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teamnsrg / ethereum-p2p

Official Go implementation of the Ethereum protocol
https://geth.ethereum.org
GNU Lesser General Public License v3.0
17 stars 9 forks source link

lock for concurrent read/write hashmap #26

Closed SimonSK closed 6 years ago

SimonSK commented 6 years ago

Fix for concurrent map read/write Error message:

fatal error: concurrent map read and map write

goroutine 2528542 [running]:
runtime.throw(0xff1610, 0x21)
        /usr/lib/go-1.8/src/runtime/panic.go:596 +0x95 fp=0xc42576f750 sp=0xc42576f730
runtime.mapaccess1(0xe65940, 0xc42029e9c0, 0xc42454e850, 0x10)
        /usr/lib/go-1.8/src/runtime/hashmap.go:319 +0x23a fp=0xc42576f798 sp=0xc42576f750
github.com/teamnsrg/go-ethereum/p2p.(*Server).getNodeAddress(0xc420285080, 0xc42454e820, 0xc427cea8a0, 0xde1500, 0xc4254e6090)
        /home/simon/go/src/github.com/teamnsrg/go-ethereum/build/_workspace/src/github.com/teamnsrg/go-ethereum/p2p/node_info.go:223 +0x193 fp=0xc42576f888 sp=0xc42576f798
github.com/teamnsrg/go-ethereum/p2p.(*Server).storeNodeInfo(0xc420285080, 0xc42454e820, 0xc427cea8a0, 0xc4254e6090)
        /home/simon/go/src/github.com/teamnsrg/go-ethereum/build/_workspace/src/github.com/teamnsrg/go-ethereum/p2p/node_info.go:265 +0x7f fp=0xc42576fbc0 sp=0xc42576f888
github.com/teamnsrg/go-ethereum/p2p.(*Server).SetupConn(0xc420285080, 0x1861860, 0xc4205d3668, 0x4, 0x0)
        /home/simon/go/src/github.com/teamnsrg/go-ethereum/build/_workspace/src/github.com/teamnsrg/go-ethereum/p2p/server.go:841 +0xe82 fp=0xc42576ff88 sp=0xc42576fbc0
github.com/teamnsrg/go-ethereum/p2p.(*Server).listenLoop.func1(0xc420285080, 0x1861860, 0xc4205d3668, 0xc420086480)
        /home/simon/go/src/github.com/teamnsrg/go-ethereum/build/_workspace/src/github.com/teamnsrg/go-ethereum/p2p/server.go:779 +0x51 fp=0xc42576ffc0 sp=0xc42576ff88
runtime.goexit()
        /usr/lib/go-1.8/src/runtime/asm_amd64.s:2197 +0x1 fp=0xc42576ffc8 sp=0xc42576ffc0
created by github.com/teamnsrg/go-ethereum/p2p.(*Server).listenLoop
        /home/simon/go/src/github.com/teamnsrg/go-ethereum/build/_workspace/src/github.com/teamnsrg/go-ethereum/p2p/server.go:781 +0x552
SimonSK commented 6 years ago

@zzma Yes. It still fails sometimes. Using read lock around the affected line did not solve the issue. I'm going to try changing the mutex to the normal one (currently RWMutex is used). The rest of the geth code seems to use that without causing problems.

SimonSK commented 6 years ago

Changed the lock around the hashmap to Mutex. Also, added lock/unlock around the entry being read.

zzma commented 6 years ago

LGTM