Many Drawable implementations have their own Invalidate and OnInvalidate functions, with an unexported onInvalidate field. However OnInvalidate and Invalidate are usually not called in the same goroutine. This results in a race on this field, e.g.: Read at 0x00c000094748 by goroutine 7: git.sr.ht/~sircmpwn/aerc2/widgets.NewDirectoryList.func1() /home/simon/src/aerc2/widgets/dirlist.go:85 +0x56 git.sr.ht/~sircmpwn/aerc2/widgets.(*Spinner).Start.func1() /home/simon/src/aerc2/widgets/spinner.go:93 +0x1bb Previous write at 0x00c000094748 by main goroutine: [failed to restore the stack] Goroutine 7 (running) created at: git.sr.ht/~sircmpwn/aerc2/widgets.(*Spinner).Start() /home/simon/src/aerc2/widgets/spinner.go:46 +0x8f git.sr.ht/~sircmpwn/aerc2/widgets.NewDirectoryList() /home/simon/src/aerc2/widgets/dirlist.go:37 +0x286 git.sr.ht/~sircmpwn/aerc2/widgets.NewAccountView() /home/simon/src/aerc2/widgets/account.go:50 +0x5ca git.sr.ht/~sircmpwn/aerc2/widgets.NewAerc() /home/simon/src/aerc2/widgets/aerc.go:60 +0x800 main.main() /home/simon/src/aerc2/aerc.go:65 +0x33e To fix this, introduce a new type, Invalidatable, which protects the field. Unfortunately the Drawable must be passed to the callback function in Invalidate, so we still need to re-implement this in each Invalidatable user.
24 lines
344 B
Go
24 lines
344 B
Go
package ui
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import (
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"sync/atomic"
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)
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type Invalidatable struct {
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onInvalidate atomic.Value
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}
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func (i *Invalidatable) OnInvalidate(f func(d Drawable)) {
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i.onInvalidate.Store(f)
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}
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func (i *Invalidatable) DoInvalidate(d Drawable) {
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v := i.onInvalidate.Load()
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if v == nil {
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return
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}
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f := v.(func(d Drawable))
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if f != nil {
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f(d)
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}
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}
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