Channel leaks (#413)

* break stream tracking by type

* use closeWithEOF to await wrapped stream

* fix cancelation leaks

* fix channel leaks

* logging

* use close monitor and always call closeUnderlying

* don't use closeWithEOF

* removing close monitor

* logging
This commit is contained in:
Dmitriy Ryajov 2020-10-27 11:21:03 -06:00 committed by GitHub
parent eeaa62feec
commit 1de1d49223
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10 changed files with 131 additions and 104 deletions

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@ -66,12 +66,6 @@ proc open*(s: LPChannel) {.async, gcsafe.} =
method closed*(s: LPChannel): bool =
s.closedLocal
proc closeUnderlying(s: LPChannel): Future[void] {.async.} =
## Channels may be closed for reading and writing in any order - we'll close
## the underlying bufferstream when both directions are closed
if s.closedLocal and s.isEof:
await procCall BufferStream(s).close()
proc reset*(s: LPChannel) {.async, gcsafe.} =
if s.isClosed:
trace "Already closed", s
@ -115,30 +109,44 @@ proc reset*(s: LPChannel) {.async, gcsafe.} =
trace "Channel reset", s
proc closeUnderlying*(s: LPChannel): Future[void] {.async.} =
## Channels may be closed for reading and writing in any order - we'll close
## the underlying bufferstream when both directions are closed
if s.closedLocal and s.isEof:
trace "Closing underlying", s, conn = s.conn
await procCall BufferStream(s).close()
method close*(s: LPChannel) {.async, gcsafe.} =
## Close channel for writing - a message will be sent to the other peer
## informing them that the channel is closed and that we're waiting for
## their acknowledgement.
if s.closedLocal:
trace "Already closed", s
return
s.closedLocal = true
##
trace "Closing channel", s, conn = s.conn, len = s.len
try:
if s.closedLocal:
trace "Already closed", s
return
s.closedLocal = true
if s.isOpen:
try:
await s.conn.writeMsg(s.id, s.closeCode) # write close
except CancelledError as exc:
raise exc
except CatchableError as exc:
# It's harmless that close message cannot be sent - the connection is
# likely down already
trace "Cannot send close message", s, id = s.id
trace "Closing channel", s, conn = s.conn, len = s.len
await s.closeUnderlying() # maybe already eofed
trace "Closed channel", s, len = s.len
if s.isOpen:
trace "Sending close msg", s, conn = s.conn
await s.conn.writeMsg(s.id, s.closeCode).wait(10.seconds) # write close
trace "Closed channel", s, len = s.len
except CancelledError as exc:
trace "Cancelling close", s, conn = s.conn
# need to reset here otherwise the close sequence doesn't complete and
# the channel leaks since none of it's `onClose` events trigger
await s.reset()
raise exc
except CatchableError as exc:
# need to reset here otherwise the close sequence doesn't complete and
# the channel leaks since none of it's `onClose` events trigger
trace "Cannot send close message", exc = exc.msg, s, conn = s.conn
await s.reset()
finally:
await s.closeUnderlying() # maybe already eofed
method initStream*(s: LPChannel) =
if s.objName.len == 0:

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@ -60,7 +60,7 @@ proc cleanupChann(m: Mplex, chann: LPChannel) {.async, inline.} =
try:
await chann.join()
m.channels[chann.initiator].del(chann.id)
trace "cleaned up channel", m, chann
trace "cleaned up channel", m, s = chann
when defined(libp2p_expensive_metrics):
libp2p_mplex_channels.set(
@ -68,7 +68,7 @@ proc cleanupChann(m: Mplex, chann: LPChannel) {.async, inline.} =
labelValues = [$chann.initiator, $m.connection.peerInfo.peerId])
except CatchableError as exc:
# This is top-level procedure which will work as separate task, so it
# do not need to propogate CancelledError, and no other exceptions should
# do not need to propagate CancelledError, and no other exceptions should
# happen here
warn "Error cleaning up mplex channel", m, chann, msg = exc.msg
@ -118,7 +118,7 @@ proc handleStream(m: Mplex, chann: LPChannel) {.async.} =
doAssert(chann.closed, "connection not closed by handler!")
except CatchableError as exc:
# This is top-level procedure which will work as separate task, so it
# do not need to propogate CancelledError.
# do not need to propagate CancelledError.
trace "Exception in mplex stream handler", m, chann, msg = exc.msg
await chann.reset()
@ -184,11 +184,13 @@ method handle*(m: Mplex) {.async, gcsafe.} =
except CancelledError:
# This procedure is spawned as task and it is not part of public API, so
# there no way for this procedure to be cancelled implicitly.
debug "Unexpected cancellation in mplex handler", m
debug "Cancellation in mplex handler", m
except LPStreamClosedError as exc:
trace "Stream Closed", m, msg = exc.msg
except LPStreamEOFError as exc:
trace "Stream EOF", m, msg = exc.msg
except CatchableError as exc:
warn "Unexpected exception in mplex read loop", m, msg = exc.msg
warn "Exception in mplex read loop", m, msg = exc.msg
finally:
await m.close()
trace "Stopped mplex handler", m

