Unity 5.3. iOS. Application hangs. WWW deadlock when loading a texture.

After update to Unity 5.3 We've got a deadlock on iOS.
WWW class works fine for simple http requests. But there is a deadlock during loading a texture with WWW class. Probably it's happens because I manually call Dispose().
Here is a call stack:

 

Confirmed. This is definitely happens because of calling Dispose in WWW.

 

Hi. This is my first bug report that I've created yesterday: 753977_lioosj0cg583a8uk

This is bug report that I've just created with steps to reproduce and test project: 754382_6haafsmbq3l2kdfk

 

Thanks Christopher. I'll install patch release and check it.

 

@christophergoy I installed version 5.3.1. Bug is fixed. Thank you.

 

i find a new bug is 5.3.1, the ios http can't work , i revert the WWWconnection.mm.it work.
is it safe to revert ??

 

I'm getting exactly the opposite behavior: WWW class worked fine on 5.3.0 and it never returns from yield when loading a texture on 5.3.1f1 or 5.3.1p1

Edit: Just wanted to thank XiaoJi! I wasn't able to downgrade to 5.3.0 anymore so reverting the wwwconnection.mm file worked as a charm

 

@XiaoJi @Elkis Did you report a bug?
When I reported a bug with example project Unity team fixed it in 24 hours.

 

Since the project that presented the bug is very big, I tried to replicate the behavior on a new project. I don't know why but I am unable to reproduce it, WWW class is working fine on new projects.

I guess it might be some other plugin causing this or the fact that I've been upgrading this project since 5.2 that is causing this issue.

Anyway, since new projects work fine and I got a workaround for this particular project, I guess all is good

 

I wrote new test application for WWW.Dispose() and report a bug.
Deadlock steel exists.
I've tested this script for iOS, android, editor.
There is a deadlock for iOS.
Script works with lags (0.5 - 1 seconds) for android.
And script crashes in editor.

Here are test script:

Code (CSharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class TestWWW : MonoBehaviour
6. {
7.  
8.     private WWW mWWW;
9.     private int mDisposeCounter;
10.     private int mDisposeThreshold;
11.     private bool mSuccess;
12.  
13.     private GUILayoutOption mMinWidth;
14.     private GUILayoutOption mMinHeight;
15.  
16.     void Awake()
17.     {
18.         mMinWidth = GUILayout.MinWidth(400);
19.         mMinHeight = GUILayout.MinHeight(150);
20.     }
21.    
22.     // Update is called once per frame
23.     void Update()
24.     {
25.         if (mWWW != null)
26.         {
27.             if (mWWW.isDone)
28.             {
29.                 mWWW.Dispose();
30.                 mWWW = null;
31.                 mSuccess = true;
32.             }
33.             else
34.             {
35.                 ++mDisposeCounter;
36.                 if (mDisposeCounter > mDisposeThreshold)
37.                 {
38.                     ++mDisposeThreshold;
39.                     Debug.Log("Dispose: " + mDisposeCounter);
40.                     mWWW.Dispose();
41.                     CreateWWW();
42.                 }
43.             }
44.         }
45.     }
46.  
47.     void OnGUI()
48.     {
49.         if (mWWW != null)
50.         {
51.             GUILayout.Label(string.Format("In progress: {0}, {1}", mDisposeCounter, mDisposeThreshold), mMinWidth, mMinHeight);
52.         }
53.         else
54.         {
55.             GUILayout.Label("Success: " + mSuccess, mMinWidth, mMinHeight);
56.             if (GUILayout.Button("Create Request", mMinWidth, mMinHeight))
57.             {
58.                 mDisposeThreshold = 0;
59.                 CreateWWW();
60.                 mWWW.Dispose();
61.                 CreateWWW();
62.             }
63.         }
64.     }
65.  
66.     private void CreateWWW()
67.     {
68.         mWWW = new WWW("http://google.com");
69.         mDisposeCounter = 0;
70.     }
71. }
72.  

 

Hi, Chis! Thanks for quick reply. The bug number is 759480.

 

This did not get into 5.3.1p3, did it?

 

@christophergoy, I replaced WWWConnection in generated XCode project. Behaviour is the same. Deadlock still exists. Maybe this is because I changed test script. Here is the final version:

