Mapbox-gl-native: Map stops updating after a second map is displayed

[millenbop]

In the latest release for iOS, it seems like the maps only work when a single instance is used. If you put one map in one UIViewController, and another map in another UIViewController, and load/display them both using a UITabBarController, the maps don't update anymore or very very seldom. Just looking at a map at a time seems to work fine, but as soon as two instances are in memory it seems like they stop working properly.

Using version 3.1.2, static library.

[millenbop]

Downgraded to 3.1.0 and seems like the bug is present there too.

[millenbop]

3.0.1 works fine, integrated using cocoapods.

[millenbop]

This bug still exists in ios-v3.2.0-pre.2

[1ec5]

Looks like #3448 didn’t completely address #3130 (a regression introduced in #2922). I think https://github.com/mapbox/mapbox-gl-native/issues/2985#issuecomment-185656388 will be a much more robust fix. Let’s track the issue there.

[1ec5]

After a second look at this issue, I’m not sure #2985 is related. I tried rigging iosapp (which uses the dynamic framework) to display two tabs, an MGLMapView in each. The maps appear to redraw at a normal rate. Is there anything unusual about your setup?

[picciano]

This has been a huge issue for us once a second map is displayed. Note that it only seems to happen when using a physical device...the iOS simulator seems unaffected.

[1ec5]

Hm, I’ve been testing on an iPhone 6 running iOS 9.3. I’ll keep looking into this.

[millenbop]

For me it works now (tried with 3.2.0-beta.2) so it appears to have been fixed somewhere sometime. @picciano have you tried one of the latest beta versions?

[vkurchatkin]

@millenbop works for us as well

[picciano]

I would have to agree. 3.2.0 beta 2 has resolved the issue.

We had been seeing CPU loads between 40 and 80% with peaks to 141%.
Now the same test show the CPU between 0 and 2% with peaks up to 5%.

Phone no longer get hot to the touch.

[1ec5]

Between 3.2.0-pre.2 and 3.2.0-beta.2, we mostly merged changes related to offline maps. I had been expecting #3448, which made it into ios-v3.1.0-pre.1, to fix the excessive CPU usage at the risk of potentially failing to update. But perhaps this was just another symptom of allowing CADisplayLink to run amok. Otherwise, maybe having multiple map views loaded is a red herring: #4368 fixed a regression related to exponential backoff when there’s clock skew from the server.

Closing for now. If you do see this issue again, please chime in. A sample project that reproduces the issue would help us narrow down the issue further.

[millenbop]

Thanks for fixing! One way or another :)