fixed the bug that method CurrentTaskFinished was executed multiple…

… times by multiple threads (Scighost#1083) (Scighost#1082)

Signed-off-by: OsakaRuma <[email protected]>

src/Starward/Services/Download/InstallGameService.cs

@@ -713,10 +713,20 @@ protected void StartTask(InstallGameState state)
             _finishBytes = 0;
         }
         State = state;
-        _cancellationTokenSource = new CancellationTokenSource();
-        for (int i = 0; i < Environment.ProcessorCount; i++)
+
+        _ = RunTasksAsync(); //不需要ConfigureAwait，因为返回值丢弃，且无需调用“.GetAwaiter().OnCompleted()”
+        return;
+
+        async Task RunTasksAsync()
         {
-            _ = ExecuteTaskItemAsync(_cancellationTokenSource.Token).ConfigureAwait(false);
+            _cancellationTokenSource = new CancellationTokenSource();
+            var tsaks = new Task[Environment.ProcessorCount];
+            for (int i = 0; i < Environment.ProcessorCount; i++)
+            {
+                tsaks[i] = ExecuteTaskItemAsync(_cancellationTokenSource.Token);
+            }
+            await Task.WhenAll(tsaks).ConfigureAwait(false);
+            CurrentTaskFinished();
         }
     }
 
@@ -1105,8 +1115,8 @@ protected async Task ExecuteTaskItemAsync(CancellationToken cancellationToken =
     {
         try
         {
-            Interlocked.Increment(ref _concurrentExecuteThreadCount);
-            if (_concurrentExecuteThreadCount > Environment.ProcessorCount)
+            var concurrentExecuteThreadCount = Interlocked.Increment(ref _concurrentExecuteThreadCount);
+            if (concurrentExecuteThreadCount > Environment.ProcessorCount)
             {
                 return;
             }
@@ -1161,10 +1171,6 @@ protected async Task ExecuteTaskItemAsync(CancellationToken cancellationToken =
         finally
         {
             Interlocked.Decrement(ref _concurrentExecuteThreadCount);
-            if (_concurrentExecuteThreadCount == 0)
-            {
-                CurrentTaskFinished();
-            }
         }
     }