Merge pull request #2189 from jhogberg/john/erts/seq-trace-on-spawn/OTP-15232/ERL-700

Propagate seq_trace tokens to spawned processes

10 files changed, 70 insertions, 19 deletions

diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index b35fe2fc02..dd04018ce6 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -1987,7 +1987,7 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm return_term, Eterm *refp,
                 trace_send(p, portid, msg);
 
             if (have_seqtrace(SEQ_TRACE_TOKEN(p))) {
-                seq_trace_update_send(p);
+                seq_trace_update_serial(p);
                 seq_trace_output(SEQ_TRACE_TOKEN(p), msg,
                                  SEQ_TRACE_SEND, portid, p);
             }
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index ff19ef018e..1329d9d55f 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -1051,7 +1051,7 @@ erts_dsig_send_msg(ErtsDSigSendContext* ctx, Eterm remote, Eterm message)
 #endif
 
     if (have_seqtrace(SEQ_TRACE_TOKEN(sender))) {
-	seq_trace_update_send(sender);
+	seq_trace_update_serial(sender);
 	token = SEQ_TRACE_TOKEN(sender);
 	seq_trace_output(token, message, SEQ_TRACE_SEND, remote, sender);
     }
@@ -1125,7 +1125,7 @@ erts_dsig_send_reg_msg(ErtsDSigSendContext* ctx, Eterm remote_name, Eterm messag
 #endif
 
     if (have_seqtrace(SEQ_TRACE_TOKEN(sender))) {
-	seq_trace_update_send(sender);
+	seq_trace_update_serial(sender);
 	token = SEQ_TRACE_TOKEN(sender);
 	seq_trace_output(token, message, SEQ_TRACE_SEND, remote_name, sender);
     }
@@ -1184,7 +1184,7 @@ erts_dsig_send_exit_tt(ErtsDSigSendContext *ctx, Eterm local, Eterm remote,
         msg = reason;
 
     if (have_seqtrace(token)) {
-	seq_trace_update_send(ctx->c_p);
+	seq_trace_update_serial(ctx->c_p);
 	seq_trace_output_exit(token, reason, SEQ_TRACE_SEND, remote, local);
         if (ctx->dep->flags & DFLAG_EXIT_PAYLOAD) {
             ctl = TUPLE4(&ctx->ctl_heap[0],
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index 711e62c795..cf5339feb9 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -1858,6 +1858,8 @@ Eterm erts_seq_trace(Process *p, Eterm arg1, Eterm arg2,
 
     if (arg1 == am_send) {
 	current_flag = SEQ_TRACE_SEND;
+    } else if (arg1 == am_spawn) {
+	current_flag = SEQ_TRACE_SPAWN;
     } else if (arg1 == am_receive) {
 	current_flag = SEQ_TRACE_RECEIVE; 
     } else if (arg1 == am_print) {
@@ -1966,8 +1968,9 @@ BIF_RETTYPE erl_seq_trace_info(Process *p, Eterm item)
     }
 
     if (have_no_seqtrace(SEQ_TRACE_TOKEN(p))) {
-	if ((item == am_send)  || (item == am_receive) || 
-	    (item == am_print) || (item == am_timestamp)
+	if ((item == am_send) || (item == am_spawn) ||
+        (item == am_receive) || (item == am_print)
+        || (item == am_timestamp)
 	    || (item == am_monotonic_timestamp)
 	    || (item == am_strict_monotonic_timestamp)) {
 	    hp = HAlloc(p,3);
@@ -1982,6 +1985,8 @@ BIF_RETTYPE erl_seq_trace_info(Process *p, Eterm item)
 
