1/*
2 * Copyright (c) 1997-1999
3 * Silicon Graphics Computer Systems, Inc.
4 *
5 * Copyright (c) 1999
6 * Boris Fomitchev
7 *
8 * This material is provided "as is", with absolutely no warranty expressed
9 * or implied. Any use is at your own risk.
10 *
11 * Permission to use or copy this software for any purpose is hereby granted
12 * without fee, provided the above notices are retained on all copies.
13 * Permission to modify the code and to distribute modified code is granted,
14 * provided the above notices are retained, and a notice that the code was
15 * modified is included with the above copyright notice.
16 *
17 */
18
19// WARNING: This is an internal header file, included by other C++
20// standard library headers.  You should not attempt to use this header
21// file directly.
22
23
24#ifndef _STLP_INTERNAL_THREADS_H
25#define _STLP_INTERNAL_THREADS_H
26
27// Supported threading models are native SGI, pthreads, uithreads
28// (similar to pthreads, but based on an earlier draft of the Posix
29// threads standard), and Win32 threads.  Uithread support by Jochen
30// Schlick, 1999, and Solaris threads generalized to them.
31
32#ifndef _STLP_INTERNAL_CSTDDEF
33#  include <stl/_cstddef.h>
34#endif
35
36#ifndef _STLP_INTERNAL_CSTDLIB
37#  include <stl/_cstdlib.h>
38#endif
39
40// On SUN and Mac OS X gcc, zero-initialization works just fine...
41#if defined (__sun) || (defined (__GNUC__) && defined(__APPLE__))
42#  define _STLP_MUTEX_INITIALIZER
43#endif
44
45/* This header defines the following atomic operation that platform should
46 * try to support as much as possible. Atomic operation are exposed as macro
47 * in order to easily test for their existance. They are:
48 * __stl_atomic_t _STLP_ATOMIC_INCREMENT(volatile __stl_atomic_t* __ptr) :
49 * increment *__ptr by 1 and returns the new value
50 * __stl_atomic_t _STLP_ATOMIC_DECREMENT(volatile __stl_atomic_t* __ptr) :
51 * decrement  *__ptr by 1 and returns the new value
52 * __stl_atomic_t _STLP_ATOMIC_EXCHANGE(volatile __stl_atomic_t* __target, __stl_atomic_t __val) :
53 * assign __val to *__target and returns former *__target value
54 * void* _STLP_ATOMIC_EXCHANGE_PTR(void* volatile* __target, void* __ptr) :
55 * assign __ptr to *__target and returns former *__target value
56 */
57
58#if defined (_STLP_THREADS)
59
60#  if defined (_STLP_SGI_THREADS)
61
62#    include <mutex.h>
63// Hack for SGI o32 compilers.
64#    if !defined(__add_and_fetch) && \
65        (__mips < 3 || !(defined (_ABIN32) || defined(_ABI64)))
66#      define __add_and_fetch(__l,__v) add_then_test((unsigned long*)__l,__v)
67#      define __test_and_set(__l,__v)  test_and_set(__l,__v)
68#    endif /* o32 */
69
70#    if __mips < 3 || !(defined (_ABIN32) || defined(_ABI64))
71#      define _STLP_ATOMIC_EXCHANGE(__p, __q) test_and_set(__p, __q)
72#    else
73#      define _STLP_ATOMIC_EXCHANGE(__p, __q) __test_and_set((unsigned long*)__p, (unsigned long)__q)
74#    endif
75
76#    define _STLP_ATOMIC_INCREMENT(__x) __add_and_fetch(__x, 1)
77#    define _STLP_ATOMIC_DECREMENT(__x) __add_and_fetch(__x, (size_t) -1)
78typedef long __stl_atomic_t;
79
80#  elif defined (_STLP_PTHREADS)
81
82#    include <pthread.h>
83#    if !defined (_STLP_USE_PTHREAD_SPINLOCK)
