/*

 * Copyright (c) 1997-1999

 * Silicon Graphics Computer Systems, Inc.

 *

 * Copyright (c) 1999 

 * Boris Fomitchev

 *

 * This material is provided "as is", with absolutely no warranty expressed

 * or implied. Any use is at your own risk.

 *

 * Permission to use or copy this software for any purpose is hereby granted 

 * without fee, provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 *

 */

// WARNING: This is an internal header file, included by other C++

// standard library headers.  You should not attempt to use this header

// file directly.

// Stl_config.h should be included before this file.

#ifndef _STLP_INTERNAL_THREADS_H

#define _STLP_INTERNAL_THREADS_H

// Supported threading models are native SGI, pthreads, uithreads

// (similar to pthreads, but based on an earlier draft of the Posix

// threads standard), and Win32 threads.  Uithread support by Jochen

// Schlick, 1999, and Solaris threads generalized to them.

#ifndef _STLP_CONFIG_H

#include <stl/_config.h>

#endif

# if ! defined (_STLP_CSTDDEF)

#  include <cstddef>

# endif

# if ! defined (_STLP_CSTDLIB)

#  include <cstdlib>

# endif

// On SUN and Mac OS X gcc, zero-initialization works just fine...

# if defined (__sun) || ( defined(__GNUC__) && defined(__APPLE__) )

# define _STLP_MUTEX_INITIALIZER

# endif

# if defined (_STLP_WIN32) || defined (__sgi) || defined (_STLP_SPARC_SOLARIS_THREADS)

  typedef long __stl_atomic_t;

# else 

# if defined (_STLP_USE_NAMESPACES) && ! defined (_STLP_VENDOR_GLOBAL_CSTD)

// using _STLP_VENDOR_CSTD::size_t;

using namespace _STLP_VENDOR_CSTD;

# endif

  typedef size_t __stl_atomic_t;

#endif  

# if defined(_STLP_SGI_THREADS)

#  include <mutex.h>

// Hack for SGI o32 compilers.

#if !defined(__add_and_fetch) && \

    (__mips < 3 || !(defined (_ABIN32) || defined(_ABI64)))

#  define __add_and_fetch(__l,__v) add_then_test((unsigned long*)__l,__v)  

#  define __test_and_set(__l,__v)  test_and_set(__l,__v)

#endif /* o32 */

# if __mips < 3 || !(defined (_ABIN32) || defined(_ABI64))

#  define _STLP_ATOMIC_EXCHANGE(__p, __q) test_and_set(__p, __q)

# else

#  define _STLP_ATOMIC_EXCHANGE(__p, __q) __test_and_set((unsigned long*)__p, (unsigned long)__q)

# endif

#  define _STLP_ATOMIC_INCREMENT(__x) __add_and_fetch(__x, 1)

#  define _STLP_ATOMIC_DECREMENT(__x) __add_and_fetch(__x, (size_t) -1)

# elif defined (__GNUC__) && defined (__i386__) && defined (__unix__) && defined (_STLP_USE_INLINE_X86_SPINLOCK) 

// gcc on i386 linux, freebsd, etc. 

// This enables the memory caching on x86 linux.  It is critical for SMP

// without it the performace is DISMAL!

static inline unsigned long __xchg(volatile __stl_atomic_t* target, int source)

{

  // The target is refernce in memory rather than the register

  // because making a copy of it from memory to the register and

  // back again would ruin the atomic nature of the call.

  // the source does not need to be delt with atomicly so it can

  // be copied about as needed.

  //

  // The casting of the source is used to prevent gcc from optimizing 

  // in such a way that breaks the atomic nature of this call.

  //

  __asm__ __volatile__("xchgl %1,%0"

		       :"=m" (*(volatile long *) target), "=r" (source)

		       :"m" (*(volatile long *) target), "r" (source) );

  return source;

  //  The assembly above does the following atomicly:

  //   int temp=source;

  //   source=(int)(*target);

  //   (int)(*target)=temp;

  // return source

}

static inline void __inc_and_fetch(volatile __stl_atomic_t* __x)

{

  // Referenced in memory rather than register to preserve the atomic nature.

  //

  __asm__ __volatile__(

      "lock; incl %0"

      :"=m" (*__x)

      :"m" (*__x) );

  //  The assembly above does the following atomicly:

  //   ++(int)(*__x);

}

static inline void __dec_and_fetch(volatile __stl_atomic_t* __x)

{

  // Referenced in memory rather than register to preserve the atomic nature.