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Experimental.Networking;
3. using System.Collections;
4.  
5. public class TestWWW : MonoBehaviour
6. {
7.  
8.     private UnityWebRequest mWebRequest;
9.     private WWW mWWW;
10.     private int mDisposeCounter;
11.     private int mDisposeThreshold;
12.     private bool mSuccess;
13.     private bool mUseWebRequests;
14.  
15.     private GUILayoutOption mMinWidth;
16.     private GUILayoutOption mMinHeight;
17.  
18.     void Awake()
19.     {
20.         mMinWidth = GUILayout.MinWidth(400);
21.         mMinHeight = GUILayout.MinHeight(150);
22.     }
23.    
24.     // Update is called once per frame
25.     void Update()
26.     {
27.         if (hasActiveRequest)
28.         {
29.             if (requestIsDone)
30.             {
31.                 DisposeRequest();
32.                 mSuccess = true;
33.             }
34.             else
35.             {
36.                 ++mDisposeCounter;
37.                 if (mDisposeCounter > mDisposeThreshold)
38.                 {
39.                     ++mDisposeThreshold;
40.                     Debug.Log("Dispose: " + mDisposeCounter);
41.                     DisposeRequest();
42.                     CreateRequest();
43.                 }
44.             }
45.         }
46.     }
47.  
48.     void OnGUI()
49.     {
50.         if (hasActiveRequest)
51.         {
52.             GUILayout.Label(string.Format("In progress: {0}, {1}", mDisposeCounter, mDisposeThreshold), mMinWidth, mMinHeight);
53.         }
54.         else
55.         {
56.             GUILayout.Label("Success: " + mSuccess, mMinWidth, mMinHeight);
57.             mUseWebRequests = GUILayout.Toggle(mUseWebRequests, "Use Web Request", mMinWidth, mMinHeight);
58.             if (GUILayout.Button("Create Request", mMinWidth, mMinHeight))
59.             {
60.                 mDisposeThreshold = 0;
61.                 CreateRequest();
62.                 DisposeRequest();
63.                 CreateRequest();
64.             }
65.         }
66.     }
67.  
68.     private void CreateRequest()
69.     {
70.         if (mUseWebRequests)
71.         {
72.             mWebRequest = UnityWebRequest.Get("http://google.com/");
73.             mWebRequest.Send();
74.         }
75.         else
76.         {
77.             mWWW = new WWW("http://google.com/");
78.         }
79.         mDisposeCounter = 0;
80.     }
81.  
82.     private void DisposeRequest()
83.     {
84.         if (mWebRequest != null)
85.         {
86.             mWebRequest.Abort();
87.             mWebRequest.Dispose();
88.             mWebRequest = null;
89.         }
90.         if (mWWW != null)
91.         {
92.             mWWW.Dispose();
93.             mWWW = null;
94.         }
95.     }
96.  
97.     private bool requestIsDone
98.     {
99.         get
100.         {
101.             if (mUseWebRequests)
102.             {
103.                 return mWebRequest.isDone;
104.             }
105.             else
106.             {
107.                 return mWWW.isDone;
108.             }
109.         }
110.     }
111.  
112.     private bool hasActiveRequest
113.     {
114.         get
115.         {
116.             if (mUseWebRequests)
117.             {
118.                 return mWebRequest != null;
119.             }
120.             else
121.             {
122.                 return mWWW != null;
123.             }
124.         }
125.     }
126. }
127.  

I tried to use new UnityWebRequest. It works with this test script. But when I inserted UnityWebRequest in our real project, game was always crashing in editor.

 

Hi,

I found that somehow when i want to load a facebook profile picture through WWW class, it doesn't work and always return 400 bad request. I had submit a bug report and wish to know is anyone has the same problem? It only happens in iOS Unity3d 5.3.1p1 and p3(I didn't try others).

The bug report i file is : 761206_0rjp4s67u5rciurs
together i had attached the project in the bug report. Only happens in device(iOS 9.2 in iPad 3 Wifi, i haven't tested others).

Thank you.

 

@Appxplore Did you try the same url in a browser? Post the code example with hardcoded url I'll try it.

 

@Andrey Postelzhuk
below are the code: when i build into my ipad, i never successfully see profile pic.

Code (CSharp):

1. using UnityEngine;
2. using System;
3. using System.Collections;
4. using System.Collections.Generic;
5. using System.Runtime.InteropServices;
6.  
7. public class TestFb : MonoBehaviour
8. {
9.     public SpriteRenderer m_sprite;
10.     protected Texture2D        m_texture;
11.     protected string        m_message;
12.  
13.     // Use this for initialization
14.     void Start ()
15.     {
16.         StartCoroutine(loadPic());
17.     }
18.  
19.     IEnumerator loadPic()
20.     {
21.         string _pic = "https://graph.facebook.com/v2.1/100001293360646/picture?height=80&width=80";
22.  
23.         WWW www = new WWW( _pic );
24.         Debug.Log("run URL: "  + _pic);
25.  
26.         yield return www;
27.  
28.         Debug.Log("run done!");
29.  
30.         if( !string.IsNullOrEmpty( www.error ) )
31.         {
32.             Debug.Log( "Error attempting to load profile image: " + www.error );
33.             m_message = "Error occurs!";
34.         }
35.         else
36.         {
37.             m_texture = www.texture;
38.         }
39.     }
40.  
41.     void OnGUI()
42.     {
43.         if(m_texture != null)
44.             GUILayout.Label(m_texture);
45.         else
46.             GUILayout.Label(m_message);
47.     }
48. }

 

@Appxplore Bug reproduces for me too (Unity version 5.3.1f1). Script works in editor but on device coroutine never finishes.

