Rename used counter

Author: JamesNK

src/Servers/Connections.Abstractions/src/MemoryPoolOptions.cs

@@ -6,7 +6,7 @@ namespace Microsoft.AspNetCore.Connections;
 /// <summary>
 /// Options for configuring a memory pool.
 /// </summary>
-public sealed class MemoryPoolOptions
+public class MemoryPoolOptions
 {
     /// <summary>
     /// Gets or sets the owner of the memory pool. This is used for logging and diagnostics purposes.

src/Servers/Kestrel/Core/test/PinnedBlockMemoryPoolFactoryTests.cs

@@ -20,6 +20,7 @@ public void CreatePool()
         var pool = factory.Create();
         Assert.NotNull(pool);
         Assert.IsType<PinnedBlockMemoryPool>(pool);
+        Assert.Null(Assert.IsType<PinnedBlockMemoryPool>(pool).Owner);
     }
 
     [Fact]

src/Shared/Buffers.MemoryPool/MemoryPoolMetrics.cs

@@ -12,13 +12,13 @@ internal sealed class MemoryPoolMetrics
 {
     public const string MeterName = "Microsoft.AspNetCore.MemoryPool";
 
-    public const string UsedMemoryName = "aspnetcore.memory_pool.used";
+    public const string PooledMemoryName = "aspnetcore.memory_pool.pooled";
     public const string AllocatedMemoryName = "aspnetcore.memory_pool.allocated";
     public const string EvictedMemoryName = "aspnetcore.memory_pool.evicted";
     public const string RentedMemoryName = "aspnetcore.memory_pool.rented";
 
     private readonly Meter _meter;
-    private readonly UpDownCounter<long> _usedMemoryCounter;
+    private readonly UpDownCounter<long> _pooledMemoryCounter;
     private readonly Counter<long> _allocatedMemoryCounter;
     private readonly Counter<long> _evictedMemoryCounter;
     private readonly Counter<long> _rentedMemoryCounter;
@@ -27,41 +27,41 @@ public MemoryPoolMetrics(IMeterFactory meterFactory)
     {
         _meter = meterFactory.Create(MeterName);
 
-        _usedMemoryCounter = _meter.CreateUpDownCounter<long>(
-            UsedMemoryName,
+        _pooledMemoryCounter = _meter.CreateUpDownCounter<long>(
+            PooledMemoryName,
             unit: "By",
-            description: "Number of bytes that are currently used by the pool.");
+            description: "Number of bytes currently held by the memory pool and available for reuse.");
 
         _allocatedMemoryCounter = _meter.CreateCounter<long>(
-           AllocatedMemoryName,
+            AllocatedMemoryName,
             unit: "By",
-            description: "Total number of allocations made by the pool.");
+            description: "Total number of allocations made by the memory pool.");
 
         _evictedMemoryCounter = _meter.CreateCounter<long>(
-           EvictedMemoryName,
+            EvictedMemoryName,
             unit: "By",
-            description: "Total number of bytes that have been evicted from the pool.");
+            description: "Total number of bytes that have been evicted from the memory pool.");
 
         _rentedMemoryCounter = _meter.CreateCounter<long>(
             RentedMemoryName,
             unit: "By",
-            description: "Total number of bytes rented from the pool.");
+            description: "Total number of bytes rented from the memory pool.");
     }
 
-    public void UpdateUsedMemory(int bytes, string? owner)
+    public void UpdatePooledMemory(int bytes, string? owner)
     {
-        if (_usedMemoryCounter.Enabled)
+        if (_pooledMemoryCounter.Enabled)
         {
-            UpdateUsedMemoryCore(bytes, owner);
+            UpdatePooledMemoryCore(bytes, owner);
         }
     }
 
-    private void UpdateUsedMemoryCore(int bytes, string? owner)
+    private void UpdatePooledMemoryCore(int bytes, string? owner)
     {
         var tags = new TagList();
         AddOwner(ref tags, owner);
 
-        _usedMemoryCounter.Add(bytes, tags);
+        _pooledMemoryCounter.Add(bytes, tags);
     }
 
     public void AddAllocatedMemory(int bytes, string? owner)

src/Shared/Buffers.MemoryPool/PinnedBlockMemoryPool.cs

@@ -63,7 +63,7 @@ internal sealed class PinnedBlockMemoryPool : MemoryPool<byte>, IThreadPoolWorkI
     private object? _onPoolDisposedState;
 
     // Internal for tests.
-    internal string Owner => _owner;
+    internal string? Owner => _owner;
 
     /// <summary>
     /// This default value passed in to Rent to use the default value for the pool.
@@ -102,7 +102,7 @@ public override IMemoryOwner<byte> Rent(int size = AnySize)
 
         if (_blocks.TryDequeue(out var block))
         {
-            _metrics?.UpdateUsedMemory(-block.Memory.Length, _owner);
+            _metrics?.UpdatePooledMemory(-block.Memory.Length, _owner);
             _metrics?.AddRentedMemory(block.Memory.Length, _owner);
 
             // block successfully taken from the stack - return it
@@ -131,16 +131,16 @@ public override IMemoryOwner<byte> Rent(int size = AnySize)
     internal void Return(MemoryPoolBlock block)
     {
 #if BLOCK_LEASE_TRACKING
-            Debug.Assert(block.Pool == this, "Returned block was not leased from this pool");
-            Debug.Assert(block.IsLeased, $"Block being returned to pool twice: {block.Leaser}{Environment.NewLine}");
-            block.IsLeased = false;
+        Debug.Assert(block.Pool == this, "Returned block was not leased from this pool");
+        Debug.Assert(block.IsLeased, $"Block being returned to pool twice: {block.Leaser}{Environment.NewLine}");
+        block.IsLeased = false;
 #endif
 
         Interlocked.Increment(ref _returnCount);
 
         if (!_isDisposed)
         {
-            _metrics?.UpdateUsedMemory(block.Memory.Length, _owner);
+            _metrics?.UpdatePooledMemory(block.Memory.Length, _owner);
 
             _blocks.Enqueue(block);
         }
@@ -214,7 +214,7 @@ internal void PerformEviction()
         // Remove from queue and let GC clean the memory up
         while (burstAmount > 0 && _blocks.TryDequeue(out var block))
         {
-            _metrics?.UpdateUsedMemory(-block.Memory.Length, _owner);
+            _metrics?.UpdatePooledMemory(-block.Memory.Length, _owner);
             _metrics?.AddEvictedMemory(block.Memory.Length, _owner);
 
             burstAmount--;