2005-11-14 Carl Worth <cworth@cworth.org>

        Server now acts as a very simple chat server.

        * src/ttt-client.h:
        * src/ttt-client.c: (ttt_client_create), (ttt_client_destroy),
        (_append_to_request), (ttt_client_read_into_request_until),
        (ttt_client_read_line), (ttt_client_send): Add support to do a
        buffering read within the client and to reuse the buffer (which
        grows by doubling) from one request to the next. Add function to
        send a message to a client.

        * src/ttt-server.c: (ttt_server_init), (ttt_server_create_client):
        Add support for a client idea. Resize the server's client list by
        doubling.
        * src/ttt-server.c: (ttt_server_destroy_client): Add support to
        destroy a client.
        * src/ttt-server.c: (_handle_client_requests_thread),
        (_accept_client): Move handling of client requests up to
        ttt-server.c from ttt-client.c. Use threads rather than a fork per
        client.
        * src/ttt-server.h:
        * src/ttt-server.h: (ttt_server_broadcast): Add function to send a
        message to all connected clients.

        * src/ttt-socket.h:
        * src/ttt-socket.c: (ttt_socket_read),
        (ttt_socket_write): Add functions to do blocking read or write of
        the specified number of bytes.

        * src/ttt-socket.c: (ttt_socket_accept): Remove fork, so that the
        accept function call can take care of anything like that itself.

        * src/x.h:
        * src/x.c: (xread), (xwrite): New wrappers for read and write.

        * src/ttt.h: Add TTT_STATUS_EOF, TRUE, and FALSE.

        * src/ttt.c: Need to include ttt-args.h explicitly now.

diff --git a/ChangeLog b/ChangeLog
index 85d24c63102f69a8328e8028f306419eb9901e10..bc176073fc7e0241c19ef2bfce625caaa48faf62 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,43 @@
+2005-11-14  Carl Worth  <cworth@cworth.org>
+
+       Server now acts as a very simple chat server.
+
+       * src/ttt-client.h:
+       * src/ttt-client.c: (ttt_client_create), (ttt_client_destroy),
+       (_append_to_request), (ttt_client_read_into_request_until),
+       (ttt_client_read_line), (ttt_client_send): Add support to do a
+       buffering read within the client and to reuse the buffer (which
+       grows by doubling) from one request to the next. Add function to
+       send a message to a client.
+
+       * src/ttt-server.c: (ttt_server_init), (ttt_server_create_client):
+       Add support for a client idea. Resize the server's client list by
+       doubling.
+       * src/ttt-server.c: (ttt_server_destroy_client): Add support to
+       destroy a client.
+       * src/ttt-server.c: (_handle_client_requests_thread),
+       (_accept_client): Move handling of client requests up to
+       ttt-server.c from ttt-client.c. Use threads rather than a fork per
+       client.
+       * src/ttt-server.h:
+       * src/ttt-server.h: (ttt_server_broadcast): Add function to send a
+       message to all connected clients.
+
+       * src/ttt-socket.h:
+       * src/ttt-socket.c: (ttt_socket_read),
+       (ttt_socket_write): Add functions to do blocking read or write of
+       the specified number of bytes.
+
+       * src/ttt-socket.c: (ttt_socket_accept): Remove fork, so that the
+       accept function call can take care of anything like that itself.
+       
+       * src/x.h:
+       * src/x.c: (xread), (xwrite): New wrappers for read and write.
+
+       * src/ttt.h: Add TTT_STATUS_EOF, TRUE, and FALSE.
+
+       * src/ttt.c: Need to include ttt-args.h explicitly now.
+

 2005-11-11  Carl Worth  <cworth@cworth.org>
 
        * src/ttt-server.h:
 2005-11-11  Carl Worth  <cworth@cworth.org>
 
        * src/ttt-server.h:

diff --git a/src/ttt-client.c b/src/ttt-client.c
index 80fca846e13ee46e4fae37b87ee966901a91de9a..e6c97a1c6ad9c2f16ba1f07d9bbc0336e68daa93 100644 (file)
--- a/src/ttt-client.c
+++ b/src/ttt-client.c
@@ -20,14 +20,10 @@
  */
 
