OS_NS_Thread.cpp | searchcode

/dep/acelite/ace/OS_NS_Thread.cpp

https://github.com/chucho/FaceCore
C++ | 1709 lines | 1221 code | 219 blank | 269 comment | 312 complexity | d92194fc64c9407eb015a8ad7a6c046e MD5 | raw file

// $Id: OS_NS_Thread.cpp 91693 2010-09-09 12:57:54Z johnnyw $

#include "ace/OS_NS_Thread.h"

#if !defined (ACE_HAS_INLINED_OSCALLS)
# include "ace/OS_NS_Thread.inl"
#endif /* ACE_HAS_INLINED_OSCALLS */

#include "ace/OS_NS_stdio.h"
#include "ace/Sched_Params.h"
#include "ace/OS_Memory.h"
#include "ace/OS_Thread_Adapter.h"
#include "ace/Min_Max.h"
#include "ace/Object_Manager_Base.h"
#include "ace/OS_NS_errno.h"
#include "ace/OS_NS_ctype.h"
#include "ace/Log_Msg.h" // for ACE_ASSERT
// This is necessary to work around nasty problems with MVS C++.
#include "ace/Auto_Ptr.h"
#include "ace/Thread_Mutex.h"
#include "ace/Condition_T.h"
#include "ace/Guard_T.h"

extern "C" void
ACE_MUTEX_LOCK_CLEANUP_ADAPTER_NAME (void *args)
{
  ACE_VERSIONED_NAMESPACE_NAME::ACE_OS::mutex_lock_cleanup (args);
}


#if !defined(ACE_WIN32) && defined (__IBMCPP__) && (__IBMCPP__ >= 400)
# define ACE_BEGINTHREADEX(STACK, STACKSIZE, ENTRY_POINT, ARGS, FLAGS, THR_ID) \
       (*THR_ID = ::_beginthreadex ((void(_Optlink*)(void*))ENTRY_POINT, STACK, STACKSIZE, ARGS), *THR_ID)
#elif defined (ACE_HAS_WINCE)
# define ACE_BEGINTHREADEX(STACK, STACKSIZE, ENTRY_POINT, ARGS, FLAGS, THR_ID) \
      CreateThread (0, STACKSIZE, (unsigned long (__stdcall *) (void *)) ENTRY_POINT, ARGS, (FLAGS) & (CREATE_SUSPENDED | STACK_SIZE_PARAM_IS_A_RESERVATION), (unsigned long *) THR_ID)
#elif defined(ACE_HAS_WTHREADS)
  // Green Hills compiler gets confused when __stdcall is imbedded in
  // parameter list, so we define the type ACE_WIN32THRFUNC_T and use it
  // instead.
  typedef unsigned (__stdcall *ACE_WIN32THRFUNC_T)(void*);
# define ACE_BEGINTHREADEX(STACK, STACKSIZE, ENTRY_POINT, ARGS, FLAGS, THR_ID) \
      ::_beginthreadex (STACK, STACKSIZE, (ACE_WIN32THRFUNC_T) ENTRY_POINT, ARGS, FLAGS, (unsigned int *) THR_ID)
#endif /* defined (__IBMCPP__) && (__IBMCPP__ >= 400) */

/*****************************************************************************/

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

void
ACE_Thread_ID::to_string (char *thr_string) const
{
  char format[128]; // Converted format string
  char *fp = 0;     // Current format pointer
  fp = format;
  *fp++ = '%';   // Copy in the %

#if defined (ACE_WIN32)
  ACE_OS::strcpy (fp, "u");
  ACE_OS::sprintf (thr_string,
                   format,
                   static_cast <unsigned> (this->thread_id_));
#else
# if defined (ACE_MVS) || defined (ACE_TANDEM_T1248_PTHREADS)
                  // MVS's pthread_t is a struct... yuck. So use the ACE 5.0
                  // code for it.
                  ACE_OS::strcpy (fp, "u");
                  ACE_OS::sprintf (thr_string, format, thread_handle_);
# else
                  // Yes, this is an ugly C-style cast, but the
                  // correct C++ cast is different depending on
                  // whether the t_id is an integral type or a pointer
                  // type. FreeBSD uses a pointer type, but doesn't
                  // have a _np function to get an integral type, like
                  // the OSes above.
                  ACE_OS::strcpy (fp, "lu");
                  ACE_OS::sprintf (thr_string,
                                   format,
                                   (unsigned long) thread_handle_);
# endif /* ACE_MVS || ACE_TANDEM_T1248_PTHREADS */
#endif /* ACE_WIN32 */
}

/*****************************************************************************/

#if defined (ACE_WIN32) || defined (ACE_HAS_TSS_EMULATION)

#if defined (ACE_HAS_TSS_EMULATION)
u_int ACE_TSS_Emulation::total_keys_ = 0;

ACE_TSS_Keys* ACE_TSS_Emulation::tss_keys_used_ = 0;

ACE_TSS_Emulation::ACE_TSS_DESTRUCTOR
ACE_TSS_Emulation::tss_destructor_[ACE_TSS_Emulation::ACE_TSS_THREAD_KEYS_MAX]
 = { 0 };

#  if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE)

bool ACE_TSS_Emulation::key_created_ = false;

ACE_OS_thread_key_t ACE_TSS_Emulation::native_tss_key_;

/* static */
#    if defined (ACE_HAS_THR_C_FUNC)
extern "C"
void
ACE_TSS_Emulation_cleanup (void *)
{
   // Really this must be used for ACE_TSS_Emulation code to make the TSS
   // cleanup
}
#    else
void
ACE_TSS_Emulation_cleanup (void *)
{
   // Really this must be used for ACE_TSS_Emulation code to make the TSS
   // cleanup
}
#    endif /* ACE_HAS_THR_C_FUNC */

void **
ACE_TSS_Emulation::tss_base (void* ts_storage[], u_int *ts_created)
{
  // TSS Singleton implementation.

  // Create the one native TSS key, if necessary.
  if (!key_created_)
    {
      // Double-checked lock . . .
      ACE_TSS_BASE_GUARD

      if (!key_created_)
        {
          ACE_NO_HEAP_CHECK;
          if (ACE_OS::thr_keycreate_native (&native_tss_key_,
                                     &ACE_TSS_Emulation_cleanup) != 0)
            {
              ACE_ASSERT (0);
              return 0; // Major problems, this should *never* happen!
            }
          key_created_ = true;
        }
    }

  void **old_ts_storage = 0;

  // Get the tss_storage from thread-OS specific storage.
  if (ACE_OS::thr_getspecific_native (native_tss_key_,
                               (void **) &old_ts_storage) == -1)
    {
      ACE_ASSERT (false);
      return 0; // This should not happen!
    }

  // Check to see if this is the first time in for this thread.
  // This block can also be entered after a fork () in the child process.
  if (old_ts_storage == 0)
    {
      if (ts_created)
        *ts_created = 1u;

      // Use the ts_storage passed as argument, if non-zero.  It is
      // possible that this has been implemented in the stack. At the
      // moment, this is unknown.  The cleanup must not do nothing.
      // If ts_storage is zero, allocate (and eventually leak) the
      // storage array.
      if (ts_storage == 0)
        {
          ACE_NO_HEAP_CHECK;

