waitgroup sync fix #37
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tklauser
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May 20, 2022
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Signed-off-by: Alexandre Perrin <alex@kaworu.ch>
Bring workerpool in line with how license / copyright is handled in Cilium, see cilium/cilium#18813 for more context. Signed-off-by: Alexandre Perrin <alex@kaworu.ch>
Drain() doesn't submit any task. Signed-off-by: Alexandre Perrin <alex@kaworu.ch>
tklauser
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rolinh
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May 20, 2022
rolinh
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Before this patch, Submit() would increment the WaitGroup without holding the WorkerPool lock. This could potentially lead to a panic when Submit() and Close() were executed concurrently: 1. The Submit() goroutine g0 acquire the lock, successfully check that the WorkerPool is neither closed nor draining, and release the lock. 2. The Close() goroutine g1 acquire the lock, update the WorkerPool state to closed, wait on the WaitGroup, and close the tasks channel (wrongly) assuming that all tasks have been submitted. 3. g0 increment the WaitGroup, and attempt to write to the (now closed) tasks channel leading to a panic. The same reasoning can be applied with Submit() and Drain() leading to a data race on the results slice. Signed-off-by: Alexandre Perrin <alex@kaworu.ch>
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See commits, the most important one is the last one workerpool: WaitGroup synchronization fix.