erts: Move tracer SecondTraceTerm to Opts map

The extra trace data has been moved to the opts map in order
for the tracer to be able to distinguish inbetween extra
trace data 'undefined' and no extra trace data. In the same
commit all opts associations have been changed so that if
the tracer should not use them, the key is left unassicated
instead of being sent to undefined. This should be give a
small performance gain and also makes the API easier to work
with.

2 files changed, 42 insertions, 30 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 8f65e71531..7fdce62bd1 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -228,9 +228,6 @@ atom endian
 atom env
 atom eof
 atom eol
-atom exception_from
-atom exception_trace
-atom extended
 atom Eq='=:='
 atom Eqeq='=='
 atom erl_tracer
@@ -243,6 +240,8 @@ atom ets
 atom ETS_TRANSFER='ETS-TRANSFER'
 atom event
 atom exact_reductions
+atom exception_from
+atom exception_trace
 atom exclusive
 atom exit_status
 atom existing
@@ -251,7 +250,9 @@ atom existing_ports
 atom existing
 atom exiting
 atom exports
+atom extended
 atom external
+atom extra
 atom false
 atom fcgi
 atom fd
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index ca001fc156..3dca58d60b 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -2625,7 +2625,7 @@ static void init_tracer_template(ErtsTracerNif *tnif) {
 
     /* default tracer functions */
     tnif->tracers[TRACE_FUN_DEFAULT].name  = "trace";
-    tnif->tracers[TRACE_FUN_DEFAULT].arity = 6;
+    tnif->tracers[TRACE_FUN_DEFAULT].arity = 5;
     tnif->tracers[TRACE_FUN_DEFAULT].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_ENABLED].name  = "enabled";
@@ -2634,35 +2634,35 @@ static void init_tracer_template(ErtsTracerNif *tnif) {
 
     /* specific tracer functions */
     tnif->tracers[TRACE_FUN_T_SEND].name  = "trace_send";
-    tnif->tracers[TRACE_FUN_T_SEND].arity = 6;
+    tnif->tracers[TRACE_FUN_T_SEND].arity = 5;
     tnif->tracers[TRACE_FUN_T_SEND].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_RECEIVE].name  = "trace_receive";
-    tnif->tracers[TRACE_FUN_T_RECEIVE].arity = 6;
+    tnif->tracers[TRACE_FUN_T_RECEIVE].arity = 5;
     tnif->tracers[TRACE_FUN_T_RECEIVE].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_CALL].name  = "trace_call";
-    tnif->tracers[TRACE_FUN_T_CALL].arity = 6;
+    tnif->tracers[TRACE_FUN_T_CALL].arity = 5;
     tnif->tracers[TRACE_FUN_T_CALL].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_SCHED_PROC].name  = "trace_running_procs";
-    tnif->tracers[TRACE_FUN_T_SCHED_PROC].arity = 6;
+    tnif->tracers[TRACE_FUN_T_SCHED_PROC].arity = 5;
     tnif->tracers[TRACE_FUN_T_SCHED_PROC].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_SCHED_PORT].name  = "trace_running_ports";
-    tnif->tracers[TRACE_FUN_T_SCHED_PORT].arity = 6;
+    tnif->tracers[TRACE_FUN_T_SCHED_PORT].arity = 5;
     tnif->tracers[TRACE_FUN_T_SCHED_PORT].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_GC].name  = "trace_garbage_collection";
-    tnif->tracers[TRACE_FUN_T_GC].arity = 6;
+    tnif->tracers[TRACE_FUN_T_GC].arity = 5;
     tnif->tracers[TRACE_FUN_T_GC].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_PROCS].name  = "trace_procs";
-    tnif->tracers[TRACE_FUN_T_PROCS].arity = 6;
+    tnif->tracers[TRACE_FUN_T_PROCS].arity = 5;
     tnif->tracers[TRACE_FUN_T_PROCS].cb    = NULL;
 
     tnif->tracers[TRACE_FUN_T_PORTS].name  = "trace_ports";
-    tnif->tracers[TRACE_FUN_T_PORTS].arity = 6;
+    tnif->tracers[TRACE_FUN_T_PORTS].arity = 5;
     tnif->tracers[TRACE_FUN_T_PORTS].cb    = NULL;
 
