rb_mutex_synchronize  712 include/ruby/intern.h VALUE rb_mutex_synchronize(VALUE mutex, VALUE (*func)(VALUE arg), VALUE arg);
rb_mutex_synchronize  573 io.c           	r = rb_mutex_synchronize(fptr->write_lock, io_flush_buffer, (VALUE)fptr);
rb_mutex_synchronize  820 io.c           	    r = rb_mutex_synchronize(fptr->write_lock, io_binwrite_string, (VALUE)&arg);
rb_mutex_synchronize 3120 io.c                       err = rb_mutex_synchronize(fptr->write_lock, finish_writeconv_sync, (VALUE)&arg);