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| | *It may require &read()/&recv() to be in the ''streamInfo'' structs to be called depening on whether the stream is a file or socket. | | *It may require &read()/&recv() to be in the ''streamInfo'' structs to be called depening on whether the stream is a file or socket. |
| | *''streamOpen()'' has been changed to allow a textual representation of the remote resource/peer to be passed with fd<0 so that it will try and resolve the text to a connected fd. | | *''streamOpen()'' has been changed to allow a textual representation of the remote resource/peer to be passed with fd<0 so that it will try and resolve the text to a connected fd. |
| − |
| |
| − | === Server Iteration - network() ===
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| − | Called by nodal reduction from ROOT loop. Each iteration must do a generic select-update, and process a single packet for one of the streams in each direction.
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| − |
| |
| − | === Select ===
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| − | Multiplexing with ''select''.
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| − | *[http://www.lowtek.com/sockets/select.html The World of Select()]
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| − |
| |
| − | === Socket ===
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| − |
| |
| − | Constants to setsockopts for buffers. This may be used for the ''iterative non-forking non-blocking socket select processing''.
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| − | SO_SNDBUF
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| − | Sets send buffer size information. This option takes an int value in the optval argument.
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| − | SO_RCVBUF
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| − | Sets receive buffer size information. This option takes an int value in the optval argument.
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| − |
| |
| − | --[[User:Rob|Rob]] 11:30, 5 Jul 2006 (NZST)
| |
| − | ----
| |
| − | *Find docs on simple socket interative no buffer no fork multiplexing (ask Rob b)
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| − | *Maybe let OS buffer stream until end of message detected, then chunk message into structure
| |
| − | **peek
| |
| − | ----
| |
| − | *added O_NONBLOCK so that the accept() returns even if no incomming requests
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| − | *made a struct-type called ''streamInfo'' and an array of them called ''streams'' so that all the corrently connected clients have their own accumulating input buffer.
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| − | *MAXCLIENTS is the size of the ''streams'' array
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| − | *BUFSIZE is the size of each streams input buffer which determines the largest message it can read
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| − | *PAKSIZE is the number of bytes read on each iteration of the server loop
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| − |
| |
| − | === Example snipits ===
| |
| − | Example select() from [http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.doc/libs/basetrf2/select.htm http://publib.boulder.ibm.com]
| |
| − | <pre>
| |
| − | int main()
| |
| − | {
| |
| − | int sockfd, cnt, i = 1;
| |
| − | struct sockaddr_in serv_addr;
| |
| − |
| |
| − | bzero((char *)&serv_addr, sizeof (serv_addr));
| |
| − | serv_addr.sin_family = AF_INET;
| |
| − | serv_addr.sin_addr.s_addr = inet_addr("172.16.55.25");
| |
| − | serv_addr.sin_port = htons(102);
| |
| − |
| |
| − | if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
| |
| − | exit(1);
| |
| − | if (fcntl(sockfd, F_SETFL, FNONBLOCK) < 0)
| |
| − | exit(1);
| |
| − | if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof
| |
| − | (serv_addr)) < 0 && errno != EINPROGRESS)
| |
| − | exit(1);
| |
| − | for (cnt=0; cnt<2; cnt++) {
| |
| − | fd_set readfds, writefds;
| |
| − |
| |
| − | FD_ZERO(&readfds);
| |
| − | FD_SET(sockfd, &readfds);
| |
| − | FD_ZERO(&writefds);
| |
| − | FD_SET(sockfd, &writefds);
| |
| − |
| |
| − | if (select(sockfd + 1, &readfds, &writefds, NULL,
| |
| − | NULL) < 0)
| |
| − | exit(1);
| |
| − | printf("Iteration %d ==============\n", i);
| |
| − | printf("FD_ISSET(sockfd, &readfds) == %d\n",
| |
| − | FD_ISSET(sockfd, &readfds));
| |
| − | printf("FD_ISSET(sockfd, &writefds) == %d\n",
| |
| − | FD_ISSET(sockfd, &writefds));
| |
| − | i++;
| |
| − | }
| |
| − | return 0;
| |
| − | }
| |
| − | </pre>
| |
| − |
| |
| − | and another example from http://docs.sun.com/app/docs/doc/817-4415/6mjum5sgc?a=view
| |
| − |
| |
| − | <pre>
| |
| − | main() {
| |
| − | int sock, length;
| |
| − | struct sockaddr_in6 server;
| |
| − | int msgsock;
| |
| − | char buf[1024];
| |
| − | int rval;
| |
| − | fd_set ready;
| |
| − | struct timeval to;
| |
| − | /* Open a socket and bind it as in previous examples. */
| |
| − | /* Start accepting connections. */
| |
| − | listen(sock, MAXCLIENTS);
| |
| − | do {
| |
| − | FD_ZERO(&ready);
| |
| − | FD_SET(sock, &ready);
| |
| − | to.tv_sec = 5;
| |
| − | to.tv_usec = 0;
| |
| − | if (select(sock + 1, &ready, (fd_set *)0,
| |
| − | (fd_set *)0, &to) == -1) {
| |
| − | perror("select");
| |
| − | continue;
| |
| − | }
| |
| − | if (FD_ISSET(sock, &ready)) {
| |
| − | msgsock = accept(sock, (struct sockaddr *)0, (int *)0);
| |
| − | if (msgsock == -1)
| |
| − | perror("accept");
| |
| − | else do {
| |
| − | memset(buf, 0, sizeof buf);
| |
| − | if ((rval = read(msgsock, buf, sizeof(buf))) == -1)
| |
| − | perror("reading stream message");
| |
| − | else if (rval == 0)
| |
| − | printf("Ending connection\n");
| |
| − | else
| |
| − | printf("-->%s\n", buf);
| |
| − | } while (rval > 0);
| |
| − | close(msgsock);
| |
| − | } else
| |
| − | printf("Do something else\n");
| |
| − | } while (TRUE);
| |
| − | exit(0);
| |
| − | }
| |
| − | </pre>
| |
