Log("This line will not execute");
15.         Debug.Log(testObject);
16.     }
17.  
18.     async Task<T> TestSubMethod<T>() where T : class, new()
19.     {
20.         T result = new T();
21.         await TestSubMethod2();
22.         Debug.Log("This line will be executed");
23.  
24.         return result;
25.     }
26.  
27.     Task TestSubMethod2()
28.     {
29.         Debug.Log("Just a dummy log");
30.         return Task.FromResult(0);
31.     }
32. }
33.  
34. class Dummy
35. {
36.     public Dummy()
37.     {
38.      
39.     }
40. }
41.  

This code works fine on standalone players. But at webgl I can't see the "This line will not execute" comment on console. It seems to be a problem related with generics and async combination. But i'm not sure.

Currently i'm implementing my method with every possible type which i use to avoid this. Any ideas?

 

Here goes the full logs

Spoiler: Browser Log

index.html:8 Resource interpreted as Stylesheet but transferred with MIME type text/plain: "http://localhost:8080/Immersion.WebGL/TemplateData/style.css".
UnityLoader.js:234 run() called, but dependencies remain, so not running
printErr @ UnityLoader.js:234
run @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441278
UnityLoader.da1f3f68d9e4c7fa12541611c3cd53e0 @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441366
UnityLoader.loadCode.Module @ UnityLoader.js:95
script.onload @ UnityLoader.js:26
blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:444 [Deprecation] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.
read @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:444
loadDynamicLibrary @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:658
(anonymous) @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:1580
(anonymous) @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:1579
callRuntimeCallbacks @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:1325
preRun @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:1354
run @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441282
runCaller @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441235
removeRunDependency @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:1570
applyMemoryInitializer @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441197
useRequest @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441212
UnityLoader.js:234 pre-main prep time: 9355 ms
printErr @ UnityLoader.js:234
doRun @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441292
run @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441307
runCaller @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:441235
removeRunDependency @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:1570
(anonymous) @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:11
doCallback @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:5591
done @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:5602
done @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:4715
storeLocalEntry @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:4633
(anonymous) @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:4726
UnityLoader.da1f3f68d9e4c7fa12541611c3cd53e0.IDBFS.loadRemoteEntry.req.onsuccess @ blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:4652
blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 PlayerConnection initialized from (debug = 0)

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 PlayerConnection disabled - listening mode not supported

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 Initialize engine version: 2017.1.0b6 (38ec4e48ade7)

UnityLoader.js:233 Creating WebGL 2.0 context.
blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 Renderer: WebKit WebGL

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 Vendor: WebKit

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 Version: OpenGL ES 3.0 (WebGL 2.0 (OpenGL ES 3.0 Chromium))

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 GLES: 3

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 EXT_color_buffer_float GL_EXT_color_buffer_float EXT_disjoint_timer_query_webgl2 GL_EXT_disjoint_timer_query_webgl2 EXT_texture_filter_anisotropic GL_EXT_texture_filter_anisotropic OES_texture_float_linear GL_OES_texture_float_linear WEBGL_compressed_texture_s3tc GL_WEBGL_compressed_texture_s3tc WEBGL_debug_renderer_info GL_WEBGL_debug_renderer_info WEBGL_debug_shaders GL_WEBGL_debug_shaders WEBGL_lose_context GL_WEBGL_lose_context

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 OPENGL LOG: Creating OpenGL ES 3.0 graphics device ; Context level <OpenGL ES 3.0> ; Context handle 1

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 UnloadTime: 25.960000 ms

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 Just a dummy log

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/WebGL/runtime/DebugBindings.gen.cpp Line: 51)


blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 This line will be executed

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/WebGL/runtime/DebugBindings.gen.cpp Line: 51)


blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:5584 warning: 2 FS.syncfs operations in flight at once, probably just doing extra work
blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:5584 warning: 2 FS.syncfs operations in flight at once, probably just doing extra work
blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:5584 warning: 2 FS.syncfs operations in flight at once, probably just doing extra work