 #include "ttt-client.h"
  */
 
 #include "ttt-client.h"

-
-struct _ttt_client {
-    ttt_server_t *server;
-    int socket;
-};
+#include "ttt-socket.h"

 
 ttt_client_t *
 
 ttt_client_t *

-ttt_client_create (ttt_server_t *server, int socket)
+ttt_client_create (ttt_server_t *server, int socket, int id)

 {
     ttt_client_t *client;
 
 {
     ttt_client_t *client;
 


@@ -36,31 +32,112 @@ ttt_client_create (ttt_server_t *server, int socket)
     client->server = server;
     client->socket = socket;
 
     client->server = server;
     client->socket = socket;
 

+    client->id = id;
+
+    client->buf_head = client->buf;
+    client->buf_tail = client->buf;
+
+    client->request = NULL;
+    client->request_size = 0;
+    client->request_len = 0;
+

     return client;
 }
 
 void
 ttt_client_destroy (ttt_client_t *client)
 {
     return client;
 }
 
 void
 ttt_client_destroy (ttt_client_t *client)
 {

-    close (client->socket);
+    shutdown (client->socket, SHUT_RDWR);
+
+    free (client->request);

 
     free (client);
 }
 
 
     free (client);
 }
 

-void
-ttt_client_handle_requests (ttt_client_t *client)
+static void
+_append_to_request (ttt_client_t       *client,
+                   const char          *buf,
+                   int                  size)

 {
 {

-#define BUF_SIZE 1024
+    int size_needed = client->request_len + size;
+
+    if (size_needed > client->request_size) {
+       if (client->request_size == 0) {
+           client->request_size = size_needed;
+       } else {
+           while (size_needed > client->request_size)
+               client->request_size *= 2;
+       }
+
+       client->request = xrealloc (client->request, client->request_size);
+    }
+
+    memcpy (client->request + client->request_len,
+           buf, size);
+
+    client->request_len += size;
+}
+
+static ttt_status_t
+ttt_client_read_into_request_until (ttt_client_t *client, char delimeter)
+{
+    ttt_bool_t found_delimeter = FALSE;
+    int bytes_read;
+    char *s;
+
+    client->request_len = 0;

 
     while (1) {
 
     while (1) {

-       char buf[BUF_SIZE];
-       int cnt;
-       cnt = read (client->socket, buf, BUF_SIZE);
-       if (cnt == 0)
-           break;
-       write (0, buf, cnt);
-       write (client->socket, buf, cnt);
+
+       if (client->buf_tail >= client->buf_head) {
+           bytes_read = xread (client->socket,
+                               client->buf,
+                               TTT_CLIENT_BUF_SIZE);
+           if (bytes_read == 0)
+               return TTT_STATUS_EOF;
+           client->buf_head = client->buf;
+           client->buf_tail = client->buf_head + bytes_read;
+       }
+
+       for (s = client->buf_head; s < client->buf_tail; s++) {
+           if (*s == delimeter) {
+               found_delimeter = TRUE;
+               s++;
+               break;
+           }
+       }
+
+       _append_to_request (client,
+                           client->buf_head,
+                           s - client->buf_head);
+       client->buf_head = s;
+
+       if (found_delimeter)
+           return TTT_STATUS_SUCCESS;

     }
 }
 
     }
 }
 

+char *
+ttt_client_read_line (ttt_client_t *client)
+{
+    ttt_status_t status;
+    static const char null_terminator = '\0';
+
+    status = ttt_client_read_into_request_until (client, '\n');
+    if (status) {
+       assert (status == TTT_STATUS_EOF);
+       return NULL;
+    }
+
+    _append_to_request (client, &null_terminator, 1);
+
+    return client->request;
+}
+
+void
+ttt_client_send (ttt_client_t *client, const char *message)
+{
+    ttt_socket_write (client->socket, message, strlen (message));
+}
+

 
 

diff --git a/src/ttt-client.h b/src/ttt-client.h
index b067674fdbc7b2fb7e1696d28462747b38e1fbe5..452b36fa0d73ec492a506f2a2fcac5b071e96b27 100644 (file)
--- a/src/ttt-client.h
+++ b/src/ttt-client.h
@@ -26,10 +26,28 @@
 #ifndef _TTT_CLIENT_H_
 #define _TTT_CLIENT_H_
 
