metrics: Connect leak detector to allocator

components/metrics/leak_detector/leak_detector.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_
 #define COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <list>
 #include <vector>
 
 #include "base/feature_list.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
+#include "components/metrics/leak_detector/leak_detector_impl.h"
 
 namespace metrics {
 
 // LeakDetector is an interface layer that connects the allocator
 // (base::allocator), the leak detector logic (LeakDetectorImpl), and any
 // external classes interested in receiving leak reports (extend the Observer
 // class).
 //
 // Currently it is stubbed out and only provides an interface for registering
 // observers to receive leak reports.
@@ skipping 49 matching lines @@
   ~LeakDetector();
 
   // Add |observer| to the list of stored Observers, i.e. |observers_|, to which
   // the leak detector will report leaks.
   void AddObserver(Observer* observer);
 
   // Remove |observer| from |observers_|.
   void RemoveObserver(Observer* observer);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(LeakDetectorTest, AllocatorHooks);
   FRIEND_TEST_ALL_PREFIXES(LeakDetectorTest, NotifyObservers);
 
+  // Allocator hook function that processes each alloc. Performs sampling and
+  // unwinds call stack if necessary. Passes the allocated memory |ptr| and
+  // allocation size |size| along with call stack info to RecordAlloc().
+  static void AllocHook(const void* ptr, size_t size);
+
+  // Allocator hook function that processes each free. Performs sampling and
+  // passes the allocation address |ptr| to |impl_|.
+  static void FreeHook(const void* ptr);
+
+  // Give an pointer |ptr|, computes a hash of the pointer value and compares it
+  // against |sampling_factor_| to determine if it should be sampled. This
+  // allows the same pointer to be sampled during both alloc and free.
+  bool ShouldSample(const void* ptr) const;
+
+  // Given an allocation |ptr| with size |size|, and a call stack |call_stack|
+  // with depth of |depth| frames, passes it all to |impl_|. Then performs leak
+  // analysis if a sufficient interval of allocated bytes has passed since the
+  // previous analysis.
+  void RecordAlloc(const void* ptr, size_t size, int depth, void** call_stack);
+
   // Notifies all Observers in |observers_| with the given vector of leak
   // reports.
   void NotifyObservers(const std::vector<LeakReport>& reports);
 
   // List of observers to notify when there's a leak report.
   base::ObserverList<Observer> observers_;
 
+  // Handles leak detection logic. Must be called under lock as LeakDetectorImpl
+  // uses shared resources.
+  scoped_ptr<leak_detector::LeakDetectorImpl> impl_;
+
   // For thread safety.
   base::ThreadChecker thread_checker_;
 
+  // Mapping size and address of Chrome binary in memory.
+  uintptr_t binary_mapping_addr_;
+  size_t binary_mapping_size_;
+
+  // Total number of bytes allocated, computed before sampling.
+  size_t total_alloc_size_;
+
+  // The value of |total_alloc_size_| the last time there was a leak analysis,
+  // rounded down to the nearest multiple of |analysis_interval_bytes_|.
+  size_t last_analysis_alloc_size_;
+
+  // Perform a leak analysis each time this many bytes have been allocated since
+  // the previous analysis.
+  size_t analysis_interval_bytes_;
+
+  // When unwinding call stacks, unwind no more than this number of frames.
+  size_t max_call_stack_unwind_depth_;
+
+  // Sampling factor used by ShouldSample(). It's full range of values
+  // corresponds to the allowable range of |sampling_rate| passed in during
+  // initialization: [0.0f, 1.0f] -> [0, UINT64_MAX].
+  uint64_t sampling_factor_;
+
   // For generating closures containing objects of this class.
   base::WeakPtrFactory<LeakDetector> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LeakDetector);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_