DPL: wait as long as possible for Sporadic inputs

Right now if we have the standard consumeWhenAll policy and we have a sporadic
input, it will wait indefinitely until all the inputs arrive or it will drop
timeframes without that sporadic input.

This changes the behavior and waits only until the oldest possible timeframe
does not allow the Sporadic input to be there. At which point, it schedules the
processing in any case, under the assumption that a task declaring a sporadic
input knows what to do in case it's not there.

Framework/Core/src/CompletionPolicyHelpers.cxx

@@ -15,6 +15,7 @@
 #include "Framework/DeviceSpec.h"
 #include "Framework/CompilerBuiltins.h"
 #include "Framework/Logger.h"
+#include "Framework/TimesliceIndex.h"
 #include "Framework/TimingInfo.h"
 #include "DecongestionService.h"
 
@@ -107,10 +108,32 @@ CompletionPolicy CompletionPolicyHelpers::consumeWhenAll(const char* name, Compl
 {
   auto callback = [](InputSpan const& inputs, std::vector<InputSpec> const& specs, ServiceRegistryRef& ref) -> CompletionPolicy::CompletionOp {
     assert(inputs.size() == specs.size());
+
+    size_t si = 0;
+    bool missingSporadic = false;
+    size_t currentTimeslice = -1;
     for (auto& input : inputs) {
-      if (input.header == nullptr) {
+      assert(si < specs.size());
+      auto& spec = specs[si++];
+      if (input.header == nullptr && spec.lifetime != Lifetime::Sporadic) {
         return CompletionPolicy::CompletionOp::Wait;
       }
+      if (input.header == nullptr && spec.lifetime == Lifetime::Sporadic) {
+        missingSporadic |= true;
+      }
+      if (input.header != nullptr) {
+        auto const* dph = framework::DataRefUtils::getHeader<o2::framework::DataProcessingHeader*>(input);
+        if (dph && !TimingInfo::timesliceIsTimer(dph->startTime)) {
+          currentTimeslice = dph->startTime;
+          break;
+        }
+      }
+    }
+    // If some sporadic inputs are missing, we wait for them util we are sure they will not come,
+    // i.e. until the oldest possible timeslice is beyond the timeslice of the input.
+    auto& timesliceIndex = ref.get<TimesliceIndex>();
+    if (missingSporadic && currentTimeslice >= timesliceIndex.getOldestPossibleInput().timeslice.value) {
+      return CompletionPolicy::CompletionOp::Wait;
     }
     return CompletionPolicy::CompletionOp::Consume;
   };