Add user tag spreading functionality to VM and use in file

User tags in a dynamic trace enabled VM are spread throughout the system
in the same way as seq_trace tokens. This is used by the file module
and various other modules to get hold of the tag from the user process
without changing the protocol.

1 files changed, 29 insertions, 5 deletions

diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 1173624f51..6771e00c7e 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -679,7 +679,11 @@ reply_sched_wall_time(void *vswtrp)
 	hpp = &hp;
     }
 
-    erts_queue_message(rp, &rp_locks, bp, msg, NIL);
+    erts_queue_message(rp, &rp_locks, bp, msg, NIL
+#ifdef HAVE_DTRACE
+			   , NIL
+#endif
+		       );
 
     if (swtrp->req_sched == esdp->no)
 	rp_locks &= ~ERTS_PROC_LOCK_MAIN;
@@ -7260,6 +7264,10 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     p->seq_trace_lastcnt = 0;
     p->seq_trace_clock = 0;
     SEQ_TRACE_TOKEN(p) = NIL;
+#ifdef HAVE_DTRACE
+    DT_UTAG(p) = NIL;
+    DT_UTAG_FLAGS(p) = 0;
+#endif
     p->parent = parent->id == ERTS_INVALID_PID ? NIL : parent->id;
 
 #ifdef HYBRID
@@ -7851,7 +7859,11 @@ static ERTS_INLINE void
 send_exit_message(Process *to, ErtsProcLocks *to_locksp,
 		  Eterm exit_term, Uint term_size, Eterm token)
 {
-    if (token == NIL) {
+    if (token == NIL 
+#ifdef HAVE_DTRACE
+	|| token == am_have_dt_utag
+#endif
+	) {
 	Eterm* hp;
 	Eterm mess;
 	ErlHeapFragment* bp;
@@ -7859,7 +7871,11 @@ send_exit_message(Process *to, ErtsProcLocks *to_locksp,
 
 	hp = erts_alloc_message_heap(term_size, &bp, &ohp, to, to_locksp);
 	mess = copy_struct(exit_term, term_size, &hp, ohp);
-	erts_queue_message(to, to_locksp, bp, mess, NIL);
+	erts_queue_message(to, to_locksp, bp, mess, NIL
+#ifdef HAVE_DTRACE
+			   , NIL
+#endif
+			   );
     } else {
 	ErlHeapFragment* bp;
 	Eterm* hp;
@@ -7875,7 +7891,11 @@ send_exit_message(Process *to, ErtsProcLocks *to_locksp,
 	/* the trace token must in this case be updated by the caller */
 	seq_trace_output(token, mess, SEQ_TRACE_SEND, to->id, NULL);
 	temp_token = copy_struct(token, sz_token, &hp, &bp->off_heap);
-	erts_queue_message(to, to_locksp, bp, mess, temp_token);
+	erts_queue_message(to, to_locksp, bp, mess, temp_token
+#ifdef HAVE_DTRACE
+			   , NIL
+#endif
+			   );
     }
 }
 
@@ -7981,7 +8001,11 @@ send_exit_signal(Process *c_p,		/* current process if and only
 
     if (ERTS_PROC_IS_TRAPPING_EXITS(rp)
 	&& (reason != am_kill || (flags & ERTS_XSIG_FLG_IGN_KILL))) {
-	if (is_not_nil(token) && token_update)
+	if (is_not_nil(token) 
+#ifdef HAVE_DTRACE
+	    && token != am_have_dt_utag
+#endif
+	    && token_update)
 	    seq_trace_update_send(token_update);
 	if (is_value(exit_tuple))
 	    send_exit_message(rp, rp_locks, exit_tuple, exit_tuple_sz, token);