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
104