     if (item == am_send) {
 	current_flag = SEQ_TRACE_SEND;
+    } else if (item == am_spawn) {
+	current_flag = SEQ_TRACE_SPAWN;
     } else if (item == am_receive) {
 	current_flag = SEQ_TRACE_RECEIVE; 
     } else if (item == am_print) {
@@ -2031,7 +2036,7 @@ BIF_RETTYPE seq_trace_print_1(BIF_ALIST_1)
     if (have_no_seqtrace(SEQ_TRACE_TOKEN(BIF_P))) {
 	BIF_RET(am_false);
     }
-    seq_trace_update_send(BIF_P);
+    seq_trace_update_serial(BIF_P);
     seq_trace_output(SEQ_TRACE_TOKEN(BIF_P), BIF_ARG_1, 
 		     SEQ_TRACE_PRINT, NIL, BIF_P);
     BIF_RET(am_true);
@@ -2055,7 +2060,7 @@ BIF_RETTYPE seq_trace_print_2(BIF_ALIST_2)
     }
     if (SEQ_TRACE_TOKEN_LABEL(BIF_P) != BIF_ARG_1)
 	BIF_RET(am_false);
-    seq_trace_update_send(BIF_P);
+    seq_trace_update_serial(BIF_P);
     seq_trace_output(SEQ_TRACE_TOKEN(BIF_P), BIF_ARG_2, 
 		     SEQ_TRACE_PRINT, NIL, BIF_P);
     BIF_RET(am_true);
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index 6645341512..c27c3b5423 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -674,7 +674,7 @@ erts_send_message(Process* sender,
          * Make sure we don't use the heap between those instances.
          */
         if (have_seqtrace(stoken)) {
-	    seq_trace_update_send(sender);
+	    seq_trace_update_serial(sender);
 	    seq_trace_output(stoken, message, SEQ_TRACE_SEND,
 			     receiver->common.id, sender);
 
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 1fbe362330..ce43cb9e71 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -815,7 +815,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
             }
 #endif
             if (have_seqtrace(stoken)) {
-                seq_trace_update_send(c_p);
+                seq_trace_update_serial(c_p);
                 seq_trace_output(stoken, msg, SEQ_TRACE_SEND,
                                  rp->common.id, c_p);
             }
diff --git a/erts/emulator/beam/erl_proc_sig_queue.c b/erts/emulator/beam/erl_proc_sig_queue.c
index f58a606d57..fb8a860b27 100644
--- a/erts/emulator/beam/erl_proc_sig_queue.c
+++ b/erts/emulator/beam/erl_proc_sig_queue.c
@@ -995,7 +995,7 @@ send_gen_exit_signal(Process *c_p, Eterm from_tag,
 
     seq_trace = c_p && have_seqtrace(token);
     if (seq_trace)
-        seq_trace_update_send(c_p);
+        seq_trace_update_serial(c_p);
 
 #ifdef USE_VM_PROBES
     utag_sz = 0;
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index e69a9b8813..70f48ddd97 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -11615,9 +11615,6 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     p->mbuf_sz = 0;
     erts_atomic_init_nob(&p->psd, (erts_aint_t) NULL);
     p->dictionary = NULL;
-    p->seq_trace_lastcnt = 0;
-    p->seq_trace_clock = 0;
-    SEQ_TRACE_TOKEN(p) = NIL;
 #ifdef USE_VM_PROBES
     DT_UTAG(p) = NIL;
     DT_UTAG_FLAGS(p) = 0;
@@ -11638,6 +11635,45 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     p->fp_exception = 0;
 #endif
 