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@ -73,12 +73,12 @@ type
msgSeqno*: uint64
anonymize*: bool # if we omit fromPeer and seqno from RPC messages we send
method unsubscribePeer*(p: PubSub, peerId: PeerID) {.base.} =
method unsubscribePeer*(p: PubSub, peer: PeerID) {.base.} =
## handle peer disconnects
##
trace "unsubscribing pubsub peer", peerId
p.peers.del(peerId)
trace "Unsubscribing pubsub peer", peer
p.peers.del(peer)
libp2p_pubsub_peers.set(p.peers.len.int64)
@ -217,6 +217,7 @@ method subscribePeer*(p: PubSub, peer: PeerID) {.base.} =
## messages
##
trace "Subscribing peer", peer
let peer = p.getOrCreatePeer(peer, p.codecs)
peer.outbound = true # flag as outbound
@ -334,9 +335,9 @@ method validate*(p: PubSub, message: Message): Future[ValidationResult] {.async,
if res != ValidationResult.Accept:
result = res
break
case result
of ValidationResult.Accept:
of ValidationResult.Accept:
libp2p_pubsub_validation_success.inc()
of ValidationResult.Reject:
libp2p_pubsub_validation_failure.inc()
@ -385,7 +386,7 @@ proc init*[PubParams: object | bool](
switch.addPeerEventHandler(peerEventHandler, PeerEvent.Left)
pubsub.initPubSub()
return pubsub

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@ -42,7 +42,8 @@ proc init*(T: type SecureConn,
peerInfo: peerInfo,
observedAddr: observedAddr,
closeEvent: conn.closeEvent,
timeout: timeout)
timeout: timeout,
dir: conn.dir)
result.initStream()
method initStream*(s: SecureConn) =
@ -52,6 +53,7 @@ method initStream*(s: SecureConn) =
procCall Connection(s).initStream()
method close*(s: SecureConn) {.async.} =
trace "closing secure conn", s, dir = s.dir
if not(isNil(s.stream)):
await s.stream.close()
@ -74,10 +76,6 @@ proc handleConn*(s: Secure,
try:
await conn.join()
await sconn.close()
except CancelledError:
# This is top-level procedure which will work as separate task, so it
# do not need to propogate CancelledError.
discard
except CatchableError as exc:
trace "error cleaning up secure connection", err = exc.msg, sconn
@ -127,18 +125,18 @@ method readOnce*(s: SecureConn,
if not isNil(err):
if not (err of LPStreamEOFError):
warn "error while reading message from secure connection, closing.",
error=err.name,
message=err.msg,
warn "error while reading message from secure connection, closing.",
error=err.name,
message=err.msg,
connection=s
await s.close()
raise err
s.activity = true
if buf.len == 0:
raise newLPStreamIncompleteError()
s.buf.add(buf)
var p = cast[ptr UncheckedArray[byte]](pbytes)

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@ -7,29 +7,6 @@
## This file may not be copied, modified, or distributed except according to
## those terms.
## This module implements an asynchronous buffer stream
## which emulates physical async IO.
##
## The stream is based on the standard library's `Deque`,
## which is itself based on a ring buffer.
##
## It works by exposing a regular LPStream interface and
## a method ``pushTo`` to push data to the internal read
## buffer; as well as a handler that can be registered
## that gets triggered on every write to the stream. This
## allows using the buffered stream as a sort of proxy,
## which can be consumed as a regular LPStream but allows
## injecting data for reads and intercepting writes.
##
## Another notable feature is that the stream is fully
## ordered and asynchronous. Reads are queued up in order
## and are suspended when not enough data available. This
## allows preserving backpressure while maintaining full
## asynchrony. Both writing to the internal buffer with
## ``pushTo`` as well as reading with ``read*` methods,
## will suspend until either the amount of elements in the
## buffer goes below ``maxSize`` or more data becomes available.
import std/strformat
import stew/byteutils
import chronos, chronicles, metrics