          ACE_NEW_RETURN (ts_storage,
                          void*[ACE_TSS_THREAD_KEYS_MAX],
                          0);

          // Zero the entire TSS array.  Do it manually instead of
          // using memset, for optimum speed.  Though, memset may be
          // faster :-)
          void **tss_base_p = ts_storage;

          for (u_int i = 0;
               i < ACE_TSS_THREAD_KEYS_MAX;
               ++i)
            *tss_base_p++ = 0;
        }

       // Store the pointer in thread-specific storage.  It gets
       // deleted via the ACE_TSS_Emulation_cleanup function when the
       // thread terminates.
       if (ACE_OS::thr_setspecific_native (native_tss_key_,
                                    (void *) ts_storage) != 0)
          {
            ACE_ASSERT (false);
            return 0; // This should not happen!
          }
    }
  else
    if (ts_created)
      ts_created = 0;

  return ts_storage  ?  ts_storage  :  old_ts_storage;
}
#  endif /* ACE_HAS_THREAD_SPECIFIC_STORAGE */

u_int
ACE_TSS_Emulation::total_keys ()
{
  ACE_OS_Recursive_Thread_Mutex_Guard (
    *static_cast <ACE_recursive_thread_mutex_t *>
                      (ACE_OS_Object_Manager::preallocated_object[
                        ACE_OS_Object_Manager::ACE_TSS_KEY_LOCK]));

  return total_keys_;
}

int
ACE_TSS_Emulation::next_key (ACE_thread_key_t &key)
{
  ACE_OS_Recursive_Thread_Mutex_Guard (
    *static_cast <ACE_recursive_thread_mutex_t *>
                      (ACE_OS_Object_Manager::preallocated_object[
                        ACE_OS_Object_Manager::ACE_TSS_KEY_LOCK]));

  // Initialize the tss_keys_used_ pointer on first use.
  if (tss_keys_used_ == 0)
    {
      ACE_NEW_RETURN (tss_keys_used_, ACE_TSS_Keys, -1);
    }

  if (total_keys_ < ACE_TSS_THREAD_KEYS_MAX)
    {
       u_int counter = 0;
       // Loop through all possible keys and check whether a key is free
       for ( ;counter < ACE_TSS_THREAD_KEYS_MAX; counter++)
         {
            ACE_thread_key_t localkey;
#  if defined (ACE_HAS_NONSCALAR_THREAD_KEY_T)
              ACE_OS::memset (&localkey, 0, sizeof (ACE_thread_key_t));
              ACE_OS::memcpy (&localkey, &counter_, sizeof (u_int));
#  else
              localkey = counter;
#  endif /* ACE_HAS_NONSCALAR_THREAD_KEY_T */
            // If the key is not set as used, we can give out this key, if not
            // we have to search further
            if (tss_keys_used_->is_set(localkey) == 0)
            {
               tss_keys_used_->test_and_set(localkey);
               key = localkey;
               break;
            }
         }

      ++total_keys_;
      return 0;
    }
  else
    {
      key = ACE_OS::NULL_key;
      return -1;
    }
}

int
ACE_TSS_Emulation::release_key (ACE_thread_key_t key)
{
  ACE_OS_Recursive_Thread_Mutex_Guard (
    *static_cast <ACE_recursive_thread_mutex_t *>
                      (ACE_OS_Object_Manager::preallocated_object[
                        ACE_OS_Object_Manager::ACE_TSS_KEY_LOCK]));

  if (tss_keys_used_ != 0 &&
      tss_keys_used_->test_and_clear (key) == 0)
  {
    --total_keys_;
    return 0;
  }
  return 1;
}

int
ACE_TSS_Emulation::is_key (ACE_thread_key_t key)
{
  ACE_OS_Recursive_Thread_Mutex_Guard (
    *static_cast <ACE_recursive_thread_mutex_t *>
                      (ACE_OS_Object_Manager::preallocated_object[
                        ACE_OS_Object_Manager::ACE_TSS_KEY_LOCK]));

  if (tss_keys_used_ != 0 &&
      tss_keys_used_->is_set (key) == 1)
  {
    return 1;
  }
  return 0;
}

void *
ACE_TSS_Emulation::tss_open (void *ts_storage[ACE_TSS_THREAD_KEYS_MAX])
{
#    if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE)
        // On VxWorks, in particular, don't check to see if the field
        // is 0.  It isn't always, specifically, when a program is run
        // directly by the shell (without spawning a new task) after
        // another program has been run.

  u_int ts_created = 0;
  tss_base (ts_storage, &ts_created);
  if (ts_created)
    {
#    else  /* ! ACE_HAS_THREAD_SPECIFIC_STORAGE */
      tss_base () = ts_storage;
#    endif

      // Zero the entire TSS array.  Do it manually instead of using
      // memset, for optimum speed.  Though, memset may be faster :-)
      void **tss_base_p = tss_base ();
      for (u_int i = 0; i < ACE_TSS_THREAD_KEYS_MAX; ++i, ++tss_base_p)
        {
          *tss_base_p = 0;
        }

      return tss_base ();
#    if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE)
    }
  else
    {
      return 0;
    }
#    endif /* ACE_HAS_THREAD_SPECIFIC_STORAGE */
}

void
ACE_TSS_Emulation::tss_close ()
{
#if defined (ACE_HAS_THREAD_SPECIFIC_STORAGE)
  ACE_OS::thr_keyfree_native (native_tss_key_);
#endif /* ACE_HAS_THREAD_SPECIFIC_STORAGE */
}

#endif /* ACE_HAS_TSS_EMULATION */

#endif /* WIN32 || ACE_HAS_TSS_EMULATION */

/*****************************************************************************/

#if defined (ACE_WIN32) || defined (ACE_HAS_TSS_EMULATION)

// Moved class ACE_TSS_Ref declaration to OS.h so it can be visible to
// the single file of template instantiations.

ACE_TSS_Ref::ACE_TSS_Ref (ACE_thread_t id)
  : tid_(id)
{
  ACE_OS_TRACE ("ACE_TSS_Ref::ACE_TSS_Ref");
}

ACE_TSS_Ref::ACE_TSS_Ref (void)
{
  ACE_OS_TRACE ("ACE_TSS_Ref::ACE_TSS_Ref");
}

// Check for equality.
bool
ACE_TSS_Ref::operator== (const ACE_TSS_Ref &info) const
{
  ACE_OS_TRACE ("ACE_TSS_Ref::operator==");

  return this->tid_ == info.tid_;
}

// Check for inequality.
ACE_SPECIAL_INLINE
bool
ACE_TSS_Ref::operator != (const ACE_TSS_Ref &tss_ref) const
{
  ACE_OS_TRACE ("ACE_TSS_Ref::operator !=");

  return !(*this == tss_ref);
}

// moved class ACE_TSS_Info declaration
// to OS.h so it can be visible to the
// single file of template instantiations

ACE_TSS_Info::ACE_TSS_Info (ACE_thread_key_t key,
                            ACE_TSS_Info::Destructor dest)
  : key_ (key),
    destructor_ (dest),
    thread_count_ (-1)
{
  ACE_OS_TRACE ("ACE_TSS_Info::ACE_TSS_Info");
}

ACE_TSS_Info::ACE_TSS_Info (void)
  : key_ (ACE_OS::NULL_key),
    destructor_ (0),
    thread_count_ (-1)
{
  ACE_OS_TRACE ("ACE_TSS_Info::ACE_TSS_Info");
}

