dolphin/Externals/wxWidgets3/include/wx/msw/tls.h

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///////////////////////////////////////////////////////////////////////////////
// Name: wx/msw/tls.h
// Purpose: Win32 implementation of wxTlsValue<>
// Author: Vadim Zeitlin
// Created: 2008-08-08
// Copyright: (c) 2008 Vadim Zeitlin <vadim@wxwidgets.org>
// Licence: wxWindows licence
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_MSW_TLS_H_
#define _WX_MSW_TLS_H_
#include "wx/msw/wrapwin.h"
#include "wx/thread.h"
#include "wx/vector.h"
// ----------------------------------------------------------------------------
// wxTlsKey is a helper class encapsulating a TLS slot
// ----------------------------------------------------------------------------
class wxTlsKey
{
public:
// ctor allocates a new key
wxTlsKey(wxTlsDestructorFunction destructor)
{
m_destructor = destructor;
m_slot = ::TlsAlloc();
}
// return true if the key was successfully allocated
bool IsOk() const { return m_slot != TLS_OUT_OF_INDEXES; }
// get the key value, there is no error return
void *Get() const
{
// Exceptionally, TlsGetValue() calls SetLastError() even on success
// which means it overwrites the previous value. This is undesirable
// here, so explicitly preserve the last error here.
const DWORD dwLastError = ::GetLastError();
void* const value = ::TlsGetValue(m_slot);
if ( dwLastError )
::SetLastError(dwLastError);
return value;
}
// change the key value, return true if ok
bool Set(void *value)
{
void *old = Get();
if ( ::TlsSetValue(m_slot, value) == 0 )
return false;
if ( old )
m_destructor(old);
// update m_allValues list of all values - remove old, add new
wxCriticalSectionLocker lock(m_csAllValues);
if ( old )
{
for ( wxVector<void*>::iterator i = m_allValues.begin();
i != m_allValues.end();
++i )
{
if ( *i == old )
{
if ( value )
*i = value;
else
m_allValues.erase(i);
return true;
}
}
wxFAIL_MSG( "previous wxTlsKey value not recorded in m_allValues" );
}
if ( value )
m_allValues.push_back(value);
return true;
}
// free the key
~wxTlsKey()
{
if ( !IsOk() )
return;
// Win32 API doesn't have the equivalent of pthread's destructor, so we
// have to keep track of all allocated values and destroy them manually;
// ideally we'd do that at thread exit time, but since we could only
// do that with wxThread and not otherwise created threads, we do it
// here.
//
// TODO: We should still call destructors for wxTlsKey used in the
// thread from wxThread's thread shutdown code, *in addition*
// to doing it in ~wxTlsKey.
//
// NB: No need to lock m_csAllValues, by the time this code is called,
// no other thread can be using this key.
for ( wxVector<void*>::iterator i = m_allValues.begin();
i != m_allValues.end();
++i )
{
m_destructor(*i);
}
::TlsFree(m_slot);
}
private:
wxTlsDestructorFunction m_destructor;
DWORD m_slot;
wxVector<void*> m_allValues;
wxCriticalSection m_csAllValues;
wxDECLARE_NO_COPY_CLASS(wxTlsKey);
};
#endif // _WX_MSW_TLS_H_