Merge branch 'optimizations'

2 files changed, 52 insertions, 48 deletions

diff --git a/client.c b/client.c
index dbbc204..07e413f 100644
--- a/client.c
+++ b/client.c
@@ -313,7 +313,7 @@ void *command_line_routine(void* args) {
         int inputInt = atoi(input);
         if (input[0] != '0' && inputInt == 0) {
             // if we're in here, it's ~likely~ not a number (ik it's not perfect, sorry :/)
-            printf("unknown command: %si", input);
+            printf("unknown command: %s", input);
             printf("snowcast_control> ");
             fflush(stdout);
             continue;
diff --git a/server.c b/server.c
index 48bd90b..22ab353 100644
--- a/server.c
+++ b/server.c
@@ -56,9 +56,12 @@ int             read_file(int fd, char buffer[FILE_READ_SIZE], int station_num);
 // ----------------------------------------------------------------------------------------------------------
 typedef struct user
 {
-    int udpPort;
-    int stationNum;
     int tcpfd;
+    int stationNum;
+    int udpPort;            // need this (& the following) for udp packet sending
+    int udpfd;
+    socklen_t addrlen;
+    struct sockaddr addr;
 } user_t;
 int             max_active_users = 0;   // maximum number of users that have been connected at once
 int             max_tcpfd = 0;          // maximum tcpfd for users that has been seen
@@ -79,7 +82,6 @@ struct send_udp_packet_routine_args {
 int             start_threads = 0;                  // for synchronization, with the cond
 pthread_cond_t  cond  = PTHREAD_COND_INITIALIZER;   // for synchronization, with the following routine
 void            *send_udp_packet_routine(void* arg); 
-void            send_udp_packet_routine_cleanup(void *arg);
 int             setup_udp_connection(int udp_port, int *udp_sockfd, socklen_t *addrlen, struct sockaddr *addr);
 int             send_all_udp(int udp_sockfd, char *buf, int *len, struct sockaddr *addr, socklen_t addrlen);
 
@@ -120,7 +122,7 @@ void    cleanup_readfds_and_sockets();
 // 7) EXTRA CREDIT
 // ---------------------------------------------------------------------------------------------------------
 // ability for client to receive station list
-void    *send_stationsinfo_routine(void *arg);  // sends station info (index, name) to client
+void    send_stationinfo_reply(int clientfd);   // sends station info (index, name) to client
 // ability for server to add/remove stations through command line
 void    add_station(char *station_name);
 void    send_newstation_reply(uint16_t station_num); // notifies users that a new station has been added
@@ -404,9 +406,15 @@ int read_file(int fd, char buffer[FILE_READ_SIZE], int station_num) {
 // ----------------------------------------------------------------------------------------------------------
 /*
     given the newfd and udp_port of a newly connected user, initializes them to the data structure
+    1) update the tcpfd_to_user map size if needed
+    2) find the first available index in the users array
+    3) make a new user, set the tcp info & udp info
+    4) map the tcpfd to the user index
+    5) send WELCOME reply
     note: this function does its best to optimize memory (dynamic resize of tcpfd map & resusing space in array)
 */
 void init_user(int newfd, int udp_port) {
+
     pthread_mutex_lock(&mutex_users);
 
     // FOLLOWING IS FOR MEMORY OPTIMIZATION
@@ -438,9 +446,20 @@ void init_user(int newfd, int udp_port) {
         if (!more_users) { perror("realloc in init_user2"); exit(1); }
         users = more_users;
     }
-    
+
+    // make new user, set tcp info
+    user_t new_user;
+    new_user.tcpfd = newfd;
+    new_user.stationNum = -1;
+    new_user.udpPort = udp_port;
+    // set the udp info
+    if(setup_udp_connection(udp_port, &new_user.udpfd, &new_user.addrlen, &new_user.addr) == -1) {
+        fprintf(stderr, "failure in init_user (setup_udp_connection)");
+        return; // error occured
+    }
+
     // map TCP tcpfd to this user index
-    users[running_index] = (user_t){udp_port, -1, newfd};
+    users[running_index] = new_user;
     tcpfd_to_user[newfd] = running_index;
 
     pthread_mutex_unlock(&mutex_users);
@@ -450,18 +469,22 @@ void init_user(int newfd, int udp_port) {
 }
 /*
     given the tcpfd of a user, destroys them from the data structures
-    1) close the tcpfd
+    1) close both tcpfd and udpfd of user
     2) remove from master set
     3) remove from data structures
     note: destroying a user sets all fields of that user to -1. often, this is how it's known if a user exists
 */
 void destroy_user(int tcpfd) {
-    close(tcpfd); // bye!
+    close(tcpfd); // close tcpfd!
     FD_CLR(tcpfd, &master); // remove from master set
 
+    if (tcpfd_to_user[tcpfd] == -1) return; // if -1, user has already been destroyed
+
+    close(users[tcpfd_to_user[tcpfd]].udpfd); // close udpfd
+
     // remove user from data structures
     pthread_mutex_lock(&mutex_users);
-    users[tcpfd_to_user[tcpfd]] = (user_t) {-1, -1, -1};
+    users[tcpfd_to_user[tcpfd]] = (user_t) { -1, -1, -1, -1, 0, 0 }; // set all fields to -1 or 0
     // map tcpfd to -1
     tcpfd_to_user[tcpfd] = -1;
 
