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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 (39)

  1. F_o

    Jan 02, 2021 13:05

    I am still experiencing this issue in 20.1.3f1

  2. Arcadian-Unity

    Oct 19, 2020 12:58

    Not fixed, 2019.4.10f1

  3. KingLlama

    Aug 19, 2020 07:00

    This is still broken for unity 2019.4.0f1.

  4. Al3xBRB

    Aug 10, 2020 08:27

    Not fixed in 2019.4.0f1.

  5. TsdTeam

    Jul 23, 2020 09:10

    Not fixed in 2019.4.4f1

  6. BrettCroomo

    May 26, 2020 10:36

    Still having this issue in 2019.3.13f using near empty scene in HDRP 7.3..
    Base line is 14.5ms then will eventuially spike to 76.6ms. Spike repeats every few seconds.
    Seems to align with "CreateCommittedResourceWithTag" under "BufferD3D12.InitializeResource" on the render thread.

  7. UDN_6c8b8a3a-8d7a-436e-9ca9-a1bf7a57bf0c

    May 10, 2020 05:00

    2020.1.0a25 also has the issue.
    In my simple project, iphone6 and android has no issue´╝îbut my iphone11 pro max has the issue.

  8. UDN_6c8b8a3a-8d7a-436e-9ca9-a1bf7a57bf0c

    May 10, 2020 04:30

    2019.3.7f1 already has the issue.

  9. PyramidGames

    Apr 28, 2020 10:37

    2019.3.7f1 still no fixed

  10. RedVonix

    Apr 08, 2020 01:09

    Reproduced in 2019.3.7f1

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