optimize LogWithThreadPoolStats

Author: mgravell

src/StackExchange.Redis/ConnectionMultiplexer.cs

@@ -484,7 +484,7 @@ private static async Task<bool> WaitAllIgnoreErrorsAsync(string name, Task[] tas
             }
 
             var watch = ValueStopwatch.StartNew();
-            log.LogWithThreadPoolStats($"Awaiting {tasks.Length} {name} task completion(s) for {timeoutMilliseconds}ms");
+            log?.LogWithThreadPoolStats($"Awaiting {tasks.Length} {name} task completion(s) for {timeoutMilliseconds}ms");
             try
             {
                 // if none error, great
@@ -497,7 +497,7 @@ private static async Task<bool> WaitAllIgnoreErrorsAsync(string name, Task[] tas
 
                 var allTasks = Task.WhenAll(tasks).ObserveErrors();
                 bool all = await allTasks.TimeoutAfter(timeoutMs: remaining).ObserveErrors().ForAwait();
-                log.LogWithThreadPoolStats(all ? $"All {tasks.Length} {name} tasks completed cleanly" : $"Not all {name} tasks completed cleanly (from {caller}#{callerLineNumber}, timeout {timeoutMilliseconds}ms)");
+                log?.LogWithThreadPoolStats(all ? $"All {tasks.Length} {name} tasks completed cleanly" : $"Not all {name} tasks completed cleanly (from {caller}#{callerLineNumber}, timeout {timeoutMilliseconds}ms)");
                 return all;
             }
             catch

src/StackExchange.Redis/LoggerExtensions.cs

@@ -32,15 +32,33 @@ internal static void LogWithThreadPoolStats(this ILogger? log, string message)
             return;
         }
 
-        var sb = new StringBuilder();
-        sb.Append(message);
         _ = PerfCounterHelper.GetThreadPoolStats(out string iocp, out string worker, out string? workItems);
-        sb.Append(", IOCP: ").Append(iocp).Append(", WORKER: ").Append(worker);
+
+#if NET6_0_OR_GREATER
+        // use DISH when possible
+        // similar to: var composed = $"{message}, IOCP: {iocp}, WORKER: {worker}, ..."; on net6+
+        var dish = new System.Runtime.CompilerServices.DefaultInterpolatedStringHandler(26, 4);
+        dish.AppendFormatted(message);
+        dish.AppendLiteral(", IOCP: ");
+        dish.AppendFormatted(iocp);
+        dish.AppendLiteral(", WORKER: ");
+        dish.AppendFormatted(worker);
+        if (workItems is not null)
+        {
+            dish.AppendLiteral(", POOL: ");
+            dish.AppendFormatted(workItems);
+        }
+        var composed = dish.ToStringAndClear();
+#else
+        var sb = new StringBuilder();
+        sb.Append(message).Append(", IOCP: ").Append(iocp).Append(", WORKER: ").Append(worker);
         if (workItems is not null)
         {
             sb.Append(", POOL: ").Append(workItems);
         }
-        log.LogInformationThreadPoolStats(sb.ToString());
+        var composed = sb.ToString();
+#endif
+        log.LogInformationThreadPoolStats(composed);
     }
 
     // Generated LoggerMessage methods