  //

  __asm__ __volatile__(

      "lock; decl %0"

      :"=m" (*__x)

      :"m" (*__x) );

  //  The assembly above does the following atomicly:

  //   --(int)(*__x);

}

#  define _STLP_ATOMIC_EXCHANGE(target, newValue) ((__xchg(target, newValue)))

#  define _STLP_ATOMIC_INCREMENT(__x) __inc_and_fetch(__x)

#  define _STLP_ATOMIC_DECREMENT(__x) __dec_and_fetch(__x)

# elif defined(_STLP_PTHREADS)

#  include <pthread.h>

#  ifndef _STLP_USE_PTHREAD_SPINLOCK

#   if defined(PTHREAD_MUTEX_INITIALIZER) && !defined(_STLP_MUTEX_INITIALIZER)

#    define _STLP_MUTEX_INITIALIZER = { PTHREAD_MUTEX_INITIALIZER }

#   endif

//HPUX variants have (on some platforms optional) non-standard "DCE" pthreads impl

#   if defined(_DECTHREADS_) && (defined(_PTHREAD_USE_D4) || defined(__hpux)) && !defined(_CMA_SUPPRESS_EXTERNALS_)

#    define _STLP_PTHREAD_ATTR_DEFAULT pthread_mutexattr_default

#   else

#    define _STLP_PTHREAD_ATTR_DEFAULT 0

#   endif

#  endif // !_STLP_USE_PTHREAD_SPINLOCK 

# elif defined(_STLP_WIN32THREADS)

#  if !defined (_STLP_WINDOWS_H_INCLUDED) && ! defined (_WINDOWS_H)

#   if ! (defined ( _STLP_MSVC ) || defined (__BORLANDC__) || defined (__ICL) || defined (__WATCOMC__) || defined (__MINGW32__) || defined (__DMC__))

#    ifdef _STLP_USE_MFC

#     include <afx.h>

#    else

#     include <windows.h>

#    endif

#    define _STLP_WINDOWS_H_INCLUDED

#   else 

// This section serves as a replacement for windows.h header for Visual C++

extern "C" {

#   if (defined(_M_MRX000) || defined(_M_ALPHA) \

       || (defined(_M_PPC) && (_MSC_VER >= 1000))) && !defined(RC_INVOKED)

#    define InterlockedIncrement       _InterlockedIncrement

#    define InterlockedDecrement       _InterlockedDecrement

#    define InterlockedExchange        _InterlockedExchange

#    define _STLP_STDCALL

#   else

#    ifdef _MAC

#     define _STLP_STDCALL _cdecl

#    else

#     define _STLP_STDCALL __stdcall

#    endif

#   endif

#if (_MSC_VER >= 1300) || defined (_STLP_NEW_PLATFORM_SDK)

_STLP_IMPORT_DECLSPEC long _STLP_STDCALL InterlockedIncrement(long volatile *);

_STLP_IMPORT_DECLSPEC long _STLP_STDCALL InterlockedDecrement(long volatile *);

_STLP_IMPORT_DECLSPEC long _STLP_STDCALL InterlockedExchange(long volatile *, long);

#else

  // boris : for the latest SDK, you may actually need the other version of the declaration (above)

  // even for earlier VC++ versions. There is no way to tell SDK versions apart, sorry ...

_STLP_IMPORT_DECLSPEC long _STLP_STDCALL InterlockedIncrement(long*);

_STLP_IMPORT_DECLSPEC long _STLP_STDCALL InterlockedDecrement(long*);

_STLP_IMPORT_DECLSPEC long _STLP_STDCALL InterlockedExchange(long*, long);

#endif

_STLP_IMPORT_DECLSPEC void _STLP_STDCALL Sleep(unsigned long);

_STLP_IMPORT_DECLSPEC void _STLP_STDCALL OutputDebugStringA( const char* lpOutputString );

#ifdef _STLP_DEBUG

typedef unsigned long DWORD;

_STLP_IMPORT_DECLSPEC DWORD _STLP_STDCALL GetCurrentThreadId();

