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