1 //===-- tsan_vector_clock.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 // This file is a part of ThreadSanitizer (TSan), a race detector.
10 //
11 //===----------------------------------------------------------------------===//
12 #ifndef TSAN_VECTOR_CLOCK_H
13 #define TSAN_VECTOR_CLOCK_H
14 
15 #include "tsan_defs.h"
16 
17 namespace __tsan {
18 
19 // Fixed-size vector clock, used both for threads and sync objects.
20 class VectorClock {
21  public:
22   VectorClock();
23 
24   Epoch Get(Sid sid) const;
25   void Set(Sid sid, Epoch v);
26 
27   void Reset();
28   void Acquire(const VectorClock* src);
29   void Release(VectorClock** dstp) const;
30   void ReleaseStore(VectorClock** dstp) const;
31   void ReleaseStoreAcquire(VectorClock** dstp);
32   void ReleaseAcquire(VectorClock** dstp);
33 
34   VectorClock& operator=(const VectorClock& other);
35 
36  private:
37   Epoch clk_[kThreadSlotCount] VECTOR_ALIGNED;
38 };
39 
40 ALWAYS_INLINE Epoch VectorClock::Get(Sid sid) const {
41   return clk_[static_cast<u8>(sid)];
42 }
43 
44 ALWAYS_INLINE void VectorClock::Set(Sid sid, Epoch v) {
45   DCHECK_GE(v, clk_[static_cast<u8>(sid)]);
46   clk_[static_cast<u8>(sid)] = v;
47 }
48 
49 }  // namespace __tsan
50 
51 #endif  // TSAN_VECTOR_CLOCK_H
52