ciaolore

.vscode/settings.json

@@ -2,6 +2,7 @@
     "files.associations": {
         "errexit.h": "c",
         "structures.h": "c",
-        "custom_msgq.h": "c"
+        "custom_msgq.h": "c",
+        "errno.h": "c"
     }
 }

inc/custom_shm.h

@@ -10,7 +10,8 @@ extern int _SHMID;
 void setupServerShm();
 void setupClientShm();
 
-int getShmid(); //FIXME: dovrebbero andare nel .c perche non vanno usate da altri file
+int getShmidServer();
+int getShmidClient(); //FIXME: dovrebbero andare nel .c perche non vanno usate da altri file
 tile_t * shmServerAt();
 tile_t * shmClientAt(); 
 void shmDt(void *shm_ptr);

src/custom_shm.c

@@ -2,34 +2,64 @@
 #include <sys/shm.h>
 #include <sys/stat.h>
 #include <custom_shm.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #include <errExit.h>
 #include <forza4.h>
 
 int _SHMID;
 
-int getShmid();
 tile_t *shmServerAt();
 
 void setupServerShm() {
-    _SHMID = getShmid();
+    _SHMID = getShmidServer();
     _BOARD = shmServerAt();
-
-    for (int i=0; i < _ROWS * _COLLUMS; i++) {
+    
+    for (int i = 0; i < _ROWS * _COLLUMS; i++) {
         _BOARD[i] = EMPTY;
     }
 }
 
 void setupClientShm() {
     printf(PCLIENT "Setting up shm\n");
-    _SHMID = getShmid();
+    _SHMID = getShmidClient();
     _BOARD = shmClientAt();
 }
 
-int getShmid() {
-    int shmid = shmget(ftok(KEYFILE, SHMKEY), _ROWS * _COLLUMS * sizeof(tile_t), IPC_CREAT | S_IRUSR | S_IWUSR);
+int getShmidClient() {
+    shmget(ftok(KEYFILE, SHMKEY), _ROWS * _COLLUMS * sizeof(tile_t), S_IRUSR | S_IWUSR);
+}
+
+int getShmidServer() {
+    key_t key = ftok(KEYFILE, SHMKEY);
+    int shmid = shmget(key, _ROWS * _COLLUMS * sizeof(tile_t), IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);
     if (shmid == -1) {
-        errExit("shmget", "getShmid");
+        // if errno was set to EEXIST, that means the memory location is alredy allocated
+        // the server fork and the child remove the memory
+        if (errno == EEXIST) {
+            char buf[100];
+            sprintf(buf, "the board alredy exit, I'll remove it now\n");
+            warningMsg(buf);
+
+            pid_t pid = fork();
+            if (pid == 0) {
+                char str_key[16];
+                sprintf(str_key, "0x%08x", key);
+                printf("%s\n", str_key);
+                char *vec[] = {"/bin/ipcrm", "-M", str_key, NULL};
+
+                if ((execv("/bin/ipcrm", vec)) == -1) {
+                    errExit("execv", "getShmidServer");
+                }
+            }
+            while (wait(0) == -1 && errno == EINTR);
+
+            return getShmidServer();
+        }
+        errExit("shmget", "getShmidServer");
     }
 
     return shmid;

src/server.c

@@ -50,7 +50,7 @@ void setupServer(int argc, char *argv[]){
 
 input_server_t checkServerInput(int argc, char *argv[]){
     if (argc < 5) {
-        printf("\033[92m<Help>\033[39m ./F4Server ROW COL PLAYER1 PLAYER2\n"
+        printf(PHELP "./F4Server ROW COL PLAYER1 PLAYER2\n"
                "\t- ROW \t\tnumber of rows\n"
                "\t- COL \t\tnumber of rows\n"
                "\t- PLAYER1 \tplayer one token\n"