Namespace test globals for external_pointer

Some times the global count was leading to a warning with a local count
in the test.

src/test/perf/external_pointer/externalpointer.cc

@@ -5,62 +5,66 @@
 
 using namespace snmalloc;
 
-constexpr size_t count_log = 20;
-constexpr size_t count = 1 << count_log;
-// Pre allocate all the objects
-size_t* objects[count];
-
-NOINLINE void setup(xoroshiro::p128r64& r, Alloc* alloc)
+namespace test
 {
-  for (size_t i = 0; i < count; i++)
+  static constexpr size_t count_log = 20;
+  static constexpr size_t count = 1 << count_log;
+  // Pre allocate all the objects
+  size_t* objects[count];
+
+
+  NOINLINE void setup(xoroshiro::p128r64& r, Alloc* alloc)
   {
-    size_t rand = (size_t)r.next();
-    size_t offset = bits::clz(rand);
-    if (offset > 30)
-      offset = 30;
-    size_t size = (rand & 15) << offset;
-    if (size < 16)
-      size = 16;
-    // store object
-    objects[i] = (size_t*)alloc->alloc(size);
-    // Store allocators size for this object
-    *objects[i] = Alloc::alloc_size(objects[i]);
-  }
-}
-
-NOINLINE void teardown(Alloc* alloc)
-{
-  // Deallocate everything
-  for (size_t i = 0; i < count; i++)
-  {
-    alloc->dealloc(objects[i]);
-  }
-
-  current_alloc_pool()->debug_check_empty();
-}
-
-void test_external_pointer(xoroshiro::p128r64& r)
-{
-  auto* alloc = ThreadAlloc::get();
-
-  setup(r, alloc);
-
-  DO_TIME("External pointer queries ", {
-    for (size_t i = 0; i < 10000000; i++)
+    for (size_t i = 0; i < count; i++)
     {
       size_t rand = (size_t)r.next();
-      size_t oid = rand & (((size_t)1 << count_log) - 1);
-      size_t* external_ptr = objects[oid];
-      size_t size = *external_ptr;
-      size_t offset = (size >> 4) * (rand & 15);
-      size_t interior_ptr = ((size_t)external_ptr) + offset;
-      void* calced_external = Alloc::external_pointer((void*)interior_ptr);
-      if (calced_external != external_ptr)
-        abort();
+      size_t offset = bits::clz(rand);
+      if (offset > 30)
+        offset = 30;
+      size_t size = (rand & 15) << offset;
+      if (size < 16)
+        size = 16;
+      // store object
+      objects[i] = (size_t*)alloc->alloc(size);
+      // Store allocators size for this object
+      *objects[i] = Alloc::alloc_size(objects[i]);
     }
-  });
+  }
 
-  teardown(alloc);
+  NOINLINE void teardown(Alloc* alloc)
+  {
+    // Deallocate everything
+    for (size_t i = 0; i < count; i++)
+    {
+      alloc->dealloc(objects[i]);
+    }
+
+    current_alloc_pool()->debug_check_empty();
+  }
+
+  void test_external_pointer(xoroshiro::p128r64& r)
+  {
+    auto* alloc = ThreadAlloc::get();
+
+    setup(r, alloc);
+
+    DO_TIME("External pointer queries ", {
+      for (size_t i = 0; i < 10000000; i++)
+      {
+        size_t rand = (size_t)r.next();
+        size_t oid = rand & (((size_t)1 << count_log) - 1);
+        size_t* external_ptr = objects[oid];
+        size_t size = *external_ptr;
+        size_t offset = (size >> 4) * (rand & 15);
+        size_t interior_ptr = ((size_t)external_ptr) + offset;
+        void* calced_external = Alloc::external_pointer((void*)interior_ptr);
+        if (calced_external != external_ptr)
+          abort();
+      }
+    });
+
+    teardown(alloc);
+  }
 }
 
 int main(int, char**)
@@ -73,6 +77,6 @@ int main(int, char**)
 #endif
 
   for (size_t n = 0; n < nn; n++)
-    test_external_pointer(r);
+    test::test_external_pointer(r);
   return 0;
 }