 #ifndef _TTT_CLIENT_H_
 #define _TTT_CLIENT_H_
 

-typedef struct _ttt_client ttt_client_t;
+#define TTT_CLIENT_BUF_SIZE 1024
+
+typedef struct _ttt_client {
+    pthread_t thread;
+
+    ttt_server_t *server;
+    int socket;
+
+    int id;
+
+    char buf[TTT_CLIENT_BUF_SIZE];
+    char *buf_head;
+    char *buf_tail;
+
+    char *request;
+    int request_size;
+    int request_len;
+} ttt_client_t;
+

 
 /* Create a new ttt_client_t for the given server and given a
 
 /* Create a new ttt_client_t for the given server and given a

- * connected socket.
+ * connected socket, and assign it the given id.

  *
  * Returns: A new ttt_client_t. Call ttt_client_destroy when finished
  * with it.
  *
  * Returns: A new ttt_client_t. Call ttt_client_destroy when finished
  * with it.


@@ -38,13 +56,26 @@ typedef struct _ttt_client ttt_client_t;
  * will not return.
  */
 ttt_client_t *
  * will not return.
  */
 ttt_client_t *

-ttt_client_create (ttt_server_t *server, int socket);
+ttt_client_create (ttt_server_t *server, int socket, int id);

 
 

+/* Destroy a client. */

 void
 ttt_client_destroy (ttt_client_t *client);
 
 void
 ttt_client_destroy (ttt_client_t *client);
 

-/* Loop forever handling client requests. Never returns. */
+/* Perform a blocking read until a newline is encountered.
+ *
+ * Returns: A pointer to the string read, or NULL if EOF occurs. This
+ * string points to data internal to the client and can be overwritten
+ * by subsequent calls to this function.
+ *
+ * Errors: If any error (other than reading EOF) occurs, this function
+ * will not return.
+ */
+char *
+ttt_client_read_line (ttt_client_t *client);
+
+/* Send a message to a client. */

 void
 void

-ttt_client_handle_requests (ttt_client_t *client);
+ttt_client_send (ttt_client_t *client, const char *message);

 
 #endif /* _TTT_CLIENT_H_ */
 
 #endif /* _TTT_CLIENT_H_ */

diff --git a/src/ttt-server.c b/src/ttt-server.c
index 316a27021ec6919a7985e80df95fafde2c3b5fc3..2bc3a529b51efca60af87679488e248facd84b46 100644 (file)
--- a/src/ttt-server.c
+++ b/src/ttt-server.c
@@ -20,13 +20,17 @@
  */
 
 #include "ttt.h"
  */
 
 #include "ttt.h"

+#include "ttt-args.h"

 #include "ttt-client.h"
 #include "ttt-socket.h"
 
 struct _ttt_server {
     pthread_mutex_t mutex;
 
 #include "ttt-client.h"
 #include "ttt-socket.h"
 
 struct _ttt_server {
     pthread_mutex_t mutex;
 

+    int next_client_id;
+

     ttt_client_t **clients;
     ttt_client_t **clients;

+    int clients_size;

     int num_clients;
 };
 
     int num_clients;
 };
 


@@ -35,22 +39,88 @@ ttt_server_init (ttt_server_t *server)
 {
     pthread_mutex_init (&server->mutex, NULL);
 
 {
     pthread_mutex_init (&server->mutex, NULL);
 

+    server->next_client_id = 0;
+

     server->clients = NULL;
     server->clients = NULL;

+    server->clients_size = 0;

     server->num_clients = 0;
 }
 
     server->num_clients = 0;
 }
 

-static void
-ttt_server_add_client (ttt_server_t *server, ttt_client_t *client)
+static ttt_client_t *
+ttt_server_create_client (ttt_server_t *server, int client_socket)

 {
 {

+    ttt_client_t *client;
+

     pthread_mutex_lock (&server->mutex);
 
     pthread_mutex_lock (&server->mutex);
 