84#      if defined (PTHREAD_MUTEX_INITIALIZER) && !defined (_STLP_MUTEX_INITIALIZER) && defined (_REENTRANT)
85#        define _STLP_MUTEX_INITIALIZER = { PTHREAD_MUTEX_INITIALIZER }
86#      endif
87//HPUX variants have (on some platforms optional) non-standard "DCE" pthreads impl
88#      if defined (_DECTHREADS_) && (defined (_PTHREAD_USE_D4) || defined (__hpux)) && !defined (_CMA_SUPPRESS_EXTERNALS_)
89#        define _STLP_PTHREAD_ATTR_DEFAULT pthread_mutexattr_default
90#      else
91#        define _STLP_PTHREAD_ATTR_DEFAULT 0
92#      endif
93#    else
94#      if defined (__OpenBSD__)
95#        include <spinlock.h>
96#      endif
97#    endif
98
99#    if defined (__GNUC__) && defined (__i386__)
100#      if !defined (_STLP_ATOMIC_INCREMENT)
101inline long _STLP_atomic_increment_gcc_x86(long volatile* p) {
102  long result;
103  __asm__ __volatile__
104    ("lock; xaddl  %1, %0;"
105    :"=m" (*p), "=r" (result)
106    :"m" (*p),  "1"  (1)
107    :"cc");
108  return result + 1;
109}
110#        define _STLP_ATOMIC_INCREMENT(__x) (_STLP_atomic_increment_gcc_x86((long volatile*)__x))
111#      endif
112
113#      if !defined (_STLP_ATOMIC_DECREMENT)
114inline long _STLP_atomic_decrement_gcc_x86(long volatile* p) {
115  long result;
116  __asm__ __volatile__
117    ("lock; xaddl  %1, %0;"
118    :"=m" (*p), "=r" (result)
119    :"m" (*p),  "1"  (-1)
120    :"cc");
121  return result - 1;
122}
123#        define _STLP_ATOMIC_DECREMENT(__x) (_STLP_atomic_decrement_gcc_x86((long volatile*)__x))
124#      endif
125typedef long __stl_atomic_t;
126#    else
127typedef size_t __stl_atomic_t;
128#    endif /* if defined(__GNUC__) && defined(__i386__) */
129
130#  elif defined (_STLP_WIN32THREADS)
131
132#    if !defined (_STLP_ATOMIC_INCREMENT)
133#      if !defined (_STLP_NEW_PLATFORM_SDK)
134#        define _STLP_ATOMIC_INCREMENT(__x)           InterlockedIncrement(__CONST_CAST(long*, __x))
135#        define _STLP_ATOMIC_DECREMENT(__x)           InterlockedDecrement(__CONST_CAST(long*, __x))
136#        define _STLP_ATOMIC_EXCHANGE(__x, __y)       InterlockedExchange(__CONST_CAST(long*, __x), __y)
137#      else
138#        define _STLP_ATOMIC_INCREMENT(__x)           InterlockedIncrement(__x)
139#        define _STLP_ATOMIC_DECREMENT(__x)           InterlockedDecrement(__x)
140#        define _STLP_ATOMIC_EXCHANGE(__x, __y)       InterlockedExchange(__x, __y)
141#      endif
142#      define _STLP_ATOMIC_EXCHANGE_PTR(__x, __y)     STLPInterlockedExchangePointer(__x, __y)
143#    endif
144typedef long __stl_atomic_t;
145
146#  elif defined (__DECC) || defined (__DECCXX)
147
148#    include <machine/builtins.h>
149#    define _STLP_ATOMIC_EXCHANGE __ATOMIC_EXCH_LONG
150#    define _STLP_ATOMIC_INCREMENT(__x) __ATOMIC_ADD_LONG(__x, 1)
151#    define _STLP_ATOMIC_DECREMENT(__x) __ATOMIC_ADD_LONG(__x, -1)
152typedef long __stl_atomic_t;
153
154#  elif defined (_STLP_SPARC_SOLARIS_THREADS)
155
156typedef long __stl_atomic_t;
157#    include <stl/_sparc_atomic.h>
158
159#  elif defined (_STLP_UITHREADS)
160
161// this inclusion is potential hazard to bring up all sorts
162// of old-style headers. Let's assume vendor already know how
163// to deal with that.
