Use ReaderWriterLockSlim

dotnet · Sep 18, 2024 · 1f2f4f4 · 1f2f4f4
1 parent 1271b8e
commit 1f2f4f4
Showing 1 changed file with 31 additions and 5 deletions.
diff --git a/src/Microsoft.TemplateEngine.Utils/InMemoryFileSystem.cs b/src/Microsoft.TemplateEngine.Utils/InMemoryFileSystem.cs
@@ -771,7 +771,7 @@ public FileSystemDirectory(string name, string fullPath)
 
         private class FileSystemFile
         {
-            private readonly object _sync = new();
+            private readonly ReaderWriterLockSlim _lock = new();
             private byte[] _data;
             private int _currentReaders;
             private int _currentWriters;
@@ -798,15 +798,31 @@ public Stream OpenRead()
                     throw new IOException("File is currently locked for writing");
                 }
 
-                lock (_sync)
+                _lock.EnterReadLock();
+                try
                 {
                     if (_currentWriters > 0)
                     {
                         throw new IOException("File is currently locked for writing");
                     }
 
                     ++_currentReaders;
-                    return new DisposingStream(new MemoryStream(_data, false), () => { lock (_sync) { --_currentReaders; } });
+                    return new DisposingStream(new MemoryStream(_data, false), () =>
+                            {
+                                _lock.EnterWriteLock();
+                                try
+                                {
+                                    --_currentReaders;
+                                }
+                                finally
+                                {
+                                    _lock.ExitWriteLock();
+                                }
+                            });
+                }
+                finally
+                {
+                    _lock.ExitReadLock();
                 }
             }
 
@@ -822,7 +838,8 @@ public Stream OpenWrite()
                     throw new IOException("File is currently locked for writing");
                 }
 
-                lock (_sync)
+                _lock.EnterWriteLock();
+                try
                 {
                     if (_currentReaders > 0)
                     {
@@ -838,16 +855,25 @@ public Stream OpenWrite()
                     MemoryStream target = new();
                     return new DisposingStream(target, () =>
                     {
-                        lock (_sync)
+                        _lock.EnterWriteLock();
+                        try
                         {
                             --_currentWriters;
                             _data = new byte[target.Length];
                             target.Position = 0;
                             _ = target.Read(_data, 0, _data.Length);
                             LastWriteTimeUtc = DateTime.UtcNow;
                         }
+                        finally
+                        {
+                            _lock.ExitWriteLock();
+                        }
                     });
                 }
+                finally
+                {
+                    _lock.ExitWriteLock();
+                }
             }
         }