We can't lock them (or there will be a deadlock), but we need to fix this:
fatal error: concurrent map iteration and map write
goroutine 1 [running]:
runtime.throw(0xdec086, 0x26)
/usr/lib64/go/1.12/src/runtime/panic.go:617 +0x72 fp=0xc02fec2bf8 sp=0xc02fec2bc8 pc=0x42d932
runtime.mapiternext(0xc02fec2d40)
/usr/lib64/go/1.12/src/runtime/map.go:860 +0x597 fp=0xc02fec2c80 sp=0xc02fec2bf8 pc=0x40efe7
github.com/nspcc-dev/neo-go/pkg/network.(*Server).Shutdown(0xc0000fc160)
/home/rik/dev/neo-go2/pkg/network/server.go:194 +0x238 fp=0xc02fec2db0 sp=0xc02fec2c80 pc=0xa89da8
github.com/nspcc-dev/neo-go/cli/server.startServer(0xc0000fcc60, 0x0, 0x0)
/home/rik/dev/neo-go2/cli/server/server.go:399 +0x7a9 fp=0xc02fec3820 sp=0xc02fec2db0 pc=0xae2079
...
GetValidators without parameter is called upon DBFT initialization and it
should receive validators for the next block (that will create it),
parameterized GetValidators is used for NextConsensus calculation where we
need a list for the current state of the chain.
In order to avoid dependency cycle at the next commits:
imports github.com/nspcc-dev/neo-go/pkg/config
imports github.com/nspcc-dev/neo-go/pkg/wallet
imports github.com/nspcc-dev/neo-go/pkg/vm
imports github.com/nspcc-dev/neo-go/pkg/smartcontract/nef
imports github.com/nspcc-dev/neo-go/pkg/config
There is no such thing as high/low priority transactions, as there are
no free transactions anymore and they are ordered by fees contained
in transaction itself.
Closes#1063.
We make it explicit in the appropriate Block/Transaction structures, not via a
singleton as C# node does. I think this approach has a bit more potential and
allows better packages reuse for different purposes.
Turns out, Neo uses block compression and not a streaming lz4 format. And it
doesn't contain uncompressed payload size which makes guessing it somewhat
suboptimal.
They actually use the same types as for messages. Fixes
2020-05-29T00:06:17.593+0300 WARN peer disconnected {"addr": "168.62.167.190:20333", "reason": "handling CMDInv message: invalid inventory type", "peerCount": 3}
Get new blocks directly from the Blockchain. It may lead to some duplications
(as we'll also receive our own blocks), but at the same time it's more
correct, because technically we can also get blocks via other means besides
network server like RPC (submitblock call). And it simplifies network server
at the same time.
Frequently one needs to check if struct serializes/deserializes
properly. This commit implements helpers for such cases including:
1. JSON
2. io.Serializable interface
Why a deadlock can occur:
1. (*DefaultDiscovery).run() has a for loop over requestCh channel.
2. (*DefaultDiscovery).RequestRemote() send to this channel while
holding a mutex.
3. (*DefaultDiscovery).RegisterBadAddr() tries to take mutex for write.
4. Second select-case can't take mutex for read because of (3).
Close transport and disconnect peers right in the Shutdown(), so that no new
connections would be accepted and so that all the peers would be disconnected
correctly (avoiding the same deadlock as in e2116e4c3f).
Implement mempool and consensus block creation policies, almost the same as
SimplePolicy plugin for C# node provides with two caveats:
* HighPriorityTxType is not configured and hardcoded to ClaimType
* BlockedAccounts are not supported
Other than that it allows us to run successfuly as testnet CN, previously our
proposals were rejected because we were proposing blocks with oversized
transactions (that are rejected by PoolTx() now).
Mainnet and testnet configuration files are updated accordingly, but privnet
is left as is with no limits.
Configuration is currently attached to the Blockchain and so is the code that
does policying, it may be moved somewhere in the future, but it works for
now.