164#    ifndef _STLP_INTERNAL_CTIME
165#      include <stl/_ctime.h>
166#    endif
167#    if defined (_STLP_USE_NAMESPACES) && ! defined (_STLP_VENDOR_GLOBAL_CSTD)
168using _STLP_VENDOR_CSTD::time_t;
169#    endif
170#    include <synch.h>
171#    ifndef _STLP_INTERNAL_CSTDIO
172#      include <stl/_cstdio.h>
173#    endif
174#    ifndef _STLP_INTERNAL_CWCHAR
175#      include <stl/_cwchar.h>
176#    endif
177typedef size_t __stl_atomic_t;
178
179#  elif defined (_STLP_BETHREADS)
180
181#    include <OS.h>
182#    include <cassert>
183#    include <stdio.h>
184#    define _STLP_MUTEX_INITIALIZER = { 0 }
185typedef size_t __stl_atomic_t;
186
187#  elif defined (_STLP_NWTHREADS)
188
189#    include <nwthread.h>
190#    include <nwsemaph.h>
191typedef size_t __stl_atomic_t;
192
193#  elif defined(_STLP_OS2THREADS)
194
195#    if defined (__GNUC__)
196#      define INCL_DOSSEMAPHORES
197#      include <os2.h>
198#    else
199// This section serves to replace os2.h for VisualAge C++
200  typedef unsigned long ULONG;
201#      if !defined (__HEV__)  /* INCL_SEMAPHORE may also define HEV */
202#        define __HEV__
203  typedef ULONG HEV;
204  typedef HEV*  PHEV;
205#      endif
206  typedef ULONG APIRET;
207  typedef ULONG HMTX;
208  typedef HMTX*  PHMTX;
209  typedef const char*  PCSZ;
210  typedef ULONG BOOL32;
211  APIRET _System DosCreateMutexSem(PCSZ pszName, PHEV phev, ULONG flAttr, BOOL32 fState);
212  APIRET _System DosRequestMutexSem(HMTX hmtx, ULONG ulTimeout);
213  APIRET _System DosReleaseMutexSem(HMTX hmtx);
214  APIRET _System DosCloseMutexSem(HMTX hmtx);
215#      define _STLP_MUTEX_INITIALIZER = { 0 }
216#    endif /* GNUC */
217typedef size_t __stl_atomic_t;
218
219#  else
220
221typedef size_t __stl_atomic_t;
222
223#  endif
224
225#else
226/* no threads */
227#  define _STLP_ATOMIC_INCREMENT(__x) ++(*__x)
228#  define _STLP_ATOMIC_DECREMENT(__x) --(*__x)
229/* We do not grant other atomic operations as they are useless if STLport do not have
230 * to be thread safe
231 */
232typedef size_t __stl_atomic_t;
233#endif
234
235#if !defined (_STLP_MUTEX_INITIALIZER)
236#  if defined(_STLP_ATOMIC_EXCHANGE)
237#    define _STLP_MUTEX_INITIALIZER = { 0 }
238#  elif defined(_STLP_UITHREADS)
239#    define _STLP_MUTEX_INITIALIZER = { DEFAULTMUTEX }
240#  else
241#    define _STLP_MUTEX_INITIALIZER
242#  endif
243#endif
244
245_STLP_BEGIN_NAMESPACE
246
247#if defined (_STLP_THREADS) && !defined (_STLP_USE_PTHREAD_SPINLOCK)
248// Helper struct.  This is a workaround for various compilers that don't
249// handle static variables in inline functions properly.
250template <int __inst>
251struct _STLP_mutex_spin {
252  enum { __low_max = 30, __high_max = 1000 };
253  // Low if we suspect uniprocessor, high for multiprocessor.