+    client = ttt_client_create (server, client_socket,
+                               server->next_client_id++);
+
+    printf ("Client %d has joined.\n", client->id);
+

     server->num_clients++;
     server->num_clients++;

-    server->clients = xrealloc (server->clients,
-                               server->num_clients * sizeof (ttt_client_t *));
+
+    if (server->num_clients > server->clients_size) {
+       if (server->clients_size == 0)
+           server->clients_size = 1;
+       else
+           server->clients_size *= 2;
+
+       server->clients = xrealloc (server->clients,
+                                   server->clients_size * sizeof (ttt_client_t *));
+    }

 
     server->clients [server->num_clients - 1] = client;
 
     pthread_mutex_unlock (&server->mutex);
 
     server->clients [server->num_clients - 1] = client;
 
     pthread_mutex_unlock (&server->mutex);

+
+    return client;
+}
+
+static void
+ttt_server_destroy_client (ttt_server_t *server, ttt_client_t *client)
+{
+    int i;
+
+    pthread_mutex_lock (&server->mutex);
+
+    for (i = 0; i < server->num_clients; i++)
+       if (server->clients[i] == client)
+           break;
+
+    assert (i < server->num_clients);
+
+    printf ("Client %d has left.\n", client->id);
+
+    memmove (&server->clients[i], &server->clients[i+1],
+            (server->num_clients - i - 1) * sizeof (ttt_client_t *));
+
+    server->num_clients--;
+
+    ttt_client_destroy (client);
+
+    pthread_mutex_unlock (&server->mutex);
+}
+
+static void *
+_handle_client_requests_thread (void *closure)
+{
+    ttt_client_t *client = closure;
+    ttt_server_t *server = client->server;
+    char *request;
+
+    while (1) {
+
+       request = ttt_client_read_line (client);
+       if (request == NULL)
+           break;
+
+       ttt_server_broadcast (client->server, request);
+    }
+
+    ttt_server_destroy_client (server, client);
+
+    return (void *) 0;

 }
 
 static void
 }
 
 static void


@@ -58,32 +128,53 @@ _accept_client (void *closure, int client_socket)
 {
     ttt_server_t *server = closure;
     ttt_client_t *client;
 {
     ttt_server_t *server = closure;
     ttt_client_t *client;

+    int err;

     
     

-    client = ttt_client_create (server, client_socket);
+    client = ttt_server_create_client (server, client_socket);
+
+    err = pthread_create (&client->thread, NULL,
+                         _handle_client_requests_thread, client);
+    if (err != 0) {
+       fprintf (stderr, "Error: pthread_create failed: %s. Aborting.\n",
+                strerror (err));
+       exit (1);
+    }
+}

 
 

-    ttt_server_add_client (server, client);
+void
+ttt_server_broadcast (ttt_server_t *server, const char *message)
+{
+    int i;

 
 

-    ttt_client_handle_requests (client);
+    pthread_mutex_lock (&server->mutex);
+
+    for (i = 0; i < server->num_clients; i++)
+       ttt_client_send (server->clients[i], message);
+
+    pthread_mutex_unlock (&server->mutex);

 }
 
 static const char *WELCOME_MESSAGE = 
 }
 
 static const char *WELCOME_MESSAGE = 

-"Welcome to ttt-server. So far, this program is simply a demonstration\n"
-"of a TCP/IP server capable of handling multiple simultaneous clients.\n"
+"Welcome to ttt-server. So far, this program is still a demonstration\n"
+"TCP/IP server, acting something like a rather braindead chat server.\n"

 "The server is currently listening on:\n"
 "\n    %s:%s\n"
 "The server is currently listening on:\n"
 "\n    %s:%s\n"

-"\nTo test this program, simply connect a client to that host and port.\n"
+"\nTo test this, simply connect one or more clients to that host and port.\n"

 "For example:\n"
 "\n    telnet %s %s\n"
 "For example:\n"
 "\n    telnet %s %s\n"

-"\nOnce you have connected a client, the server will echo any characters\n"
-"it receives back to the client as well as to stdout.\n"
+"\nOnce you have connected a client, the server will send each line of text\n"
+"it receives to all connected clients. The server reports client joins and\n"
+"departures on stdout.\n"

