annotate `upgrademngrs` with `{.async: (raises).}` (#1068)

libp2p/multistream.nim

@@ -261,20 +261,22 @@ proc addHandler*(m: MultistreamSelect,
                                match: matcher))
 
 proc start*(m: MultistreamSelect) {.async: (raises: [CancelledError]).} =
-  let
-    handlers = m.handlers
-    futs = handlers.mapIt(it.protocol.start())
+  # Nim 1.6.18: Using `mapIt` results in a seq of `.Raising([])`
+  var futs = newSeqOfCap[Future[void].Raising([CancelledError])](m.handlers.len)
+  for it in m.handlers:
+    futs.add it.protocol.start()
   try:
     await allFutures(futs)
     for fut in futs:
       await fut
   except CancelledError as exc:
     var pending: seq[Future[void].Raising([])]
+    doAssert m.handlers.len == futs.len, "Handlers modified while starting"
     for i, fut in futs:
       if not fut.finished:
         pending.add noCancel fut.cancelAndWait()
       elif fut.completed:
-        pending.add handlers[i].protocol.stop()
+        pending.add m.handlers[i].protocol.stop()
       else:
         static: doAssert typeof(fut).E is (CancelledError,)
     await noCancel allFutures(pending)

libp2p/transports/transport.nim

@@ -1,5 +1,5 @@
 # Nim-LibP2P
-# Copyright (c) 2023 Status Research & Development GmbH
+# Copyright (c) 2023-2024 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -83,11 +83,12 @@ proc dial*(
 method upgrade*(
     self: Transport,
     conn: Connection,
-  peerId: Opt[PeerId]): Future[Muxer] {.base, gcsafe.} =
+    peerId: Opt[PeerId]
+): Future[Muxer] {.base, async: (raises: [
+    CancelledError, LPError], raw: true).} =
   ## base upgrade method that the transport uses to perform
   ## transport specific upgrades
   ##
-
   self.upgrader.upgrade(conn, peerId)
 
 method handles*(
@@ -95,11 +96,10 @@ method handles*(
     address: MultiAddress): bool {.base, gcsafe.} =
   ## check if transport supports the multiaddress
   ##
-
   # by default we skip circuit addresses to avoid
   # having to repeat the check in every transport
   let protocols = address.protocols.valueOr: return false
-  return protocols
+  protocols
     .filterIt(
       it == multiCodec("p2p-circuit")
     ).len == 0

libp2p/upgrademngrs/muxedupgrade.nim

@@ -25,53 +25,61 @@ type
     muxers*: seq[MuxerProvider]
     streamHandler*: StreamHandler
 
-proc getMuxerByCodec(self: MuxedUpgrade, muxerName: string): MuxerProvider =
+func getMuxerByCodec(
+    self: MuxedUpgrade, muxerName: string): Opt[MuxerProvider] =
+  if muxerName.len == 0 or muxerName == "na":
+    return Opt.none(MuxerProvider)
   for m in self.muxers:
     if muxerName == m.codec:
-      return m
+      return Opt.some(m)
+  Opt.none(MuxerProvider)
 
-proc mux*(
+proc mux(
     self: MuxedUpgrade,
-    conn: Connection): Future[Muxer] {.async.} =
+    conn: Connection
+): Future[Opt[Muxer]] {.async: (raises: [
+    CancelledError, LPStreamError, MultiStreamError]).} =
   ## mux connection
-
   trace "Muxing connection", conn
   if self.muxers.len == 0:
     warn "no muxers registered, skipping upgrade flow", conn
-    return
+    return Opt.none(Muxer)
 
-  let muxerName =
-    if conn.dir == Out: await self.ms.select(conn, self.muxers.mapIt(it.codec))
-    else: await MultistreamSelect.handle(conn, self.muxers.mapIt(it.codec))
-
-  if muxerName.len == 0 or muxerName == "na":
-    debug "no muxer available, early exit", conn
-    return
+  let
+    muxerName =
+      case conn.dir
+      of Direction.Out:
+        await self.ms.select(conn, self.muxers.mapIt(it.codec))
+      of Direction.In:
+        await MultistreamSelect.handle(conn, self.muxers.mapIt(it.codec))
+    muxerProvider = self.getMuxerByCodec(muxerName).valueOr:
+      debug "no muxer available, early exit", conn, muxerName
+      return Opt.none(Muxer)
 
   trace "Found a muxer", conn, muxerName
 
   # create new muxer for connection
-  let muxer = self.getMuxerByCodec(muxerName).newMuxer(conn)
+  let muxer = muxerProvider.newMuxer(conn)
 