#endif /* _STLP_DEBUG */

#    if defined (InterlockedIncrement)

#     pragma intrinsic(_InterlockedIncrement)

#     pragma intrinsic(_InterlockedDecrement)

#     pragma intrinsic(_InterlockedExchange)

#    endif

} /* extern "C" */

#   endif /* STL_MSVC */

#   define _STLP_WINDOWS_H_INCLUDED

#  endif /* _STLP_WIN32 */

#  ifndef _STLP_ATOMIC_INCREMENT

#   define _STLP_ATOMIC_INCREMENT(__x)           InterlockedIncrement((long*)__x)

#   define _STLP_ATOMIC_DECREMENT(__x)           InterlockedDecrement((long*)__x)

#   define _STLP_ATOMIC_EXCHANGE(__x, __y)       InterlockedExchange((long*)__x, (long)__y)

#  endif

# elif defined(__DECC) || defined(__DECCXX)

#  include <machine/builtins.h>

#  define _STLP_ATOMIC_EXCHANGE __ATOMIC_EXCH_LONG

#  define _STLP_ATOMIC_INCREMENT(__x) __ATOMIC_ADD_LONG(__x, 1)

#  define _STLP_ATOMIC_DECREMENT(__x) __ATOMIC_ADD_LONG(__x, -1)

# elif defined(_STLP_SPARC_SOLARIS_THREADS)

#  include <stl/_sparc_atomic.h>

# elif defined (_STLP_UITHREADS)

// this inclusion is potential hazard to bring up all sorts

// of old-style headers. Let's assume vendor already know how

// to deal with that.

#  include <ctime>

# if defined (_STLP_USE_NAMESPACES) && ! defined (_STLP_VENDOR_GLOBAL_CSTD)

using _STLP_VENDOR_CSTD::time_t;

# endif

#  include <synch.h>

#  include <cstdio>

#  include <stl/_cwchar.h>

# elif defined (_STLP_BETHREADS)

#  include <OS.h>

#include <cassert>

#include <stdio.h>

#  define _STLP_MUTEX_INITIALIZER = { 0 }

#elif defined(_STLP_OS2THREADS)

# ifdef __GNUC__

#  define INCL_DOSSEMAPHORES

#  include <os2.h>

# else

  // This section serves to replace os2.h for VisualAge C++

  typedef unsigned long ULONG;

  #ifndef __HEV__  /* INCL_SEMAPHORE may also define HEV */

    #define __HEV__

    typedef ULONG HEV;

    typedef HEV*  PHEV;

  #endif

  typedef ULONG APIRET;

  typedef ULONG HMTX;

  typedef HMTX*  PHMTX;

  typedef const char*  PCSZ;

  typedef ULONG BOOL32;

  APIRET _System DosCreateMutexSem(PCSZ pszName, PHEV phev, ULONG flAttr, BOOL32 fState);

  APIRET _System DosRequestMutexSem(HMTX hmtx, ULONG ulTimeout);

  APIRET _System DosReleaseMutexSem(HMTX hmtx);

  APIRET _System DosCloseMutexSem(HMTX hmtx);

# define _STLP_MUTEX_INITIALIZER = { 0 };

#  endif /* GNUC */

# elif defined(_STLP_VXWORKS_THREADS)

#  include "semLib.h"

# endif

# ifndef _STLP_MUTEX_INITIALIZER

#   if defined(_STLP_ATOMIC_EXCHANGE)

// we are using our own spinlock. 

#     define _STLP_MUTEX_INITIALIZER = { 0 }

#   elif defined(_STLP_UITHREADS)

// known case

#     define _STLP_MUTEX_INITIALIZER = { DEFAULTMUTEX }

#   else

// we do not have static initializer available. therefore, on-demand synchronization is needed.

#     define _STLP_MUTEX_INITIALIZER

#     define _STLP_MUTEX_NEEDS_ONDEMAND_INITIALIZATION

#   endif

# endif

_STLP_BEGIN_NAMESPACE

#ifndef _STLP_USE_PTHREAD_SPINLOCK

// Helper struct.  This is a workaround for various compilers that don't

// handle static variables in inline functions properly.

template <int __inst>

struct _STLP_mutex_spin {

  enum { __low_max = 30, __high_max = 1000 };

  // Low if we suspect uniprocessor, high for multiprocessor.

  static unsigned __max;

  static unsigned __last;

  static void _STLP_CALL _M_do_lock(volatile __stl_atomic_t* __lock);

  static void _STLP_CALL _S_nsec_sleep(int __log_nsec);

};

#endif // !_STLP_USE_PTHREAD_SPINLOCK

// Locking class.  Note that this class *does not have a constructor*.

