Fixed race condition in XmlFoldParser that could cause parser threads to get stuck in an infinite loop.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@5646 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/DisplayBindings/XmlEditor/Project/Src/XmlFoldParser.cs

@@ -76,17 +76,23 @@ namespace ICSharpCode.XmlEditor
 		
 		public ICompilationUnit Parse(IProjectContent projectContent, string fileName, ITextBuffer fileContent)
 		{
-			try {
-				CreateCompilationUnit(projectContent, fileName);
-				GetFolds(fileContent.CreateReader());
-				AddFoldsToCompilationUnit(unit, folds);
-			} catch (Exception) {
-				ICompilationUnit existingUnit = FindPreviouslyParsedCompilationUnit(projectContent, fileName);
-				if (existingUnit != null) {
-					return existingUnit;
+			// SharpDevelop may call IParser.Parse in parallel. This will be done on the same IParser instance
+			// if there are two parallel parse requests for the same file. Parser implementations must be thread-safe.
+			
+			// In XmlFoldParser, we do this by simply using a big lock per IParser instance.
+			lock (this) {
+				try {
+					CreateCompilationUnit(projectContent, fileName);
+					GetFolds(fileContent.CreateReader());
+					AddFoldsToCompilationUnit(unit, folds);
+				} catch (XmlException) {
+					ICompilationUnit existingUnit = FindPreviouslyParsedCompilationUnit(projectContent, fileName);
+					if (existingUnit != null) {
+						return existingUnit;
+					}
 				}
+				return unit;
 			}
-			return unit;
 		}
 		
 		void CreateCompilationUnit(IProjectContent projectContent, string fileName)

src/AddIns/Misc/PInvokeAddIn/Project/PInvokeAddIn.csproj

@@ -53,9 +53,6 @@
     <None Include="signatures.xml">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>
-    <None Include="signatures.xml">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-    </None>
     <None Include="PInvoke.addin">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>

src/Main/Base/Project/Src/Project/IParser.cs

@@ -41,6 +41,17 @@ namespace ICSharpCode.SharpDevelop.Project
 		/// </summary>
 		bool CanParse(IProject project);
 		
+		/// <summary>
+		/// Parses a file.
+		/// </summary>
+		/// <param name="projectContent">The parent project of the file.</param>
+		/// <param name="fileName">The name of the file being parsed.</param>
+		/// <param name="fileContent">The content of the file.</param>
+		/// <returns>The compilation unit representing the parse results.</returns>
+		/// <remarks>
+		/// SharpDevelop may call IParser.Parse in parallel. This will be done on the same IParser instance
+		/// if there are two parallel parse requests for the same file. Parser implementations must be thread-safe.
+		/// </remarks>
 		ICompilationUnit Parse(IProjectContent projectContent, string fileName, ITextBuffer fileContent);
 		
 		IResolver CreateResolver();