@@ -488,20 +511,6 @@ void *send_udp_packet_routine(void *arg) {
     // setup variables
     int did_work = 1;
     pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
-    // only these two following properties of addrinfo are needed to send udp packets
-    struct sockaddr addr;
-    socklen_t addrlen;
-
-    // setup udp socket for this thread/user
-    int udp_port = users[user_index].udpPort;
-    int udp_sockfd;
-    if (setup_udp_connection(udp_port, &udp_sockfd, &addrlen, &addr) == -1){
-        fprintf(stderr, "failure in setup_udp_connection");
-        return (NULL); // error occured
-    }
-
-    // setup cleanup for thread that closes the fd if closed
-    pthread_cleanup_push(send_udp_packet_routine_cleanup, (void *)&udp_sockfd);
 
     pthread_mutex_lock(&m);
     // wait for threads
@@ -517,21 +526,12 @@ void *send_udp_packet_routine(void *arg) {
     }
 
     // send the data! (no error check since udp)
-    send_all_udp(udp_sockfd,  (char *) data_ptr, &buffer_size, &addr, addrlen);
-
-    // cleanup
-    close(udp_sockfd);
+    send_all_udp(users[user_index].udpfd, (char *) data_ptr, &buffer_size, &users[user_index].addr, users[user_index].addrlen);
     
     pthread_mutex_unlock(&m);
-    pthread_cleanup_pop(1);
 
     return (NULL);
 }
-void send_udp_packet_routine_cleanup(void *arg) // closes the udpfd if thread is cancelled
-{
-    int sockfd = * (int *) arg;
-    close(sockfd);
-}
 
 /*
     given the udp_port, makes a socket and returns it's file descriptor. (returns -1 on failure)
@@ -692,6 +692,15 @@ int handle_new_connection(int listener) {
         return 0;
     }
 
+    // determine if we've seen this udp_port before
+    for (int i = 0; i < max_active_users; i++) {
+        if (users[i].udpPort == udp_port) {
+            // if we have, we need to close the fd and move on
+            fprintf(stderr, "error connecting new user: udp port already in use\n");
+            return 0;
+        }
+    }
+
     // add the user to the set
     FD_SET(newfd, &master); // add to master set
     if (newfd > fdmax) {    // keep track of the max
@@ -787,8 +796,7 @@ int handle_client_command(int clientfd) {
     if (command_type == LISTSTATIONS) {
         if (l) printf("received a LISTSTATIONS from socket %d\n", clientfd);
 
-        pthread_t send_thread; // send STATIONINFO from a different thread
-        pthread_create(&send_thread, NULL, send_stationsinfo_routine, (void *) &clientfd);
+        send_stationinfo_reply(clientfd);
         return 1;
     }
 
@@ -869,7 +877,7 @@ uint8_t handle_setstation_command(int tcpfd) {
     station_number = ntohs(station_number);
 
     // check if user has a udpPort to stream to
-    if (users[tcpfd_to_user[tcpfd]].udpPort == -1) {
+    if (users[tcpfd_to_user[tcpfd]].udpfd == -1) {
         if (l) printf("received a SETSTATION from socket %d before HELLO command. sending INVALID reply.\n", tcpfd);
         // send back in invalid command and drop user
         char * message = "must send Hello message first";
@@ -1047,8 +1055,8 @@ void write_int_to_fd(int fd, int n) {
     free(num);
 }
 void print_user_data(int index) {
-    printf("user: %d -> udpPort: %d, stationNum: %d, tcpfd: %d\n", index,
-        users[index].udpPort, users[index].stationNum, users[index].tcpfd);
+    printf("user: %d -> tcpfd: %d, stationNum: %d, udpPort: %d, udpfd: %d, addrlen: %d\n", 
+        index, users[index].tcpfd, users[index].stationNum, users[index].udpPort, users[index].udpfd, users[index].addrlen);
 }
 void print_station_data(int station) {
     printf("station: %d -> filePath: %s, readfd: %d\n", 
@@ -1075,10 +1083,8 @@ void cleanup_readfds_and_sockets() {
 // ----------------------------------------------------------------------------------------------------------
 // 7) EXTRA CREDIT IMPLEMENTATIONS (no broad function comments below, but it is all pretty self explanatory)
 // ----------------------------------------------------------------------------------------------------------
-void *send_stationsinfo_routine(void * arg) {
-    int fd = * (int *) arg;
-
-    if (l) printf("sending STATIONSINFO reply to socket %d\n", fd);
+void send_stationinfo_reply(int clientfd) {
+    if (l) printf("sending STATIONSINFO reply to socket %d\n", clientfd);
 
     uint32_t reply_size = 0;
     for (int i = 0; i < num_stations; i++)  {
@@ -1089,13 +1095,13 @@ void *send_stationsinfo_routine(void * arg) {
 
     // send type
     uint8_t reply_num = 6;
-    if (send(fd, &reply_num, 1, 0) == -1)
+    if (send(clientfd, &reply_num, 1, 0) == -1)
         perror("send in send stations info");
 
     // send payload size
     uint32_t reply_size_endian = htonl(reply_size);
     int bytes = sizeof(uint32_t);
-    if (send_all(fd, (char *) &reply_size_endian, &bytes) == -1)
+    if (send_all(clientfd, (char *) &reply_size_endian, &bytes) == -1)
         perror("send_all in send stations info");
 
     char send_buffer[reply_size];
@@ -1106,10 +1112,8 @@ void *send_stationsinfo_routine(void * arg) {
     }
 
     int bytes_to_send = reply_size; // don't want final \n
-    if (send_all(fd, (char *) &send_buffer, &bytes_to_send) == -1)
+    if (send_all(clientfd, (char *) &send_buffer, &bytes_to_send) == -1)
         perror("send_all buffer");
-
-    return (NULL);
 }
 
 void add_station(char *file_path) {