254  static unsigned __max;
255  static unsigned __last;
256  static void _STLP_CALL _M_do_lock(volatile __stl_atomic_t* __lock);
257  static void _STLP_CALL _S_nsec_sleep(int __log_nsec, unsigned int& __iteration);
258};
259#endif // !_STLP_USE_PTHREAD_SPINLOCK
260
261// Locking class.  Note that this class *does not have a constructor*.
262// It must be initialized either statically, with _STLP_MUTEX_INITIALIZER,
263// or dynamically, by explicitly calling the _M_initialize member function.
264// (This is similar to the ways that a pthreads mutex can be initialized.)
265// There are explicit member functions for acquiring and releasing the lock.
266
267// There is no constructor because static initialization is essential for
268// some uses, and only a class aggregate (see section 8.5.1 of the C++
269// standard) can be initialized that way.  That means we must have no
270// constructors, no base classes, no virtual functions, and no private or
271// protected members.
272
273// For non-static cases, clients should use  _STLP_mutex.
274
275struct _STLP_CLASS_DECLSPEC _STLP_mutex_base {
276#if defined (_STLP_ATOMIC_EXCHANGE) || defined (_STLP_SGI_THREADS)
277  // It should be relatively easy to get this to work on any modern Unix.
278  volatile __stl_atomic_t _M_lock;
279#endif
280
281#if defined (_STLP_THREADS)
282#  if defined (_STLP_ATOMIC_EXCHANGE)
283  inline void _M_initialize() { _M_lock = 0; }
284  inline void _M_destroy() {}
285
286  void _M_acquire_lock() {
287    _STLP_mutex_spin<0>::_M_do_lock(&_M_lock);
288  }
289
290  inline void _M_release_lock() {
291    volatile __stl_atomic_t* __lock = &_M_lock;
292#    if defined(_STLP_SGI_THREADS) && defined(__GNUC__) && __mips >= 3
293    asm("sync");
294    *__lock = 0;
295#    elif defined(_STLP_SGI_THREADS) && __mips >= 3 && \
296         (defined (_ABIN32) || defined(_ABI64))
297    __lock_release(__lock);
298#    elif defined (_STLP_SPARC_SOLARIS_THREADS)
299#      if defined (__WORD64) || defined (__arch64__) || defined (__sparcv9) || defined (__sparcv8plus)
300    asm("membar #StoreStore ; membar #LoadStore");
301#      else
302    asm(" stbar ");
303#      endif
304    *__lock = 0;
305#    else
306    *__lock = 0;
307    // This is not sufficient on many multiprocessors, since
308    // writes to protected variables and the lock may be reordered.
309#    endif
310  }
311#  elif defined (_STLP_PTHREADS)
312#    if defined (_STLP_USE_PTHREAD_SPINLOCK)
313#      if !defined (__OpenBSD__)
314  pthread_spinlock_t _M_lock;
315  inline void _M_initialize() { pthread_spin_init( &_M_lock, 0 ); }
316  inline void _M_destroy() { pthread_spin_destroy( &_M_lock ); }
317
318  // sorry, but no static initializer for pthread_spinlock_t;
319  // this will not work for compilers that has problems with call
320  // constructor of static object...
