Fix PeerPool issue with peers overflow maxPeers setting. (#1285)

beacon_chain/peer_pool.nim

@@ -8,6 +8,9 @@ type
   PeerFlags = enum
     Acquired, DeleteOnRelease
 
+  EventType = enum
+    NotEmptyEvent, NotFullEvent
+
   PeerItem[T] = object
     data: T
     peerType: PeerType
@@ -62,21 +65,35 @@ iterator pairs*[A, B](pool: PeerPool[A, B]): (B, A) =
   for peerId, peerIdx in pool.registry:
     yield (peerId, pool.storage[peerIdx.data].data)
 
-proc waitNotEmptyEvent[A, B](pool: PeerPool[A, B],
+template incomingEvent(eventType: EventType): AsyncEvent =
+  case eventType
+  of EventType.NotEmptyEvent:
+    pool.incNotEmptyEvent
+  of EventType.NotFullEvent:
+    pool.incNotFullEvent
+
+template outgoingEvent(eventType: EventType): AsyncEvent =
+  case eventType
+  of EventType.NotEmptyEvent:
+    pool.outNotEmptyEvent
+  of EventType.NotFullEvent:
+    pool.outNotFullEvent
+
+proc waitForEvent[A, B](pool: PeerPool[A, B], eventType: EventType,
                         filter: set[PeerType]) {.async.} =
   if filter == {PeerType.Incoming, PeerType.Outgoing} or filter == {}:
-    var fut1 = pool.incNotEmptyEvent.wait()
+    var fut1 = incomingEvent(eventType).wait()
-    var fut2 = pool.outNotEmptyEvent.wait()
+    var fut2 = outgoingEvent(eventType).wait()
     try:
       discard await one(fut1, fut2)
       if fut1.finished:
         if not(fut2.finished):
           fut2.cancel()
-        pool.incNotEmptyEvent.clear()
+        incomingEvent(eventType).clear()
       else:
         if not(fut1.finished):
           fut1.cancel()
-        pool.outNotEmptyEvent.clear()
+        outgoingEvent(eventType).clear()
     except CancelledError:
       if not(fut1.finished):
         fut1.cancel()
@@ -84,20 +101,19 @@ proc waitNotEmptyEvent[A, B](pool: PeerPool[A, B],
         fut2.cancel()
       raise
   elif PeerType.Incoming in filter:
-    await pool.incNotEmptyEvent.wait()
+    await incomingEvent(eventType).wait()
-    pool.incNotEmptyEvent.clear()
+    incomingEvent(eventType).clear()
   elif PeerType.Outgoing in filter:
-    await pool.outNotEmptyEvent.wait()
+    await outgoingEvent(eventType).wait()
-    pool.outNotEmptyEvent.clear()
+    outgoingEvent(eventType).clear()
+
+proc waitNotEmptyEvent[A, B](pool: PeerPool[A, B],
+                             filter: set[PeerType]): Future[void] =
+  pool.waitForEvent(EventType.NotEmptyEvent, filter)
 
 proc waitNotFullEvent[A, B](pool: PeerPool[A, B],
-                            peerType: PeerType) {.async.} =
+                            filter: set[PeerType]): Future[void] =
-  if peerType == PeerType.Incoming:
+  pool.waitForEvent(EventType.NotFullEvent, filter)
-    await pool.incNotFullEvent.wait()
-    pool.incNotFullEvent.clear()
-  elif peerType == PeerType.Outgoing:
-    await pool.outNotFullEvent.wait()
-    pool.outNotFullEvent.clear()
 
 template getItem[A, B](pool: PeerPool[A, B],
                        filter: set[PeerType]): ptr PeerItem[A] =
@@ -336,20 +352,19 @@ proc addPeer*[A, B](pool: PeerPool[A, B],
   let peerKey = getKey(peer)
 
   if not(pool.registry.hasKey(peerKey)) and not(peer.getFuture().finished):
-    if len(pool.registry) >= pool.maxPeersCount:
+    while len(pool.registry) >= pool.maxPeersCount:
-      await pool.waitNotFullEvent(peerType)
+      await pool.waitNotFullEvent({PeerType.Incoming, PeerType.Outgoing})
     if peerType == PeerType.Incoming:
-      if pool.curIncPeersCount >= pool.maxIncPeersCount:
+      while pool.curIncPeersCount >= pool.maxIncPeersCount:
-        await pool.waitNotFullEvent(peerType)
+        await pool.waitNotFullEvent({peerType})
       let pindex = pool.addPeerImpl(peer, peerKey, peerType)
       inc(pool.curIncPeersCount)
       pool.incQueue.push(pindex)
       pool.incNotEmptyEvent.fire()
       res = true
     elif peerType == PeerType.Outgoing:
-      if pool.curOutPeersCount >= pool.maxOutPeersCount:
+      while pool.curOutPeersCount >= pool.maxOutPeersCount:
-        await pool.waitNotFullEvent(peerType)
+        await pool.waitNotFullEvent({peerType})
-
       let pindex = pool.addPeerImpl(peer, peerKey, peerType)
       inc(pool.curOutPeersCount)
       pool.outQueue.push(pindex)