// It must be initialized either statically, with _STLP_MUTEX_INITIALIZER,

// or dynamically, by explicitly calling the _M_initialize member function.

// (This is similar to the ways that a pthreads mutex can be initialized.)

// There are explicit member functions for acquiring and releasing the lock.

// There is no constructor because static initialization is essential for

// some uses, and only a class aggregate (see section 8.5.1 of the C++

// standard) can be initialized that way.  That means we must have no

// constructors, no base classes, no virtual functions, and no private or

// protected members.

// For non-static cases, clients should use  _STLP_mutex.

struct _STLP_CLASS_DECLSPEC _STLP_mutex_base

{

#if defined(_STLP_ATOMIC_EXCHANGE) || defined(_STLP_SGI_THREADS)

  // It should be relatively easy to get this to work on any modern Unix.

  volatile __stl_atomic_t _M_lock;

#endif

#ifdef _STLP_THREADS

# ifdef _STLP_ATOMIC_EXCHANGE

  inline void _M_initialize() { _M_lock=0; }

  inline void _M_destroy() {}

  void _M_acquire_lock() {

    _STLP_mutex_spin<0>::_M_do_lock(&_M_lock);

  }

  inline void _M_release_lock() {

    volatile __stl_atomic_t* __lock = &_M_lock;

#  if defined(_STLP_SGI_THREADS) && defined(__GNUC__) && __mips >= 3

        asm("sync");

        *__lock = 0;

#  elif defined(_STLP_SGI_THREADS) && __mips >= 3 \

	 && (defined (_ABIN32) || defined(_ABI64))

        __lock_release(__lock);

#  elif defined (_STLP_SPARC_SOLARIS_THREADS)

#   if defined (__WORD64) || defined (__arch64__) || defined (__sparcv9) || defined (__sparcv8plus)

	asm("membar #StoreStore ; membar #LoadStore");

#   else

	asm(" stbar ");

#   endif

        *__lock = 0;	

#  else

        *__lock = 0;

        // This is not sufficient on many multiprocessors, since

        // writes to protected variables and the lock may be reordered.

#  endif

  }

# elif defined(_STLP_PTHREADS)

#  ifdef _STLP_USE_PTHREAD_SPINLOCK

  pthread_spinlock_t _M_lock;

  inline void _M_initialize() { pthread_spin_init( &_M_lock, 0 ); }

  inline void _M_destroy() { pthread_spin_destroy( &_M_lock ); }

  inline void _M_acquire_lock() { 

    // we do not care about race conditions here : there is only one thread at this point 

    if(!_M_lock) pthread_spin_init( &_M_lock, 0 );

    // fbp: here, initialization on demand should happen before the lock

    // we use simple strategy as we are sure this only happens on initialization

    pthread_spin_lock( &_M_lock );

  }

  inline void _M_acquire_lock_nodemand() { 

    pthread_spin_lock( &_M_lock ); 

  }

  inline void _M_release_lock() { pthread_spin_unlock( &_M_lock ); }

#  else // !_STLP_USE_PTHREAD_SPINLOCK

  pthread_mutex_t _M_lock;

  inline void _M_initialize() {

    pthread_mutex_init(&_M_lock,_STLP_PTHREAD_ATTR_DEFAULT);

  }

  inline void _M_destroy() {

    pthread_mutex_destroy(&_M_lock);

  }

  inline void _M_acquire_lock_nodemand() { 

    pthread_mutex_lock(&_M_lock);

  }

  inline void _M_acquire_lock() { 

#    if defined (__hpux) && !defined (PTHREAD_MUTEX_INITIALIZER)

      if (!_M_lock.field1)  _M_initialize();

#    endif

     pthread_mutex_lock(&_M_lock);

  }

  inline void _M_release_lock() { pthread_mutex_unlock(&_M_lock); }

#  endif // !_STLP_USE_PTHREAD_SPINLOCK

# elif defined (_STLP_UITHREADS)

  mutex_t _M_lock;

  inline void _M_initialize() {

    mutex_init(&_M_lock,0,NULL);	

  }

  inline void _M_destroy() {

    mutex_destroy(&_M_lock);