We can still lock the (*Server).run with dead peers:
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: goroutine 40 [select, 871 minutes]:
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).putPacketIntoQueue(0xc030ab5320, 0xc02f251f20, 0xc00af0dcc0, 0x18, 0x40, 0x100000000000000, 0xffffffffffffffff)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:82 +0xf4
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).EnqueueHPPacket(0xc030ab5320, 0xc00af0dcc0, 0x18, 0x40, 0x1367240, 0xc03090ef98)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:124 +0x52
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*Server).iteratePeersWithSendMsg(0xc0000ca000, 0xc00af35800, 0xcb2a58, 0x0)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:720 +0x12a
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*Server).broadcastHPMessage(...)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:731
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*Server).run(0xc0000ca000)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:203 +0xee4
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*Server).Start(0xc0000ca000, 0xc000072ba0)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:173 +0x2ec
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: created by github.com/CityOfZion/neo-go/cli/server.startServer
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/cli/server/server.go:331 +0x476
...
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: goroutine 2199 [chan send, 870 minutes]:
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).Disconnect.func1()
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:366 +0x85
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: sync.(*Once).Do(0xc030ab403c, 0xc02f262788)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/usr/local/go/src/sync/once.go:44 +0xb3
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).Disconnect(0xc030ab4000, 0xd92440, 0xc000065a00)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:365 +0x6d
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).SendPing.func1()
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:394 +0x42
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: created by time.goFunc
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/usr/local/go/src/time/sleep.go:169 +0x44
...
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: goroutine 3448 [chan send, 854 minutes]:
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).handleConn(0xc01ed203f0)
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:143 +0x6c
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: created by github.com/CityOfZion/neo-go/pkg/network.(*TCPTransport).Accept
Feb 13 16:14:50 neo-go-node-2 neo-go[9448]: #011/go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_transport.go:62 +0x44c
...
The problem is that the select in putPacketIntoQueue() only works the way it
was intended to after the `close(p.done)`, but that happens only after
successful unregistration request send. Thus, do disconnects the other way
around, first unblock queueing and exit goroutines, then destroy the
connection (if it wasn't previously destroyed) and only after that signal to
the Server.
We can leak sending goroutines and stall broadcasts because of already gone
peers that happened to be cached by some s.Peers() user (more than 800 of
these can be seen in nodoka log along with (*Server).run blocking on
CMDGetAddr send):
Feb 10 16:35:15 nodoka neo-go[1563]: goroutine 41 [chan send, 3320 minutes]:
Feb 10 16:35:15 nodoka neo-go[1563]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).putPacketIntoQueue(...)
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:81
Feb 10 16:35:15 nodoka neo-go[1563]: github.com/CityOfZion/neo-go/pkg/network.(*TCPPeer).EnqueueHPPacket(0xc0083d57a0, 0xc017206100, 0x18, 0x40, 0x136a240, 0xc018ef9720)
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/pkg/network/tcp_peer.go:119 +0x98
Feb 10 16:35:15 nodoka neo-go[1563]: github.com/CityOfZion/neo-go/pkg/network.(*Server).iteratePeersWithSendMsg(0xc0000ca000, 0xc0001848a0, 0xcb4550, 0x0)
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:720 +0x12a
Feb 10 16:35:15 nodoka neo-go[1563]: github.com/CityOfZion/neo-go/pkg/network.(*Server).broadcastHPMessage(...)
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:731
Feb 10 16:35:15 nodoka neo-go[1563]: github.com/CityOfZion/neo-go/pkg/network.(*Server).run(0xc0000ca000)
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:203 +0xee4
Feb 10 16:35:15 nodoka neo-go[1563]: github.com/CityOfZion/neo-go/pkg/network.(*Server).Start(0xc0000ca000, 0xc000072c60)
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/pkg/network/server.go:173 +0x2ec
Feb 10 16:35:15 nodoka neo-go[1563]: created by github.com/CityOfZion/neo-go/cli/server.startServer
Feb 10 16:35:15 nodoka neo-go[1563]: /go/src/github.com/CityOfZion/neo-go/cli/server/server.go:331 +0x476
We can only add one block of the given height and we have two competing
goroutines to do that --- consensus and block queue. Whomever adds the block
first shouldn't trigger an error in another one.
Fix block relaying for blocks added via the block queue also, previously one
consensus-generated blocks were broadcasted.
Eliminate races between tx checks and adding them to the mempool, ensure the
chain doesn't change while we're working with the new tx. Ensure only one
block addition attempt could be in progress.
It can lead to some goroutine explosion, but supposedly it's better than
stalling other processing and eventually all of these goroutines should finish
their sends. Note that this doesn't change the behavior for RPC-relayed
transactions that are still waiting for the broadcast to finish ensuring
proper transaction distribution before returning the result to the client.