# if defined (ACE_HAS_NONSCALAR_THREAD_KEY_T)
static inline bool operator== (const ACE_thread_key_t &lhs,
                               const ACE_thread_key_t &rhs)
{
  return ! ACE_OS::memcmp (&lhs, &rhs, sizeof (ACE_thread_key_t));
}

static inline bool operator!= (const ACE_thread_key_t &lhs,
                               const ACE_thread_key_t &rhs)
{
  return ! (lhs == rhs);
}
# endif /* ACE_HAS_NONSCALAR_THREAD_KEY_T */

// Check for equality.
bool
ACE_TSS_Info::operator== (const ACE_TSS_Info &info) const
{
  ACE_OS_TRACE ("ACE_TSS_Info::operator==");

  return this->key_ == info.key_;
}

// Check for inequality.
bool
ACE_TSS_Info::operator != (const ACE_TSS_Info &info) const
{
  ACE_OS_TRACE ("ACE_TSS_Info::operator !=");

  return !(*this == info);
}

void
ACE_TSS_Info::dump (void)
{
# if defined (ACE_HAS_DUMP)
  //  ACE_OS_TRACE ("ACE_TSS_Info::dump");

#   if 0
  ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
  ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("key_ = %u\n"), this->key_));
  ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("destructor_ = %u\n"), this->destructor_));
  ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
#   endif /* 0 */
# endif /* ACE_HAS_DUMP */
}

// Moved class ACE_TSS_Keys declaration to OS.h so it can be visible
// to the single file of template instantiations.

ACE_TSS_Keys::ACE_TSS_Keys (void)
{
  for (u_int i = 0; i < ACE_WORDS; ++i)
    {
      key_bit_words_[i] = 0;
    }
}

ACE_SPECIAL_INLINE
void
ACE_TSS_Keys::find (const u_int key, u_int &word, u_int &bit)
{
  word = key / ACE_BITS_PER_WORD;
  bit = key % ACE_BITS_PER_WORD;
}

int
ACE_TSS_Keys::test_and_set (const ACE_thread_key_t key)
{
  ACE_KEY_INDEX (key_index, key);
  u_int word, bit;
  find (key_index, word, bit);

  if (ACE_BIT_ENABLED (key_bit_words_[word], 1 << bit))
    {
      return 1;
    }
  else
    {
      ACE_SET_BITS (key_bit_words_[word], 1 << bit);
      return 0;
    }
}

int
ACE_TSS_Keys::test_and_clear (const ACE_thread_key_t key)
{
  ACE_KEY_INDEX (key_index, key);
  u_int word, bit;
  find (key_index, word, bit);

  if (word < ACE_WORDS && ACE_BIT_ENABLED (key_bit_words_[word], 1 << bit))
    {
      ACE_CLR_BITS (key_bit_words_[word], 1 << bit);
      return 0;
    }
  else
    {
      return 1;
    }
}

int
ACE_TSS_Keys::is_set (const ACE_thread_key_t key) const
{
  ACE_KEY_INDEX (key_index, key);
  u_int word, bit;
  find (key_index, word, bit);

  return word < ACE_WORDS ? ACE_BIT_ENABLED (key_bit_words_[word], 1 << bit) : 0;
}

/**
 * @class ACE_TSS_Cleanup
 * @brief Singleton that helps to manage the lifetime of TSS objects and keys.
 */
class ACE_TSS_Cleanup
{
public:
  /// Register a newly-allocated key
  /// @param key the key to be monitored
  /// @param destructor the function to call to delete objects stored via this key
  int insert (ACE_thread_key_t key, void (*destructor)(void *));

  /// Mark a key as being used by this thread.
  void thread_use_key (ACE_thread_key_t key);

  /// This thread is no longer using this key
  /// call destructor if appropriate
  int thread_detach_key (ACE_thread_key_t key);

  /// This key is no longer used
  ///   Release key if use count == 0
  ///   fail if use_count != 0;
  /// @param key the key to be released
  int free_key (ACE_thread_key_t key);

  /// Cleanup the thread-specific objects.  Does _NOT_ exit the thread.
  /// For each used key perform the same actions as free_key.
  void thread_exit (void);

private:
  void dump (void);

  /// Release a key used by this thread
  /// @param info reference to the info for this key
  /// @param destructor out arg to receive destructor function ptr
  /// @param tss_obj out arg to receive pointer to deletable object
  void thread_release (
          ACE_TSS_Info &info,
          ACE_TSS_Info::Destructor & destructor,
          void *& tss_obj);

  /// remove key if it's unused (thread_count == 0)
  /// @param info reference to the info for this key
  int remove_key (ACE_TSS_Info &info);

  /// Find the TSS keys (if any) for this thread.
  /// @param thread_keys reference to pointer to be filled in by this function.
  /// @return false if keys don't exist.
  bool find_tss_keys (ACE_TSS_Keys *& thread_keys) const;

  /// Accessor for this threads ACE_TSS_Keys instance.
  /// Creates the keys if necessary.
  ACE_TSS_Keys *tss_keys ();

  /// Ensure singleton.
  ACE_TSS_Cleanup (void);
  ~ACE_TSS_Cleanup (void);

  /// ACE_TSS_Cleanup access only via TSS_Cleanup_Instance
  friend class TSS_Cleanup_Instance;

private:
  // Array of <ACE_TSS_Info> objects.
  typedef ACE_TSS_Info ACE_TSS_TABLE[ACE_DEFAULT_THREAD_KEYS];
  typedef ACE_TSS_Info *ACE_TSS_TABLE_ITERATOR;

  /// Table of <ACE_TSS_Info>'s.
  ACE_TSS_TABLE table_;

  /// Key for the thread-specific ACE_TSS_Keys
  /// Used by find_tss_keys() or tss_keys() to find the
  /// bit array that records whether each TSS key is in
  /// use by this thread.
  ACE_thread_key_t in_use_;
};


/*****************************************************************************/
/**
 * @class TSS_Cleanup_Instance
 * @A class to manage an instance pointer to ACE_TSS_Cleanup.
 * Note: that the double checked locking pattern doesn't allow
 * safe deletion.
 * Callers who wish to access the singleton ACE_TSS_Cleanup must
 * do so by instantiating a TSS_Cleanup_Instance, calling the valid
 * method to be sure the ACE_TSS_Cleanup is available, then using
 * the TSS_Cleanup_Instance as a pointer to the instance.
 * Construction argument to the TSS_Cleanup_Instance determines how
 * it is to be used:
 *   CREATE means allow this call to create an ACE_TSS_Cleanup if necessary.
 *   USE means use the existing ACE_TSS_Cleanup, but do not create a new one.
 *   DESTROY means provide exclusive access to the ACE_TSS_Cleanup, then
 *   delete it when the TSS_Cleanup_Instance goes out of scope.
 */

class TSS_Cleanup_Instance
{
public:
  enum Purpose
  {
    CREATE,
    USE,
    DESTROY
  };
  TSS_Cleanup_Instance (Purpose purpose = USE);
  ~TSS_Cleanup_Instance();

  bool valid();
  ACE_TSS_Cleanup * operator ->();

private:

