Sweden-Number/dlls/rsaenh/handle.c

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/*
* dlls/rsaenh/handle.c
* Support code to manage HANDLE tables.
*
* Copyright 1998 Alexandre Julliard
* Copyright 2002-2004 Mike McCormack for CodeWeavers
* Copyright 2004 Michael Jung
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <string.h>
#include <stdarg.h>
#include "windef.h"
#include "winbase.h"
#include "handle.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(handle);
#define HANDLE2INDEX(h) ((h)-1)
#define INDEX2HANDLE(i) ((i)+1)
/******************************************************************************
* init_handle_table
*
* Initializes the HANDLETABLE structure pointed to by lpTable
*
* PARAMS
* lpTable [I] Pointer to the HANDLETABLE structure, which is to be initalized.
*
* NOTES
* Note that alloc_handle_table calls init_handle_table on it's own, which
* means that you only have to call init_handle_table, if you use a global
* variable of type HANDLETABLE for your handle table. However, in this
* case you have to call destroy_handle_table when you don't need the table
* any more.
*/
void init_handle_table(HANDLETABLE *lpTable)
{
TRACE("(lpTable=%p)\n", lpTable);
lpTable->paEntries = NULL;
lpTable->iEntries = 0;
lpTable->iFirstFree = 0;
InitializeCriticalSection(&lpTable->mutex);
}
/******************************************************************************
* destroy_handle_table
*
* Destroys the handle table.
*
* PARAMS
* lpTable [I] Pointer to the handle table, which is to be destroyed.
*
* NOTES
* Note that release_handle_table takes care of this.
*/
void destroy_handle_table(HANDLETABLE *lpTable)
{
TRACE("(lpTable=%p)\n", lpTable);
HeapFree(GetProcessHeap(), 0, lpTable->paEntries);
DeleteCriticalSection(&lpTable->mutex);
}
/******************************************************************************
* is_valid_handle
*
* Tests if handle is valid given the specified handle table
*
* PARAMS
* lpTable [I] Pointer to the handle table, with respect to which the handle's
* validness is tested.
* handle [I] The handle tested for validness.
* dwType [I] A magic value that identifies the referenced object's type.
*
* RETURNS
* non zero, if handle is valid.
* zero, if handle is not valid.
*/
int is_valid_handle(HANDLETABLE *lpTable, unsigned int handle, DWORD dwType)
{
unsigned int index = HANDLE2INDEX(handle);
int ret = 0;
TRACE("(lpTable=%p, handle=%d)\n", lpTable, handle);
EnterCriticalSection(&lpTable->mutex);
/* We don't use zero handle values */
if (!handle) goto exit;
/* Check for index out of table bounds */
if (index >= lpTable->iEntries) goto exit;
/* Check if this handle is currently allocated */
if (!lpTable->paEntries[index].pObject) goto exit;
/* Check if this handle references an object of the correct type. */
if (lpTable->paEntries[index].pObject->dwType != dwType) goto exit;
ret = 1;
exit:
LeaveCriticalSection(&lpTable->mutex);
return ret;
}
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/******************************************************************************
* release_all_handles
*
* Releases all valid handles in the given handle table and shrinks the table
* to zero size.
*
* PARAMS
* lpTable [I] The table of which all valid handles shall be released.
*/
static void release_all_handles(HANDLETABLE *lpTable)
{
unsigned int i;
TRACE("(lpTable=%p)\n", lpTable);
EnterCriticalSection(&lpTable->mutex);
for (i=0; i<lpTable->iEntries; i++)
if (lpTable->paEntries[i].pObject)
release_handle(lpTable, lpTable->paEntries[i].pObject->dwType, INDEX2HANDLE(i));
LeaveCriticalSection(&lpTable->mutex);
}
/******************************************************************************
* alloc_handle_table
*
* Allocates a new handle table
*
* PARAMS
* lplpTable [O] Pointer to the variable, to which the pointer to the newly
* allocated handle table is written.
* RETURNS
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* non zero, if successful
* zero, if not successful (out of process heap memory)
*
* NOTES
* If all you need is a single handle table, you may as well declare a global
* variable of type HANDLETABLE and call init_handle_table on your own.
*/
int alloc_handle_table(HANDLETABLE **lplpTable)
{
TRACE("(lplpTable=%p)\n", lplpTable);
*lplpTable = HeapAlloc(GetProcessHeap(), 0, sizeof(HANDLETABLE));
if (*lplpTable)
{
init_handle_table(*lplpTable);
return 1;
}
else
return 0;
}
/******************************************************************************
* release_handle_table
*
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* Releases a handle table and frees the resources it used.
*
* PARAMS
* lpTable [I] Pointer to the handle table, which is to be released.
*
* RETURNS
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* non zero, if successful
* zero, if not successful
*
* NOTES
* All valid handles still in the table are released also.
