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Fixed in 2020.1.X

Fixed in 2018.4.X, 2019.3.X



Found in






Issue ID




Semaphore.WaitForSignal under Canvas.BuildBatch causes a slow editor in Play mode

Visual Effects - Legacy


Steps to reproduce:
1. Open the attached project "Temp Project" from the ownCloud link
2. Open "Main Scene"
3. Turn on the Profiler window
4. Enter Play mode
5. Notice the Spikes from Semaphore.WaitForSignal

Expected results: Semaphore.WaitForSignal does not cause spikes in the Profiler window and making Editor slow
Actual results: Semaphore.WaitForSignal causes spikes in the Profiler window and makes Editor slow

Reproducible with: 2019.2.3f1, 2019.3.0b1, 2020.1.0a1

Note: 2019.1 breaks the project and its packages

  1. richardkettlewell

    Oct 16, 2019

    We are working on a fix for this.

Comments (40)

  1. RedVonix

    Apr 08, 2020 01:09

    Reproduced in 2019.3.7f1

  2. WheresMommy

    Mar 25, 2020 16:46

    Well, not fixed at all obviously. 2019.3.4f1

  3. unity_2L-MlLDX1uzHPg

    Mar 24, 2020 15:35

    Not fixed, 2019.3.6f1.

  4. Batuhan13

    Mar 12, 2020 09:29

    I am still having this issue in universal render pipeline in my android build it is lagging extremly

  5. shaneK001

    Mar 11, 2020 14:13

    Not fixed, 2019.3.3f1.

  6. Ilturco

    Mar 05, 2020 22:57

    I've the same problem in the 2019.2.16.f1 but I "solved" .In my case, I see this fps was down exceptionally when the camera point in the direction of "DontDestroyOnLoad". I took all my scene objects and positioned in y: -1000. Now the DontDestroyOnLoad spawn in top of my scene and the problem are vanished.

  7. BigRookGames

    Feb 12, 2020 00:56

    experiencing this on 2019.3.0f6

  8. Anil5554u

    Feb 09, 2020 21:49

    Same issue on 2019.3.0f5

  9. Cec

    Jan 16, 2020 10:06

    Still not fiixed in 2019.3.0f5

  10. Liviuss

    Jan 13, 2020 20:51

    I confirm, it's not fixed in 2019.3.0f3.

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