   # install stream handler
   muxer.streamHandler = self.streamHandler
   muxer.handler = muxer.handle()
-  return muxer
+  Opt.some(muxer)
 
 method upgrade*(
     self: MuxedUpgrade,
     conn: Connection,
-    peerId: Opt[PeerId]): Future[Muxer] {.async.} =
+    peerId: Opt[PeerId]
+): Future[Muxer] {.async: (raises: [CancelledError, LPError]).} =
   trace "Upgrading connection", conn, direction = conn.dir
 
   let sconn = await self.secure(conn, peerId)  # secure the connection
   if sconn == nil:
-    raise newException(UpgradeFailedError,
+    raise (ref UpgradeFailedError)(msg:
       "unable to secure connection, stopping upgrade")
 
-  let muxer = await self.mux(sconn) # mux it if possible
-  if muxer == nil:
-    raise newException(UpgradeFailedError,
+  let muxer = (await self.mux(sconn)).valueOr:  # mux it if possible
+    raise (ref UpgradeFailedError)(msg:
       "a muxer is required for outgoing connections")
 
   when defined(libp2p_agents_metrics):
@@ -79,11 +87,11 @@ method upgrade*(
 
   if sconn.closed():
     await sconn.close()
-    raise newException(UpgradeFailedError,
+    raise (ref UpgradeFailedError)(msg:
       "Connection closed or missing peer info, stopping upgrade")
 
   trace "Upgraded connection", conn, sconn, direction = conn.dir
-  return muxer
+  muxer
 
 proc new*(
     T: type MuxedUpgrade,
@@ -101,8 +109,6 @@ proc new*(
       await upgrader.ms.handle(conn) # handle incoming connection
     except CancelledError as exc:
       return
-    except CatchableError as exc:
-      trace "exception in stream handler", conn, msg = exc.msg
     finally:
       await conn.closeWithEOF()
     trace "Stream handler done", conn

libp2p/upgrademngrs/upgrade.nim

@@ -1,5 +1,5 @@
 # Nim-LibP2P
-# Copyright (c) 2023 Status Research & Development GmbH
+# Copyright (c) 2023-2024 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -24,8 +24,10 @@ import ../stream/connection,
 
 export connmanager, connection, identify, secure, multistream
 
-declarePublicCounter(libp2p_failed_upgrades_incoming, "incoming connections failed upgrades")
-declarePublicCounter(libp2p_failed_upgrades_outgoing, "outgoing connections failed upgrades")
+declarePublicCounter(libp2p_failed_upgrades_incoming,
+  "incoming connections failed upgrades")
+declarePublicCounter(libp2p_failed_upgrades_outgoing,
+  "outgoing connections failed upgrades")
 
 logScope:
   topics = "libp2p upgrade"
@@ -40,21 +42,26 @@ type
 method upgrade*(
     self: Upgrade,
     conn: Connection,
-  peerId: Opt[PeerId]): Future[Muxer] {.base.} =
-  doAssert(false, "Not implemented!")
+    peerId: Opt[PeerId]
+): Future[Muxer] {.async: (raises: [
+    CancelledError, LPError], raw: true), base.} =
+  raiseAssert("Not implemented!")
 
 proc secure*(
     self: Upgrade,
     conn: Connection,
-  peerId: Opt[PeerId]): Future[Connection] {.async.} =
+    peerId: Opt[PeerId]
+): Future[Connection] {.async: (raises: [CancelledError, LPError]).} =
   if self.secureManagers.len <= 0:
-    raise newException(UpgradeFailedError, "No secure managers registered!")
+    raise (ref UpgradeFailedError)(msg: "No secure managers registered!")
 
   let codec =
-    if conn.dir == Out: await self.ms.select(conn, self.secureManagers.mapIt(it.codec))
-    else: await MultistreamSelect.handle(conn, self.secureManagers.mapIt(it.codec))
+    if conn.dir == Out:
+      await self.ms.select(conn, self.secureManagers.mapIt(it.codec))
+    else:
+      await MultistreamSelect.handle(conn, self.secureManagers.mapIt(it.codec))
   if codec.len == 0:
-    raise newException(UpgradeFailedError, "Unable to negotiate a secure channel!")
+    raise (ref UpgradeFailedError)(msg: "Unable to negotiate a secure channel!")
 
   trace "Securing connection", conn, codec
   let secureProtocol = self.secureManagers.filterIt(it.codec == codec)
@@ -63,4 +70,4 @@ proc secure*(
   # let's avoid duplicating checks but detect if it fails to do it properly
   doAssert(secureProtocol.len > 0)
 
-  return await secureProtocol[0].secure(conn, peerId)
+  await secureProtocol[0].secure(conn, peerId)