  ACE_TSS_Cleanup * operator *();

private:
  static unsigned int reference_count_;
  static ACE_TSS_Cleanup * instance_;
  static ACE_Thread_Mutex* mutex_;
  static ACE_Thread_Condition<ACE_Thread_Mutex>* condition_;

private:
  ACE_TSS_Cleanup * ptr_;
  unsigned short flags_;
  enum
  {
    FLAG_DELETING = 1,
    FLAG_VALID_CHECKED = 2
  };
};

TSS_Cleanup_Instance::TSS_Cleanup_Instance (Purpose purpose)
  : ptr_(0)
  , flags_(0)
{
  // During static construction or construction of the ACE_Object_Manager,
  // there can be only one thread in this constructor at any one time, so
  // it's safe to check for a zero mutex_.  If it's zero, we create a new
  // mutex and condition variable.
  if (mutex_ == 0)
    {
      ACE_NEW (mutex_, ACE_Thread_Mutex ());
      ACE_NEW (condition_, ACE_Thread_Condition<ACE_Thread_Mutex> (*mutex_));
    }

  ACE_GUARD (ACE_Thread_Mutex, m, *mutex_);

  if (purpose == CREATE)
  {
    if (instance_ == 0)
    {
      instance_ = new ACE_TSS_Cleanup();
    }
    ptr_ = instance_;
    ++reference_count_;
  }
  else if(purpose == DESTROY)
  {
    if (instance_ != 0)
    {
      ptr_ = instance_;
      instance_ = 0;
      ACE_SET_BITS(flags_, FLAG_DELETING);
      while (reference_count_ > 0)
      {
        condition_->wait();
      }
    }
  }
  else // must be normal use
  {
    ACE_ASSERT(purpose == USE);
    if (instance_ != 0)
      {
        ptr_ = instance_;
        ++reference_count_;
      }
  }
}

TSS_Cleanup_Instance::~TSS_Cleanup_Instance (void)
{
  // Variable to hold the mutex_ to delete outside the scope of the
  // guard.
  ACE_Thread_Mutex *del_mutex = 0;

  // scope the guard
  {
    ACE_GUARD (ACE_Thread_Mutex, guard, *mutex_);
    if (ptr_ != 0)
      {
        if (ACE_BIT_ENABLED (flags_, FLAG_DELETING))
          {
            ACE_ASSERT(instance_ == 0);
            ACE_ASSERT(reference_count_ == 0);
            delete ptr_;
            del_mutex = mutex_ ;
            mutex_ = 0;
          }
        else
          {
            ACE_ASSERT (reference_count_ > 0);
            --reference_count_;
            if (reference_count_ == 0 && instance_ == 0)
              condition_->signal ();
          }
      }
  }// end of guard scope

  if (del_mutex != 0)
    {
      delete condition_;
      condition_ = 0;
      delete del_mutex;
    }
}

bool
TSS_Cleanup_Instance::valid()
{
  ACE_SET_BITS(flags_, FLAG_VALID_CHECKED);
  return (this->instance_ != 0);
}

ACE_TSS_Cleanup *
TSS_Cleanup_Instance::operator *()
{
  ACE_ASSERT(ACE_BIT_ENABLED(flags_, FLAG_VALID_CHECKED));
  return instance_;
}

ACE_TSS_Cleanup *
TSS_Cleanup_Instance::operator ->()
{
  ACE_ASSERT(ACE_BIT_ENABLED(flags_, FLAG_VALID_CHECKED));
  return instance_;
}

// = Static object initialization.
unsigned int TSS_Cleanup_Instance::reference_count_ = 0;
ACE_TSS_Cleanup * TSS_Cleanup_Instance::instance_ = 0;
ACE_Thread_Mutex* TSS_Cleanup_Instance::mutex_ = 0;
ACE_Thread_Condition<ACE_Thread_Mutex>* TSS_Cleanup_Instance::condition_ = 0;

ACE_TSS_Cleanup::~ACE_TSS_Cleanup (void)
{
}

void
ACE_TSS_Cleanup::thread_exit (void)
{
  ACE_OS_TRACE ("ACE_TSS_Cleanup::thread_exit");
  // variables to hold the destructors, keys
  // and pointers to the object to be destructed
  // the actual destruction is deferred until the guard is released
  ACE_TSS_Info::Destructor destructor[ACE_DEFAULT_THREAD_KEYS];
  void * tss_obj[ACE_DEFAULT_THREAD_KEYS];
  ACE_thread_key_t keys[ACE_DEFAULT_THREAD_KEYS];
  // count of items to be destroyed
  unsigned int d_count = 0;

  // scope the guard
  {
    ACE_TSS_CLEANUP_GUARD

    // if not initialized or already cleaned up
    ACE_TSS_Keys *this_thread_keys = 0;
    if (! find_tss_keys (this_thread_keys) )
      {
        return;
      }

    // Minor hack: Iterating in reverse order means the LOG buffer which is
    // accidentally allocated first will be accidentally deallocated (almost)
    // last -- in case someone logs something from the other destructors.
    // applications should not count on this behavior because platforms which
    // do not use ACE_TSS_Cleanup may delete objects in other orders.
    unsigned int key_index = ACE_DEFAULT_THREAD_KEYS;
    while( key_index > 0)
      {
        --key_index;
        ACE_TSS_Info & info = this->table_[key_index];
        // if this key is in use by this thread
        if (info.key_in_use () && this_thread_keys->is_set(info.key_))
          {
            // defer deleting the in-use key until all others have been deleted
            if(info.key_ != this->in_use_)
              {
                destructor[d_count] = 0;
                tss_obj[d_count] = 0;
                keys[d_count] = 0;
                this->thread_release (info, destructor[d_count], tss_obj[d_count]);
                if (destructor[d_count] != 0 && tss_obj[d_count] != 0)
                  {
                    keys[d_count] = info.key_;
                    ++d_count;
                  }
              }
          }
      }

    // remove the in_use bit vector last
    ACE_KEY_INDEX (use_index, this->in_use_);
    ACE_TSS_Info & info = this->table_[use_index];
    destructor[d_count] = 0;
    tss_obj[d_count] = 0;
    keys[d_count] = 0;
    this->thread_release (info, destructor[d_count], tss_obj[d_count]);
    if (destructor[d_count] != 0 &&  tss_obj[d_count] != 0)
      {
        keys[d_count] = info.key_;
        ++d_count;
      }
  } // end of guard scope
  for (unsigned int d_index = 0; d_index < d_count; ++d_index)
    {
      (*destructor[d_index])(tss_obj[d_index]);
#if defined (ACE_HAS_TSS_EMULATION)
      ACE_TSS_Emulation::ts_object (keys[d_index]) = 0;
#else // defined (ACE_HAS_TSS_EMULATION)
      ACE_OS::thr_setspecific_native (keys[d_index], 0);
#endif // defined (ACE_HAS_TSS_EMULATION)
    }
}

extern "C" void
ACE_TSS_Cleanup_keys_destroyer (void *tss_keys)
{
  delete static_cast <ACE_TSS_Keys *> (tss_keys);
}

ACE_TSS_Cleanup::ACE_TSS_Cleanup (void)
  : in_use_ (ACE_OS::NULL_key)
{
  ACE_OS_TRACE ("ACE_TSS_Cleanup::ACE_TSS_Cleanup");
}

int
ACE_TSS_Cleanup::insert (ACE_thread_key_t key,
                         void (*destructor)(void *))
{
  ACE_OS_TRACE ("ACE_TSS_Cleanup::insert");
  ACE_TSS_CLEANUP_GUARD

