sal/inc/internal/once.h

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  30
  31 #ifndef INCLUDED_SAL_INTERNAL_ONCE_H
  32 #define INCLUDED_SAL_INTERNAL_ONCE_H
  33
  34 /** sal_once_type
  35  *  (platform dependent)
  36  */
  37
  38 #if defined(SAL_UNX) || defined(SAL_OS2)
  39
  40 #include <pthread.h>
  41
  42 typedef pthread_once_t sal_once_type;
  43
  44 #define SAL_ONCE_INIT PTHREAD_ONCE_INIT
  45 #define SAL_ONCE(once, init) pthread_once((once), (init))
  46
  47 #elif defined(SAL_W32)
  48
  49 #define WIN32_LEAN_AND_MEAN
  50 #pragma warning(push,1) /* disable warnings within system headers */
  51 #include <windows.h>
  52 #pragma warning(pop)
  53
  54 typedef struct sal_once_st sal_once_type;
  55 struct sal_once_st
  56 {
  57     LONG volatile m_done;
  58     LONG volatile m_lock;
  59 };
  60
  61 #define SAL_ONCE_INIT { 0, 0 }
  62 #define SAL_ONCE(once, init) \
  63 { \
  64     sal_once_type * control = (once); \
  65     if (!(control->m_done)) \
  66     { \
  67         while (InterlockedExchange(&(control->m_lock), 1) == 1) Sleep(0); \
  68         if (!(control->m_done)) \
  69         { \
  70             void (*init_routine)(void) = (init); \
  71             (*init_routine)(); \
  72             control->m_done = 1; \
  73         } \
  74         InterlockedExchange(&(control->m_lock), 0); \
  75     } \
  76 }
  77
  78 #else
  79 #error Unknown platform
  80 #endif /* SAL_UNX | SAL_W32 */
  81
  82 #endif /* INCLUDED_SAL_INTERNAL_ONCE_H */