From e35f0e203cb7600b208fe8b6367a4021350503e2 Mon Sep 17 00:00:00 2001
From: Fedor Indutny <fedor@indutny.com>
Date: Sat, 12 Nov 2016 16:49:40 -0500
Subject: [PATCH] process: add `process.memoryUsage.external`

---
 doc/api/process.md                 | 6 +++++-
 src/env.h                          | 1 +
 src/node.cc                        | 4 ++++
 test/parallel/test-memory-usage.js | 1 +
 4 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/doc/api/process.md b/doc/api/process.md
index d4779e6a2f8c77..379c1cc85901b8 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -1175,6 +1175,7 @@ added: v0.1.16
     * `rss` {Integer}
     * `heapTotal` {Integer}
     * `heapUsed` {Integer}
+    * `external` {Integer}
 
 The `process.memoryUsage()` method returns an object describing the memory usage
 of the Node.js process measured in bytes.
@@ -1193,11 +1194,14 @@ Will generate:
 {
   rss: 4935680,
   heapTotal: 1826816,
-  heapUsed: 650472
+  heapUsed: 650472,
+  external: 49879
 }
 ```
 
 `heapTotal` and `heapUsed` refer to V8's memory usage.
+`external` refers to the memory usage of C++ objects bound to JavaScript
+objects managed by V8.
 
 ## process.nextTick(callback[, ...args])
 <!-- YAML
diff --git a/src/env.h b/src/env.h
index fe49ac0c876a47..51049ed2bea473 100644
--- a/src/env.h
+++ b/src/env.h
@@ -103,6 +103,7 @@ namespace node {
   V(exponent_string, "exponent")                                              \
   V(exports_string, "exports")                                                \
   V(ext_key_usage_string, "ext_key_usage")                                    \
+  V(external_string, "external")                                              \
   V(external_stream_string, "_externalStream")                                \
   V(family_string, "family")                                                  \
   V(fatal_exception_string, "_fatalException")                                \
diff --git a/src/node.cc b/src/node.cc
index 82965f189bc7b7..e4c17af3ec23ed 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -2246,11 +2246,15 @@ void MemoryUsage(const FunctionCallbackInfo<Value>& args) {
       Number::New(env->isolate(), v8_heap_stats.total_heap_size());
   Local<Number> heap_used =
       Number::New(env->isolate(), v8_heap_stats.used_heap_size());
+  Local<Number> external_mem =
+      Number::New(env->isolate(),
+                  env->isolate()->AdjustAmountOfExternalAllocatedMemory(0));
 
   Local<Object> info = Object::New(env->isolate());
   info->Set(env->rss_string(), Number::New(env->isolate(), rss));
   info->Set(env->heap_total_string(), heap_total);
   info->Set(env->heap_used_string(), heap_used);
+  info->Set(env->external_string(), external_mem);
 
   args.GetReturnValue().Set(info);
 }
diff --git a/test/parallel/test-memory-usage.js b/test/parallel/test-memory-usage.js
index f704c8812801ba..c5905c537ac613 100644
--- a/test/parallel/test-memory-usage.js
+++ b/test/parallel/test-memory-usage.js
@@ -6,3 +6,4 @@ var r = process.memoryUsage();
 assert.ok(r.rss > 0);
 assert.ok(r.heapTotal > 0);
 assert.ok(r.heapUsed > 0);
+assert.ok(r.external > 0);