  ACE_KEY_INDEX (key_index, key);
  ACE_ASSERT (key_index < ACE_DEFAULT_THREAD_KEYS);
  if (key_index < ACE_DEFAULT_THREAD_KEYS)
    {
      ACE_ASSERT (table_[key_index].thread_count_ == -1);
      table_[key_index] = ACE_TSS_Info (key, destructor);
      table_[key_index].thread_count_ = 0; // inserting it does not use it
                                           // but it does "allocate" it
      return 0;
    }
  else
    {
      return -1;
    }
}

int
ACE_TSS_Cleanup::free_key (ACE_thread_key_t key)
{
  ACE_OS_TRACE ("ACE_TSS_Cleanup::free_key");
  ACE_TSS_CLEANUP_GUARD
  ACE_KEY_INDEX (key_index, key);
  if (key_index < ACE_DEFAULT_THREAD_KEYS)
    {
      return remove_key (this->table_ [key_index]);
    }
  return -1;
}

int
ACE_TSS_Cleanup::remove_key (ACE_TSS_Info &info)
{
  // assume CLEANUP_GUARD is held by caller
  ACE_OS_TRACE ("ACE_TSS_Cleanup::remove_key");

#if 0 // This was a good idea, but POSIX says it's legal to delete used keys.
      // When this is done, any existing TSS objects controlled by this key are leaked
      // There is no "right thing" to do in this case

  // only remove it if all threads are done with it
  if (info.thread_count_ != 0)
    {
      return -1;
    }
#endif // 0

#if !defined (ACE_HAS_TSS_EMULATION)
  ACE_OS_thread_key_t temp_key = info.key_;
  ACE_OS::thr_keyfree_native (temp_key);
#endif /* !ACE_HAS_TSS_EMULATION */
  if (info.key_ == this->in_use_)
    {
      this->in_use_ = ACE_OS::NULL_key;
    }
  info.key_in_use (0);
  info.destructor_ = 0;
  return 0;
}

int
ACE_TSS_Cleanup::thread_detach_key (ACE_thread_key_t key)
{
  // variables to hold the destructor and the object to be destructed
  // the actual call is deferred until the guard is released
  ACE_TSS_Info::Destructor destructor = 0;
  void * tss_obj = 0;

  // scope the guard
  {
    ACE_TSS_CLEANUP_GUARD

    ACE_KEY_INDEX (key_index, key);
    ACE_ASSERT (key_index < sizeof(this->table_)/sizeof(this->table_[0])
        && this->table_[key_index].key_ == key);
    ACE_TSS_Info &info = this->table_ [key_index];

    // sanity check
    if (!info.key_in_use ())
      {
        return -1;
      }

    this->thread_release (info, destructor, tss_obj);
  } // end of scope for the Guard
  // if there's a destructor and an object to be destroyed
  if (destructor != 0 && tss_obj != 0)
    {
      (*destructor) (tss_obj);
    }
  return 0;
}

void
ACE_TSS_Cleanup::thread_release (
        ACE_TSS_Info &info,
        ACE_TSS_Info::Destructor & destructor,
        void *& tss_obj)
{
  // assume guard is held by caller
  // Find the TSS keys (if any) for this thread
  // do not create them if they don't exist
  ACE_TSS_Keys * thread_keys = 0;
  if (find_tss_keys (thread_keys))
    {
        // if this key is in use by this thread
      if (thread_keys->test_and_clear(info.key_) == 0)
      {
        // save destructor & pointer to tss object
        // until after the guard is released
        destructor = info.destructor_;
        ACE_OS::thr_getspecific (info.key_, &tss_obj);
        ACE_ASSERT (info.thread_count_ > 0);
        --info.thread_count_;
      }
    }
}

void
ACE_TSS_Cleanup::thread_use_key (ACE_thread_key_t key)
{
  // If the key's ACE_TSS_Info in-use bit for this thread is not set,
  // set it and increment the key's thread_count_.
  if (! tss_keys ()->test_and_set (key))
    {
      ACE_TSS_CLEANUP_GUARD

      // Retrieve the key's ACE_TSS_Info and increment its thread_count_.
      ACE_KEY_INDEX (key_index, key);
      ACE_TSS_Info &key_info = this->table_ [key_index];

      ACE_ASSERT (key_info.key_in_use ());
      ++key_info.thread_count_;
    }
}

void
ACE_TSS_Cleanup::dump (void)
{
# if defined (ACE_HAS_DUMP)
  // Iterate through all the thread-specific items and dump them all.

  ACE_TSS_TABLE_ITERATOR key_info = table_;
  for (unsigned int i = 0;
       i < ACE_DEFAULT_THREAD_KEYS;
       ++key_info, ++i)
    key_info->dump ();
# endif /* ACE_HAS_DUMP */
}

bool
ACE_TSS_Cleanup::find_tss_keys (ACE_TSS_Keys *& tss_keys) const
{
  if (this->in_use_ == ACE_OS::NULL_key)
    return false;
  if (ACE_OS::thr_getspecific (in_use_,
          reinterpret_cast<void **> (&tss_keys)) == -1)
    {
      ACE_ASSERT (false);
      return false; // This should not happen!
    }
  return tss_keys != 0;
}

ACE_TSS_Keys *
ACE_TSS_Cleanup::tss_keys ()
{
  if (this->in_use_ == ACE_OS::NULL_key)
    {
      ACE_TSS_CLEANUP_GUARD
      // Double-check;
      if (in_use_ == ACE_OS::NULL_key)
        {
          // Initialize in_use_ with a new key.
          if (ACE_OS::thr_keycreate (&in_use_,
                                     &ACE_TSS_Cleanup_keys_destroyer))
            {
              ACE_ASSERT (false);
              return 0; // Major problems, this should *never* happen!
            }
        }
    }

  void *ts_keys = 0;
  if (ACE_OS::thr_getspecific (in_use_, &ts_keys) == -1)
    {
      ACE_ASSERT (false);
      return 0; // This should not happen!
    }

  if (ts_keys == 0)
    {
      ACE_NEW_RETURN (ts_keys,
                      ACE_TSS_Keys,
                      0);
      // Store the dynamically allocated pointer in thread-specific
      // storage.
      if (ACE_OS::thr_setspecific (in_use_, ts_keys) == -1)
        {
          ACE_ASSERT (false);
          delete reinterpret_cast <ACE_TSS_Keys*> (ts_keys);
          return 0; // Major problems, this should *never* happen!
        }
    }

  return reinterpret_cast <ACE_TSS_Keys*>(ts_keys);
}

#endif /* ACE_WIN32 || ACE_HAS_TSS_EMULATION */

/*****************************************************************************/

// = Static initialization.

