1 //===-- tsan_mutexset.cc --------------------------------------------------===//
2 //
3 // This file is distributed under the University of Illinois Open Source
4 // License. See LICENSE.TXT for details.
5 //
6 //===----------------------------------------------------------------------===//
7 //
8 // This file is a part of ThreadSanitizer (TSan), a race detector.
9 //
10 //===----------------------------------------------------------------------===//
11 #include "tsan_mutexset.h"
12 #include "tsan_rtl.h"
13
14 namespace __tsan {
15
16 const uptr MutexSet::kMaxSize;
17
MutexSet()18 MutexSet::MutexSet() {
19 size_ = 0;
20 internal_memset(&descs_, 0, sizeof(descs_));
21 }
22
Add(u64 id,bool write,u64 epoch)23 void MutexSet::Add(u64 id, bool write, u64 epoch) {
24 // Look up existing mutex with the same id.
25 for (uptr i = 0; i < size_; i++) {
26 if (descs_[i].id == id) {
27 descs_[i].count++;
28 descs_[i].epoch = epoch;
29 return;
30 }
31 }
32 // On overflow, find the oldest mutex and drop it.
33 if (size_ == kMaxSize) {
34 u64 minepoch = (u64)-1;
35 u64 mini = (u64)-1;
36 for (uptr i = 0; i < size_; i++) {
37 if (descs_[i].epoch < minepoch) {
38 minepoch = descs_[i].epoch;
39 mini = i;
40 }
41 }
42 RemovePos(mini);
43 CHECK_EQ(size_, kMaxSize - 1);
44 }
45 // Add new mutex descriptor.
46 descs_[size_].id = id;
47 descs_[size_].write = write;
48 descs_[size_].epoch = epoch;
49 descs_[size_].count = 1;
50 size_++;
51 }
52
Del(u64 id,bool write)53 void MutexSet::Del(u64 id, bool write) {
54 for (uptr i = 0; i < size_; i++) {
55 if (descs_[i].id == id) {
56 if (--descs_[i].count == 0)
57 RemovePos(i);
58 return;
59 }
60 }
61 }
62
Remove(u64 id)63 void MutexSet::Remove(u64 id) {
64 for (uptr i = 0; i < size_; i++) {
65 if (descs_[i].id == id) {
66 RemovePos(i);
67 return;
68 }
69 }
70 }
71
RemovePos(uptr i)72 void MutexSet::RemovePos(uptr i) {
73 CHECK_LT(i, size_);
74 descs_[i] = descs_[size_ - 1];
75 size_--;
76 }
77
Size() const78 uptr MutexSet::Size() const {
79 return size_;
80 }
81
Get(uptr i) const82 MutexSet::Desc MutexSet::Get(uptr i) const {
83 CHECK_LT(i, size_);
84 return descs_[i];
85 }
86
87 } // namespace __tsan
88