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serv02.c
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serv02.c
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/* include serv02 */
#include "unp.h"
static int nchildren;
static pid_t *pids;
int
main(int argc, char **argv)
{
int listenfd, i;
socklen_t addrlen;
void sig_int(int);
pid_t child_make(int, int, int);
if (argc == 3)
listenfd = Tcp_listen(NULL, argv[1], &addrlen);
else if (argc == 4)
listenfd = Tcp_listen(argv[1], argv[2], &addrlen);
else
err_quit("usage: serv02 [ <host> ] <port#> <#children>");
nchildren = atoi(argv[argc-1]);//最后一个参数指明子进程的数量
//pids指向子进程ID的数组
pids = Calloc(nchildren, sizeof(pid_t));
//派生nchildren个子进程
for (i = 0; i < nchildren; i++)
pids[i] = child_make(i, listenfd, addrlen); /* parent returns */
Signal(SIGINT, sig_int);//ctrl+c会发送SIGINT信号,终止进程
for ( ; ; )
pause(); /* everything done by children */
}
/* end serv02 */
/* include sigint */
void
sig_int(int signo)
{
int i;
void pr_cpu_time(void);
//终止nchildren个子进程
for (i = 0; i < nchildren; i++)
kill(pids[i], SIGTERM);
while (wait(NULL) > 0) /* wait for all children */
;
if (errno != ECHILD)
err_sys("wait error");
pr_cpu_time(); //统计CPU使用情况,用于观察进程控制带来的开销
exit(0);
}
/* end sigint */