+    /* seq_trace is handled before regular tracing as the latter may touch the
+     * trace token. */
+    if (have_seqtrace(SEQ_TRACE_TOKEN(parent))) {
+        Eterm token;
+        Uint token_sz;
+        Eterm *hp;
+
+        ASSERT(SEQ_TRACE_TOKEN_ARITY(parent) == 5);
+        ASSERT(is_immed(SEQ_TRACE_TOKEN_FLAGS(parent)));
+        ASSERT(is_immed(SEQ_TRACE_TOKEN_SERIAL(parent)));
+        ASSERT(is_immed(SEQ_TRACE_TOKEN_LASTCNT(parent)));
+
+        seq_trace_update_serial(parent);
+
+        token = SEQ_TRACE_TOKEN(parent);
+        token_sz = size_object(token);
+
+        hp = HAlloc(p, token_sz);
+        SEQ_TRACE_TOKEN(p) = copy_struct(token, token_sz, &hp, &MSO(p));
+
+        /* The counters behave the same way on spawning as they do on messages;
+         * we don't inherit our parent's lastcnt. */
+        p->seq_trace_lastcnt = parent->seq_trace_clock;
+        p->seq_trace_clock = parent->seq_trace_clock;
+
+        ASSERT((locks & (ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE)) ==
+               (ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE));
+
+        locks &= ~(ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+        erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+        erts_proc_unlock(parent, ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+
+        seq_trace_output(token, NIL, SEQ_TRACE_SPAWN, p->common.id, parent);
+    } else {
+        SEQ_TRACE_TOKEN(p) = NIL;
+        p->seq_trace_lastcnt = 0;
+        p->seq_trace_clock = 0;
+    }
+
     if (IS_TRACED(parent)) {
 	if (ERTS_TRACE_FLAGS(parent) & F_TRACE_SOS) {
 	    ERTS_TRACE_FLAGS(p) |= (ERTS_TRACE_FLAGS(parent) & TRACEE_FLAGS);
@@ -11659,9 +11695,14 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 		}
         }
         if (ARE_TRACE_FLAGS_ON(parent, F_TRACE_PROCS)) {
-            locks &= ~(ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
-            erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
-            erts_proc_unlock(parent, ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+            /* The locks may already be released if seq_trace is enabled as
+             * well. */
+            if ((locks & (ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE))
+                  == (ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE)) {
+                locks &= ~(ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+                erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+                erts_proc_unlock(parent, ERTS_PROC_LOCK_STATUS|ERTS_PROC_LOCK_TRACE);
+            }
             trace_proc_spawn(parent, am_spawn, p->common.id, mod, func, args);
             if (so->flags & SPO_LINK)
                 trace_proc(parent, locks, parent, am_link, p->common.id);
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 6118c671ee..93a3215c17 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -1481,6 +1481,8 @@ extern int erts_system_profile_ts_type;
 #define SEQ_TRACE_SEND     (1 << 0)
 #define SEQ_TRACE_RECEIVE  (1 << 1)
 #define SEQ_TRACE_PRINT    (1 << 2)
+/* (This three-bit gap contains the timestamp.) */
+#define SEQ_TRACE_SPAWN    (1 << 6)
 
 #define ERTS_SEQ_TRACE_FLAGS_TS_TYPE_SHIFT 3
 
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index c85a7df5ec..6e462b64ef 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -826,7 +826,7 @@ trace_receive(Process* receiver,
 }
 
 int
-seq_trace_update_send(Process *p)
+seq_trace_update_serial(Process *p)
 {
     ErtsTracer seq_tracer = erts_get_system_seq_tracer();
     ASSERT((is_tuple(SEQ_TRACE_TOKEN(p)) || is_nil(SEQ_TRACE_TOKEN(p))));
@@ -894,6 +894,7 @@ seq_trace_output_generic(Eterm token, Eterm msg, Uint type,
 
     switch (type) {
     case SEQ_TRACE_SEND:    type_atom = am_send; break;
+    case SEQ_TRACE_SPAWN:   type_atom = am_spawn; break;
     case SEQ_TRACE_PRINT:   type_atom = am_print; break;
     case SEQ_TRACE_RECEIVE: type_atom = am_receive; break;
     default:
diff --git a/erts/emulator/beam/erl_trace.h b/erts/emulator/beam/erl_trace.h
index b7844d1cb0..bb5c9ac276 100644
--- a/erts/emulator/beam/erl_trace.h
+++ b/erts/emulator/beam/erl_trace.h
@@ -163,7 +163,9 @@ seq_trace_output_generic((token), (msg), (type), (receiver), NULL, (exitfrom))
 void seq_trace_output_generic(Eterm token, Eterm msg, Uint type, 
 			      Eterm receiver, Process *process, Eterm exitfrom);
 
-int seq_trace_update_send(Process *process);
+/* Bump the sequence number if tracing is enabled; must be used before sending
+ * send/spawn trace messages. */
+int seq_trace_update_serial(Process *process);
 
 Eterm erts_seq_trace(Process *process, 
 		     Eterm atom_type, Eterm atom_true_or_false,