get rid of the data_ready mutex and condition variable

src/varnishevent.c

@@ -622,8 +622,6 @@ main(int argc, char *argv[])
         exit(EXIT_FAILURE);
     }
 
-    AZ(pthread_cond_init(&data_ready_cond, NULL));
-    AZ(pthread_mutex_init(&data_ready_lock, NULL));
     AZ(pthread_cond_init(&spscq_ready_cond, NULL));
     AZ(pthread_mutex_init(&spscq_ready_lock, NULL));
 
@@ -725,8 +723,6 @@ main(int argc, char *argv[])
     SPSCQ_Shutdown();
     MON_Shutdown();
     FMT_Fini();
-    AZ(pthread_cond_destroy(&data_ready_cond));
-    AZ(pthread_mutex_destroy(&data_ready_lock));
     AZ(pthread_cond_destroy(&spscq_ready_cond));
     AZ(pthread_mutex_destroy(&spscq_ready_lock));
     LOG_Log0(LOG_INFO, "Exiting");

src/varnishevent.h

@@ -152,11 +152,6 @@ VSTAILQ_HEAD(freehead_s, logline_t);
 
 unsigned global_nfree_tx, global_nfree_line, global_nfree_chunk;
 
-/* Reader waits for this condition when the freelist is exhausted.
-   Writer signals the condition after returning space to the freelist. */
-pthread_cond_t  data_ready_cond;
-pthread_mutex_t data_ready_lock;
-
 /* Writer (consumer) waits for this condition when the SPSC queue is empty.
    Reader (producer) signals the condition after enqueue. */
 pthread_cond_t  spscq_ready_cond;