三个条件必须都不成立
int quit_sig = 0;
int exit_sig = 0;
int tx_status = 0;
do {
cout << "hello,world" << endl;
} while ((tx_status != 1) && (quit_sig != 1) && (exit_sig != 1));
int quit_sig = 0;
int exit_sig = 0;
int tx_status = 0;
do {
cout << "hello,world" << endl;
} while ((tx_status != 1) && (quit_sig != 1) && (exit_sig != 1));