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deadsy / sdfx

A simple CAD package using signed distance functions
MIT License
518 stars 52 forks source link

Threads on package import #56

Closed Megidd closed 1 year ago

Megidd commented 1 year ago

SDFX package starts empty routines even though it is not used. It means just importing the package itself opens up some threads by the init method. Is it the intended behavior?

https://github.com/deadsy/sdfx/blob/81635b49281851b9c85332e30c8ffe6c695ddb68/render/march3.go#L52

goroutine 20 [chan receive, 3 minutes]:
github.com/deadsy/sdfx/render.init.0.func1()
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:57 +0x75
created by github.com/deadsy/sdfx/render.init.0
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:54 +0x29

goroutine 21 [chan receive, 3 minutes]:
github.com/deadsy/sdfx/render.init.0.func1()
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:57 +0x75
created by github.com/deadsy/sdfx/render.init.0
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:54 +0x29

goroutine 22 [chan receive, 3 minutes]:
github.com/deadsy/sdfx/render.init.0.func1()
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:57 +0x75
created by github.com/deadsy/sdfx/render.init.0
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:54 +0x29

goroutine 23 [chan receive, 3 minutes]:
github.com/deadsy/sdfx/render.init.0.func1()
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:57 +0x75
created by github.com/deadsy/sdfx/render.init.0
    /home/***/go/pkg/mod/github.com/deadsy/sdfx@v0.0.0-20221027125250-c456ed660b0c/render/march3.go:54 +0x29
deadsy commented 1 year ago

It's intentional in so far as it was programmed, but it's undesirable behavior. That's not the sort of thing you want in an init() routine.

Megidd commented 1 year ago

Thanks @deadsy :slightly_smiling_face:

Does it make sense to prepare a PR to implement the following?

  1. Remove init function.
  2. Create a new function named parallel.
  3. Move statements of init function into the new parallel function.
  4. Make channels local and limit them to number of cores.
    1. The number of goroutines are equal to number of CPU cores.
    2. When parallel execution is finished, the goroutines are terminated.
  5. Call parallel function whenever the actual logic is called.
deadsy commented 1 year ago

Does it make sense to prepare a PR to implement the following?

Yes. The threads should be setup when the render is called. I would say that the number of threads should probably be >= the number of CPU cores. I think the typical peak performance is reached when there are plenty of potential threads to schedule against the CPUs.

deadsy commented 1 year ago

Resolved in:

https://github.com/deadsy/sdfx/commit/40b1da67c85a6dfa6c097ce63d813b4a217d49f9