fix: discovery AyncFilter deadlock on shutdown#32572
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cskiraly merged 1 commit intoethereum:masterfrom Oct 2, 2025
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fix: discovery AyncFilter deadlock on shutdown#32572cskiraly merged 1 commit intoethereum:masterfrom
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The rootcause of the hang is caused by the extra 1 slot, which was designed to make sure the routines in AsyncFilter(...) can be finished. This PR fixes it by making sure the extra 1 shot can always be resumed when node shutdown.
I don't see how the extra slot could cause the hang here. I think it should be either the check or the internal iterator. Still, the change is good and it seems to solve the issue.
Sahil-4555
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Oct 12, 2025
…2572) Description: We found a occasionally node hang issue on BSC, I think Geth may also have the issue, so pick the fix patch here. The fix on BSC repo: bnb-chain/bsc#3347 When the hang occurs, there are two routines stuck. - routine 1: AsyncFilter(...) On node start, it will run part of the DiscoveryV4 protocol, which could take considerable time, here is its hang callstack: ``` goroutine 9711 [chan receive]: // this routine was stuck on read channel: `<-f.slots` github.com/ethereum/go-ethereum/p2p/enode.AsyncFilter.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:206 +0x125 created by github.com/ethereum/go-ethereum/p2p/enode.AsyncFilter in goroutine 1 github.com/ethereum/go-ethereum/p2p/enode/iter.go:192 +0x205 ``` - Routine 2: Node Stop It is the main routine to shutdown the process, but it got stuck when it tries to shutdown the discovery components, as it tries to drain the channel of `<-f.slots`, but the extra 1 slot will never have chance to be resumed. ``` goroutine 11796 [chan receive]: github.com/ethereum/go-ethereum/p2p/enode.(*asyncFilterIter).Close.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:248 +0x5c sync.(*Once).doSlow(0xc032a97cb8?, 0xc032a97d18?) sync/once.go:78 +0xab sync.(*Once).Do(...) sync/once.go:69 github.com/ethereum/go-ethereum/p2p/enode.(*asyncFilterIter).Close(0xc092ff8d00?) github.com/ethereum/go-ethereum/p2p/enode/iter.go:244 +0x36 github.com/ethereum/go-ethereum/p2p/enode.(*bufferIter).Close.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:299 +0x24 sync.(*Once).doSlow(0x11a175f?, 0x2bfe63e?) sync/once.go:78 +0xab sync.(*Once).Do(...) sync/once.go:69 github.com/ethereum/go-ethereum/p2p/enode.(*bufferIter).Close(0x30?) github.com/ethereum/go-ethereum/p2p/enode/iter.go:298 +0x36 github.com/ethereum/go-ethereum/p2p/enode.(*FairMix).Close(0xc0004bfea0) github.com/ethereum/go-ethereum/p2p/enode/iter.go:379 +0xb7 github.com/ethereum/go-ethereum/eth.(*Ethereum).Stop(0xc000997b00) github.com/ethereum/go-ethereum/eth/backend.go:960 +0x4a github.com/ethereum/go-ethereum/node.(*Node).stopServices(0xc0001362a0, {0xc012e16330, 0x1, 0xc000111410?}) github.com/ethereum/go-ethereum/node/node.go:333 +0xb3 github.com/ethereum/go-ethereum/node.(*Node).Close(0xc0001362a0) github.com/ethereum/go-ethereum/node/node.go:263 +0x167 created by github.com/ethereum/go-ethereum/cmd/utils.StartNode.func1.1 in goroutine 9729 github.com/ethereum/go-ethereum/cmd/utils/cmd.go:101 +0x78 ``` The rootcause of the hang is caused by the extra 1 slot, which was designed to make sure the routines in `AsyncFilter(...)` can be finished. This PR fixes it by making sure the extra 1 shot can always be resumed when node shutdown.
atkinsonholly
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Nov 24, 2025
…2572) Description: We found a occasionally node hang issue on BSC, I think Geth may also have the issue, so pick the fix patch here. The fix on BSC repo: bnb-chain/bsc#3347 When the hang occurs, there are two routines stuck. - routine 1: AsyncFilter(...) On node start, it will run part of the DiscoveryV4 protocol, which could take considerable time, here is its hang callstack: ``` goroutine 9711 [chan receive]: // this routine was stuck on read channel: `<-f.slots` github.com/ethereum/go-ethereum/p2p/enode.AsyncFilter.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:206 +0x125 created by github.com/ethereum/go-ethereum/p2p/enode.AsyncFilter in goroutine 1 github.com/ethereum/go-ethereum/p2p/enode/iter.go:192 +0x205 ``` - Routine 2: Node Stop It is the main routine to shutdown the process, but it got stuck when it tries to shutdown the discovery components, as it tries to drain the channel of `<-f.slots`, but the extra 1 slot will never have chance to be resumed. ``` goroutine 11796 [chan receive]: github.com/ethereum/go-ethereum/p2p/enode.(*asyncFilterIter).Close.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:248 +0x5c sync.(*Once).doSlow(0xc032a97cb8?, 0xc032a97d18?) sync/once.go:78 +0xab sync.(*Once).Do(...) sync/once.go:69 github.com/ethereum/go-ethereum/p2p/enode.(*asyncFilterIter).Close(0xc092ff8d00?) github.com/ethereum/go-ethereum/p2p/enode/iter.go:244 +0x36 github.com/ethereum/go-ethereum/p2p/enode.(*bufferIter).Close.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:299 +0x24 sync.(*Once).doSlow(0x11a175f?, 0x2bfe63e?) sync/once.go:78 +0xab sync.(*Once).Do(...) sync/once.go:69 github.com/ethereum/go-ethereum/p2p/enode.(*bufferIter).Close(0x30?) github.com/ethereum/go-ethereum/p2p/enode/iter.go:298 +0x36 github.com/ethereum/go-ethereum/p2p/enode.(*FairMix).Close(0xc0004bfea0) github.com/ethereum/go-ethereum/p2p/enode/iter.go:379 +0xb7 github.com/ethereum/go-ethereum/eth.(*Ethereum).Stop(0xc000997b00) github.com/ethereum/go-ethereum/eth/backend.go:960 +0x4a github.com/ethereum/go-ethereum/node.(*Node).stopServices(0xc0001362a0, {0xc012e16330, 0x1, 0xc000111410?}) github.com/ethereum/go-ethereum/node/node.go:333 +0xb3 github.com/ethereum/go-ethereum/node.(*Node).Close(0xc0001362a0) github.com/ethereum/go-ethereum/node/node.go:263 +0x167 created by github.com/ethereum/go-ethereum/cmd/utils.StartNode.func1.1 in goroutine 9729 github.com/ethereum/go-ethereum/cmd/utils/cmd.go:101 +0x78 ``` The rootcause of the hang is caused by the extra 1 slot, which was designed to make sure the routines in `AsyncFilter(...)` can be finished. This PR fixes it by making sure the extra 1 shot can always be resumed when node shutdown.
