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2008-01-12 13:19 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)

Browse Source 
* harbour/ChangeLog
  * harbour/include/hbapiitm.h
  * harbour/source/vm/itemapi.c
    - removed hb_itemLockReadCPtr()/hb_itemLockWriteCPtr()/hb_itemUnLockCPtr()
      Whole modification which will address all different aspects it to
      complex to introduce it now. I'll return to this problem after
      1.0 release
This commit is contained in:
Przemyslaw Czerpak
2008-01-12 12:20:12 +00:00
parent 046ef2656f
commit 74e6b4f63f
3 changed files with 7 additions and 126 deletions
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85
harbour/ChangeLog
View File

@@ -8,14 +8,14 @@
2002-12-01 13:30 UTC+0100 Foo Bar <foo.bar@foobar.org>
*/
2008-01-12 13:12 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
2008-01-12 13:19 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
* harbour/ChangeLog
* harbour/include/hbapiitm.h
* harbour/source/vm/itemapi.c
! fixed hb_itemLockReadCPtr() used for static strings
2008-01-11 22:35 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
* harbour/source/vm/itemapi.c
! use hb_xRefFree() instead of hb_xRefDec() in hb_itemUnLockCPtr()
It's necessary when source item is cleared before.
- removed hb_itemLockReadCPtr()/hb_itemLockWriteCPtr()/hb_itemUnLockCPtr()
Whole modification which will address all different aspects it to
complex to introduce it now. I'll return to this problem after
1.0 release
2008-01-11 18:13 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
* harbour/include/hbexprb.c
@@ -30,77 +30,6 @@
They copy/move pItem body to parameter passed by reference and
return TRUE when operation was done successfully (uiParam was passed
by reference)
+ added new functions for string manipulation:
char * hb_itemLockReadCPtr( PHB_ITEM pItem, ULONG * pulLen );
char * hb_itemLockWriteCPtr( PHB_ITEM pItem, ULONG * pulLen );
void hb_itemUnLockCPtr( char * pszString );
It's recommended to use them instead of hb_itemGetCPtr().
Pointer to string buffer returned by hb_itemLockReadCPtr() will
be always valid even if source item will be cleared, destroyed or
overwritten until hb_itemUnLockCPtr() is called. Each locked string
has to be unlocked to avoid memory leaks. After unlocking the string
pointer cannot be longer used.
hb_itemLockWriteCPtr() works like hb_itemLockReadCPtr() but string
pointer returned by this function is writable so user can change
the body of string item. It's the _ONLY_ one way when it's possible.
Modifying string items using pointers returned by hb_parc() or
hb_itemGetCPtr() or extracted directly from HB_ITEM body is _FORBIDDEN_
and can cause unpredictable results (GPF when constant/readonly memory
pages are changed, changing many different items which share the same
memory buffer, etc.).
This is code illustrates how to use hb_itemLockReadCPtr()/
hb_itemUnLockCPtr() and it's also good example why hb_itemGetCPtr()
is very danger function and cannot be used in such case - if you
replace hb_itemLockReadCPtr() with hb_itemGetCPtr() and remove
hb_itemUnLockCPtr() then you will have buggy code.
HB_FUNC( MYFUNC )
{
PHB_ITEM pObject = hb_param( 1, HB_IT_OBJECT )
if( pObject )
{
char * pszName1, * pszName2;
PHB_ITEM pResult;
pResult = hb_objSendMsg( pObject, "POP", 0 );
pszName1 = hb_itemLockReadCPtr( pResult, NULL );
pResult = hb_objSendMsg( pObject, "POP", 0 );
pszName2 = hb_itemLockReadCPtr( pResult, NULL );
if( pszName1 && pszName2 )
hb_retc_buffer( hb_xstrcpy( NULL,
"[", pszName1, "]-[", pszName2, "]", NULL ) );
hb_itemUnLockCPtr( pszName1 );
hb_itemUnLockCPtr( pszName2 );
}
}
This code shows how to use hb_itemLockWriteCPtr():
proc main()
local cVal, cVal2
cVal := cVal2 := "ABC"
STRPUT( @cVal2, 2, 42 )
? cVal, cVal2
return
#pragma begindump
#include "hbapiitm.h"
HB_FUNC( STRPUT )
{
PHB_ITEM pString = hb_param( 1, HB_IT_STRING );
ULONG ulAt = hb_parnl( 2 );
if( pString && ulAt && ISNUM( 3 ) )
{
ULONG ulLen;
char * pszValue;
pszValue = hb_itemLockWriteCPtr( pString, &ulLen );
if( pszValue )
{
if( ulAt <= ulLen )
pszValue[ ulAt - 1 ] = ( char ) hb_parni( 3 );
hb_itemUnLockCPtr( pszValue );
}
}
}
#pragma enddump
* harbour/include/hbcompdf.h
* harbour/include/hbexprop.h

