Don't attempt to inspect thread from native code

Author: dalehamel

ext/vernier/vernier.cc

@@ -859,6 +859,7 @@ class Thread {
                     markers->record(Marker::Type::MARKER_GVL_THREAD_EXITED);
 
                     stopped_at = now;
+                    capture_name();
 
                     break;
             }
@@ -871,6 +872,13 @@ class Thread {
             return state != State::STOPPED;
         }
 
+        void capture_name() {
+            //char buf[128];
+            //int rc = pthread_getname_np(pthread_id, buf, sizeof(buf));
+            //if (rc == 0)
+            //    name = std::string(buf);
+        }
+
         void mark() {
         }
 };
@@ -937,12 +945,8 @@ class ThreadTable {
                     thread.set_state(new_state);
 
                     if (thread.state == Thread::State::RUNNING) {
-                        // rb_inspect should be safe here, as RUNNING should correspond to RESUMED hook from internal_thread_event_cb
-                        // which is called with GVL per https://github.com/ruby/ruby/blob/v3_3_0/include/ruby/thread.h#L247-L248
-                        VALUE thread_str  = rb_inspect(th);
                         thread.pthread_id = pthread_self();
                         thread.native_tid = get_native_thread_id();
-                        thread.name = StringValueCStr(thread_str);
                     } else {
                         thread.pthread_id = 0;
                         thread.native_tid = 0;
@@ -1492,6 +1496,13 @@ class TimeCollector : public BaseCollector {
         rb_remove_event_hook(internal_gc_event_cb);
         rb_remove_event_hook(internal_thread_event_cb);
 
+        // capture thread names
+        for (auto& thread: this->threads.list) {
+            if (thread.running()) {
+                thread.capture_name();
+            }
+        }
+
         frame_list.finalize();
 
         VALUE result = build_collector_result();