[ruby/fiddle] test: ensure GC-ing closures

GitHub: fix GH-102

We can't use Fiddle::Closure before we fork the process. If we do it,
the process may be crashed with SELinux.

See https://github.com/ruby/fiddle/issues/102#issuecomment-1241763091
for details.

Reported by Vít Ondruch. Thanks!!!

https://github.com/ruby/fiddle/commit/1343ac7a95

4 files changed, 24 insertions, 6 deletions

diff --git a/test/fiddle/test_closure.rb b/test/fiddle/test_closure.rb
index 9e748bf5ee..1a7c41fd95 100644
--- a/test/fiddle/test_closure.rb
+++ b/test/fiddle/test_closure.rb
@@ -6,6 +6,14 @@ end
 
 module Fiddle
   class TestClosure < Fiddle::TestCase
+    def teardown
+      super
+      # Ensure freeing all closures.
+      # See https://github.com/ruby/fiddle/issues/102#issuecomment-1241763091 .
+      GC.start
+      assert_equal(0, ObjectSpace.each_object(Fiddle::Closure) {})
+    end
+
     def test_argument_errors
       assert_raise(TypeError) do
         Closure.new(TYPE_INT, TYPE_INT)
@@ -103,6 +111,9 @@ module Fiddle
           func = Function.new(clos, [t], t)
           assert_equal(v, func.call(v))
           assert_equal(arg, v, n)
+        ensure
+          clos = nil
+          func = nil
         end
       end
     end
diff --git a/test/fiddle/test_func.rb b/test/fiddle/test_func.rb
index 44893017e8..45fed916ba 100644
--- a/test/fiddle/test_func.rb
+++ b/test/fiddle/test_func.rb
@@ -79,6 +79,12 @@ module Fiddle
         qsort.call(buff, buff.size, 1, cb)
       end
       assert_equal("1349", buff, bug4929)
+    ensure
+      # Ensure freeing all closures.
+      # See https://github.com/ruby/fiddle/issues/102#issuecomment-1241763091 .
+      cb = nil
+      GC.start
+      assert_equal(0, ObjectSpace.each_object(Fiddle::Closure) {})
     end
 
     def test_snprintf
diff --git a/test/fiddle/test_function.rb b/test/fiddle/test_function.rb
index 8ac4f60aa3..0a1159b7bc 100644
--- a/test/fiddle/test_function.rb
+++ b/test/fiddle/test_function.rb
@@ -15,6 +15,13 @@ module Fiddle
       end
     end
 
+    def teardown
+      # Ensure freeing all closures.
+      # See https://github.com/ruby/fiddle/issues/102#issuecomment-1241763091 .
+      GC.start
+      assert_equal(0, ObjectSpace.each_object(Fiddle::Closure) {})
+    end
+
     def test_default_abi
       func = Function.new(@libm['sin'], [TYPE_DOUBLE], TYPE_DOUBLE)
       assert_equal Function::DEFAULT, func.abi
diff --git a/test/fiddle/test_import.rb b/test/fiddle/test_import.rb
index afa8df9e00..831c1d310f 100644
--- a/test/fiddle/test_import.rb
+++ b/test/fiddle/test_import.rb
@@ -22,7 +22,6 @@ module Fiddle
     extern "int fprintf(FILE*, char*)" rescue nil
     extern "int gettimeofday(timeval*, timezone*)" rescue nil
 
-    BoundQsortCallback = bind("void *bound_qsort_callback(void*, void*)"){|ptr1,ptr2| ptr1[0] <=> ptr2[0]}
     Timeval = struct [
       "long tv_sec",
       "long tv_usec",
@@ -59,11 +58,6 @@ module Fiddle
         ]
       }
     ]
-
-    CallCallback = bind("void call_callback(void*, void*)"){ | ptr1, ptr2|
-      f = Function.new(ptr1.to_i, [TYPE_VOIDP], TYPE_VOID)
-      f.call(ptr2)
-    }
   end
 
   class TestImport < TestCase