Ajout d'un exeple de chat serveur avec kqueue. ça fait un peu chier de regrouper la partie gestion des accept et gestion des clients. (Et si un accept bloque ? Possible ?)origin/trunk

git-svn-id: file:///var/svn/2011-usi/trunk@17 db941bf7-0cb3-4dda-9634-87faf64f93a7

1 files changed, 201 insertions, 0 deletions

diff --git a/app/v3_c/examples/kqueue_chat.c b/app/v3_c/examples/kqueue_chat.c
new file mode 100644
index 0000000..b9d913c
--- /dev/null
+++ b/app/v3_c/examples/kqueue_chat.c
@@ -0,0 +1,201 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/event.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <err.h>
+
+/*
+ * simple kqueue chat server by Peter Werner <peterw@ifost.org.au>
+ */
+
+#define NUSERS 10
+
+/*
+ * we store each connected clients filedescriptor 
+ * and ip address in an array, which places an upper 
+ * bound of 10 users. This is done for simplicity.
+ */
+
+struct uc {
+	int uc_fd;
+	char *uc_addr;
+} users[NUSERS];
+
+/*
+ * bind(2) and listen(2) to a tcp port
+ */
+int
+mksock(char *addr, int port)
+{
+	int i, sock;
+	struct sockaddr_in serv;
+
+	sock = socket(AF_INET, SOCK_STREAM, 0);
+	if (sock == -1)
+		err(1, "socket");
+
+	i = 1;
+	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&i,
+	    (socklen_t)sizeof(i)) == -1)
+		warn("setsockopt");
+
+	memset(&serv, 0, sizeof(struct sockaddr_in));
+	serv.sin_family = AF_INET;
+	serv.sin_port = htons(port);
+	serv.sin_addr.s_addr = inet_addr(addr);
+
+	i = bind(sock, (struct sockaddr *)&serv, (socklen_t)sizeof(serv));
+	if (i == -1)
+		err(1, "bind");
+
+	i = listen(sock, 5);
+	if (i == -1)
+		err(1, "listen");
+
+	return(sock);
+}
+
+int
+main(void)
+{
+	int servsock, kq, i, uidx;
+	struct kevent ke;
+	struct sockaddr_in c; /* client */
+	socklen_t len;
+	char buf[1024];
+	char *umsg = "too many users!\n";
+	
+	/* get a listening socket */
+	servsock = mksock("127.0.0.1", 5000);
+
+	/* get our kqueue descriptor */
+	kq = kqueue();
+	if (kq == -1)
+		err(1, "kqueue!");
+
+	memset(&ke, 0, sizeof(struct kevent));
+	memset(users, 0, sizeof(struct uc) * NUSERS);
+	
+	/* fill out the kevent struct */
+	EV_SET(&ke, servsock, EVFILT_READ, EV_ADD, 0, 5, NULL);
+
+	/* set the event */
+	i = kevent(kq, &ke, 1, NULL, 0, NULL);
+	if (i == -1)
+		err(1, "set kevent");
+
+	while (1) {
+
+		memset(&ke, 0, sizeof(ke));
+
+		/* receive an event, a blocking call as timeout is NULL */
+		i = kevent(kq, NULL, 0, &ke, 1, NULL);
+		if (i == -1)
+			err(1, "kevent!");
+
+		if (i == 0)
+			continue;
+
+		/*
+		 * since we only have one kevent in the eventlist, we're only
+		 * going to get one event at a time
+		 */
+
+		if (ke.ident == servsock) {
+
+			/* server socket, theres a client to accept */
+
+			len = (socklen_t)sizeof(c);
+			i = accept(servsock, (struct sockaddr *)&c, &len);
+			if (i == -1)
+				err(1, "accept!");
+						
+			for (uidx = 0; uidx < NUSERS; uidx++)
+				if (users[uidx].uc_fd == 0)
+					break;
+
+			if (uidx == NUSERS) {
+				warnx("%s", umsg);
+				write(i, umsg, strlen(umsg));
+				close(i);
+				continue;
+			}
+
+			users[uidx].uc_fd = i; /* users file descriptor */
+			users[uidx].uc_addr = strdup(inet_ntoa(c.sin_addr));
+			if (users[uidx].uc_addr == NULL)
+				err(1, "strdup");
+			
+			EV_SET(&ke, i, EVFILT_READ, EV_ADD, 0, 0, NULL);
+			i = kevent(kq, &ke, 1, NULL, 0, NULL);
+			if (i == -1)
+				err(1, "kevent add user!");
+
+			printf("connection from %s added\n",
+			    users[uidx].uc_addr);
+		} else {
+
+			/*
+			 * got a message to distribute, first find the user
+			 * and read their message
+			 */
+
+			for (uidx = 0; uidx < NUSERS; uidx++)
+				if (users[uidx].uc_fd == ke.ident)
+					break;
+
+			if (uidx == NUSERS)
+				errx(1, "bogus message!");
+
+			memset(buf, 0, sizeof(buf));
+
+			i = read(users[uidx].uc_fd, buf, sizeof(buf));
+			if (i == -1)
+				continue;
+
+			if (i == 0) { /* EOF from a client */
+
+				printf("removing %s\n", users[uidx].uc_addr);
+
+				EV_SET(&ke, users[uidx].uc_fd, EVFILT_READ,
+				    EV_DELETE, 0, 0, NULL);
+
+				i = kevent(kq, &ke, 1, 0, 0, NULL);
+				if (i == -1)
+					err(1, "rm user from kq");
+	
+				close(users[uidx].uc_fd);
+				free(users[uidx].uc_addr);
+
+				users[uidx].uc_fd = 0;
+				users[uidx].uc_addr = NULL;
+
+				continue;
+			}
+
+			printf("got a message from %s\n", users[uidx].uc_addr);
+
+			/* now write it to the other users */
+
+			for (uidx = 0; uidx < NUSERS; uidx++) {
+
+				if (users[uidx].uc_fd == 0 ||
+				    users[uidx].uc_fd == ke.ident)
+					continue;
+
+				i = write(users[uidx].uc_fd, buf, sizeof(buf));
+				if (i == -1)
+					warn("write failed!");
+			}
+		} /* end if */
+	} /* end while */
+
+	return(0);
+}
+