trackrdrd: now attempting a read memory barrier in the VSL reader

           thread after copying from VSM, and a write barrier in
           the worker thread before sending the data

trackrdrd/src/child.c

@@ -55,6 +55,7 @@
 #include <dlfcn.h>
 
 #include "vsb.h"
+#include "vmb.h"
 #include "vpf.h"
 
 #include "libvarnish.h"
@@ -637,6 +638,7 @@ append(dataentry *entry, enum VSL_tag_e tag, unsigned xid, char *data,
     entry->data[entry->end] = '&';
     entry->end++;
     memcpy(&entry->data[entry->end], data, datalen);
+    VWMB();
     entry->end += datalen;
     if (entry->end > dtbl.w_stats.data_hi)
         dtbl.w_stats.data_hi = entry->end;

trackrdrd/src/worker.c

@@ -130,7 +130,7 @@ wrk_send(void **mq_worker, dataentry *entry, worker_data_t *wrk)
     AN(mq_worker);
 
     /* XXX: report entry->incomplete to backend ? */
-    VMB();
+    VRMB();
     errnum = mqf.send(*mq_worker, entry->data, entry->end,
                       entry->key, entry->keylen, &err);
     if (errnum != 0) {