fix race in get_prolongation_matrix()

tjhei · tjhei · commit 648f224c265a · 2024-12-11T16:26:49.000-05:00
diff --git a/include/deal.II/fe/fe_dgq.h b/include/deal.II/fe/fe_dgq.h
@@ -371,7 +371,6 @@ class FE_DGQ : public FE_Poly<dim, spacedim>
    * and embedding matrices.
    */
   mutable Threads::Mutex restriction_matrix_mutex;
-  mutable Threads::Mutex prolongation_matrix_mutex;
 
   // Allow access from other dimensions.
   template <int dim1, int spacedim1>
diff --git a/source/fe/fe_dgq.cc b/source/fe/fe_dgq.cc
@@ -435,7 +435,7 @@ FE_DGQ<dim, spacedim>::get_prolongation_matrix(
   // initialization upon first request
   if (this->prolongation[refinement_case - 1][child].n() == 0)
     {
-      std::lock_guard<std::mutex> lock(prolongation_matrix_mutex);
+      std::lock_guard<std::mutex> lock(restriction_matrix_mutex);
 
       // if matrix got updated while waiting for the lock
       if (this->prolongation[refinement_case - 1][child].n() ==

Original file line number	Diff line number	Diff line change
`@@ -435,7 +435,7 @@ FE_DGQ<dim, spacedim>::get_prolongation_matrix(`
`435`	`435`	`// initialization upon first request`
`436`	`436`	`if (this->prolongation[refinement_case - 1][child].n() == 0)`
`437`	`437`	`{`
`438`		`- std::lock_guard<std::mutex> lock(prolongation_matrix_mutex);`
	`438`	`+ std::lock_guard<std::mutex> lock(restriction_matrix_mutex);`
`439`	`439`
`440`	`440`	`// if matrix got updated while waiting for the lock`
`441`	`441`	`if (this->prolongation[refinement_case - 1][child].n() ==`