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.

1 files changed, 15 insertions, 19 deletions

diff --git a/erts/emulator/nifs/common/erl_tracer_nif.c b/erts/emulator/nifs/common/erl_tracer_nif.c
index 6dddc80607..c0cc48ff42 100644
--- a/erts/emulator/nifs/common/erl_tracer_nif.c
+++ b/erts/emulator/nifs/common/erl_tracer_nif.c
@@ -45,7 +45,7 @@ static ERL_NIF_TERM trace(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
 
 static ErlNifFunc nif_funcs[] = {
     {"enabled", 3, enabled},
-    {"trace", 6, trace}
+    {"trace", 5, trace}
 };
 
 
@@ -57,6 +57,7 @@ ERL_NIF_INIT(erl_tracer, nif_funcs, load, NULL, upgrade, unload)
     ATOM_DECL(cpu_timestamp);                      \
     ATOM_DECL(discard);                            \
     ATOM_DECL(exception_from);                     \
+    ATOM_DECL(extra);                              \
     ATOM_DECL(match_spec_result);                  \
     ATOM_DECL(monotonic);                          \
     ATOM_DECL(ok);                                 \
@@ -76,8 +77,7 @@ ERL_NIF_INIT(erl_tracer, nif_funcs, load, NULL, upgrade, unload)
     ATOM_DECL(gc_minor_start);                     \
     ATOM_DECL(gc_minor_end);                       \
     ATOM_DECL(gc_major_start);                     \
-    ATOM_DECL(gc_major_end);                       \
-    ATOM_DECL(undefined);
+    ATOM_DECL(gc_major_end);
 
 #define ATOM_DECL(A) static ERL_NIF_TERM atom_##A
 ATOMS
@@ -154,11 +154,6 @@ static ERL_NIF_TERM enabled(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
               Tracee :: pid() || port() || undefined,
               Msg :: term(),
               Opts :: map()) -> ignored().
-   -spec trace(Tag :: atom(), TracerState :: pid() | port(),
-              Tracee :: pid() || port() || undefined,
-              Msg :: term(),
-              Extra :: term(),
-              Opts :: map()) -> ignored().
 */
 static ERL_NIF_TERM trace(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
@@ -167,7 +162,8 @@ static ERL_NIF_TERM trace(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     ErlNifPort to_port;
     size_t tt_sz = 0;
     int is_port = 0;
-    ASSERT(argc == 6);
+    size_t opts_sz = 0;
+    ASSERT(argc == 5);
 
     if (!enif_get_local_pid(env, argv[1], &to_pid)) {
         if (!enif_get_local_port(env, argv[1], &to_port)) {
@@ -179,12 +175,17 @@ static ERL_NIF_TERM trace(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
         is_port = 1;
     }
 
-    if (!enif_is_identical(argv[4], atom_undefined)) {
+    opts = argv[4];
+
+    if (!enif_get_map_size(env, opts, &opts_sz))
+        opts_sz = 0;
+
+    if (opts_sz && enif_get_map_value(env, opts, atom_extra, &value)) {
         tt[tt_sz++] = atom_trace;
         tt[tt_sz++] = argv[2];
         tt[tt_sz++] = argv[0];
         tt[tt_sz++] = argv[3];
-        tt[tt_sz++] = argv[4];
+        tt[tt_sz++] = value;
     } else {
         if (enif_is_identical(argv[0], atom_seq_trace)) {
             tt[tt_sz++] = atom_seq_trace;
@@ -198,21 +199,16 @@ static ERL_NIF_TERM trace(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
         }
     }
 
-    opts = argv[5];
 
-    if (enif_get_map_value(env, opts, atom_match_spec_result,
-                           &value)
-        && !enif_is_identical(value, atom_true)) {
+    if (opts_sz && enif_get_map_value(env, opts, atom_match_spec_result, &value)) {
         tt[tt_sz++] = value;
     }
 
-    if (enif_get_map_value(env, opts, atom_scheduler_id, &value)
-        && !enif_is_identical(value, atom_undefined)) {
+    if (opts_sz && enif_get_map_value(env, opts, atom_scheduler_id, &value)) {
         tt[tt_sz++] = value;
     }
 
-    if (enif_get_map_value(env, opts, atom_timestamp, &value)
-        && !enif_is_identical(value, atom_undefined)) {
+    if (opts_sz && enif_get_map_value(env, opts, atom_timestamp, &value)) {
         ERL_NIF_TERM ts;
         if (enif_is_identical(value, atom_monotonic)) {
             ErlNifTime mon = enif_monotonic_time(ERL_NIF_NSEC);