move EOF flag after local close and comments

libp2p/muxers/mplex/lpchannel.nim

@@ -31,6 +31,19 @@ logScope:
 ## | Write    | No                | Yes
 ##
 
+# TODO: this is one place where we need to use
+# a proper state machine, but I've opted out of
+# it for now for two reasons:
+#
+# 1) we don't have that many states to manage
+# 2) I'm not sure if adding the state machine
+# would have simplified or complicated the code
+#
+# But now that this is in place, we should perhaps
+# reconsider reworking it again, this time with a
+# more formal approach.
+#
+
 type
   LPChannel* = ref object of BufferStream
     id*: uint64                   # channel id
@@ -38,7 +51,7 @@ type
     conn*: Connection             # wrapped connection used to for writing
     initiator*: bool              # initiated remotely or locally flag
     isLazy*: bool                 # is channel lazy
-    isOpen*: bool                 # has channel been oppened (only used with isLazy)
+    isOpen*: bool                 # has channel been opened (only used with isLazy)
     closedLocal*: bool            # has channel been closed locally
     msgCode*: MessageType         # cached in/out message code
     closeCode*: MessageType       # cached in/out close code
@@ -99,7 +112,7 @@ proc newChannel*(id: uint64,
                             chan.msgCode,
                             data).wait(2.minutes) # write header
       except AsyncTimeoutError:
-        trace "timeout writting channel, resetting"
+        trace "timeout writing channel, resetting"
         asyncCheck chan.reset()
     except CatchableError as exc:
       trace "unable to write in bufferstream handler", exc = exc.msg
@@ -139,7 +152,7 @@ proc open*(s: LPChannel) {.async, gcsafe.} =
   ## which is locked
   withEOFExceptions:
     await s.conn.writeMsg(s.id, MessageType.New, s.name)
-    trace "oppened channel", oid = s.oid,
+    trace "opened channel", oid = s.oid,
                              name = s.name,
                              initiator = s.initiator
     s.isOpen = true
@@ -155,9 +168,9 @@ proc closeRemote*(s: LPChannel) {.async.} =
     await s.dataReadEvent.wait()
     s.dataReadEvent.clear()
 
-  await s.close() # close local end
   s.isEof = true # set EOF immediately to prevent further reads
-  # call to avoid leacks
+  await s.close() # close local end
+  # call to avoid leaks
   await procCall BufferStream(s).close() # close parent bufferstream
 
   trace "channel closed on EOF", id = s.id,
@@ -168,7 +181,7 @@ proc closeRemote*(s: LPChannel) {.async.} =
 method closed*(s: LPChannel): bool =
   ## this emulates half-closed behavior
   ## when closed locally writing is
-  ## dissabled - see the table in the
+  ## disabled - see the table in the
   ## header of the file
   s.closedLocal
 
@@ -177,9 +190,6 @@ method reset*(s: LPChannel) {.base, async, gcsafe.} =
   # might be dead already - reset is always
   # optimistic
   asyncCheck s.resetMessage()
-  # # because of the async check above,
-  # # give the message time to depart
-  # await sleepAsync(100.millis)
   await procCall BufferStream(s).close()
   s.isEof = true
   s.closedLocal = true
@@ -198,16 +208,12 @@ method close*(s: LPChannel) {.async, gcsafe.} =
                                        initiator = s.initiator,
                                        name = s.name,
                                        oid = s.oid
-      # TODO: we should install a timer that on expire
-      # will make sure the channel did close by the remote
-      # so the hald-closed flow completed, if it didn't
-      # we should send a `reset` and move on.
       await s.closeMessage().wait(2.minutes)
       s.closedLocal = true
-      if s.atEof: # already closed by remote close parent buffer imediately
+      if s.atEof: # already closed by remote close parent buffer immediately
         await procCall BufferStream(s).close()
     except AsyncTimeoutError:
-      trace "close timeoud, reset channel"
+      trace "close timed out, reset channel"
       asyncCheck s.reset() # reset on timeout
     except CatchableError as exc:
       trace "exception closing channel"