Spoiler: Standalone Log

Mono path[0] = 'E:/Develop/Immersion.Binary/Immersion_Data/Managed'
Mono config path = 'E:/Develop/Immersion.Binary/Immersion_Data/MonoBleedingEdge/etc'
PlayerConnection initialized from E:/Develop/Immersion.Binary/Immersion_Data (debug = 0)
PlayerConnection initialized network socket : 0.0.0.0 55198
Multi-casting "[IP] 192.168.1.247 [Port] 55198 [Flags] 2 [Guid] 3289737884 [EditorId] 1575425679 [Version] 1048832 [Id] WindowsPlayer(KORAY-PC) [Debug] 0" to [225.0.0.222:54997]...
Started listening to [0.0.0.0:55198]
PlayerConnection already initialized - listening to [0.0.0.0:55198]
Player data archive not found at `E:/Develop/Immersion.Binary/Immersion_Data/data.unity3d`, using local filesystemInitialize engine version: 2017.1.0b6 (38ec4e48ade7)
GfxDevice: creating device client; threaded=1
Direct3D:
Version: Direct3D 11.0 [level 11.1]
Renderer: NVIDIA GeForce GTX 1080 (ID=0x1b80)
Vendor: NVIDIA
VRAM: 8110 MB
Driver: 21.21.13.7892
Begin MonoManager ReloadAssembly
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\UnityEngine.dll into Unity Child Domain
Platform assembly: E:\Develop\Immersion.Binary\Immersion_Data\Managed\System.Core.dll (this message is harmless)
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\Assembly-CSharp-firstpass.dll into Unity Child Domain
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\Assembly-CSharp.dll into Unity Child Domain
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\UnityEngine.UI.dll into Unity Child Domain
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\UnityEngine.Networking.dll into Unity Child Domain
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\UnityEngine.Timeline.dll into Unity Child Domain
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\UnityEngine.Analytics.dll into Unity Child Domain
Loading E:\Develop\Immersion.Binary\Immersion_Data\Managed\Newtonsoft.Json.dll into Unity Child Domain
Platform assembly: E:\Develop\Immersion.Binary\Immersion_Data\Managed\System.dll (this message is harmless)
- Completed reload, in 0.289 seconds
<RI> Initializing input.

XInput1_3.dll not found. Trying XInput9_1_0.dll instead...
<RI> Input initialized.

<RI> Initialized touch support.

UnloadTime: 0.714602 ms
Just a dummy log
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
ExampleAsyncAwait:TestSubMethod2() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:29)
<TestSubMethod>c__async1`1:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:21)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1:Start(<TestSubMethod>c__async1`1&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:471)
ExampleAsyncAwait:TestSubMethod()
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:13)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 471)

This line will be executed
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
<TestSubMethod>c__async1`1:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:22)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1:Start(<TestSubMethod>c__async1`1&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:471)
ExampleAsyncAwait:TestSubMethod()
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:13)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 471)

This line will not execute
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:14)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 316)

Dummy
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:15)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 316)

Setting up 4 worker threads for Enlighten.
Thread -> id: 4350 -> priority: 1
Thread -> id: 7aa8 -> priority: 1
Thread -> id: a71c -> priority: 1
Thread -> id: 5c58 -> priority: 1

 

Smaller logs if you wish to see;

Spoiler: Browser Log

blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 Just a dummy log

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/WebGL/runtime/DebugBindings.gen.cpp Line: 51)


blob:http://localhost:8080/d8398a8e-4e84-46f6-a460-e7776dcffabb:9301 This line will be executed

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/WebGL/runtime/DebugBindings.gen.cpp Line: 51)

Spoiler: Standalone Log

Just a dummy log
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
ExampleAsyncAwait:TestSubMethod2() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:29)
<TestSubMethod>c__async1`1:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:21)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1:Start(<TestSubMethod>c__async1`1&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:471)
ExampleAsyncAwait:TestSubMethod()
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:13)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 471)

This line will be executed
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
<TestSubMethod>c__async1`1:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:22)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1:Start(<TestSubMethod>c__async1`1&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:471)
ExampleAsyncAwait:TestSubMethod()
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:13)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 471)

This line will not execute
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:14)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 316)