tests/test_peer_pool.nim

@@ -80,7 +80,7 @@ suiteReport "PeerPool testing suite":
       doAssert(fut1.finished == false)
       doAssert(fut2.finished == false)
       peer0.close()
-      await sleepAsync(100.milliseconds)
+      await sleepAsync(10.milliseconds)
       doAssert(fut1.finished == false)
       doAssert(fut2.finished == true and fut2.failed == false)
       result = true
@@ -102,11 +102,11 @@ suiteReport "PeerPool testing suite":
       doAssert(fut2.finished == false)
       doAssert(fut3.finished == false)
       peer0.close()
-      await sleepAsync(100.milliseconds)
+      await sleepAsync(10.milliseconds)
       doAssert(fut2.finished == true and fut2.failed == false)
       doAssert(fut3.finished == false)
       peer1.close()
-      await sleepAsync(100.milliseconds)
+      await sleepAsync(10.milliseconds)
       doAssert(fut3.finished == true and fut3.failed == false)
       result = true
 
@@ -128,18 +128,61 @@ suiteReport "PeerPool testing suite":
       doAssert(fut2.finished == true and fut2.failed == false)
       doAssert(fut3.finished == false)
       peer0.close()
-      await sleepAsync(100.milliseconds)
+      await sleepAsync(10.milliseconds)
       doAssert(fut1.finished == true and fut1.failed == false)
       doAssert(fut3.finished == false)
       peer2.close()
-      await sleepAsync(100.milliseconds)
+      await sleepAsync(10.milliseconds)
       doAssert(fut3.finished == true and fut3.failed == false)
       result = true
 
+    proc testAddPeer4(): Future[bool] {.async.} =
+      var pool = newPeerPool[PeerTest, PeerTestID](maxPeers = 3)
+
+      var peer0 = PeerTest.init("idInc0")
+      var peer1 = PeerTest.init("idInc1")
+      var peer2 = PeerTest.init("idOut0")
+      var peer3 = PeerTest.init("idOut1")
+      var peer4 = PeerTest.init("idOut2")
+      var peer5 = PeerTest.init("idInc2")
+
+      var fut0 = pool.addIncomingPeer(peer0)
+      var fut1 = pool.addIncomingPeer(peer1)
+      var fut2 = pool.addOutgoingPeer(peer2)
+      var fut3 = pool.addOutgoingPeer(peer3)
+      var fut4 = pool.addOutgoingPeer(peer4)
+      var fut5 = pool.addIncomingPeer(peer5)
+
+      doAssert(fut0.finished == true and fut0.failed == false)
+      doAssert(fut1.finished == true and fut1.failed == false)
+      doAssert(fut2.finished == true and fut2.failed == false)
+      doAssert(fut3.finished == false)
+      doAssert(fut4.finished == false)
+      doAssert(fut5.finished == false)
+
+      await sleepAsync(10.milliseconds)
+      doAssert(fut3.finished == false)
+      doAssert(fut4.finished == false)
+      doAssert(fut5.finished == false)
+      peer0.close()
+      await sleepAsync(10.milliseconds)
+      doAssert(fut3.finished == true and fut3.failed == false)
+      doAssert(fut4.finished == false)
+      doAssert(fut5.finished == false)
+      peer1.close()
+      await sleepAsync(10.milliseconds)
+      doAssert(fut4.finished == true and fut4.failed == false)
+      doAssert(fut5.finished == false)
+      peer2.close()
+      await sleepAsync(10.milliseconds)
+      doAssert(fut5.finished == true and fut5.failed == false)
+      result = true
+
     check:
       waitFor(testAddPeer1()) == true
       waitFor(testAddPeer2()) == true
       waitFor(testAddPeer3()) == true
+      waitFor(testAddPeer4()) == true
 
   timedTest "Acquire from empty pool":
     var pool0 = newPeerPool[PeerTest, PeerTestID]()
@@ -399,7 +442,7 @@ suiteReport "PeerPool testing suite":
 
     proc testConsumer() {.async.} =
       var p = await pool.acquire()
-      await sleepAsync(100.milliseconds)
+      await sleepAsync(10.milliseconds)
       pool.release(p)
 
     proc testClose(): Future[bool] {.async.} =