Rename ScopedThreadHeapUsage to ThreadHeapUsageTracker.

base/debug/scoped_thread_heap_usage.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 BASE_DEBUG_SCOPED_THREAD_HEAP_USAGE_H_
-#define BASE_DEBUG_SCOPED_THREAD_HEAP_USAGE_H_
-
-#include <stdint.h>
-
-#include "base/allocator/features.h"
-#include "base/base_export.h"
-#include "base/threading/thread_checker.h"
-
-namespace base {
-namespace allocator {
-struct AllocatorDispatch;
-}  // namespace allocator
-
-namespace debug {
-
-// By keeping a tally on heap operations, it's possible to track:
-// - the number of alloc/free operations, where a realloc is zero or one
-//   of each, depending on the input parameters (see man realloc).
-// - the number of bytes allocated/freed.
-// - the number of estimated bytes of heap overhead used.
-// - the high-watermark amount of bytes allocated in the scope.
-// This in turn allows measuring the memory usage and memory usage churn over
-// a scope. Scopes must be cleanly nested, and each scope must be
-// destroyed on the thread where it's created.
-//
-// Note that this depends on the capabilities of the underlying heap shim. If
-// that shim can not yield a size estimate for an allocation, it's not possible
-// to keep track of overhead, freed bytes and the allocation high water mark.
-class BASE_EXPORT ScopedThreadHeapUsage {
- public:
-  struct ThreadAllocatorUsage {
-    // The cumulative number of allocation operations.
-    uint64_t alloc_ops;
-
-    // The cumulative number of allocated bytes. Where available, this is
-    // inclusive heap padding and estimated or actual heap overhead.
-    uint64_t alloc_bytes;
-
-    // Where available, cumulative number of heap padding heap
-    // and overhead bytes.
-    uint64_t alloc_overhead_bytes;
-
-    // The cumulative number of free operations.
-    uint64_t free_ops;
-
-    // The cumulative number of bytes freed.
-    // Only recorded if the underlying heap shim can return the size of an
-    // allocation.
-    uint64_t free_bytes;
-
-    // The maximal value of alloc_bytes - free_bytes seen for this thread.
-    // Only recorded if the underlying heap shim supports returning the size of
-    // an allocation.
-    uint64_t max_allocated_bytes;
-  };
-
-  ScopedThreadHeapUsage();
-  ~ScopedThreadHeapUsage();
-
-  const ThreadAllocatorUsage& usage_at_creation() const {
-    return usage_at_creation_;
-  }
-
-  // Returns this thread's allocator usage from the creation of the innermost
-  // enclosing ScopedThreadHeapUsage instance, if any. Note that this is
-  // inclusive allocator usage in all inner scopes.
-  static ThreadAllocatorUsage CurrentUsage();
-
-  // Initializes the TLS machinery this class uses. Must be called before
-  // creating instances of this class.
-  static void Initialize();
-
-  // Enables the heap intercept. May only be called once, and only if the heap
-  // shim is available, e.g. if BUILDFLAG(USE_EXPERIMENTAL_ALLOCATOR_SHIM) is
-  // true.
-  static void EnableHeapTracking();
-
- protected:
-  // Exposed for testing only - note that it's safe to re-EnableHeapTracking()
-  // after calling this function in tests.
-  static void DisableHeapTrackingForTesting();
-
-  // Exposed to allow testing the shim without inserting it in the allocator
-  // shim chain.
-  static base::allocator::AllocatorDispatch* GetDispatchForTesting();
-
- private:
-  static void EnsureTLSInitialized();
-
-  ThreadChecker thread_checker_;
-  // The allocator usage captured at creation of this instance.
-  ThreadAllocatorUsage usage_at_creation_;
-};
-
-}  // namespace debug
-}  // namespace base
-
-#endif  // BASE_DEBUG_SCOPED_THREAD_HEAP_USAGE_H_