Raise ArgumentError when trying to use GVL profiling on unsupported R…

…ubies

ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c

@@ -802,8 +802,8 @@ static VALUE release_gvl_and_run_sampling_trigger_loop(VALUE instance) {
     ;
   }
 
-  #ifndef NO_GVL_INSTRUMENTATION
-    if (state->gvl_profiling_enabled) {
+  if (state->gvl_profiling_enabled) {
+    #ifndef NO_GVL_INSTRUMENTATION
       state->gvl_profiling_hook = rb_internal_thread_add_event_hook(
         on_gvl_event,
         (
@@ -814,8 +814,10 @@ static VALUE release_gvl_and_run_sampling_trigger_loop(VALUE instance) {
         ),
         NULL
       );
-    }
-  #endif
+    #else
+      rb_raise(rb_eArgError, "GVL profiling is not supported in this Ruby version");
+    #endif
+  }
 
   // Flag the profiler as running before we release the GVL, in case anyone's waiting to know about it
   rb_funcall(instance, rb_intern("signal_running"), 0);

spec/datadog/profiling/collectors/cpu_and_wall_time_worker_spec.rb

@@ -148,6 +148,18 @@
       end
     end
 
+    context "when gvl_profiling_enabled is true on an unsupported Ruby" do
+      before { skip "Behavior does not apply to current Ruby version" if RUBY_VERSION >= "3.3." }
+
+      let(:gvl_profiling_enabled) { true }
+
+      it do
+        expect(Datadog.logger).to receive(:warn).with(/GVL profiling is not supported/)
+
+        cpu_and_wall_time_worker.start
+      end
+    end
+
     context "when gvl_profiling_enabled is false" do
       let(:gvl_profiling_enabled) { false }
 
@@ -935,6 +947,8 @@
 
     context "after starting" do
       before do
+        skip_if_gvl_profiling_not_supported(self) if gvl_profiling_enabled
+
         cpu_and_wall_time_worker.start
         wait_until_running
       end
@@ -967,8 +981,6 @@
       end
 
       context "when GVL profiling is enabled" do
-        before { skip_if_gvl_profiling_not_supported(self) { stop } }
-
         let(:gvl_profiling_enabled) { true }
 
         it "disables the GVL profiling hook" do
@@ -1005,6 +1017,8 @@
     let(:options) { {thread_context_collector: thread_context_collector} }
 
     before do
+      skip_if_gvl_profiling_not_supported(self) if gvl_profiling_enabled
+
       # This is important -- the real #reset_after_fork must not be called concurrently with the worker running,
       # which we do in this spec to make it easier to test the reset_after_fork behavior
       allow(thread_context_collector).to receive(:reset_after_fork)
@@ -1024,8 +1038,6 @@
     end
 
     context "when gvl_profiling_enabled is true" do
-      before { skip_if_gvl_profiling_not_supported(self) }
-
       let(:gvl_profiling_enabled) { true }
 
       it "disables the gvl profiling hook" do

spec/datadog/profiling/spec_helper.rb

@@ -122,9 +122,8 @@ def self.maybe_fix_label_range(key, value)
     end
   end
 
-  def skip_if_gvl_profiling_not_supported(testcase, &skip_steps)
+  def skip_if_gvl_profiling_not_supported(testcase)
     if RUBY_VERSION < "3.3."
-      yield if skip_steps
       testcase.skip "GVL profiling is only supported on Ruby >= 3.3"
     end
   end