add `rb_th_serial()`

`rb_th_serial(th)` returns th's serial for debug print purpose.

1 files changed, 6 insertions, 0 deletions

diff --git a/vm_core.h b/vm_core.h
index 4de0777292..58fb1e7e3b 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -1078,6 +1078,12 @@ typedef struct rb_thread_struct {
 #endif
 } rb_thread_t;
 
+static inline unsigned int
+rb_th_serial(const rb_thread_t *th)
+{
+    return (unsigned int)th->serial;
+}
+
 typedef enum {
     VM_DEFINECLASS_TYPE_CLASS           = 0x00,
     VM_DEFINECLASS_TYPE_SINGLETON_CLASS = 0x01,