From 84a7e8eea3bd7dcb204b7e07e641e6ef50d97fa6 Mon Sep 17 00:00:00 2001
From: Giulio Eulisse <10544+ktf@users.noreply.github.com>
Date: Tue, 16 Jan 2024 14:20:51 +0100
Subject: [PATCH] DPL: discard timeframe in case there is nothing which needs
 processing

---
 Framework/Core/src/CompletionPolicyHelpers.cxx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Framework/Core/src/CompletionPolicyHelpers.cxx b/Framework/Core/src/CompletionPolicyHelpers.cxx
index 8c4b38ba3355c..b2b2fe7323742 100644
--- a/Framework/Core/src/CompletionPolicyHelpers.cxx
+++ b/Framework/Core/src/CompletionPolicyHelpers.cxx
@@ -111,6 +111,7 @@ CompletionPolicy CompletionPolicyHelpers::consumeWhenAll(const char* name, Compl
 
     size_t si = 0;
     bool missingSporadic = false;
+    bool needsProcessing = false;
     size_t currentTimeslice = -1;
     for (auto& input : inputs) {
       assert(si < specs.size());
@@ -126,6 +127,9 @@ CompletionPolicy CompletionPolicyHelpers::consumeWhenAll(const char* name, Compl
         if (dph && !TimingInfo::timesliceIsTimer(dph->startTime)) {
           currentTimeslice = dph->startTime;
         }
+        // Prepare for processing if we have at least some data, we can consume, otherwise we can Discard once
+        // we are sure that no more data will come.
+        needsProcessing |= (spec.lifetime != Lifetime::Condition);
       }
     }
     // If some sporadic inputs are missing, we wait for them util we are sure they will not come,
@@ -136,7 +140,8 @@ CompletionPolicy CompletionPolicyHelpers::consumeWhenAll(const char* name, Compl
     if (missingSporadic && currentTimeslice >= oldestPossibleTimeslice) {
       return CompletionPolicy::CompletionOp::Retry;
     }
-    return CompletionPolicy::CompletionOp::Consume;
+    // We only consume if we have something which needs processing.
+    return needsProcessing ? CompletionPolicy::CompletionOp::Consume : CompletionPolicy::CompletionOp::Discard;
   };
   return CompletionPolicy{name, matcher, callback};
 }