321
322  // _STLP_mutex_base()
323  //   { pthread_spin_init( &_M_lock, 0 ); }
324
325  // ~_STLP_mutex_base()
326  //   { pthread_spin_destroy( &_M_lock ); }
327
328  inline void _M_acquire_lock() { pthread_spin_lock( &_M_lock ); }
329  inline void _M_release_lock() { pthread_spin_unlock( &_M_lock ); }
330#      else // __OpenBSD__
331  spinlock_t _M_lock;
332  inline void _M_initialize() { _SPINLOCK_INIT( &_M_lock ); }
333  inline void _M_destroy() { }
334  inline void _M_acquire_lock() { _SPINLOCK( &_M_lock ); }
335  inline void _M_release_lock() { _SPINUNLOCK( &_M_lock ); }
336#      endif // __OpenBSD__
337#    else // !_STLP_USE_PTHREAD_SPINLOCK
338  pthread_mutex_t _M_lock;
339  inline void _M_initialize()
340  { pthread_mutex_init(&_M_lock,_STLP_PTHREAD_ATTR_DEFAULT); }
341  inline void _M_destroy()
342  { pthread_mutex_destroy(&_M_lock); }
343  inline void _M_acquire_lock() {
344#      if defined ( __hpux ) && ! defined (PTHREAD_MUTEX_INITIALIZER)
345    if (!_M_lock.field1)  _M_initialize();
346#      endif
347    pthread_mutex_lock(&_M_lock);
348  }
349  inline void _M_release_lock() { pthread_mutex_unlock(&_M_lock); }
350#    endif // !_STLP_USE_PTHREAD_SPINLOCK
351
352#  elif defined (_STLP_UITHREADS)
353  mutex_t _M_lock;
354  inline void _M_initialize()
355  { mutex_init(&_M_lock, 0, NULL); }
356  inline void _M_destroy()
357  { mutex_destroy(&_M_lock); }
358  inline void _M_acquire_lock() { mutex_lock(&_M_lock); }
359  inline void _M_release_lock() { mutex_unlock(&_M_lock); }
360
361#  elif defined (_STLP_OS2THREADS)
362  HMTX _M_lock;
363  inline void _M_initialize() { DosCreateMutexSem(NULL, &_M_lock, 0, false); }
364  inline void _M_destroy() { DosCloseMutexSem(_M_lock); }
365  inline void _M_acquire_lock() {
366    if (!_M_lock) _M_initialize();
367    DosRequestMutexSem(_M_lock, SEM_INDEFINITE_WAIT);
368  }
369  inline void _M_release_lock() { DosReleaseMutexSem(_M_lock); }
370#  elif defined (_STLP_BETHREADS)
371  sem_id sem;
372  inline void _M_initialize() {
373    sem = create_sem(1, "STLPort");
374    assert(sem > 0);
375  }
376  inline void _M_destroy() {
377    int t = delete_sem(sem);
378    assert(t == B_NO_ERROR);
379  }
380  inline void _M_acquire_lock();
381  inline void _M_release_lock() {
382    status_t t = release_sem(sem);
383    assert(t == B_NO_ERROR);
384  }
385#  elif defined (_STLP_NWTHREADS)
386  LONG _M_lock;
387  inline void _M_initialize()
388  { _M_lock = OpenLocalSemaphore(1); }
389  inline void _M_destroy()
390  { CloseLocalSemaphore(_M_lock); }
391  inline void _M_acquire_lock()
392  { WaitOnLocalSemaphore(_M_lock); }
393  inline void _M_release_lock() { SignalLocalSemaphore(_M_lock); }
394#  else      //*ty 11/24/2001 - added configuration check
395#    error "Unknown thread facility configuration"
396#  endif
397#else /* No threads */
398  inline void _M_initialize() {}
399  inline void _M_destroy() {}
400  inline void _M_acquire_lock() {}
401  inline void _M_release_lock() {}
402#endif // _STLP_PTHREADS
403};
404
405// Locking class.  The constructor initializes the lock, the destructor destroys it.
406// Well - behaving class, does not need static initializer
407
408class _STLP_CLASS_DECLSPEC _STLP_mutex : public _STLP_mutex_base {
409  public:
410    inline _STLP_mutex () { _M_initialize(); }
411    inline ~_STLP_mutex () { _M_destroy(); }
412  private:
413    _STLP_mutex(const _STLP_mutex&);
414    void operator=(const _STLP_mutex&);
415};
416
417// A locking class that uses _STLP_STATIC_MUTEX.  The constructor takes
418// a reference to an _STLP_STATIC_MUTEX, and acquires a lock.  The destructor
419// releases the lock.
