Start removing allFutures (#125)

* Start removing allFutures

* More allfutures removal

* Complete allFutures removal except legacy and tests

* Introduce table values copies to prevent error

* Switch to allFinished

* Resolve TODOs in flood/gossip

* muxer handler, log and re-raise

* Add a common and flexible way to check multiple futures

libp2p/errors.nim

@@ -0,0 +1,39 @@
+# this module will be further extended in PR
+# https://github.com/status-im/nim-libp2p/pull/107/
+
+import chronos
+import chronicles
+import macros
+
+# could not figure how to make it with a simple template
+# sadly nim needs more love for hygenic templates
+# so here goes the macro, its based on the proc/template version
+# and uses quote do so it's quite readable
+
+macro checkFutures*[T](futs: seq[Future[T]], exclude: untyped = []): untyped =
+  let nexclude = exclude.len
+  case nexclude
+  of 0:
+    quote do:
+      let pos = instantiationInfo()
+      for res in `futs`:
+        if res.failed:
+          let exc = res.readError()
+          # We still don't abort but warn
+          warn "Something went wrong in a future",
+              error=exc.name, file=pos.filename, line=pos.line
+  else:
+    quote do:
+      let pos = instantiationInfo()
+      for res in `futs`:
+        block check:
+          if res.failed:
+            let exc = res.readError()
+            for i in 0..<`nexclude`:
+              if exc of `exclude`[i]:
+                trace "Ignoring an error (no warning)",
+                    error=exc.name, file=pos.filename, line=pos.line
+                break check
+            # We still don't abort but warn
+            warn "Something went wrong in a future",
+                error=exc.name, file=pos.filename, line=pos.line

libp2p/muxers/mplex/lpchannel.nim

@@ -14,7 +14,8 @@ import types,
        ../../stream/bufferstream,
        ../../stream/lpstream,
        ../../connection,
-       ../../utility
+       ../../utility,
+       ../../errors
 
 logScope:
   topic = "MplexChannel"
@@ -93,12 +94,27 @@ proc resetMessage(s: LPChannel) {.async.} =
   await s.conn.writeMsg(s.id, s.resetCode)
 
 proc resetByRemote*(s: LPChannel) {.async.} =
-  await allFutures(s.close(), s.closedByRemote())
+  # Immediately block futher calls
   s.isReset = true
-  await s.cleanUp()
+
+  # start and await async teardown
+  let
+    futs = await allFinished(
+      s.close(),
+      s.closedByRemote(),
+      s.cleanUp()
+    )
+
+  checkFutures(futs, [LPStreamEOFError])
 
 proc reset*(s: LPChannel) {.async.} =
-  await allFutures(s.resetMessage(), s.resetByRemote())
+  let
+    futs = await allFinished(
+      s.resetMessage(),
+      s.resetByRemote()
+    )
+
+  checkFutures(futs, [LPStreamEOFError])
 
 method closed*(s: LPChannel): bool =
   trace "closing lpchannel", id = s.id, initiator = s.initiator

libp2p/muxers/mplex/mplex.nim

@@ -17,6 +17,7 @@ import ../muxer,
        ../../connection,
        ../../stream/lpstream,
        ../../utility,
+       ../../errors,
        coder,
        types,
        lpchannel
@@ -154,10 +155,16 @@ method newStream*(m: Mplex,
 
 method close*(m: Mplex) {.async, gcsafe.} =
   trace "closing mplex muxer"
+
   if not m.connection.closed():
     await m.connection.close()
 
-  await allFutures(@[allFutures(toSeq(m.remote.values).mapIt(it.reset())),
-                      allFutures(toSeq(m.local.values).mapIt(it.reset()))])
+  let
+    futs = await allFinished(
+      toSeq(m.remote.values).mapIt(it.reset()) &
+        toSeq(m.local.values).mapIt(it.reset()))
+
+  checkFutures(futs)
+
   m.remote.clear()
   m.local.clear()

libp2p/muxers/muxer.nim

@@ -9,7 +9,8 @@
 
 import chronos, chronicles
 import ../protocols/protocol,
-       ../connection
+       ../connection,
+       ../errors
 
 logScope:
   topic = "Muxer"
@@ -45,15 +46,22 @@ proc newMuxerProvider*(creator: MuxerConstructor, codec: string): MuxerProvider
 
 method init(c: MuxerProvider) =
   proc handler(conn: Connection, proto: string) {.async, gcsafe, closure.} =
-    let muxer = c.newMuxer(conn)
-    var handlerFut = if not isNil(c.muxerHandler):
-      c.muxerHandler(muxer)
-    else:
-      var dummyFut = newFuture[void]()
-      dummyFut.complete(); dummyFut
+    let
+      muxer = c.newMuxer(conn)
 
     if not isNil(c.streamHandler):
       muxer.streamHandler = c.streamHandler
 
-    await allFutures(muxer.handle(), handlerFut)
+    var futs = newSeq[Future[void]]()
+
+    futs &= muxer.handle()
+
+    # finally await both the futures
+    if not isNil(c.muxerHandler):
+      futs &= c.muxerHandler(muxer)
+
+    # log and re-raise on errors
+    futs = await allFinished(futs)
+    checkFutures(futs)
+
   c.handler = handler

libp2p/protocols/pubsub/floodsub.nim

@@ -17,7 +17,8 @@ import pubsub,
        ../../connection,
        ../../peerinfo,
        ../../peer,
-       ../../utility
+       ../../utility,
+       ../../errors
 
 logScope:
   topic = "FloodSub"
@@ -85,10 +86,13 @@ method rpcHandler*(f: FloodSub,
 