Dummy
UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
<TestMethod>c__async0:MoveNext() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:15)
System.Runtime.CompilerServices.AsyncTaskMethodBuilder:Start(<TestMethod>c__async0&) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:316)
ExampleAsyncAwait:TestMethod()
ExampleAsyncAwait:Start() (at E:\Develop\Immersion\Immersion.Unity\Assets\Sources\ExampleAsyncAwait.cs:8)

(Filename: /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs Line: 316)

 

Posted a bug report using Unity. Case number is 916582.
Thanks for your time

 

Thread necro, but issue was fixed in 2018.1

https://issuetracker.unity3d.com/issues/generic-async-method-does-not-continue-on-webgl

 

Unfortunately, this bug has reappeared. Tested in Unity 2019.3.9f1 w/ WASM threading enabled. Opened as case #1243010. The reproduction code is very simple.

Code (CSharp):

1.  private void Start()
2.     {
3.         LogThreadSafe("Start");
4.      
5.         Task task1 = Task.Run(() =>
6.         {
7.             LogThreadSafe("task1.Run()");
8.         });
9.  
10.         Task task2 = Task.Run(async () =>
11.         {
12.             await Task.Delay(1);
13.             LogThreadSafe("task2.Run() - Async");
14.         });
15.  
16.         Task.WhenAll(task1, task2);
17.      
18.         LogThreadSafe("Stop");
19.     }

Gist: https://gist.github.com/stonstad/bf0de9cb7e77096c9600a652a74be3db

 

I have a separate issue opened w/ Unity regarding ConcurrentDictionary. Switching the above example from ConcurrentQueue to Queue does not change the behavior. Tasks still don't run.

 

For anyone coming to this I was able to replace all tasks in my project with UniTask and it worked on the WebGL build.
https://github.com/Cysharp/UniTask

 

Hi @JoshPeterson

I'm trying to integrate the addressable asset into the WebGL project and facing some serious issues like-
1. Not able to play audio/video using addressable.
2. not able to make an asset bundle addressable that was built on another project.
3. What's the alternate of AsynOperationHandle while working on WebGL platform.

 

@JoshPeterson Is there any sense of urgency around WebGL threading issues? Similarly, my mind is blown that ConcurrentDictionary.Count causes the WebGL player to crash.

 

Josh, I reported both but it seems like there is no activity from QA/Dev other than to confirm the behavior. It's in a holding pattern of sorts -- despite the severity of the issues.

1243010 (Regression) Async Tasks Do Not Run on WebGL w/ Threading Enabled

1243361 (Open) WebGL Blows up on ConcurrentDictionary.Count

 

Hello, I too have been working with Addressables in WebGL and am having similar issues. I was able to get AsynOperationHandle to work in a Coroutine but it is still slow and unstable. I ended up having to abandon Addressables on WebGL as it is just not stable.

 

@JoshPeterson Are there any updates you can share?

 

Awesome, thank you so much!

 

We'd be O.K. with these limitations, especially if we can detect them, work around them, and/or notify customers in our apps to turn on threads in the browser.

Any possibility of being able to test or preview WebGL threads to start seeing how they impact our games?

 

@brendanduncan_u3d It would be important to see this fix in 2019.4 LTS. Otherwise, we would have to wait six months upwards to a year to see it become available in a non-beta release.

 

Hey @brendanduncan_u3d I'm interested in knowing if you found out whether this will make it to 2019.4 LTS. We tested our project with 2020.2 and WebGL build bugs are preventing us from testing and moving forward. We're stuck on this particular issue ATM because of no release build contains the fix.

 

I'm looking forward to this fix. I see it is in 2020.1.0.b17 which looks to drop soon. For 2020.2.0a18 it might work but I hit other errors with the WebGL build process.

 

@brendanduncan_u3d It looks like it did not make it into 2020.1.0.... should it be in there?

 

Brendan, I appreciate the communication. Yep, it is definitely disappointing and it has a sizable impact on our project. I recall threading working in WebGL circa Unity 2018.x ... before the feature was disabled due to browser-based security issues. This was quite a while ago and my memory is hazy.

