getShareMemory(char *address, int size, int offset) hinzufuegen, ob man es braucht.

src/SharedMemoryAccess.cpp

@@ -61,10 +61,27 @@ void writeSharedMemory(char *data, int size, int offset) {
         return;
         /* we could return -1, not sure if it will be useful to continue after there is no shm allocated for any reason*/
     } else {
+        std::cout << "writing" << std::endl;
         char *shm_pointer = (char *) shmat(shmId, NULL, 0);
         semaphoreOperation(LOCK);
         memcpy(shm_pointer + offset, data, size);
+        shmdt(shm_pointer);                                     //close shm_pointer
         semaphoreOperation(UNLOCK);
+        std::cout << "writing successed" << std::endl;
+    }
+}
+
+void getSharedMemory(char *address, int size, int offset) {
+    int shmId = shmget(impl.sharedMemoryKey, NULL, 0);
+    if(shmId < 0) {
+        return;
+    } else {
+        char *shm_pointer = (char *) shmat(shmId, NULL, 0);
+        semaphoreOperation(LOCK);
+        memcpy(address, shm_pointer + offset, size);
+        shmdt(shm_pointer);                             //close shm_pointer
+        semaphoreOperation(UNLOCK);
+        return;
     }
 }
 

src/SharedMemoryAccess.h

@@ -12,6 +12,15 @@
  */
 char *getSharedMemory();
 
+/**
+ * use lock and unlock when writing,
+ * set content to the address
+ * @param *address target address
+ * @param size of data
+ * @param offset where the data is written on the shared memory
+ */
+void getSharedMemory(char *address, int size, int offset);
+
 /**
  *
  * @return the size of the shared memory
@@ -24,10 +33,10 @@ void unlockSharedMemory();
 
 /**
  *
- * @param data poiter to data
+ * @param data pointer to data
  * @param size of data
  * @param offset where the data is written on the shared memory
  */
-void writeSharedMemory(char *data, int size, int offset);
+void writeSharedMemory(char *date, int size, int offset);
 
 #endif //LIBRARY_SHAREDMEMORYACCESSS_H