From 7c8e34373dbb26d58fc4cf76093e234804765956 Mon Sep 17 00:00:00 2001
From: Giulio Eulisse <10544+ktf@users.noreply.github.com>
Date: Fri, 14 Mar 2025 11:48:16 +0100
Subject: [PATCH] DPL: account for IO time correctly

Now that we lazily read into the shared memory directly, we need to
compute the time delta up to the destruction of the FragmentToBatch,
which is where the actual reading ultimately finishes.
---
 .../AnalysisSupport/src/DataInputDirector.cxx | 56 +++++++++++++------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/Framework/AnalysisSupport/src/DataInputDirector.cxx b/Framework/AnalysisSupport/src/DataInputDirector.cxx
index 2c51360cd9923..cfb5ca34b062b 100644
--- a/Framework/AnalysisSupport/src/DataInputDirector.cxx
+++ b/Framework/AnalysisSupport/src/DataInputDirector.cxx
@@ -387,18 +387,53 @@ int DataInputDescriptor::findDFNumber(int file, std::string dfName)
   return it - dfList.begin();
 }
 
+struct CalculateDelta {
+  CalculateDelta(uint64_t& target)
+    : mTarget(target)
+  {
+    start = uv_hrtime();
+  }
+  ~CalculateDelta()
+  {
+    if (!active) {
+      return;
+    }
+    O2_SIGNPOST_ACTION(reader_memory_dump, [](void*) {
+      void (*dump_)(const char*);
+      if (void* sym = dlsym(nullptr, "igprof_dump_now")) {
+        dump_ = __extension__(void (*)(const char*)) sym;
+        if (dump_) {
+          std::string filename = fmt::format("reader-memory-dump-{}.gz", uv_hrtime());
+          dump_(filename.c_str());
+        }
+      }
+    });
+    mTarget += (uv_hrtime() - start);
+  }
+
+  void deactivate() {
+    active = false;
+  }
+
+  bool active = true;
+  uint64_t& mTarget;
+  uint64_t start;
+  uint64_t stop;
+};
+
 bool DataInputDescriptor::readTree(DataAllocator& outputs, header::DataHeader dh, int counter, int numTF, std::string treename, size_t& totalSizeCompressed, size_t& totalSizeUncompressed)
 {
-  auto ioStart = uv_hrtime();
-
+  CalculateDelta t(mIOTime);
   auto folder = getFileFolder(counter, numTF);
   if (!folder.filesystem()) {
+    t.deactivate();
     return false;
   }
 
   auto rootFS = std::dynamic_pointer_cast<TFileFileSystem>(folder.filesystem());
 
   if (!rootFS) {
+    t.deactivate();
     throw std::runtime_error(fmt::format(R"(Not a TFile filesystem!)"));
   }
   // FIXME: Ugly. We should detect the format from the treename, good enough for now.
@@ -420,6 +455,7 @@ bool DataInputDescriptor::readTree(DataAllocator& outputs, header::DataHeader dh
   // FIXME: we should distinguish between an actually missing object and one which has a non compatible
   // format.
   if (!format) {
+    t.deactivate();
     LOGP(debug, "Could not find tree {}. Trying in parent file.", fullpath.path());
     auto parentFile = getParentFile(counter, numTF, treename);
     if (parentFile != nullptr) {
@@ -460,19 +496,6 @@ bool DataInputDescriptor::readTree(DataAllocator& outputs, header::DataHeader dh
   f2b->setLabel(treename.c_str());
   f2b->fill(datasetSchema, format);
 
-  mIOTime += (uv_hrtime() - ioStart);
-
-  O2_SIGNPOST_ACTION(reader_memory_dump, [](void*) {
-    void (*dump_)(const char*);
-    if (void* sym = dlsym(nullptr, "igprof_dump_now")) {
-      dump_ = __extension__(void (*)(const char*)) sym;
-      if (dump_) {
-        std::string filename = fmt::format("reader-memory-dump-{}.gz", uv_hrtime());
-        dump_(filename.c_str());
-      }
-    }
-  });
-
   return true;
 }
 
@@ -820,7 +843,8 @@ bool DataInputDirector::readTree(DataAllocator& outputs, header::DataHeader dh,
     treename = aod::datamodel::getTreeName(dh);
   }
 
-  return didesc->readTree(outputs, dh, counter, numTF, treename, totalSizeCompressed, totalSizeUncompressed);
+  auto result = didesc->readTree(outputs, dh, counter, numTF, treename, totalSizeCompressed, totalSizeUncompressed);
+  return result;
 }
 
 void DataInputDirector::closeInputFiles()