// This is necessary to deal with POSIX pthreads insanity.  This
// guarantees that we've got a "zero'd" thread id even when
// ACE_thread_t, ACE_hthread_t, and ACE_thread_key_t are implemented
// as structures...  Under no circumstances should these be given
// initial values.
// Note: these three objects require static construction.
ACE_thread_t ACE_OS::NULL_thread;
ACE_hthread_t ACE_OS::NULL_hthread;
#if defined (ACE_HAS_TSS_EMULATION)
  ACE_thread_key_t ACE_OS::NULL_key = static_cast <ACE_thread_key_t> (-1);
#else  /* ! ACE_HAS_TSS_EMULATION */
  ACE_thread_key_t ACE_OS::NULL_key;
#endif /* ! ACE_HAS_TSS_EMULATION */

/*****************************************************************************/

void
ACE_OS::cleanup_tss (const u_int main_thread)
{
#if defined (ACE_HAS_TSS_EMULATION) || defined (ACE_WIN32)
  { // scope the cleanup instance
    // Call TSS destructors for current thread.
    TSS_Cleanup_Instance cleanup;
    if (cleanup.valid ())
      {
        cleanup->thread_exit ();
      }
  }
#endif /* ACE_HAS_TSS_EMULATION || ACE_WIN32 */

  if (main_thread)
    {
#if !defined (ACE_HAS_TSS_EMULATION)  &&  !defined (ACE_HAS_MINIMAL_ACE_OS)
      // Just close the ACE_Log_Msg for the current (which should be
      // main) thread.  We don't have TSS emulation; if there's native
      // TSS, it should call its destructors when the main thread
      // exits.
      ACE_Base_Thread_Adapter::close_log_msg ();
#endif /* ! ACE_HAS_TSS_EMULATION  &&  ! ACE_HAS_MINIMAL_ACE_OS */

#if defined (ACE_WIN32) || defined (ACE_HAS_TSS_EMULATION)
      // Finally, free up the ACE_TSS_Cleanup instance.  This method gets
      // called by the ACE_Object_Manager.
      TSS_Cleanup_Instance cleanup(TSS_Cleanup_Instance::DESTROY);
      if (cleanup.valid ())
      {
        ; // the pointer deletes the Cleanup when it goes out of scope
      }

#endif /* WIN32 || ACE_HAS_TSS_EMULATION */

#if defined (ACE_HAS_TSS_EMULATION)
      ACE_TSS_Emulation::tss_close ();
#endif /* ACE_HAS_TSS_EMULATION */
    }
}

/*****************************************************************************/
// CONDITIONS BEGIN
/*****************************************************************************/

#if defined (ACE_LACKS_COND_T)
int
ACE_OS::cond_broadcast (ACE_cond_t *cv)
{
  ACE_OS_TRACE ("ACE_OS::cond_broadcast");
# if defined (ACE_HAS_THREADS)
  // The <external_mutex> must be locked before this call is made.

  // This is needed to ensure that <waiters_> and <was_broadcast_> are
  // consistent relative to each other.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    {
      return -1;
    }

  bool have_waiters = false;

  if (cv->waiters_ > 0)
    {
      // We are broadcasting, even if there is just one waiter...
      // Record the fact that we are broadcasting.  This helps the
      // cond_wait() method know how to optimize itself.  Be sure to
      // set this with the <waiters_lock_> held.
      cv->was_broadcast_ = 1;
      have_waiters = true;
    }

  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    {
      // This is really bad, we have the lock but can't release it anymore
      return -1;
    }

  int result = 0;
  if (have_waiters)
    {
      // Wake up all the waiters.
      if (ACE_OS::sema_post (&cv->sema_, cv->waiters_) == -1)
        result = -1;
      // Wait for all the awakened threads to acquire their part of
      // the counting semaphore.
#   if defined (ACE_VXWORKS)
      else if (ACE_OS::sema_wait (&cv->waiters_done_) == -1)
#   else
      else if (ACE_OS::event_wait (&cv->waiters_done_) == -1)
#   endif /* ACE_VXWORKS */
        result = -1;
      // This is okay, even without the <waiters_lock_> held because
      // no other waiter threads can wake up to access it.
      cv->was_broadcast_ = 0;
    }
  return result;
# else
  ACE_UNUSED_ARG (cv);
  ACE_NOTSUP_RETURN (-1);
# endif /* ACE_HAS_THREADS */
}

int
ACE_OS::cond_destroy (ACE_cond_t *cv)
{
  ACE_OS_TRACE ("ACE_OS::cond_destroy");
# if defined (ACE_HAS_THREADS)
#   if defined (ACE_HAS_WTHREADS)
  ACE_OS::event_destroy (&cv->waiters_done_);
#   elif defined (ACE_VXWORKS)
  ACE_OS::sema_destroy (&cv->waiters_done_);
#   endif /* ACE_VXWORKS */
  int result = 0;
  if (ACE_OS::thread_mutex_destroy (&cv->waiters_lock_) != 0)
    result = -1;

  if (ACE_OS::sema_destroy (&cv->sema_) != 0)
    result = -1;

  return result;
# else
  ACE_UNUSED_ARG (cv);
  ACE_NOTSUP_RETURN (-1);
# endif /* ACE_HAS_THREADS */
}

int
ACE_OS::cond_init (ACE_cond_t *cv,
                   ACE_condattr_t &attributes,
                   const char *name, void *arg)
{
  return
    ACE_OS::cond_init (cv, static_cast<short> (attributes.type), name, arg);
}

# if defined (ACE_HAS_WCHAR)
int
ACE_OS::cond_init (ACE_cond_t *cv,
                   ACE_condattr_t &attributes,
                   const wchar_t *name, void *arg)
{
  return
    ACE_OS::cond_init (cv, static_cast<short> (attributes.type), name, arg);
}
# endif /* ACE_HAS_WCHAR */

int
ACE_OS::cond_init (ACE_cond_t *cv, short type, const char *name, void *arg)
{
  ACE_OS_TRACE ("ACE_OS::cond_init");
# if defined (ACE_HAS_THREADS)
  cv->waiters_ = 0;
  cv->was_broadcast_ = 0;

  int result = 0;
  if (ACE_OS::sema_init (&cv->sema_, 0, type, name, arg) == -1)
    result = -1;
  else if (ACE_OS::thread_mutex_init (&cv->waiters_lock_) == -1)
    result = -1;
#   if defined (ACE_VXWORKS)
  else if (ACE_OS::sema_init (&cv->waiters_done_, 0, type) == -1)
#   else
  else if (ACE_OS::event_init (&cv->waiters_done_) == -1)
#   endif /* ACE_VXWORKS */
    result = -1;
  return result;
# else
  ACE_UNUSED_ARG (cv);
  ACE_UNUSED_ARG (type);
  ACE_UNUSED_ARG (name);
  ACE_UNUSED_ARG (arg);
  ACE_NOTSUP_RETURN (-1);
# endif /* ACE_HAS_THREADS */
}

