Make InitRootHandlers safe for the threaded framework

FWCore/Services/src/InitRootHandlers.cc

@@ -35,8 +35,10 @@ namespace {
     kSysError,
     kFatal
   };
+
+  static thread_local bool s_ignoreWarnings = false;
 
-  void RootErrorHandlerImpl(int level, char const* location, char const* message, bool ignoreWarnings) {
+  void RootErrorHandlerImpl(int level, char const* location, char const* message) {
 
   bool die = false;
 
@@ -51,7 +53,7 @@ namespace {
     } else if (level >= kError) {
       el_severity = SeverityLevel::kError;
     } else if (level >= kWarning) {
-      el_severity = ignoreWarnings ? SeverityLevel::kInfo : SeverityLevel::kWarning;
+      el_severity = s_ignoreWarnings ? SeverityLevel::kInfo : SeverityLevel::kWarning;
     }
 
   // Adapt C-strings to std::strings
@@ -157,11 +159,7 @@ namespace {
   }
 
   void RootErrorHandler(int level, bool, char const* location, char const* message) {
-    RootErrorHandlerImpl(level, location, message, false);
-  }
-
-  void RootErrorHandlerWithoutWarnings(int level, bool, char const* location, char const* message) {
-    RootErrorHandlerImpl(level, location, message, true);
+    RootErrorHandlerImpl(level, location, message);
   }
 
   extern "C" {
@@ -279,18 +277,13 @@ namespace edm {
     }
 
     void
-    InitRootHandlers::disableErrorHandler_() {
-        SetErrorHandler(DefaultErrorHandler);
-    }
-
-    void
-    InitRootHandlers::enableErrorHandler_() {
-        SetErrorHandler(RootErrorHandler);
+    InitRootHandlers::enableWarnings_() {
+      s_ignoreWarnings =false;
     }
 
     void
-    InitRootHandlers::enableErrorHandlerWithoutWarnings_() {
-        SetErrorHandler(RootErrorHandlerWithoutWarnings);
+    InitRootHandlers::ignoreWarnings_() {
+      s_ignoreWarnings = true;
     }
 
   }  // end of namespace service

FWCore/Services/src/InitRootHandlers.h

@@ -17,9 +17,8 @@ namespace edm {
       static void fillDescriptions(ConfigurationDescriptions& descriptions);
 
     private:
-      virtual void disableErrorHandler_();
-      virtual void enableErrorHandler_();
-      virtual void enableErrorHandlerWithoutWarnings_();
+      virtual void enableWarnings_() override;
+      virtual void ignoreWarnings_() override;
       bool unloadSigHandler_;
       bool resetErrHandler_;
       bool autoLibraryLoader_;

FWCore/Utilities/interface/RootHandlers.h

@@ -3,16 +3,30 @@
 
 namespace edm {
   class RootHandlers {
+  private:
+    struct WarningSentry {
+      WarningSentry(RootHandlers* iHandler): m_handler(iHandler){
+        m_handler->ignoreWarnings_();
+      };
+      ~WarningSentry() {
+        m_handler->enableWarnings_();
+      }
+      RootHandlers* m_handler;
+    };
+    friend struct edm::RootHandlers::WarningSentry;
+
   public:
     RootHandlers () {}
     virtual ~RootHandlers () {}
-    void disableErrorHandler() {disableErrorHandler_();}
-    void enableErrorHandler() {enableErrorHandler_();}
-    void enableErrorHandlerWithoutWarnings() {enableErrorHandlerWithoutWarnings_();}
+
+    template<typename F>
+    void ignoreWarningsWhileDoing(F iFunc) {
+      WarningSentry sentry(this);
+      iFunc();
+    }
   private: 
-    virtual void disableErrorHandler_() = 0;
-    virtual void enableErrorHandler_() = 0;
-    virtual void enableErrorHandlerWithoutWarnings_() = 0;
+    virtual void enableWarnings_() = 0;
+    virtual void ignoreWarnings_() = 0;
   };
 }  // end of namespace edm
 

IOPool/Output/src/RootOutputTree.cc

@@ -195,9 +195,7 @@ namespace edm {
       }
       tree_->SetEntries(tree_->GetEntries() + in->GetEntries());
       Service<RootHandlers> rootHandler;
-      rootHandler->enableErrorHandlerWithoutWarnings();
-      cloner.Exec();
-      rootHandler->enableErrorHandler();
+      rootHandler->ignoreWarningsWhileDoing([&cloner] { cloner.Exec(); });
       if(mustRemoveSomeAuxs) {
         for(std::map<Int_t, TBranch *>::const_iterator it = auxIndexes.begin(), itEnd = auxIndexes.end();
              it != itEnd; ++it) {