trackrdrd: - try a read memory barrier when the client bit is not

	set -- false fd's tend to come after this, maybe data are
	stale
	- dump the data table before abort

src/child.c

@@ -55,6 +55,7 @@
 
 #include "vsb.h"
 #include "vpf.h"
+#include "vmb.h"
 
 #include "libvarnish.h"
 #include "vsl.h"
@@ -695,9 +696,12 @@ OSL_Track(void *priv, enum VSL_tag_e tag, unsigned fd, unsigned len,
     }
     
     /* spec != 'c' */
-    if ((spec & VSL_S_CLIENT) == 0)
+    if ((spec & VSL_S_CLIENT) == 0) {
         LOG_Log(LOG_WARNING, "%s: Client bit ('c') not set [%.*s]",
             VSL_tags[tag], len, ptr);
+        /* This may signal that data are not fresh */
+        VRMB();
+    }
     
     switch (tag) {
     case SLT_ReqStart:

src/handler.c

@@ -185,6 +185,7 @@ HNDL_Abort(int sig)
     LOG_Log(LOG_ALERT, "Received signal %d (%s), stacktrace follows", sig,
         strsignal(sig));
     stacktrace();
+    DATA_Dump();
     MON_Output();
     LOG_Log0(LOG_ALERT, "Aborting");
     abort();