Improvements based on review feedback

- explicitly delete compiler generated routines
- improved RAII
- avoid unnecessary temporary
- add arena isolations

Author: Dr15Jones

DataFormats/Common/interface/RefCoreStreamer.h

@@ -38,6 +38,10 @@ namespace edm {
   public:
     RefCoreStreamerGuard(EDProductGetter const* ep) { setRefCoreStreamer(ep); }
     ~RefCoreStreamerGuard() { unsetRefCoreStreamer(); }
+    RefCoreStreamerGuard(RefCoreStreamerGuard const&) = delete;
+    RefCoreStreamerGuard& operator=(RefCoreStreamerGuard const&) = delete;
+    RefCoreStreamerGuard(RefCoreStreamerGuard&&) = delete;
+    RefCoreStreamerGuard& operator=(RefCoreStreamerGuard&&) = delete;
 
   private:
     static void unsetRefCoreStreamer();

IOPool/Input/src/InputFile.h

@@ -57,19 +57,22 @@ namespace edm {
 
     class CacheGuard {
     public:
-      CacheGuard(TFile* file, TObject* tree) : file_(file), tree_(tree) {}
+      CacheGuard(TFile* file, TObject* tree, TFileCacheRead* tfcr) : file_(file), tree_(tree) {
+        file_->SetCacheRead(tfcr, tree_, TFile::kDoNotDisconnect);
+      }
       CacheGuard() = delete;
       CacheGuard(CacheGuard const&) = delete;
       CacheGuard& operator=(CacheGuard const&) = delete;
+      CacheGuard(CacheGuard&&) = delete;
+      CacheGuard& operator=(CacheGuard&&) = delete;
       ~CacheGuard() { file_->SetCacheRead(nullptr, tree_, TFile::kDoNotDisconnect); }
 
     private:
       TFile* file_;
       TObject* tree_;
     };
     [[nodiscard]] CacheGuard setCacheReadTemporarily(TFileCacheRead* tfcr, TObject* iTree) {
-      file_->SetCacheRead(tfcr, iTree, TFile::kDoNotDisconnect);
-      return CacheGuard(file_.get(), iTree);
+      return CacheGuard(file_.get(), iTree, tfcr);
     }
     void clearCacheRead(TObject* iTree) { file_->SetCacheRead(nullptr, iTree, TFile::kDoNotDisconnect); }
     void logFileAction(char const* msg, char const* fileName) const;

IOPool/Input/src/RootPromptReadDelayedReader.h

@@ -42,8 +42,10 @@ namespace edm {
 
     ~RootPromptReadDelayedReader() override;
 
-    RootPromptReadDelayedReader(RootPromptReadDelayedReader const&) = delete;             // Disallow copying and moving
-    RootPromptReadDelayedReader& operator=(RootPromptReadDelayedReader const&) = delete;  // Disallow copying and moving
+    RootPromptReadDelayedReader(RootPromptReadDelayedReader const&) = delete;
+    RootPromptReadDelayedReader& operator=(RootPromptReadDelayedReader const&) = delete;
+    RootPromptReadDelayedReader(RootPromptReadDelayedReader&&) = delete;
+    RootPromptReadDelayedReader& operator=(RootPromptReadDelayedReader&&) = delete;
 
     struct Cache {
       std::unique_ptr<edm::WrapperBase> wrapperBase_;
@@ -66,8 +68,8 @@ namespace edm {
     RootTree const& tree_;
     edm::propagate_const<std::shared_ptr<InputFile>> filePtr_;
     edm::propagate_const<DelayedReader*> nextReader_;
-    std::unique_ptr<SharedResourcesAcquirer>
-        resourceAcquirer_;  // We do not use propagate_const because the acquirer is itself mutable.
+    // We do not use propagate_const because the acquirer is itself mutable.
+    std::unique_ptr<SharedResourcesAcquirer> resourceAcquirer_;
     std::shared_ptr<std::recursive_mutex> mutex_;
     InputType inputType_;
 

IOPool/Input/src/RootTree.cc

@@ -10,6 +10,7 @@
 #include "TTreeCache.h"
 #include "TLeaf.h"
 
+#include "oneapi/tbb/task_arena.h"
 #include <cassert>
 
 namespace edm {
@@ -176,8 +177,7 @@ namespace edm {
   std::unique_ptr<WrapperBase> roottree::BranchInfo::newWrapper() const {
     assert(nullptr != classCache_);
     void* p = classCache_->New();
-    std::unique_ptr<WrapperBase> edp = getWrapperBasePtr(p, offsetToWrapperBase_);
-    return edp;
+    return getWrapperBasePtr(p, offsetToWrapperBase_);
   }
 
   void RootTree::addBranch(ProductDescription const& prod, std::string const& oldBranchName) {
@@ -426,8 +426,10 @@ namespace edm {
   }
 
   void RootTree::getEntryForAllBranches() const {
-    auto guard = filePtr_->setCacheReadTemporarily(rawTreeCache_.get(), tree_);
-    tree_->GetEntry(entryNumber_);
+    oneapi::tbb::this_task_arena::isolate([&]() {
+      auto guard = filePtr_->setCacheReadTemporarily(treeCache_.get(), tree_);
+      tree_->GetEntry(entryNumber_);
+    });
   }
 
   void RootTree::getEntry(TBranch* branch, EntryNumber entryNumber) const {