420// It's not clear that this is exactly the right functionality.
421// It will probably change in the future.
422
423struct _STLP_CLASS_DECLSPEC _STLP_auto_lock {
424  _STLP_auto_lock(_STLP_STATIC_MUTEX& __lock) : _M_lock(__lock)
425  { _M_lock._M_acquire_lock(); }
426  ~_STLP_auto_lock()
427  { _M_lock._M_release_lock(); }
428
429private:
430  _STLP_STATIC_MUTEX& _M_lock;
431  void operator=(const _STLP_auto_lock&);
432  _STLP_auto_lock(const _STLP_auto_lock&);
433};
434
435/*
436 * Class _Refcount_Base provides a type, __stl_atomic_t, a data member,
437 * _M_ref_count, and member functions _M_incr and _M_decr, which perform
438 * atomic preincrement/predecrement.  The constructor initializes
439 * _M_ref_count.
440 */
441class _STLP_CLASS_DECLSPEC _Refcount_Base {
442  // The data member _M_ref_count
443#if defined (__DMC__)
444public:
445#endif
446  _STLP_VOLATILE __stl_atomic_t _M_ref_count;
447
448#if defined (_STLP_THREADS) && \
449   (!defined (_STLP_ATOMIC_INCREMENT) || !defined (_STLP_ATOMIC_DECREMENT) || \
450    defined (_STLP_WIN95_LIKE))
451#  define _STLP_USE_MUTEX
452  _STLP_mutex _M_mutex;
453#endif
454
455  public:
456  // Constructor
457  _Refcount_Base(__stl_atomic_t __n) : _M_ref_count(__n) {}
458#if defined (__BORLANDC__)
459  ~_Refcount_Base(){};
460#endif
461
462  // _M_incr and _M_decr
463#if defined (_STLP_THREADS)
464#  if !defined (_STLP_USE_MUTEX)
465   __stl_atomic_t _M_incr() { return _STLP_ATOMIC_INCREMENT(&_M_ref_count); }
466   __stl_atomic_t _M_decr() { return _STLP_ATOMIC_DECREMENT(&_M_ref_count); }
467#  else
468#    undef _STLP_USE_MUTEX
469  __stl_atomic_t _M_incr() {
470    _STLP_auto_lock l(_M_mutex);
471    return ++_M_ref_count;
472  }
473  __stl_atomic_t _M_decr() {
474    _STLP_auto_lock l(_M_mutex);
475    return --_M_ref_count;
476  }
477#  endif
478#else  /* No threads */
479  __stl_atomic_t _M_incr() { return ++_M_ref_count; }
480  __stl_atomic_t _M_decr() { return --_M_ref_count; }
481#endif
482};
483
484/* Atomic swap on __stl_atomic_t
485 * This is guaranteed to behave as though it were atomic only if all
486 * possibly concurrent updates use _Atomic_swap.
487 * In some cases the operation is emulated with a lock.
488 * Idem for _Atomic_swap_ptr
489 */
490/* Helper struct to handle following cases:
491 * - on platforms where sizeof(__stl_atomic_t) == sizeof(void*) atomic
492 *   exchange can be done on pointers
493 * - on platform without atomic operation swap is done in a critical section,
494 *   portable but inefficient.
