include/wx/os2/tls.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/os2/tls.h
   3 // Purpose:     OS/2 implementation of wxTlsValue<>
   4 // Author:      Stefan Neis
   5 // Created:     2008-08-30
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2008 Stefan Neis
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_OS2_TLS_H_
  12 #define _WX_OS2_TLS_H_
  13
  14 #include "wx/os2/private.h"
  15 #include "wx/thread.h"
  16 #include "wx/vector.h"
  17
  18 // ----------------------------------------------------------------------------
  19 // wxTlsKey is a helper class encapsulating a TLS slot
  20 // ----------------------------------------------------------------------------
  21
  22 class wxTlsKey
  23 {
  24 public:
  25     // ctor allocates a new key
  26     wxTlsKey(wxTlsDestructorFunction destructor)
  27     {
  28         m_destructor = destructor;
  29         APIRET rc = ::DosAllocThreadLocalMemory(1, &m_slot);
  30         if (rc != NO_ERROR)
  31             m_slot = NULL;
  32     }
  33
  34     // return true if the key was successfully allocated
  35     bool IsOk() const { return m_slot != NULL; }
  36
  37     // get the key value, there is no error return
  38     void *Get() const
  39     {
  40         return (void *)m_slot;
  41     }
  42
  43     // change the key value, return true if ok
  44     bool Set(void *value)
  45     {
  46         void *old = Get();
  47
  48         m_slot = (ULONG*)value;
  49
  50         if ( old )
  51             m_destructor(old);
  52
  53         // update m_allValues list of all values - remove old, add new
  54         wxCriticalSectionLocker lock(m_csAllValues);
  55         if ( old )
  56         {
  57             for ( wxVector<void*>::iterator i = m_allValues.begin();
  58                   i != m_allValues.end();
  59                   ++i )
  60             {
  61                 if ( *i == old )
  62                 {
  63                     if ( value )
  64                         *i = value;
  65                     else
  66                         m_allValues.erase(i);
  67                     return true;
  68                 }
  69             }
  70             wxFAIL_MSG( "previous wxTlsKey value not recorded in m_allValues" );
  71         }
  72
  73         if ( value )
  74             m_allValues.push_back(value);
  75
  76         return true;
  77     }
  78
  79     // free the key
  80     ~wxTlsKey()
  81     {
  82         if ( !IsOk() )
  83             return;
  84
  85         // Win32 and OS/2 API doesn't have the equivalent of pthread's
  86         // destructor, so we have to keep track of all allocated values and
  87         // destroy them manually; ideally we'd do that at thread exit time, but
  88         // since we could only do that with wxThread and not otherwise created
  89         // threads, we do it here.
  90         //
  91         // TODO: We should still call destructors for wxTlsKey used in the
  92         //       thread from wxThread's thread shutdown code, *in addition*
  93         //       to doing it in ~wxTlsKey.
  94         //
  95         // NB: No need to lock m_csAllValues, by the time this code is called,
  96         //     no other thread can be using this key.
  97         for ( wxVector<void*>::iterator i = m_allValues.begin();
  98               i != m_allValues.end();
  99               ++i )
 100         {
 101             m_destructor(*i);
 102         }
 103
 104         ::DosFreeThreadLocalMemory(m_slot);
 105     }
 106
 107 private:
 108     wxTlsDestructorFunction m_destructor;
 109     ULONG* m_slot;
 110
 111     wxVector<void*> m_allValues;
 112     wxCriticalSection m_csAllValues;
 113
 114     wxDECLARE_NO_COPY_CLASS(wxTlsKey);
 115 };
 116
 117 #endif // _WX_OS2_TLS_H_
 118