These things happen. What is surprising to me is that there is impact on the overall runtime. User threads that do not touch game engine components (i.e. spinning off a thread to execute a pure math algorithm) seem like the safest category of threading. Just curious -- WASM exposes a pthread implementation and what does Unity use?

 

Thank you @JoshPeterson and @brendanduncan_u3d for the forthright communication. I genuinely appreciate your communication because it helps with planning.

I am going to try https://github.com/Cysharp/UniTask as an interim solution and I'll report back here on compatibility and performance.

 

@JoshPeterson Was this behavior/bug fixed previously? If so, in either Unity 2019.4 or 2020.1, do user threads work if the WebPlayer compile target is not WASM?

 

I converted all usage of System.Threading.Tasks.Task to UniTask (https://github.com/Cysharp/UniTask). This allows me to run through all workflows in the WebGL player. However, crashes occur inconsistently, with very nebulous stack traces that make it hard to pinpoint the associated line of code. To be certain, I went through all dependent libraries and source to make sure all System.Threading.Task dependencies were eliminated. The fact that it can work, but just fails frequently, shows me I am still experiencing a threading/race-condition-like issue.

I'm turning on threading for WASM output builds so that I may use the async keyword, which is required by UniTask. One theory that I'm working with is that the internal threading you mentioned, used by Unity when this flag is enabled, is also unstable.

 

I have all threading code (system.threading, system.threading.tasks) removed. I do enable the WASM multithreading flag for async/await keyword support via UniTask. (async/await does not imply multi-threading).

The cause of instability I am seeing in WebGL WASM w/ threading enabled is directly related to usage of ConcurrentQueue, ConcurrentDictionary, and ConcurrentList. Access to these collections randomly fails in a single threaded context.

I don't know whether this is possible or whether it even makes sense. Experimentally, that is what I found and once I switched to thread unsafe collections the random WebGL player errors went away (WebGL error: Uncaught RuntimeError: memory access out of bounds).

Originally, I kept these collections around because they were used in a multithreaded context within the stand-alone player.

 

How did you do this? Is "PlayerSettings.WebGL.threadsSupport = true" the correct way to turn on threads support now? Cause unity build 2020.1.2 fails when I try with this setting

edit:
my bug was reproduced with Unity QA Team
https://forum.unity.com/threads/can...settings-webgl-threadssupport-is-true.952772/

 

I'm getting the same compile error in 2020.1.2. Thank you for your post @DrViJ I was confused by these new IL2CPP compilation errors and I hadn't connected it with the upgrade. I reverted to 2020.1.0 and it is compiling again. I sincerely hope threading in WebGL is getting the love and attention it needs at Unity.

 

@DrViJ how is your runtime stability w/ the WebGL player? I get frequent random crashes. Some were caused by use of concurrent collections -- but I have a few remaining that I can't pinpoint the cause of. One occurred inside a call stack for when material/shader properties are applied by the engine, which leads me to suspect that Unity internal threading might be bugged.

 

@stonstad, Our WebGL with synchronous execution are very stable at work. We are using Unity Pro, 2019.4.x LTS at this moment at my work now, we have 4 programs in preproduction stage, and 3 are in development now, all are WebGL, generally, everything works fine.

But unfortunatly I cannot tell you just anything about builds with custom threads usage, cause I cannot make them work at all yet. We used Tasks and Synchronization contexts in our standalone builds, but we did not try them in wasm at all, cause we thought threading "settings" are disabled in different browsers for webassembly (I think cause of Spectre security vulnerability)

I am experimenting with my pet projects at this moment, but I have no success with threading yet.

2020.1.2 Build fails, my 2020.1.0 Build shows error at startup



All I can say: async methods work fine, Unity Job System shedules jobs and works fine too, and its great! UniTasks can be used to await Unity Job System JobHandle for example.

var cutterJobHandle = cutterJob.Schedule();
await UniTask.WaitUntil(() => cutterJobHandle.IsCompleted);

These things work fine.
But I cant use UniTask.Run(), cause enabling threads breaks my builds now.
In other cases WebGL are very stable.

I hope my answer was something useful)

 

I see they are working hard, and we have 2020.1 with new loader, project Tiny, and threading from 2019.1. These are all good things for us.