# if defined (ACE_HAS_WCHAR)
int
ACE_OS::cond_init (ACE_cond_t *cv, short type, const wchar_t *name, void *arg)
{
  ACE_OS_TRACE ("ACE_OS::cond_init");
#   if defined (ACE_HAS_THREADS)
  cv->waiters_ = 0;
  cv->was_broadcast_ = 0;

  int result = 0;
  if (ACE_OS::sema_init (&cv->sema_, 0, type, name, arg) == -1)
    result = -1;
  else if (ACE_OS::thread_mutex_init (&cv->waiters_lock_) == -1)
    result = -1;
#     if defined (ACE_VXWORKS)
  else if (ACE_OS::sema_init (&cv->waiters_done_, 0, type) == -1)
#     else
  else if (ACE_OS::event_init (&cv->waiters_done_) == -1)
#     endif /* ACE_VXWORKS */
    result = -1;
  return result;
#   else
  ACE_UNUSED_ARG (cv);
  ACE_UNUSED_ARG (type);
  ACE_UNUSED_ARG (name);
  ACE_UNUSED_ARG (arg);
  ACE_NOTSUP_RETURN (-1);
#   endif /* ACE_HAS_THREADS */
}
# endif /* ACE_HAS_WCHAR */

int
ACE_OS::cond_signal (ACE_cond_t *cv)
{
  ACE_OS_TRACE ("ACE_OS::cond_signal");
# if defined (ACE_HAS_THREADS)
  // If there aren't any waiters, then this is a no-op.  Note that
  // this function *must* be called with the <external_mutex> held
  // since other wise there is a race condition that can lead to the
  // lost wakeup bug...  This is needed to ensure that the <waiters_>
  // value is not in an inconsistent internal state while being
  // updated by another thread.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;
  bool const have_waiters = cv->waiters_ > 0;
  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

  if (have_waiters)
    return ACE_OS::sema_post (&cv->sema_);
  else
    return 0; // No-op
# else
  ACE_UNUSED_ARG (cv);
  ACE_NOTSUP_RETURN (-1);
# endif /* ACE_HAS_THREADS */
}

int
ACE_OS::cond_wait (ACE_cond_t *cv,
                   ACE_mutex_t *external_mutex)
{
  ACE_OS_TRACE ("ACE_OS::cond_wait");
# if defined (ACE_HAS_THREADS)
  // Prevent race conditions on the <waiters_> count.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;

  ++cv->waiters_;

  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

  int result = 0;

#   if defined (ACE_HAS_SIGNAL_OBJECT_AND_WAIT)
  if (external_mutex->type_ == USYNC_PROCESS)
    {
      // This call will automatically release the mutex and wait on the semaphore.
      ACE_WIN32CALL (ACE_ADAPT_RETVAL (::SignalObjectAndWait (external_mutex->proc_mutex_,
                                                              cv->sema_, INFINITE, FALSE),
                                      result),
                    int, -1, result);
      if (result == -1)
        return result;
    }
  else
#   endif /* ACE_HAS_SIGNAL_OBJECT_AND_WAIT */
    {
      // We keep the lock held just long enough to increment the count of
      // waiters by one.  Note that we can't keep it held across the call
      // to ACE_OS::sema_wait() since that will deadlock other calls to
      // ACE_OS::cond_signal().
      if (ACE_OS::mutex_unlock (external_mutex) != 0)
        return -1;

      // Wait to be awakened by a ACE_OS::cond_signal() or
      // ACE_OS::cond_broadcast().
      result = ACE_OS::sema_wait (&cv->sema_);
    }

  // Reacquire lock to avoid race conditions on the <waiters_> count.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;

  // We're ready to return, so there's one less waiter.
  --cv->waiters_;

  bool const last_waiter = cv->was_broadcast_ && cv->waiters_ == 0;

  // Release the lock so that other collaborating threads can make
  // progress.
  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

  if (result == -1)
    // Bad things happened, so let's just return below.
    /* NOOP */;
#   if defined (ACE_HAS_SIGNAL_OBJECT_AND_WAIT)
  else if (external_mutex->type_ == USYNC_PROCESS)
    {
      if (last_waiter)

        // This call atomically signals the <waiters_done_> event and
        // waits until it can acquire the mutex.  This is important to
        // prevent unfairness.
        ACE_WIN32CALL (ACE_ADAPT_RETVAL (::SignalObjectAndWait (cv->waiters_done_,
                                                                external_mutex->proc_mutex_,
                                                                INFINITE, FALSE),
                                         result),
                       int, -1, result);
      else
        // We must always regain the <external_mutex>, even when
        // errors occur because that's the guarantee that we give to
        // our callers.
        if (ACE_OS::mutex_lock (external_mutex) != 0)
          return -1;

      return result;
      /* NOTREACHED */
    }
#   endif /* ACE_HAS_SIGNAL_OBJECT_AND_WAIT */
  // If we're the last waiter thread during this particular broadcast
  // then let all the other threads proceed.
  else if (last_waiter)
#   if defined (ACE_VXWORKS)
    ACE_OS::sema_post (&cv->waiters_done_);
#   else
    ACE_OS::event_signal (&cv->waiters_done_);
#   endif /* ACE_VXWORKS */

  // We must always regain the <external_mutex>, even when errors
  // occur because that's the guarantee that we give to our callers.
  ACE_OS::mutex_lock (external_mutex);

  return result;
# else
  ACE_UNUSED_ARG (cv);
  ACE_UNUSED_ARG (external_mutex);
  ACE_NOTSUP_RETURN (-1);
# endif /* ACE_HAS_THREADS */
}

int
ACE_OS::cond_timedwait (ACE_cond_t *cv,
                        ACE_mutex_t *external_mutex,
                        ACE_Time_Value *timeout)
{
  ACE_OS_TRACE ("ACE_OS::cond_timedwait");
# if defined (ACE_HAS_THREADS)
  // Handle the easy case first.
  if (timeout == 0)
    return ACE_OS::cond_wait (cv, external_mutex);
#   if defined (ACE_HAS_WTHREADS) || defined (ACE_VXWORKS)

  // Prevent race conditions on the <waiters_> count.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;

  ++cv->waiters_;

  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

  int result = 0;
  ACE_Errno_Guard error (errno, 0);
  int msec_timeout = 0;

  if (timeout != 0 && *timeout != ACE_Time_Value::zero)
    {
      // Note that we must convert between absolute time (which is
      // passed as a parameter) and relative time (which is what
      // WaitForSingleObjects() expects).
      ACE_Time_Value relative_time (*timeout - ACE_OS::gettimeofday ());

      // Watchout for situations where a context switch has caused the
      // current time to be > the timeout.
      if (relative_time > ACE_Time_Value::zero)
        msec_timeout = relative_time.msec ();
    }

#     if defined (ACE_HAS_SIGNAL_OBJECT_AND_WAIT)
  if (external_mutex->type_ == USYNC_PROCESS)
    // This call will automatically release the mutex and wait on the
    // semaphore.
    result = ::SignalObjectAndWait (external_mutex->proc_mutex_,
                                    cv->sema_,
                                    msec_timeout,
                                    FALSE);
  else
#     endif /* ACE_HAS_SIGNAL_OBJECT_AND_WAIT */
    {
      // We keep the lock held just long enough to increment the count
      // of waiters by one.  Note that we can't keep it held across
      // the call to WaitForSingleObject since that will deadlock
      // other calls to ACE_OS::cond_signal().
      if (ACE_OS::mutex_unlock (external_mutex) != 0)
        return -1;

