algo: Fix issue with freeing buffers in constant memory.

algo/detectors/sts/StsHitfinderChain.cxx

@@ -15,6 +15,14 @@ void sts::HitfinderChain::SetParameters(const sts::HitfinderPars& parameters)
   AllocateStatic();
 }
 
+void sts::HitfinderChain::Finalize()
+{
+  // Explicitly free buffers in constant memory.
+  // This avoids an issue in xpu with teardown order of static variables when using CPU.
+  fHitfinder = {};
+  xpu::set<TheHitfinder>(fHitfinder);
+}
+
 void sts::HitfinderChain::operator()(gsl::span<const CbmStsDigi> digis)
 {
   EnsureParameters();

algo/detectors/sts/StsHitfinderChain.h

@@ -43,6 +43,11 @@ namespace cbm::algo::sts
     void SetParameters(const sts::HitfinderPars& parameters);
     const sts::HitfinderPars& GetParameters() const { return *fPars; }
 
+    /**
+     * Teardown chain.
+     */
+    void Finalize();
+
     void operator()(gsl::span<const CbmStsDigi>);
 
   private:

algo/global/Reco.cxx

@@ -106,6 +106,8 @@ void Reco::Run(const fles::Timeslice& ts)
 
 void Reco::Finalize()
 {
+  fStsHitFinder.Finalize();
+
   // Pop timer that was started in Init()
   xpu::timings t = xpu::pop_timer();
   if (Opts().CollectKernelTimes()) {