Merge pull request #1551 from dahlia/fix-maintain-static-peers

Fix `Swarm<T>.MaintainStaticPeersAsync()` throwing `PingTimeoutException`
planetarium · Oct 26, 2021 · e555137 · e555137
2 parents 2e80048 + 3736e1d
commit e555137
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Showing 3 changed files with 29 additions and 16 deletions.
diff --git a/CHANGES.md b/CHANGES.md
@@ -46,6 +46,9 @@ To be released.
     silently no-op when a given `sourceChainId` had not existed, which had not
     been compliant with `IStore.ForkBlockIndexes()` method's specification.
     [[#1544]]
+ -  Fixed `Swarm<T>`'s bug that it had thrown `PingTimeoutException` if any
+    peer in configured `SwarmOptions.StaticPeers` is unreachable.
+    [[#1550], [#1551]]
  -  (Libplanet.RocksDBStore) Fixed `RocksDBStore.ForkBlockIndexes()` method's
     bug that it had done silently no-op when a given `sourceChainId` had not
     existed, which had not been compliant with `IStore.ForkBlockIndexes()`
@@ -62,6 +65,8 @@ To be released.
 [#1535]: https://github.com/planetarium/libplanet/pull/1535
 [#1537]: https://github.com/planetarium/libplanet/pull/1537
 [#1544]: https://github.com/planetarium/libplanet/pull/1544
+[#1550]: https://github.com/planetarium/libplanet/issues/1550
+[#1551]: https://github.com/planetarium/libplanet/pull/1551
 
 
 Version 0.18.2

diff --git a/Libplanet.Tests/Net/SwarmTest.cs b/Libplanet.Tests/Net/SwarmTest.cs
@@ -30,6 +30,7 @@
 using xRetry;
 using Xunit;
 using Xunit.Abstractions;
+using static Libplanet.Tests.TestUtils;
 
 namespace Libplanet.Tests.Net
 {
@@ -300,14 +301,18 @@ public async Task MaintainStaticPeers()
                         {
                             (BoundPeer)swarmA.AsPeer,
                             (BoundPeer)swarmB.AsPeer,
+                            // Unreachable peer:
+                            new BoundPeer(
+                                new PrivateKey().PublicKey,
+                                new DnsEndPoint("127.0.0.1", 65535)
+                            ),
                         }.ToImmutableHashSet(),
                         StaticPeersMaintainPeriod = TimeSpan.FromMilliseconds(100),
                     });
 
                 await StartAsync(swarm);
-                await Task.Delay(500);
-                Assert.Contains(swarmA.AsPeer, swarm.Peers);
-                Assert.Contains(swarmB.AsPeer, swarm.Peers);
+                await AssertThatEventually(() => swarm.Peers.Contains(swarmA.AsPeer), 5_000);
+                await AssertThatEventually(() => swarm.Peers.Contains(swarmB.AsPeer), 5_000);
 
                 _logger.Debug("Address of swarmA: {Address}", swarmA.Address);
                 await StopAsync(swarmA);
@@ -324,9 +329,8 @@ public async Task MaintainStaticPeers()
                 Assert.Contains(swarmB.AsPeer, swarm.Peers);
 
                 await StartAsync(swarmC);
-                await Task.Delay(500);
-                Assert.Contains(swarmC.AsPeer, swarm.Peers);
-                Assert.Contains(swarmB.AsPeer, swarm.Peers);
+                await AssertThatEventually(() => swarm.Peers.Contains(swarmB.AsPeer), 5_000);
+                await AssertThatEventually(() => swarm.Peers.Contains(swarmC.AsPeer), 5_000);
 
                 await StopAsync(swarm);
             }

diff --git a/Libplanet/Net/Swarm.cs b/Libplanet/Net/Swarm.cs
@@ -1286,19 +1286,23 @@ private bool IsBlockNeeded(IBlockExcerpt target)
             TimeSpan period,
             CancellationToken cancellationToken)
         {
+            TimeSpan timeout = TimeSpan.FromSeconds(3);
             while (!cancellationToken.IsCancellationRequested)
             {
-                await Task.Delay(period, cancellationToken);
-                Options.StaticPeers.AsParallel().ForAll(async boundPeer =>
-                {
-                    if (!RoutingTable.Contains(boundPeer))
+                var tasks = Options.StaticPeers
+                    .Where(peer => !RoutingTable.Contains(peer))
+                    .Select(async peer =>
                     {
-                        await AddPeersAsync(
-                            new[] { boundPeer },
-                            TimeSpan.FromSeconds(3),
-                            cancellationToken);
-                    }
-                });
+                        try
+                        {
+                            await AddPeersAsync(new[] { peer }, timeout, cancellationToken);
+                        }
+                        catch (TimeoutException)
+                        {
+                        }
+                    });
+                await Task.WhenAll(tasks);
+                await Task.Delay(period, cancellationToken);
             }
         }
     }