Clean up locks after use to prevent memory leak

FastGithub.DomainResolve/DnsClient.cs

@@ -1,4 +1,5 @@
-using DNS.Client;
+using AsyncKeyedLock;
+using DNS.Client;
 using DNS.Client.RequestResolver;
 using DNS.Protocol;
 using DNS.Protocol.ResourceRecords;
@@ -7,7 +8,6 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net;
@@ -30,7 +30,7 @@ sealed class DnsClient
         private readonly FastGithubConfig fastGithubConfig;
         private readonly ILogger<DnsClient> logger;
 
-        private readonly ConcurrentDictionary<string, SemaphoreSlim> semaphoreSlims = new();
+        private readonly AsyncKeyedLocker<string> locks = new();
         private readonly IMemoryCache dnsStateCache = new MemoryCache(Options.Create(new MemoryCacheOptions()));
         private readonly IMemoryCache dnsLookupCache = new MemoryCache(Options.Create(new MemoryCacheOptions()));
 
@@ -123,9 +123,8 @@ private async ValueTask<bool> IsDnsAvailableAsync(IPEndPoint dns, CancellationTo
             }
 
             var key = dns.ToString();
-            var semaphore = this.semaphoreSlims.GetOrAdd(key, _ => new SemaphoreSlim(1, 1));
-            await semaphore.WaitAsync(CancellationToken.None);
 
+            using var _ = await locks.LockAsync(key);
             try
             {
                 using var timeoutTokenSource = new CancellationTokenSource(tcpConnectTimeout);
@@ -139,10 +138,6 @@ private async ValueTask<bool> IsDnsAvailableAsync(IPEndPoint dns, CancellationTo
                 cancellationToken.ThrowIfCancellationRequested();
                 return this.dnsStateCache.Set(dns, false, this.stateExpiration);
             }
-            finally
-            {
-                semaphore.Release();
-            }
         }
 
         /// <summary>
@@ -156,9 +151,7 @@ private async ValueTask<bool> IsDnsAvailableAsync(IPEndPoint dns, CancellationTo
         private async Task<IList<IPAddress>> LookupAsync(IPEndPoint dns, DnsEndPoint endPoint, bool fastSort, CancellationToken cancellationToken = default)
         {
             var key = $"{dns}/{endPoint}";
-            var semaphore = this.semaphoreSlims.GetOrAdd(key, _ => new SemaphoreSlim(1, 1));
-            await semaphore.WaitAsync(CancellationToken.None);
-
+            using var _ = await locks.LockAsync(key);
             try
             {
                 if (this.dnsLookupCache.TryGetValue<IList<IPAddress>>(key, out var value))
@@ -178,10 +171,6 @@ private async Task<IList<IPAddress>> LookupAsync(IPEndPoint dns, DnsEndPoint end
                 var expiration = IsSocketException(ex) ? this.maxTimeToLive : this.minTimeToLive;
                 return this.dnsLookupCache.Set(key, Array.Empty<IPAddress>(), expiration);
             }
-            finally
-            {
-                semaphore.Release();
-            }
         }
 
         /// <summary>

FastGithub.DomainResolve/FastGithub.DomainResolve.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<ItemGroup>
+		<PackageReference Include="AsyncKeyedLock" Version="8.0.0" />
 		<PackageReference Include="PInvoke.AdvApi32" Version="0.7.124" />
 		<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="6.0.1" />
 		<PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.1" />

FastGithub.DomainResolve/PersistenceService.cs

@@ -1,4 +1,5 @@
-using FastGithub.Configuration;
+using AsyncKeyedLock;
+using FastGithub.Configuration;
 using Microsoft.Extensions.Logging;
 using System;
 using System.Collections.Generic;
@@ -18,7 +19,7 @@ namespace FastGithub.DomainResolve
     sealed partial class PersistenceService
     {
         private static readonly string dataFile = "dnsendpoints.json";
-        private static readonly SemaphoreSlim dataLocker = new(1, 1); 
+        private static readonly AsyncNonKeyedLocker dataLocker = new(1); 
 
         private readonly FastGithubConfig fastGithubConfig;
         private readonly ILogger<PersistenceService> logger;
@@ -60,10 +61,9 @@ public IList<DnsEndPoint> ReadDnsEndPoints()
                 return Array.Empty<DnsEndPoint>();
             }
 
+            using var _ = dataLocker.Lock();
             try
             {
-                dataLocker.Wait();
-
                 var utf8Json = File.ReadAllBytes(dataFile);
                 var endPointItems = JsonSerializer.Deserialize(utf8Json, EndPointItemsContext.Default.EndPointItemArray);
                 if (endPointItems == null)
@@ -86,10 +86,6 @@ public IList<DnsEndPoint> ReadDnsEndPoints()
                 this.logger.LogWarning(ex.Message, "读取dns记录异常");
                 return Array.Empty<DnsEndPoint>();
             }
-            finally
-            {
-                dataLocker.Release();
-            }
         }
 
         /// <summary>
@@ -100,10 +96,9 @@ public IList<DnsEndPoint> ReadDnsEndPoints()
         /// <returns></returns>
         public async Task WriteDnsEndPointsAsync(IEnumerable<DnsEndPoint> dnsEndPoints, CancellationToken cancellationToken)
         {
+            using var _ = await dataLocker.LockAsync();
             try
             {
-                await dataLocker.WaitAsync(CancellationToken.None);
-
                 var endPointItems = dnsEndPoints.Select(item => new EndPointItem(item.Host, item.Port)).ToArray();
                 var utf8Json = JsonSerializer.SerializeToUtf8Bytes(endPointItems, EndPointItemsContext.Default.EndPointItemArray);
                 await File.WriteAllBytesAsync(dataFile, utf8Json, cancellationToken);
@@ -112,10 +107,6 @@ public async Task WriteDnsEndPointsAsync(IEnumerable<DnsEndPoint> dnsEndPoints,
             {
                 this.logger.LogWarning(ex.Message, "保存dns记录异常");
             }
-            finally
-            {
-                dataLocker.Release();
-            }
         }
     }
 }