diff --git a/src/plugins/clangcodemodel/clangeditordocumentparser.cpp b/src/plugins/clangcodemodel/clangeditordocumentparser.cpp
index fd2c60dbaee..1f7d100fb63 100644
--- a/src/plugins/clangcodemodel/clangeditordocumentparser.cpp
+++ b/src/plugins/clangcodemodel/clangeditordocumentparser.cpp
@@ -88,10 +88,9 @@ ClangEditorDocumentParser::ClangEditorDocumentParser(const QString &filePath)
 {
 }
 
-void ClangEditorDocumentParser::update(CppTools::WorkingCopy workingCopy)
+void ClangEditorDocumentParser::updateHelper(CppTools::WorkingCopy workingCopy)
 {
     QTC_ASSERT(m_marker, return);
-    QMutexLocker locker(&m_updateIsRunning);
 
     // Determine project part
     State state_ = state();
diff --git a/src/plugins/clangcodemodel/clangeditordocumentparser.h b/src/plugins/clangcodemodel/clangeditordocumentparser.h
index e86cf50f949..37039eb5399 100644
--- a/src/plugins/clangcodemodel/clangeditordocumentparser.h
+++ b/src/plugins/clangcodemodel/clangeditordocumentparser.h
@@ -46,13 +46,13 @@ class ClangEditorDocumentParser : public CppTools::BaseEditorDocumentParser
 public:
     ClangEditorDocumentParser(const QString &filePath);
 
-    void update(CppTools::WorkingCopy workingCopy) override;
-
     QList<Diagnostic> diagnostics() const;
     QList<SemanticMarker::Range> ifdefedOutBlocks() const;
     SemanticMarker::Ptr semanticMarker() const;
 
 private:
+    void updateHelper(CppTools::WorkingCopy workingCopy) override;
+
     SemanticMarker::Ptr m_marker;
 };
 
diff --git a/src/plugins/cpptools/baseeditordocumentparser.cpp b/src/plugins/cpptools/baseeditordocumentparser.cpp
index 31d08bd4317..d075a86622a 100644
--- a/src/plugins/cpptools/baseeditordocumentparser.cpp
+++ b/src/plugins/cpptools/baseeditordocumentparser.cpp
@@ -31,6 +31,7 @@
 #include "baseeditordocumentparser.h"
 #include "baseeditordocumentprocessor.h"
 
+#include "cppworkingcopy.h"
 #include "editordocumenthandle.h"
 
 namespace CppTools {
@@ -44,14 +45,13 @@ namespace CppTools {
     It's meant to be used in the C++ editor to get precise results by using
     the "best" project part for a file.
 
-    Derived classes are expected to implement update() this way:
+    Derived classes are expected to implement updateHelper() this way:
 
     \list
         \li Get a copy of the configuration and the last state.
-        \li Acquire the protected m_updateIsRunning for the duration of update().
         \li Work on the data and do whatever is necessary. At least, update
             the project part with the help of determineProjectPart().
-        \li Ensure the new state is set before update() returns.
+        \li Ensure the new state is set before updateHelper() returns.
     \endlist
 */
 
@@ -81,6 +81,12 @@ void BaseEditorDocumentParser::setConfiguration(const Configuration &configurati
     m_configuration = configuration;
 }
 
+void BaseEditorDocumentParser::update(WorkingCopy workingCopy)
+{
+    QMutexLocker locker(&m_updateIsRunning);
+    updateHelper(workingCopy);
+}
+
 BaseEditorDocumentParser::State BaseEditorDocumentParser::state() const
 {
     QMutexLocker locker(&m_stateAndConfigurationMutex);
diff --git a/src/plugins/cpptools/baseeditordocumentparser.h b/src/plugins/cpptools/baseeditordocumentparser.h
index 42ce6c12b33..c5a19748118 100644
--- a/src/plugins/cpptools/baseeditordocumentparser.h
+++ b/src/plugins/cpptools/baseeditordocumentparser.h
@@ -56,11 +56,10 @@ public:
     virtual ~BaseEditorDocumentParser();
 
     QString filePath() const;
-
     Configuration configuration() const;
     void setConfiguration(const Configuration &configuration);
 
-    virtual void update(WorkingCopy workingCopy) = 0;
+    void update(WorkingCopy workingCopy);
 
     ProjectPart::Ptr projectPart() const;
 
@@ -69,7 +68,6 @@ protected:
         QByteArray editorDefines;
         ProjectPart::Ptr projectPart;
     };
-
     State state() const;
     void setState(const State &state);
 
@@ -77,14 +75,15 @@ protected:
                                                  const Configuration &config,
                                                  const State &state);
 
-    mutable QMutex m_updateIsRunning;
     mutable QMutex m_stateAndConfigurationMutex;
 
 private:
-    const QString m_filePath;
+    virtual void updateHelper(WorkingCopy workingCopy) = 0;
 
+    const QString m_filePath;
     Configuration m_configuration;
     State m_state;
+    mutable QMutex m_updateIsRunning;
 };
 
 } // namespace CppTools
diff --git a/src/plugins/cpptools/builtineditordocumentparser.cpp b/src/plugins/cpptools/builtineditordocumentparser.cpp
index 3871cb2bb0b..f244595fde0 100644
--- a/src/plugins/cpptools/builtineditordocumentparser.cpp
+++ b/src/plugins/cpptools/builtineditordocumentparser.cpp
@@ -44,10 +44,8 @@ BuiltinEditorDocumentParser::BuiltinEditorDocumentParser(const QString &filePath
     qRegisterMetaType<CPlusPlus::Snapshot>("CPlusPlus::Snapshot");
 }
 
-void BuiltinEditorDocumentParser::update(WorkingCopy workingCopy)
+void BuiltinEditorDocumentParser::updateHelper(WorkingCopy workingCopy)
 {
-    QMutexLocker locker(&m_updateIsRunning);
-
     const Configuration baseConfig = configuration();
     const bool releaseSourceAndAST_ = releaseSourceAndAST();
 
diff --git a/src/plugins/cpptools/builtineditordocumentparser.h b/src/plugins/cpptools/builtineditordocumentparser.h
index a495be4787a..fee17882eb7 100644
--- a/src/plugins/cpptools/builtineditordocumentparser.h
+++ b/src/plugins/cpptools/builtineditordocumentparser.h
@@ -51,8 +51,6 @@ public:
     bool releaseSourceAndAST() const;
     void setReleaseSourceAndAST(bool release);
 
-    void update(WorkingCopy workingCopy) override;
-
     CPlusPlus::Document::Ptr document() const;
     CPlusPlus::Snapshot snapshot() const;
     ProjectPart::HeaderPaths headerPaths() const;
@@ -66,6 +64,7 @@ public:
     static BuiltinEditorDocumentParser *get(const QString &filePath);
 
 private:
+    void updateHelper(WorkingCopy workingCopy) override;
     void addFileAndDependencies(CPlusPlus::Snapshot *snapshot,
                                 QSet<Utils::FileName> *toRemove,
                                 const Utils::FileName &fileName) const;
@@ -80,7 +79,6 @@ private:
         CPlusPlus::Snapshot snapshot;
         bool forceSnapshotInvalidation = false;
     };
-
     ExtraState extraState() const;
     void setExtraState(const ExtraState &extraState);