3
harbour/include/hbapiitm.h
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@@ -84,9 +84,6 @@ extern HB_EXPORT PHB_ITEM hb_itemArrayNew ( ULONG ulLen );
extern HB_EXPORT PHB_ITEM hb_itemArrayPut ( PHB_ITEM pArray, ULONG ulIndex, PHB_ITEM pItem );
extern HB_EXPORT ULONG hb_itemCopyC ( PHB_ITEM pItem, char * szBuffer, ULONG ulLen );
extern HB_EXPORT BOOL hb_itemFreeC ( char * szText );
extern HB_EXPORT char * hb_itemLockReadCPtr( PHB_ITEM pItem, ULONG * pulLen );
extern HB_EXPORT char * hb_itemLockWriteCPtr( PHB_ITEM pItem, ULONG * pulLen );
extern HB_EXPORT void hb_itemUnLockCPtr( char * pszString );
extern HB_EXPORT char * hb_itemGetC ( PHB_ITEM pItem );
extern HB_EXPORT char * hb_itemGetCPtr ( PHB_ITEM pItem );
extern HB_EXPORT ULONG hb_itemGetCLen ( PHB_ITEM pItem );

45
harbour/source/vm/itemapi.c
View File

@@ -439,51 +439,6 @@ HB_EXPORT ULONG hb_itemGetCLen( PHB_ITEM pItem )
return 0;
}
HB_EXPORT char * hb_itemLockReadCPtr( PHB_ITEM pItem, ULONG * pulLen )
{
HB_TRACE(HB_TR_DEBUG, ("hb_itemLockReadCPtr(%p,%p)", pItem, pulLen));
if( pItem && HB_IS_STRING( pItem ) )
{
if( pItem->item.asString.allocated == 0 )
hb_itemUnShareString( pItem );
if( pulLen )
*pulLen = pItem->item.asString.length;
hb_xRefInc( pItem->item.asString.value );
return pItem->item.asString.value;
}
else if( pulLen )
*pulLen = 0;
return NULL;
}
HB_EXPORT char * hb_itemLockWriteCPtr( PHB_ITEM pItem, ULONG * pulLen )
{
HB_TRACE(HB_TR_DEBUG, ("hb_itemLockWriteCPtr(%p,%p)", pItem, pulLen));
if( pItem && HB_IS_STRING( pItem ) )
{
hb_itemUnShareString( pItem );
if( pulLen )
*pulLen = pItem->item.asString.length;
hb_xRefInc( pItem->item.asString.value );
return pItem->item.asString.value;
}
else if( pulLen )
*pulLen = 0;
return NULL;
}
HB_EXPORT void hb_itemUnLockCPtr( char * pszString )
{
HB_TRACE(HB_TR_DEBUG, ("hb_itemUnLockCPtr(%p,%p)", pszString));
if( pszString )
hb_xRefFree( pszString );
}
HB_EXPORT ULONG hb_itemCopyC( PHB_ITEM pItem, char * szBuffer, ULONG ulLen )
{
HB_TRACE(HB_TR_DEBUG, ("hb_itemCopyC(%p, %s, %lu)", pItem, szBuffer, ulLen));