         # forward the message to all peers interested in it
         var sent: seq[Future[void]]
+        # start the future but do not wait yet
         for p in toSendPeers:
           if p in f.peers and f.peers[p].id != peer.id:
             sent.add(f.peers[p].send(@[RPCMsg(messages: m.messages)]))
-        await allFutures(sent)
+        # wait for all the futures now
+        sent = await allFinished(sent)
+        checkFutures(sent)
 
 method init(f: FloodSub) =
   proc handler(conn: Connection, proto: string) {.async.} =
@@ -118,10 +122,13 @@ method publish*(f: FloodSub,
   trace "publishing on topic", name = topic
   let msg = newMessage(f.peerInfo, data, topic)
   var sent: seq[Future[void]]
+  # start the future but do not wait yet
   for p in f.floodsub[topic]:
     trace "publishing message", name = topic, peer = p, data = data.shortLog
     sent.add(f.peers[p].send(@[RPCMsg(messages: @[msg])]))
-  await allFutures(sent)
+  # wait for all the futures now
+  sent = await allFinished(sent)
+  checkFutures(sent)
 
 method unsubscribe*(f: FloodSub,
                     topics: seq[TopicPair]) {.async.} =

libp2p/protocols/pubsub/gossipsub.nim

@@ -19,7 +19,8 @@ import pubsub,
        ../protocol,
        ../../peerinfo,
        ../../connection,
-       ../../peer
+       ../../peer,
+       ../../errors
 
 logScope:
   topic = "GossipSub"
@@ -220,7 +221,8 @@ method rpcHandler(g: GossipSub,
             if msgs.len > 0:
               trace "forwarding message to", peerId = id
               sent.add(g.peers[p].send(@[RPCMsg(messages: msgs)]))
-            await allFutures(sent)
+            sent = await allFinished(sent)
+            checkFutures(sent)
 
     var respControl: ControlMessage
     if m.control.isSome:
@@ -408,7 +410,8 @@ method publish*(g: GossipSub,
       trace "publishing on topic", name = topic
       g.mcache.put(msg)
       sent.add(g.peers[p].send(@[RPCMsg(messages: @[msg])]))
-    await allFutures(sent)
+    sent = await allFinished(sent)
+    checkFutures(sent)
 
 method start*(g: GossipSub) {.async.} =
   ## start pubsub

libp2p/protocols/pubsub/pubsub.nim

@@ -238,9 +238,8 @@ method validate*(p: PubSub, message: Message): Future[bool] {.async, base.} =
       # TODO: add timeout to validator
       pending.add(p.validators[topic].mapIt(it(topic, message)))
 
-  await allFutures(pending)
-  if pending.allIt(it.read()): # only if all passed
-    result = true
+  let futs = await allFinished(pending)
+  result = futs.allIt(not it.failed and it.read())
 
 proc newPubSub*(p: typedesc[PubSub],
                 peerInfo: PeerInfo,

libp2p/switch.nim

@@ -19,6 +19,7 @@ import connection,
        protocols/identify,
        protocols/pubsub/pubsub,
        muxers/muxer,
+       errors,
        peer
 
 logScope:
@@ -309,11 +310,19 @@ proc start*(s: Switch): Future[seq[Future[void]]] {.async, gcsafe.} =
 proc stop*(s: Switch) {.async.} =
   trace "stopping switch"
 
-  if s.pubSub.isSome:
-    await s.pubSub.get().stop()
+  # we want to report erros but we do not want to fail
+  # or crash here, cos we need to clean possibly MANY items
+  # and any following conn/transport won't be cleaned up
+  var futs = newSeq[Future[void]]()
 
-  await allFutures(toSeq(s.connections.values).mapIt(s.cleanupConn(it)))
-  await allFutures(s.transports.mapIt(it.close()))
+  if s.pubSub.isSome:
+    futs &= s.pubSub.get().stop()
+
+  futs &= toSeq(s.connections.values).mapIt(s.cleanupConn(it))
+  futs &= s.transports.mapIt(it.close())
+
+  futs = await allFinished(futs)
+  checkFutures(futs)
 
 proc subscribeToPeer(s: Switch, peerInfo: PeerInfo) {.async, gcsafe.} =
   ## Subscribe to pub sub peer

libp2p/transports/tcptransport.nim

@@ -61,7 +61,8 @@ method close*(t: TcpTransport): Future[void] {.async, gcsafe.} =
     t.server.stop()
     t.server.close()
     await t.server.join()
-    trace "transport stopped"
+
+  trace "transport stopped"
 
 method listen*(t: TcpTransport,
                ma: MultiAddress,

libp2p/transports/transport.nim

@@ -11,7 +11,8 @@ import sequtils
 import chronos, chronicles
 import ../connection,
        ../multiaddress,
-       ../multicodec
+       ../multicodec,
+       ../errors
 
 type
   ConnHandler* = proc (conn: Connection): Future[void] {.gcsafe.}
@@ -33,7 +34,8 @@ proc newTransport*(t: typedesc[Transport]): t {.gcsafe.} =
 method close*(t: Transport) {.base, async, gcsafe.} =
   ## stop and cleanup the transport
   ## including all outstanding connections
-  await allFutures(t.connections.mapIt(it.close()))
+  let futs = await allFinished(t.connections.mapIt(it.close()))
+  checkFutures(futs)
 
 method listen*(t: Transport,
                ma: MultiAddress,