Updated MallocHooks to collect stack traces when memory is allocated.

runtime/vm/profiler.h

Index: runtime/vm/profiler.h
diff --git a/runtime/vm/profiler.h b/runtime/vm/profiler.h
index ee87a31d954051b61af6a7a822b7f2bb78da23eb..f23dd065192eb066aa97fe845a38716e59e59740 100644
--- a/runtime/vm/profiler.h
+++ b/runtime/vm/profiler.h
@@ -58,6 +58,7 @@ class Profiler : public AllStatic {
   static void DumpStackTrace();
 
   static void SampleAllocation(Thread* thread, intptr_t cid);
+  static Sample* SampleNativeAllocation(intptr_t skip_count);
 
   // SampleThread is called from inside the signal handler and hence it is very
   // critical that the implementation of SampleThread does not do any of the
@@ -91,7 +92,7 @@ class Profiler : public AllStatic {
 
 class SampleVisitor : public ValueObject {
  public:
-  explicit SampleVisitor(Isolate* isolate) : isolate_(isolate), visited_(0) {}
+  explicit SampleVisitor(Dart_Port port) : port_(port), visited_(0) {}
   virtual ~SampleVisitor() {}
 
   virtual void VisitSample(Sample* sample) = 0;
@@ -100,10 +101,10 @@ class SampleVisitor : public ValueObject {
 
   void IncrementVisited() { visited_++; }
 
-  Isolate* isolate() const { return isolate_; }
+  Dart_Port port() const { return port_; }
 
  private:
-  Isolate* isolate_;
+  Dart_Port port_;
   intptr_t visited_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(SampleVisitor);
@@ -112,11 +113,11 @@ class SampleVisitor : public ValueObject {
 
 class SampleFilter : public ValueObject {
  public:
-  SampleFilter(Isolate* isolate,
+  SampleFilter(Dart_Port port,
                intptr_t thread_task_mask,
                int64_t time_origin_micros,
                int64_t time_extent_micros)
-      : isolate_(isolate),
+      : port_(port),
         thread_task_mask_(thread_task_mask),
         time_origin_micros_(time_origin_micros),
         time_extent_micros_(time_extent_micros) {
@@ -130,7 +131,7 @@ class SampleFilter : public ValueObject {
   // Return |true| if |sample| passes the filter.
   virtual bool FilterSample(Sample* sample) { return true; }
 
-  Isolate* isolate() const { return isolate_; }
+  Dart_Port port() const { return port_; }
 
   // Returns |true| if |sample| passes the time filter.
   bool TimeFilterSample(Sample* sample);
@@ -139,7 +140,7 @@ class SampleFilter : public ValueObject {
   bool TaskFilterSample(Sample* sample);
 
  private:
-  Isolate* isolate_;
+  Dart_Port port_;
   intptr_t thread_task_mask_;
   int64_t time_origin_micros_;
   int64_t time_extent_micros_;
@@ -157,21 +158,20 @@ class ClearProfileVisitor : public SampleVisitor {
 // Each Sample holds a stack trace from an isolate.
 class Sample {
  public:
-  void Init(Isolate* isolate, int64_t timestamp, ThreadId tid) {
+  void Init(Dart_Port port, int64_t timestamp, ThreadId tid) {
     Clear();
     timestamp_ = timestamp;
     tid_ = tid;
-    isolate_ = isolate;
+    port_ = port;
   }
 
-  // Isolate sample was taken from.
-  Isolate* isolate() const { return isolate_; }
+  Dart_Port port() const { return port_; }
 
   // Thread sample was taken on.
   ThreadId tid() const { return tid_; }
 
   void Clear() {
-    isolate_ = NULL;
+    port_ = ILLEGAL_PORT;
     pc_marker_ = 0;
     for (intptr_t i = 0; i < kStackBufferSizeInWords; i++) {
       stack_buffer_[i] = 0;
@@ -268,6 +268,15 @@ class Sample {
     state_ = ClassAllocationSampleBit::update(allocation_sample, state_);
   }
 
+  bool is_native_allocation_sample() const {
+    return NativeAllocationSampleBit::decode(state_);
+  }
+
+  void set_is_native_allocation_sample(bool native_allocation_sample) {
+    state_ =
+        NativeAllocationSampleBit::update(native_allocation_sample, state_);
+  }
+
   Thread::TaskKind thread_task() const { return ThreadTaskBit::decode(state_); }
 
   void set_thread_task(Thread::TaskKind task) {
@@ -331,7 +340,8 @@ class Sample {
     kClassAllocationSampleBit = 6,
     kContinuationSampleBit = 7,
     kThreadTaskBit = 8,  // 5 bits.
-    kNextFreeBit = 13,
+    kNativeAllocationSampleBit = 13,
+    kNextFreeBit = 14,
   };
   class HeadSampleBit : public BitField<uword, bool, kHeadSampleBit, 1> {};
   class LeafFrameIsDart : public BitField<uword, bool, kLeafFrameIsDartBit, 1> {
@@ -344,6 +354,8 @@ class Sample {
       : public BitField<uword, bool, kTruncatedTraceBit, 1> {};
   class ClassAllocationSampleBit
       : public BitField<uword, bool, kClassAllocationSampleBit, 1> {};
+  class NativeAllocationSampleBit
+      : public BitField<uword, bool, kNativeAllocationSampleBit, 1> {};
   class ContinuationSampleBit
       : public BitField<uword, bool, kContinuationSampleBit, 1> {};
   class ThreadTaskBit
@@ -351,7 +363,7 @@ class Sample {
 
   int64_t timestamp_;
   ThreadId tid_;
-  Isolate* isolate_;
+  Dart_Port port_;
   uword pc_marker_;
   uword stack_buffer_[kStackBufferSizeInWords];
   uword vm_tag_;
@@ -474,7 +486,8 @@ class SampleBuffer {
         // Bad sample.
         continue;
       }
-      if (sample->isolate() != visitor->isolate()) {
+      if ((sample->port() != visitor->port()) &&

[Cutch, 2017/02/21 18:53:35]

It seems like native samples have a port of ILLEGAL_PORT_ID. Do we need the
!sample->is_native_allocation_sample condition?

[bkonyi, 2017/02/22 19:12:51]

No, we don't. I've removed the code associated with is_native_allocation_sample.

+          !sample->is_native_allocation_sample()) {
         // Another isolate.
         continue;
       }