libsanitizer/tsan/tsan_clock.h

   1 //===-- tsan_clock.h --------------------------------------------*- C++ -*-===//
   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 #ifndef TSAN_CLOCK_H
  12 #define TSAN_CLOCK_H
  13
  14 #include "tsan_defs.h"
  15 #include "tsan_vector.h"
  16
  17 namespace __tsan {
  18
  19 // The clock that lives in sync variables (mutexes, atomics, etc).
  20 class SyncClock {
  21  public:
  22   SyncClock();
  23
  24   uptr size() const {
  25     return clk_.Size();
  26   }
  27
  28   void Reset() {
  29     clk_.Reset();
  30   }
  31
  32  private:
  33   Vector<u64> clk_;
  34   friend struct ThreadClock;
  35 };
  36
  37 // The clock that lives in threads.
  38 struct ThreadClock {
  39  public:
  40   ThreadClock();
  41
  42   u64 get(unsigned tid) const {
  43     DCHECK_LT(tid, kMaxTidInClock);
  44     return clk_[tid];
  45   }
  46
  47   void set(unsigned tid, u64 v) {
  48     DCHECK_LT(tid, kMaxTid);
  49     DCHECK_GE(v, clk_[tid]);
  50     clk_[tid] = v;
  51     if (nclk_ <= tid)
  52       nclk_ = tid + 1;
  53   }
  54
  55   void tick(unsigned tid) {
  56     DCHECK_LT(tid, kMaxTid);
  57     clk_[tid]++;
  58     if (nclk_ <= tid)
  59       nclk_ = tid + 1;
  60   }
  61
  62   uptr size() const {
  63     return nclk_;
  64   }
  65
  66   void acquire(const SyncClock *src);
  67   void release(SyncClock *dst) const;
  68   void acq_rel(SyncClock *dst);
  69   void ReleaseStore(SyncClock *dst) const;
  70
  71  private:
  72   uptr nclk_;
  73   u64 clk_[kMaxTidInClock];
  74 };
  75
  76 }  // namespace __tsan
  77
  78 #endif  // TSAN_CLOCK_H