 "\nNote that to terminate the telnet client you type Control-], then\n"
 "<Enter>, then \"close\" (and <Enter>) at the \"telnet> \" prompt.\n"
 "\nHave fun!\n"
 "-Carl\n"
 "\nNote that to terminate the telnet client you type Control-], then\n"
 "<Enter>, then \"close\" (and <Enter>) at the \"telnet> \" prompt.\n"
 "\nHave fun!\n"
 "-Carl\n"

-"\nPS. The server does support multiple clients, but there is not yet any\n"
-"interaction between the clients. The next step is probably to turn the\n"
-"server into a simple chat server. After that, we should have the necessary\n"
-"structure in place to start implementing the real tic-tac-toe protocol.\n\n";
+"\nPS. At this point we're ready to leave the demonstration phase and to\n"
+"begin implementing TTTP (tic-tac-toe protocol) as well as fixing the\n"
+"protocol specifcation. We don't need a custom client to move forward on\n"
+"the server (that is one of the ideas behind using a telnet-compatible\n"
+"protocol), but a custom client would still be a fine project for a\n"
+"motivated beginning programmer.\n\n";

 
 int 
 main (int argc, char **argv)
 
 int 
 main (int argc, char **argv)

diff --git a/src/ttt-server.h b/src/ttt-server.h
index 773b0349491742ab1e42d1a564e54ada515d4534..b8d2496e2149d44285b302a14d6fb28da13714a7 100644 (file)
--- a/src/ttt-server.h
+++ b/src/ttt-server.h
@@ -26,4 +26,8 @@
 
 typedef struct _ttt_server ttt_server_t;
 
 
 typedef struct _ttt_server ttt_server_t;
 

+/* Send a message to all connected clients. */
+void
+ttt_server_broadcast (ttt_server_t *server, const char *message);
+

 #endif /* _TTT_SERVER_H_ */
 #endif /* _TTT_SERVER_H_ */

diff --git a/src/ttt-socket.c b/src/ttt-socket.c
index f185d363780af7e5c43cb334f9e7ae42c52a258d..199535f300e200d0970341ea6177e53cf35bbf70 100644 (file)
--- a/src/ttt-socket.c
+++ b/src/ttt-socket.c
@@ -150,16 +150,41 @@ ttt_socket_accept (int                             listen_socket,
                   ttt_socket_accept_func_t      accept,
                   void                         *closure)
 {
                   ttt_socket_accept_func_t      accept,
                   void                         *closure)
 {

-    pid_t pid;

     int connected_socket;
 
     connected_socket = _wait_for_connection (listen_socket);
 
     int connected_socket;
 
     connected_socket = _wait_for_connection (listen_socket);
 

-    pid = xfork();
+    (accept) (closure, connected_socket);
+}
+
+/* Exported: see ttt-socket.h for documentation. */
+void
+ttt_socket_read (int    socket,
+                void   *buf,
+                size_t  count)
+{
+    int bytes_read;
+    char *cbuf = buf;
+
+    while (count) {
+       bytes_read = xread (socket, cbuf, count);
+       cbuf += bytes_read;
+       count -= bytes_read;
+    }
+}
+
+/* Exported: see ttt-socket.h for documentation. */
+void
+ttt_socket_write (int           socket,
+                 const void    *buf,
+                 size_t         count)
+{
+    int written;
+    const char *cbuf = buf;

 
 

-    if (pid == 0) {
-       /* Child process. */
-       (accept) (closure, connected_socket);
-       return;
+    while (count) {
+       written = xwrite (socket, cbuf, count);
+       cbuf += written;
+       count -= written;

     }
 }
     }
 }

diff --git a/src/ttt-socket.h b/src/ttt-socket.h
index 909501e0e37880c0f44d178d12e5d71b069b058d..6b35ef23649111dca03457b95925b4640b075ab6 100644 (file)
--- a/src/ttt-socket.h
+++ b/src/ttt-socket.h
@@ -55,4 +55,24 @@ ttt_socket_accept (int                                listen_socket,
                   ttt_socket_accept_func_t      accept,
                   void                         *closure);
 
                   ttt_socket_accept_func_t      accept,
                   void                         *closure);
 