prestoalvarez
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Nov 27, 2025
…2572) Description: We found a occasionally node hang issue on BSC, I think Geth may also have the issue, so pick the fix patch here. The fix on BSC repo: bnb-chain/bsc#3347 When the hang occurs, there are two routines stuck. - routine 1: AsyncFilter(...) On node start, it will run part of the DiscoveryV4 protocol, which could take considerable time, here is its hang callstack: ``` goroutine 9711 [chan receive]: // this routine was stuck on read channel: `<-f.slots` github.com/ethereum/go-ethereum/p2p/enode.AsyncFilter.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:206 +0x125 created by github.com/ethereum/go-ethereum/p2p/enode.AsyncFilter in goroutine 1 github.com/ethereum/go-ethereum/p2p/enode/iter.go:192 +0x205 ``` - Routine 2: Node Stop It is the main routine to shutdown the process, but it got stuck when it tries to shutdown the discovery components, as it tries to drain the channel of `<-f.slots`, but the extra 1 slot will never have chance to be resumed. ``` goroutine 11796 [chan receive]: github.com/ethereum/go-ethereum/p2p/enode.(*asyncFilterIter).Close.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:248 +0x5c sync.(*Once).doSlow(0xc032a97cb8?, 0xc032a97d18?) sync/once.go:78 +0xab sync.(*Once).Do(...) sync/once.go:69 github.com/ethereum/go-ethereum/p2p/enode.(*asyncFilterIter).Close(0xc092ff8d00?) github.com/ethereum/go-ethereum/p2p/enode/iter.go:244 +0x36 github.com/ethereum/go-ethereum/p2p/enode.(*bufferIter).Close.func1() github.com/ethereum/go-ethereum/p2p/enode/iter.go:299 +0x24 sync.(*Once).doSlow(0x11a175f?, 0x2bfe63e?) sync/once.go:78 +0xab sync.(*Once).Do(...) sync/once.go:69 github.com/ethereum/go-ethereum/p2p/enode.(*bufferIter).Close(0x30?) github.com/ethereum/go-ethereum/p2p/enode/iter.go:298 +0x36 github.com/ethereum/go-ethereum/p2p/enode.(*FairMix).Close(0xc0004bfea0) github.com/ethereum/go-ethereum/p2p/enode/iter.go:379 +0xb7 github.com/ethereum/go-ethereum/eth.(*Ethereum).Stop(0xc000997b00) github.com/ethereum/go-ethereum/eth/backend.go:960 +0x4a github.com/ethereum/go-ethereum/node.(*Node).stopServices(0xc0001362a0, {0xc012e16330, 0x1, 0xc000111410?}) github.com/ethereum/go-ethereum/node/node.go:333 +0xb3 github.com/ethereum/go-ethereum/node.(*Node).Close(0xc0001362a0) github.com/ethereum/go-ethereum/node/node.go:263 +0x167 created by github.com/ethereum/go-ethereum/cmd/utils.StartNode.func1.1 in goroutine 9729 github.com/ethereum/go-ethereum/cmd/utils/cmd.go:101 +0x78 ``` The rootcause of the hang is caused by the extra 1 slot, which was designed to make sure the routines in `AsyncFilter(...)` can be finished. This PR fixes it by making sure the extra 1 shot can always be resumed when node shutdown.
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Description
Hi, we found a occasionally node hang issue on BSC, I think Geth may also have the issue, so pick the fix patch here.
The fix on BSC repo: bnb-chain/bsc#3347
When the hang occurs, there are two routines stuck.
On node start, it will run part of the DiscoveryV4 protocol, which could take considerable time, here is its hang callstack:
It is the main routine to shutdown the process, but it got stuck when it tries to shutdown the discovery components, as it tries to drain the channel of
<-f.slots, but the extra 1 slot will never have chance to be resumed.The rootcause of the hang is caused by the extra 1 slot, which was designed to make sure the routines in
AsyncFilter(...)can be finished. This PR fixes it by making sure the extra 1 shot can always be resumed when node shutdown.