BIO_should_read
if (BIO_should_read(bio)) {
} else if (BIO_should_read(bio)) {
if (BIO_should_read(ssl->rbio))
if (BIO_should_read(c_bio))
if (BIO_should_read(c_bio))
if (BIO_should_read(s_bio))
if (BIO_should_read(s_bio))
if ((!BIO_should_read(ocsp->ocsp_cbio) || (event & EV_READ)) &&
if (BIO_should_read(ocsp->ocsp_cbio))
if (BIO_should_read(cbio)) {