+/* Performa a blocking read, until all count bytes are read from the
+ * socket to buf, which must be of size count or larger.
+ *
+ * Errors: If any errors occur, this function does not return.
+ */
+void
+ttt_socket_read (int    socket,
+                void   *buf,
+                size_t  count);
+
+/* Perform a blocking write, until all count bytes are written from
+ * buf to the socket.
+ *
+ * Errors: If any errors occur, this function does not return.
+ */
+void
+ttt_socket_write (int           socket,
+                 const void    *buf,
+                 size_t         count);
+

 #endif
 #endif

diff --git a/src/ttt.c b/src/ttt.c
index f211ae6da0a782ad9ab7ab556a34e31f32e321ee..fba2ddee7d6cb9dc9685aea556355279e107914d 100644 (file)
--- a/src/ttt.c
+++ b/src/ttt.c
@@ -20,6 +20,7 @@
  */
 
 #include "ttt.h"
  */
 
 #include "ttt.h"

+#include "ttt-args.h"

 
 int 
 main (int argc, char **argv)
 
 int 
 main (int argc, char **argv)

diff --git a/src/ttt.h b/src/ttt.h
index 316d74494c6e34ae1fde8d7684cbfc84f5d24cea..aaa1ed0ab4d524bd4ec7468916e315a0173acc20 100644 (file)
--- a/src/ttt.h
+++ b/src/ttt.h
@@ -56,14 +56,17 @@ do {                                        \
 #define TTT_PRINTF_FORMAT(fmt_index, va_index)
 #endif
 
 #define TTT_PRINTF_FORMAT(fmt_index, va_index)
 #endif
 

-#include "ttt-args.h"

 #include "x.h"
 
 typedef int ttt_bool_t;
 
 #include "x.h"
 
 typedef int ttt_bool_t;
 

+#define FALSE 0
+#define TRUE  1
+

 typedef enum {
     TTT_STATUS_SUCCESS = 0,
 typedef enum {
     TTT_STATUS_SUCCESS = 0,

-    TTT_STATUS_FAILURE
+    TTT_STATUS_FAILURE,
+    TTT_STATUS_EOF

 } ttt_status_t;
 
 #endif
 } ttt_status_t;
 
 #endif

diff --git a/src/x.c b/src/x.c
index 18c69a47457bf786aa9899999ed419ea96cdb4dd..8da355e3e015b0c390cb0869e53a96d1e2bb01e1 100644 (file)
--- a/src/x.c
+++ b/src/x.c
@@ -248,3 +248,33 @@ xselect (int                n,
 
     return ret;
 }
 
     return ret;
 }

+
+ssize_t
+xread (int fd, void *buf, size_t count)
+{
+    int ret;
+
+    ret = read (fd, buf, count);
+    if (ret == -1) {
+       fprintf (stderr, "Error: read failed: %s. Aborting.\n",
+                strerror (errno));
+       exit (1);
+    }
+
+    return ret;
+}
+
+ssize_t
+xwrite (int fd, const void *buf, size_t count)
+{
+    int ret;
+
+    ret = write (fd, buf, count);
+    if (ret == -1) {
+       fprintf (stderr, "Error: write failed: %s. Aborting.\n",
+                strerror (errno));
+       exit (1);
+    }
+
+    return ret;
+}

diff --git a/src/x.h b/src/x.h
index 868a5674689ee90f4e52a1c59f3dd9dccaabfffd..b3384af43d93b37aad0a96523cef97d2f616ab66 100644 (file)
--- a/src/x.h
+++ b/src/x.h
@@ -76,4 +76,10 @@ xselect (int          n,
         fd_set         *exceptfds,
         struct timeval *timeout);
 
         fd_set         *exceptfds,
         struct timeval *timeout);
 

+ssize_t
+xread (int fd, void *buf, size_t count);
+
+ssize_t
+xwrite (int fd, const void *buf, size_t count);
+

 #endif /* _X_H_ */
 #endif /* _X_H_ */