 

I already file the bug, I just dunno when this will be solved. This is important for me since I'm using facebook friends' profile pictures as one of my game feature and it doesn't work now!

 

Hi @christophergoy, I had try your solution and it seems that that fixed the problem wait for your patch to be release ASAP. thank you.

 

Hello,

May I ask if my current problem with WWW request is the same as the bug mentioned here ? I have problems to make it working on iOS devices.

I need to check Internet connection on the device before initializing UnityAds, because of this case : http://forum.unity3d.com/threads/ad-not-ready-and-data-connection.381577/

I launch this script at the start of the application :

Code (CSharp):

1.  public IEnumerator checkInternetConnection()
2.     {
3.         float t1 = Time.fixedTime;
4.         while(!StaticDatas.adsInitialized)
5.         {
6.             WWW www = new WWW(System.Uri.EscapeUriString("http://www.google.com/"));
7.             t1 = Time.fixedTime;
8.             yield return www;
9.             if (www.error == null)
10.             {
11.                 StaticDatas.adsInitialized = true;
12.                 if (Advertisement.isSupported) // If the platform is supported,
13.                 {
14.                     #if UNITY_ANDROID
15.                     Advertisement.Initialize(StaticDatas.androidGameID); // initialize Unity Ads.
16.                     #elif UNITY_IOS
17.                     Advertisement.Initialize(StaticDatas.iosGameID); // initialize Unity Ads.
18.                     #endif
19.                 }
20.                 #endif
21.                 break;
22.             }
23.  
24.             if(Time.fixedTime - t1<2.0f)//every two seconds min
25.                 yield return new WaitForSeconds(2.0f-(Time.fixedTime - t1));
26.         }
27.     }

No problem in Editor and Android, but on iOS devices it never reach "Advertisement.Initialize".
(stuck on yield, tested on iPad iOS 9.2, using Cloud Build with Unity 5.3.1f1 for the current build)

The WWWConnection fix is for XCode , isn't it ? I can't use that, I have to use the Cloud Build functionnality to create the binary for iOS !

Is there another way to secure an Internet connection check on iOS without a third party plugin until a fix ?

EDIT : finally the "Advertissement.IsReady" bug ( http://forum.unity3d.com/threads/ad-not-ready-and-data-connection.381577/ ) doesn't occur on iOS for me (maybe the problem is only for Android). So I don't need to use the WWW class in my iOS build. Problem resolved for me ! (that don't change the fact that I can't use WWW for now on iOS devices, and if I need it later it will be a problem ^^)

 

I am actually seeing the issue with 5.3.2p2 latest patch from Feb 3rd.

I have removed all www.Dispose and I still see the problem.

If I build with a 5.0 version it goes fine.

Is this supposed to be fixed? I am confused as some old posts say it would be done quickly.

The used code is fairly simple and gets stuck at the WWW call. I remember putting some debug before the yield and it would not call.

The code below contains Dispose but I tried with and without.

Code (CSharp):

1. private IEnumerator CheckOnlineConnection()
2.     {
3.         WWW www = new WWW("http://www.google.com");
4.         yield return www;
5.         if  (www.error != null)
6.         {
7.             www.Dispose ();
8.             yield break;
9.         }
10.         www.Dispose ();
11.     }

 

As noted above, this bug is reproducible with a simple "yield return www;" from a coroutine. Reported a week ago as bug number 767775. We've narrowed it down to being present in any version > 5.3.0f4.

 

For some reasons, the code works on iPhone 6 but hangs on iPhone5.

 

I'm still experiencing this problem with 5.3.3p1... Any ideas or is there regression??

In release notes there's a mention

• (759480) - iOS: Fix for WWWConnection deadlock.

 

We are on Unity 5.3.2p3, started seeing weird behaviour with the WWW class.

It seems like it deadlocks in the WWWConnection.mm class, inside this function:

static void WaitOnCondition(UnityWWWConnectionDelegate* delegate)
{
NSCondition *condition = delegate.condition;
[condition lock];
[condition wait];
[condition unlock];
}

If we pause the debugger in xcode and then resume, it will unlock and continue fine.

Is this the fixed deadlock bug ? if so, can we apply the fix without upgrading to the latest Unity ?

 

Thanks.

I managed to fix our deadlock issue by avoiding the call to www.Dispose() for now... it seemed to cause a deadlock that froze the game (note that this only occurred when the request times out). Not sure this is a separate bug from the one that was fixed...

 

I'm getting an odd behaviour where I am experiencing no bug on my end, while another engineer is experiencing this hanging bug on his end. Both of us are using 5.3.3f1. Is this bug consistent or does this randomness line up with this bug.

 

hey @christophergoy yeah a clean install of unity did the trick. Not sure what happened but just reinstalling fixed it D=