      // Wait to be awakened by a ACE_OS::signal() or
      // ACE_OS::broadcast().
#     if defined (ACE_WIN32)
#       if !defined (ACE_USES_WINCE_SEMA_SIMULATION)
      result = ::WaitForSingleObject (cv->sema_, msec_timeout);
#       else /* ACE_USES_WINCE_SEMA_SIMULATION */
      // Can't use Win32 API on our simulated semaphores.
      result = ACE_OS::sema_wait (&cv->sema_,
                                  timeout);
#       endif /* ACE_USES_WINCE_SEMA_SIMULATION */
#     elif defined (ACE_VXWORKS)
      // Inline the call to ACE_OS::sema_wait () because it takes an
      // ACE_Time_Value argument.  Avoid the cost of that conversion . . .
      int const ticks_per_sec = ::sysClkRateGet ();
      int const ticks = msec_timeout * ticks_per_sec / ACE_ONE_SECOND_IN_MSECS;
      result = ::semTake (cv->sema_.sema_, ticks);
#     endif /* ACE_WIN32 || VXWORKS */
    }

  // Reacquire lock to avoid race conditions.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;

  --cv->waiters_;

  bool const last_waiter = cv->was_broadcast_ && cv->waiters_ == 0;

  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

#     if defined (ACE_WIN32)
  if (result != WAIT_OBJECT_0)
    {
      switch (result)
        {
        case WAIT_TIMEOUT:
          error = ETIME;
          break;
        default:
          error = ::GetLastError ();
          break;
        }
      result = -1;
    }
#     elif defined (ACE_VXWORKS)
  if (result == ERROR)
    {
      switch (errno)
        {
        case S_objLib_OBJ_TIMEOUT:
          error = ETIME;
          break;
        case S_objLib_OBJ_UNAVAILABLE:
          if (msec_timeout == 0)
            error = ETIME;
          break;
        default:
          error = errno;
          break;
        }
      result = -1;
    }
#     endif /* ACE_WIN32 || VXWORKS */
#     if defined (ACE_HAS_SIGNAL_OBJECT_AND_WAIT)
  if (external_mutex->type_ == USYNC_PROCESS)
    {
      if (last_waiter)
        // This call atomically signals the <waiters_done_> event and
        // waits until it can acquire the mutex.  This is important to
        // prevent unfairness.
        ACE_WIN32CALL (ACE_ADAPT_RETVAL (::SignalObjectAndWait (cv->waiters_done_,
                                                                external_mutex->proc_mutex_,
                                                                INFINITE, FALSE),
                                         result),
                       int, -1, result);
      else
        {
          // We must always regain the <external_Mutex>, even when
          // errors occur because that's the guarantee that we give to
          // our callers.
          if (ACE_OS::mutex_lock (external_mutex) != 0)
            return -1;
        }

      return result;
      /* NOTREACHED */
    }
#     endif /* ACE_HAS_SIGNAL_OBJECT_AND_WAIT */
  // Note that this *must* be an "if" statement rather than an "else
  // if" statement since the caller may have timed out and hence the
  // result would have been -1 above.
  if (last_waiter)
    {
      // Release the signaler/broadcaster if we're the last waiter.
#     if defined (ACE_WIN32)
      if (ACE_OS::event_signal (&cv->waiters_done_) != 0)
#     else
      if (ACE_OS::sema_post (&cv->waiters_done_) != 0)
#     endif /* ACE_WIN32 */
        return -1;
    }

  // We must always regain the <external_mutex>, even when errors
  // occur because that's the guarantee that we give to our callers.
  if (ACE_OS::mutex_lock (external_mutex) != 0)
    return -1;

  return result;
#   endif /* ACE_HAS_WTHREADS || ACE_HAS_VXWORKS */
# else
  ACE_UNUSED_ARG (cv);
  ACE_UNUSED_ARG (external_mutex);
  ACE_UNUSED_ARG (timeout);
  ACE_NOTSUP_RETURN (-1);
# endif /* ACE_HAS_THREADS */
}
#else
int
ACE_OS::cond_init (ACE_cond_t *cv, short type, const char *name, void *arg)
{
  ACE_condattr_t attributes;
  if (ACE_OS::condattr_init (attributes, type) == 0
      && ACE_OS::cond_init (cv, attributes, name, arg) == 0)
    {
      (void) ACE_OS::condattr_destroy (attributes);
      return 0;
    }
  return -1;
}
#endif /* ACE_LACKS_COND_T */

#if defined (ACE_WIN32) && defined (ACE_HAS_WTHREADS)
int
ACE_OS::cond_timedwait (ACE_cond_t *cv,
                        ACE_thread_mutex_t *external_mutex,
                        ACE_Time_Value *timeout)
{
  ACE_OS_TRACE ("ACE_OS::cond_timedwait");
#   if defined (ACE_HAS_THREADS)
  // Handle the easy case first.
  if (timeout == 0)
    return ACE_OS::cond_wait (cv, external_mutex);

#   if defined (ACE_HAS_WTHREADS_CONDITION_VARIABLE)
  int msec_timeout = 0;
  int result = 0;

  ACE_Time_Value relative_time (*timeout - ACE_OS::gettimeofday ());
  // Watchout for situations where a context switch has caused the
  // current time to be > the timeout.
  if (relative_time > ACE_Time_Value::zero)
     msec_timeout = relative_time.msec ();

  ACE_OSCALL (ACE_ADAPT_RETVAL (::SleepConditionVariableCS (cv, external_mutex, msec_timeout),
                                result),
              int, -1, result);
  return result;
#else
  // Prevent race conditions on the <waiters_> count.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;

  ++cv->waiters_;

  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

  int result = 0;
  int error = 0;
  int msec_timeout = 0;

  if (timeout != 0 && *timeout != ACE_Time_Value::zero)
    {
      // Note that we must convert between absolute time (which is
      // passed as a parameter) and relative time (which is what
      // WaitForSingleObjects() expects).
      ACE_Time_Value relative_time (*timeout - ACE_OS::gettimeofday ());

      // Watchout for situations where a context switch has caused the
      // current time to be > the timeout.
      if (relative_time > ACE_Time_Value::zero)
        msec_timeout = relative_time.msec ();
    }

  // We keep the lock held just long enough to increment the count of
  // waiters by one.  Note that we can't keep it held across the call
  // to WaitForSingleObject since that will deadlock other calls to
  // ACE_OS::cond_signal().
  if (ACE_OS::thread_mutex_unlock (external_mutex) != 0)
    return -1;

  // Wait to be awakened by a ACE_OS::signal() or ACE_OS::broadcast().
#     if defined (ACE_USES_WINCE_SEMA_SIMULATION)
  // Can't use Win32 API on simulated semaphores.
  result = ACE_OS::sema_wait (&cv->sema_,
                              timeout);

  if (result == -1 && errno == ETIME)
    result = WAIT_TIMEOUT;
#     else
  result = ::WaitForSingleObject (cv->sema_, msec_timeout);
#     endif /* ACE_USES_WINCE_SEMA_SIMULATION */

  // Reacquire lock to avoid race conditions.
  if (ACE_OS::thread_mutex_lock (&cv->waiters_lock_) != 0)
    return -1;

  --cv->waiters_;

  bool const last_waiter = cv->was_broadcast_ && cv->waiters_ == 0;

  if (ACE_OS::thread_mutex_unlock (&cv->waiters_lock_) != 0)
    return -1;

  if (result != WAIT_OBJECT_0)
    {
      switch (result)
        {
        case WAIT_TIMEOUT:
          error = ETIME;
          break;
        default:
          error = ::GetLastError ();
          break;
        }
      result = -1;
    }

  if (last_waiter)
    {
      // Release the signaler/broadcaster if we're the