Added page to Observatory to display native memory allocation information.

runtime/vm/malloc_hooks.cc

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 
 #if defined(DART_USE_TCMALLOC) && !defined(PRODUCT) &&                         \
     !defined(TARGET_ARCH_DBC) && !defined(TARGET_OS_FUCHSIA)
 
 #include "vm/malloc_hooks.h"
@@ skipping 113 matching lines @@
   Mutex* mutex_;
   ThreadId* owner_;
 };
 
 // AllocationInfo contains all information related to a given allocation
 // including:
 //   -Allocation size in bytes
 //   -Stack trace corresponding to the location of allocation, if applicable
 class AllocationInfo {
  public:
-  explicit AllocationInfo(intptr_t allocation_size)
-      : sample_(NULL), allocation_size_(allocation_size) {
+  AllocationInfo(uword address, intptr_t allocation_size)
+      : sample_(NULL), address_(address), allocation_size_(allocation_size) {
     // Stack trace collection is disabled when we are in the process of creating
     // the first OSThread in order to prevent deadlocks.
     if (MallocHooksState::ProfilingEnabled() &&
         MallocHooksState::stack_trace_collection_enabled()) {
-      sample_ = Profiler::SampleNativeAllocation(kSkipCount);
+      sample_ = Profiler::SampleNativeAllocation(kSkipCount, address,
+                                                 allocation_size);
+      ASSERT(sample_->native_allocation_address() == address_);
     }
   }
 
   Sample* sample() const { return sample_; }
   intptr_t allocation_size() const { return allocation_size_; }
 
  private:
+  // Note: sample_ is not owned by AllocationInfo, but by the SampleBuffer
+  // created by the profiler. As such, this is only here to track if the sample
+  // is still associated with a native allocation, and its fields are never
+  // accessed from this class.
   Sample* sample_;
+  uword address_;
   intptr_t allocation_size_;
 
   // The number of frames that are generated by the malloc hooks and collection
   // of the stack trace. These frames are ignored when collecting the stack
   // trace for a memory allocation. If this number is incorrect, some tests in
   // malloc_hook_tests.cc might fail, particularily
   // StackTraceMallocHookLengthTest. If this value is updated, please make sure
   // that the MallocHooks test cases pass on all platforms.
-  static const intptr_t kSkipCount = 5;
+  static const intptr_t kSkipCount = 6;
 };
 
 
 // Custom key/value trait specifically for address/size pairs. Unlike
 // RawPointerKeyValueTrait, the default value is -1 as 0 can be a valid entry.
 class AddressKeyValueTrait : public AllStatic {
  public:
   typedef const void* Key;
   typedef AllocationInfo* Value;
 
@@ skipping 241 matching lines @@
   if (MallocHooksState::IsLockHeldByCurrentThread() ||
       !MallocHooksState::IsOriginalProcess()) {
     return;
   }
 
   MallocLocker ml(MallocHooksState::malloc_hook_mutex(),
                   MallocHooksState::malloc_hook_mutex_owner());
   // Now that we hold the lock, check to make sure everything is still active.
   if ((ptr != NULL) && MallocHooksState::Active()) {
     MallocHooksState::IncrementHeapAllocatedMemoryInBytes(size);
-    MallocHooksState::address_map()->Insert(ptr, new AllocationInfo(size));
+    MallocHooksState::address_map()->Insert(
+        ptr, new AllocationInfo(reinterpret_cast<uword>(ptr), size));
   }
 }
 
 
 void MallocHooksState::RecordFreeHook(const void* ptr) {
   if (MallocHooksState::IsLockHeldByCurrentThread() ||
       !MallocHooksState::IsOriginalProcess()) {
     return;
   }
 
   MallocLocker ml(MallocHooksState::malloc_hook_mutex(),
                   MallocHooksState::malloc_hook_mutex_owner());
   // Now that we hold the lock, check to make sure everything is still active.
   if ((ptr != NULL) && MallocHooksState::Active()) {
     AllocationInfo* allocation_info = NULL;
     if (MallocHooksState::address_map()->Lookup(ptr, &allocation_info)) {
       MallocHooksState::DecrementHeapAllocatedMemoryInBytes(
           allocation_info->allocation_size());
-      MallocHooksState::address_map()->Remove(ptr);
+      ASSERT(MallocHooksState::address_map()->Remove(ptr));
       delete allocation_info;
     }
   }
 }
 
 }  // namespace dart
 
 #endif  // defined(DART_USE_TCMALLOC) && !defined(PRODUCT) &&
         // !defined(TARGET_ARCH_DBC) && !defined(TARGET_OS_FUCHSIA)