495 */
496template <int __use_ptr_atomic_swap>
497class _Atomic_swap_struct {
498public:
499#if defined (_STLP_THREADS) && \
500    !defined (_STLP_ATOMIC_EXCHANGE) && \
501    (defined (_STLP_PTHREADS) || defined (_STLP_UITHREADS) || defined (_STLP_OS2THREADS) || \
502     defined (_STLP_USE_PTHREAD_SPINLOCK) || defined (_STLP_NWTHREADS))
503#  define _STLP_USE_ATOMIC_SWAP_MUTEX
504  static _STLP_STATIC_MUTEX _S_swap_lock;
505#endif
506
507  static __stl_atomic_t _S_swap(_STLP_VOLATILE __stl_atomic_t* __p, __stl_atomic_t __q) {
508#if defined (_STLP_THREADS)
509#  if defined (_STLP_ATOMIC_EXCHANGE)
510  return _STLP_ATOMIC_EXCHANGE(__p, __q);
511#  elif defined (_STLP_USE_ATOMIC_SWAP_MUTEX)
512  _S_swap_lock._M_acquire_lock();
513  __stl_atomic_t __result = *__p;
514  *__p = __q;
515  _S_swap_lock._M_release_lock();
516  return __result;
517#  else
518#    error Missing atomic swap implementation
519#  endif
520#else
521  /* no threads */
522  __stl_atomic_t __result = *__p;
523  *__p = __q;
524  return __result;
525#endif // _STLP_THREADS
526  }
527
528  static void* _S_swap_ptr(void* _STLP_VOLATILE* __p, void* __q) {
529#if defined (_STLP_THREADS)
530#  if defined (_STLP_ATOMIC_EXCHANGE_PTR)
531  return _STLP_ATOMIC_EXCHANGE_PTR(__p, __q);
532#  elif defined (_STLP_ATOMIC_EXCHANGE)
533  _STLP_STATIC_ASSERT(sizeof(__stl_atomic_t) == sizeof(void*))
534  return __REINTERPRET_CAST(void*, _STLP_ATOMIC_EXCHANGE(__REINTERPRET_CAST(volatile __stl_atomic_t*, __p),
535                                                         __REINTERPRET_CAST(__stl_atomic_t, __q))
536                            );
537#  elif defined (_STLP_USE_ATOMIC_SWAP_MUTEX)
538  _S_swap_lock._M_acquire_lock();
539  void *__result = *__p;
540  *__p = __q;
541  _S_swap_lock._M_release_lock();
542  return __result;
543#  else
544#    error Missing pointer atomic swap implementation
545#  endif
546#else
547  /* no thread */
548  void *__result = *__p;
549  *__p = __q;
550  return __result;
551#endif
552  }
553};
554
555_STLP_TEMPLATE_NULL
556class _Atomic_swap_struct<0> {
557public:
558#if defined (_STLP_THREADS) && \
559    (!defined (_STLP_ATOMIC_EXCHANGE) || !defined (_STLP_ATOMIC_EXCHANGE_PTR)) && \
560    (defined (_STLP_PTHREADS) || defined (_STLP_UITHREADS) || defined (_STLP_OS2THREADS) || \
561     defined (_STLP_USE_PTHREAD_SPINLOCK) || defined (_STLP_NWTHREADS))
562#  define _STLP_USE_ATOMIC_SWAP_MUTEX
563  static _STLP_STATIC_MUTEX _S_swap_lock;
564#endif
565
566  static __stl_atomic_t _S_swap(_STLP_VOLATILE __stl_atomic_t* __p, __stl_atomic_t __q) {
567#if defined (_STLP_THREADS)
568#  if defined (_STLP_ATOMIC_EXCHANGE)
569  return _STLP_ATOMIC_EXCHANGE(__p, __q);
570#  elif defined (_STLP_USE_ATOMIC_SWAP_MUTEX)
571  /* This should be portable, but performance is expected
572   * to be quite awful.  This really needs platform specific
573   * code.
