/* TCPmtechod.c - main, TCPechod, prstats */#include <unistd.h>#include <stdlib.h>#include <stdio.h>#include <string.h>#include <pthread.h>#include <sys/types.h>#include <sys/signal.h>#include <sys/socket.h>#include <sys/time.h>#include <sys/resource.h>#include <sys/wait.h>#include <sys/errno.h>#include <netinet/in.h>#define	QLEN		  32	/* maximum connection queue length	*/#define	BUFSIZE		4096#define	INTERVAL	5	/* secs */struct {	pthread_mutex_t	st_mutex;	unsigned int	st_concount;	unsigned int	st_contotal;	unsigned long	st_contime;	unsigned long	st_bytecount;} stats;void	prstats(void);int	TCPechod(int fd);int	errexit(const char *format, ...);int	passiveTCP(const char *service, int qlen);/*------------------------------------------------------------------------ * main - Concurrent TCP server for ECHO service *------------------------------------------------------------------------ */intmain(int argc, char *argv[]){	pthread_t	th;	pthread_attr_t	ta;	char	*service = "echo";	/* service name or port number	*/	struct	sockaddr_in fsin;	/* the address of a client	*/	unsigned int	alen;		/* length of client's address	*/	int	msock;			/* master server socket		*/	int	ssock;			/* slave server socket		*/	switch (argc) {	case	1:		break;	case	2:		service = argv[1];		break;	default:		errexit("usage: TCPechod [port]\n");	}	msock = passiveTCP(service, QLEN);	(void) pthread_attr_init(&ta);	(void) pthread_attr_setdetachstate(&ta, PTHREAD_CREATE_DETACHED);	(void) pthread_mutex_init(&stats.st_mutex, 0);	if (pthread_create(&th, &ta, (void * (*)(void *))prstats, 0) < 0)		errexit("pthread_create(prstats): %s\n", strerror(errno));	while (1) {		alen = sizeof(fsin);		ssock = accept(msock, (struct sockaddr *)&fsin, &alen);		if (ssock < 0) {			if (errno == EINTR)				continue;			errexit("accept: %s\n", strerror(errno));		}		if (pthread_create(&th, &ta, (void * (*)(void *))TCPechod,		    (void *)ssock) < 0)			errexit("pthread_create: %s\n", strerror(errno));	}}/*------------------------------------------------------------------------ * TCPechod - echo data until end of file *------------------------------------------------------------------------ */intTCPechod(int fd){	time_t	start;	char	buf[BUFSIZ];	int	cc;	start = time(0);	(void) pthread_mutex_lock(&stats.st_mutex);	stats.st_concount++;	(void) pthread_mutex_unlock(&stats.st_mutex);	while (cc = read(fd, buf, sizeof buf)) {		if (cc < 0)			errexit("echo read: %s\n", strerror(errno));		if (write(fd, buf, cc) < 0)			errexit("echo write: %s\n", strerror(errno));		(void) pthread_mutex_lock(&stats.st_mutex);		stats.st_bytecount += cc;		(void) pthread_mutex_unlock(&stats.st_mutex);	}	(void) close(fd);	(void) pthread_mutex_lock(&stats.st_mutex);	stats.st_contime += time(0) - start;	stats.st_concount--;	stats.st_contotal++;	(void) pthread_mutex_unlock(&stats.st_mutex);	return 0;}/*------------------------------------------------------------------------ * prstats - print server statistical data *------------------------------------------------------------------------ */voidprstats(void){	time_t	now;	while (1) {		(void) sleep(INTERVAL);		(void) pthread_mutex_lock(&stats.st_mutex);		now = time(0);		(void) printf("--- %s", ctime(&now));		(void) printf("%-32s: %u\n", "Current connections",			stats.st_concount);		(void) printf("%-32s: %u\n", "Completed connections",			stats.st_contotal);		if (stats.st_contotal) {			(void) printf("%-32s: %.2f (secs)\n",				"Average complete connection time",				(float)stats.st_contime /				(float)stats.st_contotal);			(void) printf("%-32s: %.2f\n",				"Average byte count",				(float)stats.st_bytecount /				(float)(stats.st_contotal +				stats.st_concount));		}		(void) printf("%-32s: %lu\n\n", "Total byte count",			stats.st_bytecount);		(void) pthread_mutex_unlock(&stats.st_mutex);	}}