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@ -32,23 +32,23 @@ method initStream*(s: ChronosStream) =
s.objName = "ChronosStream"
s.timeoutHandler = proc() {.async, gcsafe.} =
trace "idle timeout expired, closing ChronosStream"
trace "Idle timeout expired, closing ChronosStream", s
await s.close()
procCall Connection(s).initStream()
proc init*(C: type ChronosStream,
client: StreamTransport,
dir: Direction,
timeout = DefaultChronosStreamTimeout): ChronosStream =
result = C(client: client,
timeout: timeout)
timeout: timeout,
dir: dir)
result.initStream()
template withExceptions(body: untyped) =
try:
body
except CancelledError as exc:
raise exc
except TransportIncompleteError:
# for all intents and purposes this is an EOF
raise newLPStreamIncompleteError()

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@ -7,7 +7,7 @@
## This file may not be copied, modified, or distributed except according to
## those terms.
import std/[hashes, oids, strformat]
import std/[hashes, oids, strformat, sugar]
import chronicles, chronos, metrics
import lpstream,
../multiaddress,
@ -25,9 +25,6 @@ const
type
TimeoutHandler* = proc(): Future[void] {.gcsafe.}
Direction* {.pure.} = enum
None, In, Out
Connection* = ref object of LPStream
activity*: bool # reset every time data is sent or received
timeout*: Duration # channel timeout if no activity
@ -35,7 +32,6 @@ type
timeoutHandler*: TimeoutHandler # timeout handler
peerInfo*: PeerInfo
observedAddr*: Multiaddress
dir*: Direction
ConnectionTracker* = ref object of TrackerBase
opened*: uint64
@ -85,7 +81,9 @@ method initStream*(s: Connection) =
s.timerTaskFut = s.timeoutMonitor()
if isNil(s.timeoutHandler):
s.timeoutHandler = proc(): Future[void] = s.close()
s.timeoutHandler = proc(): Future[void] =
trace "Idle timeout expired, closing connection", s
s.close()
inc getConnectionTracker().opened
@ -104,7 +102,7 @@ func hash*(p: Connection): Hash =
cast[pointer](p).hash
proc timeoutMonitor(s: Connection) {.async, gcsafe.} =
## monitor the channel for innactivity
## monitor the channel for inactivity
##
## if the timeout was hit, it means that
## neither incoming nor outgoing activity
@ -125,9 +123,10 @@ proc timeoutMonitor(s: Connection) {.async, gcsafe.} =
break
# reset channel on innactivity timeout
# reset channel on inactivity timeout
trace "Connection timed out", s
if not(isNil(s.timeoutHandler)):
trace "Calling timeout handler", s
await s.timeoutHandler()
except CancelledError as exc:

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@ -15,7 +15,8 @@ import ../varint,
../peerinfo,
../multiaddress
declareGauge(libp2p_open_streams, "open stream instances", labels = ["type"])
declareGauge(libp2p_open_streams,
"open stream instances", labels = ["type", "dir"])
export oids
@ -23,12 +24,16 @@ logScope:
topics = "lpstream"
type
Direction* {.pure.} = enum
In, Out
LPStream* = ref object of RootObj
closeEvent*: AsyncEvent
isClosed*: bool
isEof*: bool
objName*: string
oid*: Oid
dir*: Direction
LPStreamError* = object of CatchableError
LPStreamIncompleteError* = object of LPStreamError
@ -86,8 +91,8 @@ method initStream*(s: LPStream) {.base.} =
s.closeEvent = newAsyncEvent()
s.oid = genOid()
libp2p_open_streams.inc(labelValues = [s.objName])
trace "Stream created", s, objName = s.objName
libp2p_open_streams.inc(labelValues = [s.objName, $s.dir])
trace "Stream created", s, objName = s.objName, dir = $s.dir
proc join*(s: LPStream): Future[void] =
s.closeEvent.wait()
@ -214,8 +219,8 @@ method closeImpl*(s: LPStream): Future[void] {.async, base.} =
## Implementation of close - called only once
trace "Closing stream", s, objName = s.objName
s.closeEvent.fire()
libp2p_open_streams.dec(labelValues = [s.objName])
trace "Closed stream", s, objName = s.objName
libp2p_open_streams.dec(labelValues = [s.objName, $s.dir])
trace "Closed stream", s, objName = s.objName, dir = $s.dir
method close*(s: LPStream): Future[void] {.base, async.} = # {.raises [Defect].}
## close the stream - this may block, but will not raise exceptions
@ -223,6 +228,7 @@ method close*(s: LPStream): Future[void] {.base, async.} = # {.raises [Defect].}
if s.isClosed:
trace "Already closed", s
return
s.isClosed = true # Set flag before performing virtual close
# An separate implementation method is used so that even when derived types

