Peeking, Unix Sockets & Threads

Ø Peeking at received data

Ø Unix domain sockets

ü Stream

ü Datagram

Ø Threads

ü Functions

ü Simple Example

ü Synchronization

Ø Peeking at received data:

ü PeekServer.c &

ü PeekClient.c

Peek:
 cc = recv(fd, buf, sizeof buf, MSG_PEEK);

Read:

cc = recv(fd, buf, sizeof buf,0);

Ø Unix domain sockets:

ü Stream

à unixstrcli01.c &

à unixstrserv01c

The client and server communicate via the common file:

#define UNIXSTR_PATH "/tmp/unix.str"

ü Datagram

à unixdgcli01.c &

à unixdgserv01.c

The client and server communicate via the common file:

#define UNIXDG_PATH "/tmp/unix.dg"

Ø Threads

ü Functions:

à pthread_create  (ThreadID, Priority, Starting Fun, Fun Args)

à pthread_join    // similar to waitpid

à pthread_self     // similar to getpid

à pthread_detach  // not joinable

à pthread_exit     // terminate a thread;

à // calling exit() kills ALL threads.

ü Simple Exampls:

à tcpcli01.c uses (strclithread.c)  & 

à tcpserv01.c

ü Synchronization:

à non-synch example: example01.c

use: % script file
        % example01
        % look at file to see the problem

à synchronized example: example02.c

It uses:

Pthread_mutex_lock()

{ Critical Section}

Pthread_mutex_unlock()