  }

  inline void _M_acquire_lock() { mutex_lock(&_M_lock); }

  inline void _M_release_lock() { mutex_unlock(&_M_lock); }

# elif defined(_STLP_OS2THREADS)

  HMTX _M_lock;

  inline void _M_initialize() { DosCreateMutexSem(NULL, &_M_lock, 0, false); }

  inline void _M_destroy() { DosCloseMutexSem(_M_lock); }

  inline void _M_acquire_lock_nodemand() {

    DosRequestMutexSem(_M_lock, SEM_INDEFINITE_WAIT);

  }  

  inline void _M_acquire_lock() {

    if(!_M_lock) _M_initialize();

    DosRequestMutexSem(_M_lock, SEM_INDEFINITE_WAIT);

  }

  inline void _M_release_lock() { DosReleaseMutexSem(_M_lock); }

# elif defined(_STLP_BETHREADS)

  sem_id sem;

  inline void _M_initialize() 

  {

     sem = create_sem(1, "STLPort");

     assert(sem > 0);

  }

  inline void _M_destroy() 

  {

     int t = delete_sem(sem);

     assert(t == B_NO_ERROR);

  }

  inline void _M_acquire_lock_nodemand()

  {

    status_t t;

    t = acquire_sem(sem);

    assert(t == B_NO_ERROR);

  }

  inline void _M_acquire_lock();

  inline void _M_release_lock() 

  {

     status_t t = release_sem(sem);

     assert(t == B_NO_ERROR);

  }

# elif defined(_STLP_VXWORKS_THREADS)

  SEM_ID _M_sem;

  inline void _M_initialize() 

  {

     _M_sem = semMCreate(SEM_Q_FIFO);

     assert(_M_sem > 0);

  }

  inline void _M_destroy() 

  {

    STATUS __s;

    semDelete (_M_sem);

    assert(__s == OK);

  }

  inline void _M_acquire_lock_nodemand()

  {

    STATUS __s;

    semTake (_M_sem, WAIT_FOREVER);

    assert(__s == OK);

  }

  inline void _M_acquire_lock()

  {

    if (!_M_sem)

      _M_initialize();

    _M_acquire_lock_nodemand();

  }

  inline void _M_release_lock() 

  {

    STATUS __s;

    semGive (_M_sem, WAIT_FOREVER);

    assert(__s == OK);

  }

# else		//*ty 11/24/2001 - added configuration check

#  error "Unknown thread facility configuration"

# endif

#else /* No threads */

  inline void _M_initialize() {}

  inline void _M_destroy() {}

  inline void _M_acquire_lock() {}

  inline void _M_release_lock() {}

#endif // _STLP_PTHREADS

};

#if defined (_STLP_THREADS) && defined (_STLP_MUTEX_NEEDS_ONDEMAND_INITIALIZATION)

// for use in _STLP_mutex, our purposes do not require ondemand initialization

// also, mutex_base may use some hacks to determine uninitialized state by zero data, which only works for globals.

class _STLP_CLASS_DECLSPEC _STLP_mutex_nodemand : public _STLP_mutex_base {

  inline void _M_acquire_lock() { 

    _M_acquire_lock_nodemand();

  }

};

#else

typedef _STLP_mutex_base _STLP_mutex_nodemand;

#endif

// Locking class.  The constructor initializes the lock, the destructor destroys it.

// Well - behaving class, does not need static initializer

class _STLP_CLASS_DECLSPEC _STLP_mutex : public _STLP_mutex_nodemand {

  public:

    inline _STLP_mutex () { _M_initialize(); }

    inline ~_STLP_mutex () { _M_destroy(); }

  private:

    _STLP_mutex(const _STLP_mutex&);

    void operator=(const _STLP_mutex&);

};

/*

 * Class _Refcount_Base provides a type, __stl_atomic_t, a data member,

 * _M_ref_count, and member functions _M_incr and _M_decr, which perform

 * atomic preincrement/predecrement.  The constructor initializes 

 * _M_ref_count.

 */

struct _STLP_CLASS_DECLSPEC _Refcount_Base

{

  // The data member _M_ref_count

  volatile __stl_atomic_t _M_ref_count;

# if !defined (_STLP_ATOMIC_EXCHANGE)

  _STLP_mutex _M_mutex;

# endif

  // Constructor

  _Refcount_Base(__stl_atomic_t __n) : _M_ref_count(__n) {}

  // _M_incr and _M_decr

# if defined (_STLP_THREADS) && defined (_STLP_ATOMIC_EXCHANGE)

   void _M_incr() { _STLP_ATOMIC_INCREMENT((__stl_atomic_t*)&_M_ref_count); }