Matakuliah : H0483 / Network Programming
Tahun
: 2008
Versi
: 2.0
Pertemuan 6
Server dengan Multi Thread
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• mendemonstrasikan program aplikasi
client- server dengan multithread
Outline Materi
•
•
•
•
•
Pengertian program
Pengertian proses
Pengertian threads
Beda multiproses vs multithread
Kasus: Server dengan multithread
The Process Model
a. Multiprogramming of four programs
b. Conceptual model of 4 independent, sequential
processes
c. Only one program active at any instant
Process States
• Possible process states
– running
– blocked
– ready
• Transitions between states shown
Threads
The Thread Model
(a) Three processes each with one thread
(b) One process with three threads
The Thread Model
• Items shared by all threads in a process
• Items private to each thread
The Thread Model
Each thread has its own stack
Thread Usage (1)
A word processor with three threads
Pop-Up Threads
• Creation of a new thread when message arrives
(a) before message arrives
(b) after message arrives
CONTOH PROGRAM
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <pthread.h>
void* thread_proc(void *arg);
int main(int argc, char *argv[])
{
struct sockaddr_in sAddr;
int listensock;
int newsock;
int result;
pthread_t thread_id;
int val;
listensock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
CONTOH PROGRAM
val = 1;
result = setsockopt(listensock, SOL_SOCKET, SO_REUSEADDR,
&val, sizeof(val));
if(result < 0){ perror("serverthread1");
return 0;
}
sAddr.sin_family = AF_INET;
sAddr.sin_port = htons(1972);
sAddr.sin_addr.s_addr = INADDR_ANY;
result = bind(listensock, (struct sockaddr *) &sAddr, sizeof(sAddr));
if(result < 0) { perror("serverthread1");
return 0;
}
result=listen(listensock, 5);
if(result < 0) { perror("serverthread1");
return 0;
}
CONTOH PROGRAM
while(1){
newsock = accept(listensock, NULL ,NULL);
result = pthread_create(&thread_id, NULL, thread_proc, (void *)
newsock);
if(result != 0){
printf("Could not create thread.\n");
return 0;
}
pthread_detach(thread_id); // melepaskan/detach a thread
sched_yield(); /*function shall force the running thread to relinquish
the processor until it again becomes the head of its thread lis */
}
}
CONTOH PROGRAM
void* thread_proc(void *arg)
{
int sock;
char buffer[25];
int nread;
printf("child thread %u with pid %i created.\n", pthread_self(),
getpid());
sock = (int) arg;
nread = recv(sock, buffer, 25, 0);
buffer[nread] = '\0';
printf("%s\n", buffer);
send(sock, buffer, nread, 0);
close(sock);
printf("child thread %u with pid %i finished.\n", pthread_self(),
getpid());
}
Latihan
1.
2.
3.
Perhatikan contoh program diatas, bolehkan variabel
newsocket diatas dibuat menjadi variabel global?,
sehingga pada fungsi “thread_proc” variabel
newsocket bisa digunakan ?
Setelah accept mengapa tidak perlu
close(listensocket) ?, seperti pada server dengan
fork() ?
Variabel int sock pada fungsi “thread_proc”, digunakan
untuk menyimpan socket dari client yang connect
dengan server. Jelaskan mengapa bisa demikian ?