1//===-- sanitizer_allocator_stats.h -----------------------------*- C++ -*-===//
  2//
  3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4// See https://llvm.org/LICENSE.txt for license information.
  5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6//
  7//===----------------------------------------------------------------------===//
  8//
  9// Part of the Sanitizer Allocator.
 10//
 11//===----------------------------------------------------------------------===//
 12#ifndef SANITIZER_ALLOCATOR_H
 13#error This file must be included inside sanitizer_allocator.h
 14#endif
 15
 16// Memory allocator statistics
 17enum AllocatorStat {
 18  AllocatorStatAllocated,
 19  AllocatorStatMapped,
 20  AllocatorStatCount
 21};
 22
 23typedef uptr AllocatorStatCounters[AllocatorStatCount];
 24
 25// Per-thread stats, live in per-thread cache.
 26class AllocatorStats {
 27 public:
 28  void Init() { internal_memset(this, 0, sizeof(*this)); }
 29  void Add(AllocatorStat i, uptr v) {
 30    atomic_fetch_add(&stats_[i], v, memory_order_relaxed);
 31  }
 32
 33  void Sub(AllocatorStat i, uptr v) {
 34    atomic_fetch_sub(&stats_[i], v, memory_order_relaxed);
 35  }
 36
 37  void Set(AllocatorStat i, uptr v) {
 38    atomic_store(&stats_[i], v, memory_order_relaxed);
 39  }
 40
 41  uptr Get(AllocatorStat i) const {
 42    return atomic_load(&stats_[i], memory_order_relaxed);
 43  }
 44
 45 private:
 46  friend class AllocatorGlobalStats;
 47  AllocatorStats *next_;
 48  AllocatorStats *prev_;
 49  atomic_uintptr_t stats_[AllocatorStatCount];
 50};
 51
 52// Global stats, used for aggregation and querying.
 53class AllocatorGlobalStats : public AllocatorStats {
 54 public:
 55  void Init() {
 56    internal_memset(this, 0, sizeof(*this));
 57  }
 58
 59  void Register(AllocatorStats *s) {
 60    SpinMutexLock l(&mu_);
 61    LazyInit();
 62    s->next_ = next_;
 63    s->prev_ = this;
 64    next_->prev_ = s;
 65    next_ = s;
 66  }
 67
 68  void Unregister(AllocatorStats *s) {
 69    SpinMutexLock l(&mu_);
 70    s->prev_->next_ = s->next_;
 71    s->next_->prev_ = s->prev_;
 72    for (int i = 0; i < AllocatorStatCount; i++)
 73      Add(AllocatorStat(i), s->Get(AllocatorStat(i)));
 74  }
 75
 76  void Get(AllocatorStatCounters s) const {
 77    internal_memset(s, 0, AllocatorStatCount * sizeof(uptr));
 78    SpinMutexLock l(&mu_);
 79    const AllocatorStats *stats = this;
 80    for (; stats;) {
 81      for (int i = 0; i < AllocatorStatCount; i++)
 82        s[i] += stats->Get(AllocatorStat(i));
 83      stats = stats->next_;
 84      if (stats == this)
 85        break;
 86    }
 87    // All stats must be non-negative.
 88    for (int i = 0; i < AllocatorStatCount; i++)
 89      s[i] = ((sptr)s[i]) >= 0 ? s[i] : 0;
 90  }
 91
 92 private:
 93  void LazyInit() {
 94    if (!next_) {
 95      next_ = this;
 96      prev_ = this;
 97    }
 98  }
 99
100  mutable StaticSpinMutex mu_;
101};
102
103