From 4d352f6f73912b7ccb34a48433d6ec8cd2443448 Mon Sep 17 00:00:00 2001
From: Ali Ijaz Sheikh <ofrobots@google.com>
Date: Tue, 11 Sep 2018 15:40:28 -0700
Subject: [PATCH 1/2] deps: cherry-pick 2363cdf from upstream V8

Original commit message:

    [tracing] do not add traces when disabled

    https://github.com/nodejs/node/issues/21038

    Change-Id: Ic4c9f403b5e54a97d3170b2311dd5aab8c8357c8
    Reviewed-on: https://chromium-review.googlesource.com/1217726
    Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
    Reviewed-by: Yang Guo <yangguo@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#55809}

Refs: https://github.com/v8/v8/commit/2363cdfefeb643285cbe8593b7c17d80e5d06cd9
---
 common.gypi                                   |  2 +-
 .../libplatform/tracing/tracing-controller.cc | 32 +++++++++++--------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/common.gypi b/common.gypi
index 9864e8374e74da..21fa89c4dd3225 100644
--- a/common.gypi
+++ b/common.gypi
@@ -29,7 +29,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.9',
+    'v8_embedder_string': '-node.10',
 
     # Enable disassembler for `--print-code` v8 options
     'v8_enable_disassembler': 1,
diff --git a/deps/v8/src/libplatform/tracing/tracing-controller.cc b/deps/v8/src/libplatform/tracing/tracing-controller.cc
index b4aa7baf724d4f..e0a6a1234c5970 100644
--- a/deps/v8/src/libplatform/tracing/tracing-controller.cc
+++ b/deps/v8/src/libplatform/tracing/tracing-controller.cc
@@ -63,13 +63,15 @@ uint64_t TracingController::AddTraceEvent(
     const uint64_t* arg_values,
     std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
     unsigned int flags) {
-  uint64_t handle;
-  TraceObject* trace_object = trace_buffer_->AddTraceEvent(&handle);
-  if (trace_object) {
-    trace_object->Initialize(
-        phase, category_enabled_flag, name, scope, id, bind_id, num_args,
-        arg_names, arg_types, arg_values, arg_convertables, flags,
-        CurrentTimestampMicroseconds(), CurrentCpuTimestampMicroseconds());
+  uint64_t handle = 0;
+  if (mode_ != DISABLED) {
+    TraceObject* trace_object = trace_buffer_->AddTraceEvent(&handle);
+    if (trace_object) {
+      trace_object->Initialize(
+          phase, category_enabled_flag, name, scope, id, bind_id, num_args,
+          arg_names, arg_types, arg_values, arg_convertables, flags,
+          CurrentTimestampMicroseconds(), CurrentCpuTimestampMicroseconds());
+    }
   }
   return handle;
 }
@@ -81,13 +83,15 @@ uint64_t TracingController::AddTraceEventWithTimestamp(
     const uint64_t* arg_values,
     std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables,
     unsigned int flags, int64_t timestamp) {
-  uint64_t handle;
-  TraceObject* trace_object = trace_buffer_->AddTraceEvent(&handle);
-  if (trace_object) {
-    trace_object->Initialize(phase, category_enabled_flag, name, scope, id,
-                             bind_id, num_args, arg_names, arg_types,
-                             arg_values, arg_convertables, flags, timestamp,
-                             CurrentCpuTimestampMicroseconds());
+  uint64_t handle = 0;
+  if (mode_ != DISABLED) {
+    TraceObject* trace_object = trace_buffer_->AddTraceEvent(&handle);
+    if (trace_object) {
+      trace_object->Initialize(phase, category_enabled_flag, name, scope, id,
+                               bind_id, num_args, arg_names, arg_types,
+                               arg_values, arg_convertables, flags, timestamp,
+                               CurrentCpuTimestampMicroseconds());
+    }
   }
   return handle;
 }

From ac565801bf5a1e5ff66a14ee1ddd189643586d9c Mon Sep 17 00:00:00 2001
From: Ali Ijaz Sheikh <ofrobots@google.com>
Date: Tue, 11 Sep 2018 17:12:43 -0700
Subject: [PATCH 2/2] tracing: avoid flusing uninitialized traces

Fixes: https://github.com/nodejs/node/issues/21038
---
 src/tracing/node_trace_buffer.cc | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/tracing/node_trace_buffer.cc b/src/tracing/node_trace_buffer.cc
index 70a0ad4b311610..3b7119f6d57f68 100644
--- a/src/tracing/node_trace_buffer.cc
+++ b/src/tracing/node_trace_buffer.cc
@@ -59,7 +59,13 @@ void InternalTraceBuffer::Flush(bool blocking) {
       for (size_t i = 0; i < total_chunks_; ++i) {
         auto& chunk = chunks_[i];
         for (size_t j = 0; j < chunk->size(); ++j) {
-          agent_->AppendTraceEvent(chunk->GetEventAt(j));
+          TraceObject* trace_event = chunk->GetEventAt(j);
+          // Another thread may have added a trace that is yet to be
+          // initialized. Skip such traces.
+          // https://github.com/nodejs/node/issues/21038.
+          if (trace_event->name()) {
+            agent_->AppendTraceEvent(trace_event);
+          }
         }
       }
       total_chunks_ = 0;