Use pipes to store pubsub messages

include/pubsub.h

@@ -17,15 +17,6 @@
 
 #define MAX_STR_SIZE 1024
 
-struct strNode {
-  char *str;
-  struct strNode *next;
-};
-typedef struct {
-  struct strNode *head;
-  struct strNode *tail;
-} StrQueue;
-
 typedef struct {
     UA_UInt16 id;
     UA_Double latitude;
@@ -36,8 +27,8 @@ typedef struct {
     UA_Float  yaw;
     UA_Float  speed;
     UA_Float  climbRate;
-    StrQueue receiveMessageQueue;
-    StrQueue receiveLogQueue;
+    int receiveMessagePipefds[2];
+    int receiveLogPipefds[2];
 } JSDroneData;
 
 typedef struct {