1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
| //===-- tsan_mutexset.cpp -------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
//===----------------------------------------------------------------------===//
#include "tsan_mutexset.h"
#include "tsan_rtl.h"
namespace __tsan {
const uptr MutexSet::kMaxSize;
MutexSet::MutexSet() {
size_ = 0;
internal_memset(&descs_, 0, sizeof(descs_));
}
void MutexSet::Add(u64 id, bool write, u64 epoch) {
// Look up existing mutex with the same id.
for (uptr i = 0; i < size_; i++) {
if (descs_[i].id == id) {
descs_[i].count++;
descs_[i].epoch = epoch;
return;
}
}
// On overflow, find the oldest mutex and drop it.
if (size_ == kMaxSize) {
u64 minepoch = (u64)-1;
u64 mini = (u64)-1;
for (uptr i = 0; i < size_; i++) {
if (descs_[i].epoch < minepoch) {
minepoch = descs_[i].epoch;
mini = i;
}
}
RemovePos(mini);
CHECK_EQ(size_, kMaxSize - 1);
}
// Add new mutex descriptor.
descs_[size_].id = id;
descs_[size_].write = write;
descs_[size_].epoch = epoch;
descs_[size_].count = 1;
size_++;
}
void MutexSet::Del(u64 id, bool write) {
for (uptr i = 0; i < size_; i++) {
if (descs_[i].id == id) {
if (--descs_[i].count == 0)
RemovePos(i);
return;
}
}
}
void MutexSet::Remove(u64 id) {
for (uptr i = 0; i < size_; i++) {
if (descs_[i].id == id) {
RemovePos(i);
return;
}
}
}
void MutexSet::RemovePos(uptr i) {
CHECK_LT(i, size_);
descs_[i] = descs_[size_ - 1];
size_--;
}
uptr MutexSet::Size() const {
return size_;
}
MutexSet::Desc MutexSet::Get(uptr i) const {
CHECK_LT(i, size_);
return descs_[i];
}
} // namespace __tsan
|