Expose ruby_thread_has_gvl_p.

Author: ioquatix

include/ruby/thread.h

@@ -333,6 +333,13 @@ void *rb_internal_thread_specific_get(VALUE thread_val, rb_internal_thread_speci
  */
 void rb_internal_thread_specific_set(VALUE thread_val, rb_internal_thread_specific_key_t key, void *data);
 
+/**
+ * Whether the current thread is holding the GVL.
+ *
+ * @return true if the current thread is holding the GVL, false otherwise.
+ */
+int ruby_thread_has_gvl_p(void);
+
 RBIMPL_SYMBOL_EXPORT_END()
 
 #endif /* RUBY_THREAD_H */

spec/ruby/optional/capi/ext/thread_spec.c

@@ -118,7 +118,6 @@ static VALUE thread_spec_rb_thread_wait_for(VALUE self, VALUE s, VALUE ms) {
   return Qnil;
 }
 
-
 VALUE thread_spec_call_proc(void *arg_ptr) {
   VALUE arg_array = (VALUE)arg_ptr;
   VALUE arg = rb_ary_pop(arg_array);
@@ -167,6 +166,12 @@ static VALUE thread_spec_ruby_native_thread_p_new_thread(VALUE self) {
 #endif
 }
 
+#ifdef RUBY_VERSION_IS_3_5
+static VALUE thread_spec_ruby_thread_has_gvl_p(VALUE self) {
+  return ruby_thread_has_gvl_p() ? Qtrue : Qfalse;
+}
+#endif
+
 void Init_thread_spec(void) {
   VALUE cls = rb_define_class("CApiThreadSpecs", rb_cObject);
   rb_define_method(cls, "rb_thread_alone", thread_spec_rb_thread_alone, 0);
@@ -180,6 +185,9 @@ void Init_thread_spec(void) {
   rb_define_method(cls,  "rb_thread_create", thread_spec_rb_thread_create, 2);
   rb_define_method(cls,  "ruby_native_thread_p", thread_spec_ruby_native_thread_p, 0);
   rb_define_method(cls,  "ruby_native_thread_p_new_thread", thread_spec_ruby_native_thread_p_new_thread, 0);
+#ifdef RUBY_VERSION_IS_3_5
+  rb_define_method(cls,  "ruby_thread_has_gvl_p", thread_spec_ruby_thread_has_gvl_p, 0);
+#endif
 }
 
 #ifdef __cplusplus

spec/ruby/optional/capi/thread_spec.rb

@@ -184,4 +184,12 @@ def call_capi_rb_thread_wakeup
       thr.value.should be_true
     end
   end
+
+  ruby_version_is "3.5" do
+    describe "ruby_thread_has_gvl_p" do
+      it "returns true if the current thread has the GVL" do
+        @t.ruby_thread_has_gvl_p.should be_true
+      end
+    end
+  end
 end

thread.c

@@ -1937,11 +1937,6 @@ rb_thread_call_with_gvl(void *(*func)(void *), void *data1)
 
 /*
  * ruby_thread_has_gvl_p - check if current native thread has GVL.
- *
- ***
- *** This API is EXPERIMENTAL!
- *** We do not guarantee that this API remains in ruby 1.9.2 or later.
- ***
  */
 
 int