1 files changed, 24 insertions, 14 deletions
diff --git a/test/ruby/test_string_memory.rb b/test/ruby/test_string_memory.rb
index 3b4694f36f..a93a3bd54a 100644
--- a/test/ruby/test_string_memory.rb
+++ b/test/ruby/test_string_memory.rb
@@ -6,21 +6,31 @@ class TestStringMemory < Test::Unit::TestCase
   def capture_allocations(klass)
     allocations = []
 
-    GC.start
-    GC.disable
-    generation = GC.count
+    EnvUtil.without_gc do
+      GC.start
+      generation = GC.count
 
-    ObjectSpace.trace_object_allocations do
-      yield
+      ObjectSpace.trace_object_allocations do
+        yield
 
-      ObjectSpace.each_object(klass) do |instance|
-        allocations << instance if ObjectSpace.allocation_generation(instance) == generation
+        ObjectSpace.each_object(klass) do |instance|
+          allocations << instance if ObjectSpace.allocation_generation(instance) == generation
+        end
       end
-    end
 
-    return allocations
-  ensure
-    GC.enable
+      return allocations.map do |instance|
+        [
+          ObjectSpace.allocation_sourcefile(instance),
+          ObjectSpace.allocation_sourceline(instance),
+          instance.class,
+          instance,
+        ]
+      end.select do |path,|
+        # drop strings not created in this file
+        # (the parallel testing framework may create strings in a separate thread)
+        path == __FILE__
+      end
+    end
   end
 
   def test_byteslice_prefix
@@ -30,7 +40,7 @@ class TestStringMemory < Test::Unit::TestCase
       string.byteslice(0, 50_000)
     end
 
-    assert_equal 1, allocations.size
+    assert_equal 1, allocations.size, "One object allocation is expected, but allocated: #{ allocations.inspect }"
   end
 
   def test_byteslice_postfix
@@ -40,7 +50,7 @@ class TestStringMemory < Test::Unit::TestCase
       string.byteslice(50_000, 100_000)
     end
 
-    assert_equal 1, allocations.size
+    assert_equal 1, allocations.size, "One object allocation is expected, but allocated: #{ allocations.inspect }"
   end
 
   def test_byteslice_postfix_twice
@@ -50,6 +60,6 @@ class TestStringMemory < Test::Unit::TestCase
       string.byteslice(50_000, 100_000).byteslice(25_000, 50_000)
     end
 
-    assert_equal 2, allocations.size
+    assert_equal 2, allocations.size, "Two object allocations are expected, but allocated: #{ allocations.inspect }"
   end
 end