574   */
575  _S_swap_lock._M_acquire_lock();
576  __stl_atomic_t __result = *__p;
577  *__p = __q;
578  _S_swap_lock._M_release_lock();
579  return __result;
580#  else
581#    error Missing atomic swap implementation
582#  endif
583#else
584  /* no threads */
585  __stl_atomic_t __result = *__p;
586  *__p = __q;
587  return __result;
588#endif // _STLP_THREADS
589  }
590
591  static void* _S_swap_ptr(void* _STLP_VOLATILE* __p, void* __q) {
592#if defined (_STLP_THREADS)
593#  if defined (_STLP_ATOMIC_EXCHANGE_PTR)
594  return _STLP_ATOMIC_EXCHANGE_PTR(__p, __q);
595#  elif defined (_STLP_ATOMIC_EXCHANGE)
596  _STLP_STATIC_ASSERT(sizeof(__stl_atomic_t) == sizeof(void*))
597  return __REINTERPRET_CAST(void*, _STLP_ATOMIC_EXCHANGE(__REINTERPRET_CAST(volatile __stl_atomic_t*, __p),
598                                                         __REINTERPRET_CAST(__stl_atomic_t, __q))
599                            );
600#  elif defined (_STLP_USE_ATOMIC_SWAP_MUTEX)
601  _S_swap_lock._M_acquire_lock();
602  void *__result = *__p;
603  *__p = __q;
604  _S_swap_lock._M_release_lock();
605  return __result;
606#  else
607#    error Missing pointer atomic swap implementation
608#  endif
609#else
610  /* no thread */
611  void *__result = *__p;
612  *__p = __q;
613  return __result;
614#endif
615  }
616};
617
618#if defined (_STLP_MSVC) && (_STLP_MSVC == 1300)
619#  pragma warning (push)
620#  pragma warning (disable : 4189) //__use_ptr_atomic_swap initialized but not used
621#endif
622
623inline __stl_atomic_t _STLP_CALL _Atomic_swap(_STLP_VOLATILE __stl_atomic_t * __p, __stl_atomic_t __q) {
624  const int __use_ptr_atomic_swap = sizeof(__stl_atomic_t) == sizeof(void*);
625  return _Atomic_swap_struct<__use_ptr_atomic_swap>::_S_swap(__p, __q);
626}
627
628inline void* _STLP_CALL _Atomic_swap_ptr(void* _STLP_VOLATILE* __p, void* __q) {
629  const int __use_ptr_atomic_swap = sizeof(__stl_atomic_t) == sizeof(void*);
630  return _Atomic_swap_struct<__use_ptr_atomic_swap>::_S_swap_ptr(__p, __q);
631}
632
633#if defined (_STLP_MSVC) && (_STLP_MSVC == 1300)
634#  pragma warning (pop)
635#endif
636
637#if defined (_STLP_BETHREADS)
638template <int __inst>
639struct _STLP_beos_static_lock_data {
640  static bool is_init;
641  struct mutex_t : public _STLP_mutex {
642    mutex_t()
643    { _STLP_beos_static_lock_data<0>::is_init = true; }
644    ~mutex_t()
645    { _STLP_beos_static_lock_data<0>::is_init = false; }
646  };
647  static mutex_t mut;
648};
649
650template <int __inst>
651bool _STLP_beos_static_lock_data<__inst>::is_init = false;
652template <int __inst>
653typename _STLP_beos_static_lock_data<__inst>::mutex_t _STLP_beos_static_lock_data<__inst>::mut;
654
655inline void _STLP_mutex_base::_M_acquire_lock() {
656  if (sem == 0) {
657    // we need to initialise on demand here
658    // to prevent race conditions use our global
659    // mutex if it's available:
660    if (_STLP_beos_static_lock_data<0>::is_init) {
661      _STLP_auto_lock al(_STLP_beos_static_lock_data<0>::mut);
662      if (sem == 0) _M_initialize();
663    }
664    else {
665      // no lock available, we must still be
666      // in startup code, THERE MUST BE ONE THREAD
667      // ONLY active at this point.
668      _M_initialize();
669    }
670  }
671  status_t t;
672  t = acquire_sem(sem);
673  assert(t == B_NO_ERROR);
674}
675#endif
676
677_STLP_END_NAMESPACE
678
679#if !defined (_STLP_LINK_TIME_INSTANTIATION)
680#  include <stl/_threads.c>
681#endif
682
683#endif /* _STLP_INTERNAL_THREADS_H */
684
685// Local Variables:
686// mode:C++
687// End:
688