compiler-rt/test/tsan/custom_mutex.h

   1 #include "test.h"
   2 #include <atomic>
   3 #include <vector>
   4 #include <sanitizer/tsan_interface.h>
   5
   6 // A very primitive mutex annotated with tsan annotations.
   7 class Mutex {
   8  public:
   9   Mutex(bool prof, unsigned create_flags, unsigned destroy_flags=0)
  10       : prof_(prof)
  11       , locked_(false)
  12       , seq_(0)
  13       , destroy_flags_(destroy_flags) {
  14     __tsan_mutex_create(this, create_flags);
  15   }
  16
  17   ~Mutex() {
  18     __tsan_mutex_destroy(this, destroy_flags_);
  19   }
  20
  21   void Lock() {
  22     __tsan_mutex_pre_lock(this, 0);
  23     LockImpl();
  24     __tsan_mutex_post_lock(this, 0, 0);
  25   }
  26
  27   bool TryLock() {
  28     __tsan_mutex_pre_lock(this, __tsan_mutex_try_lock);
  29     bool ok = TryLockImpl();
  30     __tsan_mutex_post_lock(this, __tsan_mutex_try_lock |
  31         (ok ? 0 : __tsan_mutex_try_lock_failed), 0);
  32     return ok;
  33   }
  34
  35   void Unlock() {
  36     __tsan_mutex_pre_unlock(this, 0);
  37     UnlockImpl();
  38     __tsan_mutex_post_unlock(this, 0);
  39   }
  40
  41   void Wait() {
  42     for (int seq = seq_; seq == seq_;) {
  43       Unlock();
  44       usleep(100);
  45       Lock();
  46     }
  47   }
  48
  49   void Broadcast() {
  50     __tsan_mutex_pre_signal(this, 0);
  51     LockImpl(false);
  52     seq_++;
  53     UnlockImpl();
  54     __tsan_mutex_post_signal(this, 0);
  55   }
  56
  57  private:
  58   const bool prof_;
  59   std::atomic<bool> locked_;
  60   int seq_;
  61   unsigned destroy_flags_;
  62
  63   // This models mutex profiling subsystem.
  64   static Mutex prof_mu_;
  65   static int prof_data_;
  66
  67   void LockImpl(bool prof = true) {
  68     while (!TryLockImpl())
  69       usleep(100);
  70     if (prof && prof_)
  71       Prof();
  72   }
  73
  74   bool TryLockImpl() {
  75     return !locked_.exchange(true);
  76   }
  77
  78   void UnlockImpl() {
  79     locked_.store(false);
  80   }
  81
  82   void Prof() {
  83       // This happens inside of mutex lock annotations.
  84       __tsan_mutex_pre_divert(this, 0);
  85       prof_mu_.Lock();
  86       prof_data_++;
  87       prof_mu_.Unlock();
  88       __tsan_mutex_post_divert(this, 0);
  89   }
  90 };
  91
  92 Mutex Mutex::prof_mu_(false, __tsan_mutex_linker_init);
  93 int Mutex::prof_data_;