1//===-- tsan_mutexset.cpp -------------------------------------------------===//
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// This file is a part of ThreadSanitizer (TSan), a race detector.
10//
11//===----------------------------------------------------------------------===//
12#include "tsan_mutexset.h"
13
14#include "sanitizer_common/sanitizer_placement_new.h"
15#include "tsan_rtl.h"
16
17namespace __tsan {
18
19MutexSet::MutexSet() {
20}
21
22void MutexSet::Reset() { internal_memset(s: this, c: 0, n: sizeof(*this)); }
23
24void MutexSet::AddAddr(uptr addr, StackID stack_id, bool write) {
25 // Look up existing mutex with the same id.
26 for (uptr i = 0; i < size_; i++) {
27 if (descs_[i].addr == addr) {
28 descs_[i].count++;
29 descs_[i].seq = seq_++;
30 return;
31 }
32 }
33 // On overflow, find the oldest mutex and drop it.
34 if (size_ == kMaxSize) {
35 uptr min = 0;
36 for (uptr i = 0; i < size_; i++) {
37 if (descs_[i].seq < descs_[min].seq)
38 min = i;
39 }
40 RemovePos(i: min);
41 CHECK_EQ(size_, kMaxSize - 1);
42 }
43 // Add new mutex descriptor.
44 descs_[size_].addr = addr;
45 descs_[size_].stack_id = stack_id;
46 descs_[size_].write = write;
47 descs_[size_].seq = seq_++;
48 descs_[size_].count = 1;
49 size_++;
50}
51
52void MutexSet::DelAddr(uptr addr, bool destroy) {
53 for (uptr i = 0; i < size_; i++) {
54 if (descs_[i].addr == addr) {
55 if (destroy || --descs_[i].count == 0)
56 RemovePos(i);
57 return;
58 }
59 }
60}
61
62void MutexSet::RemovePos(uptr i) {
63 CHECK_LT(i, size_);
64 descs_[i] = descs_[size_ - 1];
65 size_--;
66}
67
68uptr MutexSet::Size() const {
69 return size_;
70}
71
72MutexSet::Desc MutexSet::Get(uptr i) const {
73 CHECK_LT(i, size_);
74 return descs_[i];
75}
76
77DynamicMutexSet::DynamicMutexSet() : ptr_(New<MutexSet>()) {}
78DynamicMutexSet::~DynamicMutexSet() { DestroyAndFree(p&: ptr_); }
79
80} // namespace __tsan
81