check for allocations from mortars (trixi-framework#1405)

* check for allocations from mortars

* update comment

test/test_p4est_2d.jl

@@ -23,6 +23,15 @@ isdir(outdir) && rm(outdir, recursive=true)
     @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_advection_nonconforming_flag.jl"),
       l2   = [3.198940059144588e-5],
       linf = [0.00030636069494005547])
+
+    # Ensure that we do not have excessive memory allocations 
+    # (e.g., from type instabilities)
+    let
+      t = sol.t[end]
+      u_ode = sol.u[end]
+      du_ode = similar(u_ode)
+      @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 1000
+    end
   end
 
   @trixi_testset "elixir_advection_unstructured_flag.jl" begin

test/test_p4est_3d.jl

@@ -29,6 +29,15 @@ isdir(outdir) && rm(outdir, recursive=true)
     @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_advection_nonconforming.jl"),
       l2   = [0.00253595715323843],
       linf = [0.016486952252155795])
+
+    # Ensure that we do not have excessive memory allocations 
+    # (e.g., from type instabilities)
+    let
+      t = sol.t[end]
+      u_ode = sol.u[end]
+      du_ode = similar(u_ode)
+      @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 1000
+    end
   end
 
   @trixi_testset "elixir_advection_amr.jl" begin

test/test_tree_2d_advection.jl

@@ -37,6 +37,15 @@ EXAMPLES_DIR = joinpath(pathof(Trixi) |> dirname |> dirname, "examples", "tree_2
       # Expected errors are exactly the same as in the parallel test!
       l2   = [0.0015188466707237375],
       linf = [0.008446655719187679])
+
+    # Ensure that we do not have excessive memory allocations 
+    # (e.g., from type instabilities)
+    let
+      t = sol.t[end]
+      u_ode = sol.u[end]
+      du_ode = similar(u_ode)
+      @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 1000
+    end
   end
 
   @trixi_testset "elixir_advection_amr.jl" begin

test/test_tree_3d_advection.jl

@@ -47,6 +47,15 @@ EXAMPLES_DIR = joinpath(pathof(Trixi) |> dirname |> dirname, "examples", "tree_3
     @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_advection_mortar.jl"),
       l2   = [0.001810141301577316],
       linf = [0.017848192256602058])
+
+    # Ensure that we do not have excessive memory allocations 
+    # (e.g., from type instabilities)
+    let
+      t = sol.t[end]
+      u_ode = sol.u[end]
+      du_ode = similar(u_ode)
+      @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 1000
+    end
   end
 
   @trixi_testset "elixir_advection_amr.jl" begin