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@ -292,10 +292,10 @@ proc internalConnect(s: Switch,
let dialed = try:
await t.dial(a)
except CancelledError as exc:
trace "Dialing canceled", msg = exc.msg, peerId
trace "Dialing canceled", msg = exc.msg, peerId, address = $a
raise exc
except CatchableError as exc:
trace "Dialing failed", msg = exc.msg, peerId
trace "Dialing failed", msg = exc.msg, peerId, address = $a
libp2p_failed_dials.inc()
continue # Try the next address

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@ -62,31 +62,57 @@ proc setupTcpTransportTracker(): TcpTransportTracker =
proc connHandler*(t: TcpTransport,
client: StreamTransport,
initiator: bool): Connection =
trace "handling connection", address = $client.remoteAddress
let conn: Connection = Connection(ChronosStream.init(client))
conn.observedAddr = MultiAddress.init(client.remoteAddress).tryGet()
debug "Handling tcp connection", address = $client.remoteAddress,
initiator = initiator,
clients = t.clients.len
let conn = Connection(
ChronosStream.init(
client,
dir = if initiator:
Direction.Out
else:
Direction.In))
if not initiator:
if not isNil(t.handler):
t.handlers &= t.handler(conn)
proc cleanup() {.async.} =
try:
await client.join()
trace "cleaning up client", addrs = $client.remoteAddress, connoid = $conn.oid
if not(isNil(conn)):
await client.join() or conn.join()
trace "Cleaning up client", addrs = $client.remoteAddress,
conn = $conn.oid
t.clients.keepItIf( it != client )
if not(isNil(conn) and not conn.closed()):
await conn.close()
t.clients.keepItIf(it != client)
except CancelledError:
# This is top-level procedure which will work as separate task, so it
# do not need to propogate CancelledError.
trace "Unexpected cancellation in transport's cleanup"
if not(isNil(client) and client.closed()):
await client.closeWait()
trace "Cleaned up client", addrs = $client.remoteAddress,
conn = $conn.oid
except CatchableError as exc:
trace "error cleaning up client", exc = exc.msg
let useExc {.used.} = exc
debug "Error cleaning up client", errMsg = exc.msg, s = conn
t.clients.add(client)
# All the errors are handled inside `cleanup()` procedure.
asyncSpawn cleanup()
result = conn
try:
conn.observedAddr = MultiAddress.init(client.remoteAddress).tryGet()
except CatchableError as exc:
trace "Unable to get remote address", exc = exc.msg
if not isNil(client):
client.close()
raise exc
return conn
proc connCb(server: StreamServer,
client: StreamTransport) {.async, gcsafe.} =
@ -97,10 +123,12 @@ proc connCb(server: StreamServer,
# as it's added inside connHandler
discard t.connHandler(client, false)
except CancelledError as exc:
debug "Connection setup cancelled", exc = exc.msg
await client.closeWait()
raise exc
except CatchableError as err:
debug "Connection setup failed", err = err.msg
client.close()
except CatchableError as exc:
debug "Connection setup failed", exc = exc.msg
await client.closeWait()
proc init*(T: type TcpTransport, flags: set[ServerFlags] = {}): T =
result = T(flags: flags)
@ -169,8 +197,16 @@ method dial*(t: TcpTransport,
Future[Connection] {.async, gcsafe.} =
trace "dialing remote peer", address = $address
## dial a peer
let client: StreamTransport = await connect(address)
result = t.connHandler(client, true)
var client: StreamTransport
try:
client = await connect(address)
except CatchableError as exc:
trace "Exception dialing peer", exc = exc.msg
if not(isNil(client)):
await client.closeWait()
raise exc
return t.connHandler(client, true)
method handles*(t: TcpTransport, address: MultiAddress): bool {.gcsafe.} =
if procCall Transport(t).handles(address):