PHP_SAFE_FD_SET   198 main/php_network.h # define PHP_SAFE_FD_SET(fd, set)	FD_SET(fd, set)
PHP_SAFE_FD_SET   203 main/php_network.h # define PHP_SAFE_FD_SET(fd, set)	do { if (fd < FD_SETSIZE) FD_SET(fd, set); } while(0)