Updated structure field comments.

src/gdns.h

@@ -35,19 +35,19 @@
 
 typedef struct GDnsThread_
 {
-  pthread_cond_t not_empty;
-  pthread_cond_t not_full;
+  pthread_cond_t not_empty;     /* not empty queue condition */
+  pthread_cond_t not_full;      /* not full queue condition */
   pthread_mutex_t mutex;
   pthread_t thread;
 } GDnsThread;
 
 typedef struct GDnsQueue_
 {
-  int head;
-  int tail;
-  int size;
-  int capacity;
-  char buffer[QUEUE_SIZE][H_SIZE];
+  int head;                     /* index to head of queue */
+  int tail;                     /* index to tail of queue */
+  int size;                     /* queue size */
+  int capacity;                 /* length at most */
+  char buffer[QUEUE_SIZE][H_SIZE];      /* data item */
 } GDnsQueue;
 
 extern GDnsThread gdns_thread;