libsanitizer/tsan/tsan_mutexset.h

   1 //===-- tsan_mutexset.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 // MutexSet holds the set of mutexes currently held by a thread.
  11 //===----------------------------------------------------------------------===//
  12 #ifndef TSAN_MUTEXSET_H
  13 #define TSAN_MUTEXSET_H
  14
  15 #include "tsan_defs.h"
  16
  17 namespace __tsan {
  18
  19 class MutexSet {
  20  public:
  21   // Holds limited number of mutexes.
  22   // The oldest mutexes are discarded on overflow.
  23   static const uptr kMaxSize = 16;
  24   struct Desc {
  25     u64 id;
  26     u64 epoch;
  27     int count;
  28     bool write;
  29   };
  30
  31   MutexSet();
  32   // The 'id' is obtained from SyncVar::GetId().
  33   void Add(u64 id, bool write, u64 epoch);
  34   void Del(u64 id, bool write);
  35   void Remove(u64 id);  // Removes the mutex completely (if it's destroyed).
  36   uptr Size() const;
  37   Desc Get(uptr i) const;
  38
  39  private:
  40 #ifndef TSAN_GO
  41   uptr size_;
  42   Desc descs_[kMaxSize];
  43 #endif
  44
  45   void RemovePos(uptr i);
  46 };
  47
  48 // Go does not have mutexes, so do not spend memory and time.
  49 // (Go sync.Mutex is actually a semaphore -- can be unlocked
  50 // in different goroutine).
  51 #ifdef TSAN_GO
  52 MutexSet::MutexSet() {}
  53 void MutexSet::Add(u64 id, bool write, u64 epoch) {}
  54 void MutexSet::Del(u64 id, bool write) {}
  55 void MutexSet::Remove(u64 id) {}
  56 void MutexSet::RemovePos(uptr i) {}
  57 uptr MutexSet::Size() const { return 0; }
  58 MutexSet::Desc MutexSet::Get(uptr i) const { return Desc(); }
  59 #endif
  60
  61 }  // namespace __tsan
  62
  63 #endif  // TSAN_MUTEXSET_H