rb_mutex_synchronize  905 include/ruby/intern.h VALUE rb_mutex_synchronize(VALUE mutex, VALUE (*func)(VALUE arg), VALUE arg);
rb_mutex_synchronize 1080 io.c           	    return (int)rb_mutex_synchronize(fptr->write_lock, io_flush_buffer_async2, (VALUE)fptr);
rb_mutex_synchronize 1330 io.c           	    r = rb_mutex_synchronize(fptr->write_lock, io_binwrite_string, (VALUE)&arg);
rb_mutex_synchronize 4213 io.c                       err = rb_mutex_synchronize(fptr->write_lock, finish_writeconv_sync, (VALUE)&arg);
rb_mutex_synchronize  508 thread_sync.c      return rb_mutex_synchronize(self, rb_yield, Qundef);