     /* specific enabled functions */
@@ -2834,10 +2834,12 @@ send_to_tracer_nif_raw(Process *c_p, Process *tracee,
                        Eterm tag, Eterm msg, Eterm extra, Eterm pam_result)
 {
     if (tnif || (tnif = lookup_tracer_nif(tracer)) != NULL) {
-#define MAP_SIZE 3
-        Eterm argv[6], local_heap[3+MAP_SIZE /* values */ + (MAP_SIZE+1 /* keys */)];
+#define MAP_SIZE 4
+        Eterm argv[5], local_heap[3+MAP_SIZE /* values */ + (MAP_SIZE+1 /* keys */)];
         flatmap_t *map = (flatmap_t*)(local_heap+(MAP_SIZE+1));
         Eterm *map_values = flatmap_get_values(map);
+        Eterm *map_keys = local_heap + 1;
+        Uint map_elem_count = 0;
 
         topt = (tnif->tracers[topt].cb) ? topt : TRACE_FUN_DEFAULT;
         ASSERT(topt < NIF_TRACER_TYPES);
@@ -2846,31 +2848,40 @@ send_to_tracer_nif_raw(Process *c_p, Process *tracee,
         argv[1] = ERTS_TRACER_STATE(tracer);
         argv[2] = t_p_id;
         argv[3] = msg;
-        argv[4] = extra == THE_NON_VALUE ? am_undefined : extra;
-        argv[5] = make_flatmap(map);
+        argv[4] = make_flatmap(map);
 
         map->thing_word = MAP_HEADER_FLATMAP;
-        map->size = MAP_SIZE;
-        map->keys = TUPLE3(local_heap, am_match_spec_result, am_scheduler_id, am_timestamp);
-
-        *map_values++ = pam_result;
-        if (tracee_flags & F_TRACE_SCHED_NO)
-            *map_values++ = make_small(erts_get_scheduler_id());
-        else
-            *map_values++ = am_undefined;
+
+        if (extra != THE_NON_VALUE) {
+            map_keys[map_elem_count] = am_extra;
+            map_values[map_elem_count++] = extra;
+        }
+
+        if (pam_result != am_true) {
+            map_keys[map_elem_count] = am_match_spec_result;
+            map_values[map_elem_count++] = pam_result;
+        }
+
+        if (tracee_flags & F_TRACE_SCHED_NO) {
+            map_keys[map_elem_count] = am_scheduler_id;
+            map_values[map_elem_count++] = make_small(erts_get_scheduler_id());
+        }
+        map_keys[map_elem_count] = am_timestamp;
         if (tracee_flags & F_NOW_TS)
 #ifdef HAVE_ERTS_NOW_CPU
             if (erts_cpu_timestamp)
-                *map_values++ = am_cpu_timestamp;
+                map_values[map_elem_count++] = am_cpu_timestamp;
             else
 #endif
-                *map_values++ = am_timestamp;
+                map_values[map_elem_count++] = am_timestamp;
         else if (tracee_flags & F_STRICT_MON_TS)
-            *map_values++ = am_strict_monotonic;
+            map_values[map_elem_count++] = am_strict_monotonic;
         else if (tracee_flags & F_MON_TS)
-            *map_values++ = am_monotonic;
-        else
-            *map_values++ = am_undefined;
+            map_values[map_elem_count++] = am_monotonic;
+
+        map->size = map_elem_count;
+        map->keys = make_tuple(local_heap);
+        local_heap[0] = make_arityval(map_elem_count);
 
 #undef MAP_SIZE
         erts_nif_call_function(c_p, tracee ? tracee : c_p,