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