rb_blocking_function_t  534 ext/socket/basicsocket.c     rb_blocking_function_t *func;
rb_blocking_function_t  457 ext/socket/init.c     rb_blocking_function_t *func = connect_blocking;
rb_blocking_function_t 1518 internal.h     VALUE rb_thread_io_blocking_region(rb_blocking_function_t *func, void *data1, int fd);
rb_blocking_function_t 1412 thread.c       rb_thread_io_blocking_region(rb_blocking_function_t *func, void *data1, int fd)