*/
int release_handle_table(HANDLETABLE *lpTable)
{
TRACE("(lpTable=%p)\n", lpTable);
release_all_handles(lpTable);
destroy_handle_table(lpTable);
return (int)HeapFree(GetProcessHeap(), 0, lpTable);
}
/******************************************************************************
* grow_handle_table [Internal]
*
* Grows the number of entries in the given table by TABLE_SIZE_INCREMENT
*
* PARAMS
* lpTable [I] Pointer to the table, which is to be grown
*
* RETURNS
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* non zero, if successful
* zero, if not successful (out of memory on process heap)
*
* NOTES
* This is a support function for alloc_handle. Do not call!
*/
static int grow_handle_table(HANDLETABLE *lpTable)
{
HANDLETABLEENTRY *newEntries;
unsigned int i, newIEntries;
newIEntries = lpTable->iEntries + TABLE_SIZE_INCREMENT;
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newEntries = HeapAlloc(GetProcessHeap(), 0, sizeof(HANDLETABLEENTRY)*newIEntries);
if (!newEntries)
return 0;
if (lpTable->paEntries)
{
memcpy(newEntries, lpTable->paEntries, sizeof(HANDLETABLEENTRY)*lpTable->iEntries);
HeapFree(GetProcessHeap(), 0, lpTable->paEntries);
}
for (i=lpTable->iEntries; i<newIEntries; i++)
{
newEntries[i].pObject = NULL;
newEntries[i].iNextFree = i+1;
}
lpTable->paEntries = newEntries;
lpTable->iEntries = newIEntries;
return 1;
}
/******************************************************************************
* alloc_handle
*
* Allocates a new handle to the specified object in a given handle table.
*
* PARAMS
* lpTable [I] Pointer to the handle table, from which the new handle is
* allocated.
* lpObject [I] Pointer to the object, for which a handle shall be allocated.
* lpHandle [O] Pointer to a handle variable, into which the handle value will
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* be stored. If not successful, this will be
* INVALID_HANDLE_VALUE
* RETURNS
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* non zero, if successful
* zero, if not successful (no free handle)
*/
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static int alloc_handle(HANDLETABLE *lpTable, OBJECTHDR *lpObject, unsigned int *lpHandle)
{
int ret = 0;
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TRACE("(lpTable=%p, lpObject=%p, lpHandle=%p)\n", lpTable, lpObject, lpHandle);
EnterCriticalSection(&lpTable->mutex);
if (lpTable->iFirstFree >= lpTable->iEntries)
if (!grow_handle_table(lpTable))
{
*lpHandle = (unsigned int)INVALID_HANDLE_VALUE;
goto exit;
}
*lpHandle = INDEX2HANDLE(lpTable->iFirstFree);
lpTable->paEntries[lpTable->iFirstFree].pObject = lpObject;
lpTable->iFirstFree = lpTable->paEntries[lpTable->iFirstFree].iNextFree;
InterlockedIncrement(&lpObject->refcount);
ret = 1;
exit:
LeaveCriticalSection(&lpTable->mutex);
return ret;
}
/******************************************************************************
* release_handle
*
* Releases resources occupied by the specified handle in the given table.
* The reference count of the handled object is decremented. If it becomes
* zero and if the 'destructor' function pointer member is non NULL, the
* destructor function will be called. Note that release_handle does not
* release resources other than the handle itself. If this is wanted, do it
* in the destructor function.
*
* PARAMS
* lpTable [I] Pointer to the handle table, from which a handle is to be
* released.
* handle [I] The handle, which is to be released
* dwType [I] Identifier for the type of the object, for which a handle is
* to be released.
*
* RETURNS
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* non zero, if successful
* zero, if not successful (invalid handle)
*/
int release_handle(HANDLETABLE *lpTable, unsigned int handle, DWORD dwType)
{
unsigned int index = HANDLE2INDEX(handle);
OBJECTHDR *pObject;
int ret = 0;
TRACE("(lpTable=%p, hande=%d)\n", lpTable, handle);
EnterCriticalSection(&lpTable->mutex);
if (!is_valid_handle(lpTable, handle, dwType))
goto exit;
pObject = lpTable->paEntries[index].pObject;
if (InterlockedDecrement(&pObject->refcount) == 0)
{
TRACE("destroying handle %d\n", handle);
if (pObject->destructor)
pObject->destructor(pObject);
}
lpTable->paEntries[index].pObject = NULL;
lpTable->paEntries[index].iNextFree = lpTable->iFirstFree;
lpTable->iFirstFree = index;
ret = 1;
exit:
LeaveCriticalSection(&lpTable->mutex);
return ret;
}
/******************************************************************************
* lookup_handle
*
* Returns the object identified by the handle in the given handle table
*
* PARAMS
* lpTable [I] Pointer to the handle table, in which the handle is looked up.
* handle [I] The handle, which is to be looked up
* lplpObject [O] Pointer to the variable, into which the pointer to the
* object looked up is copied.
* RETURNS
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* non zero, if successful
* zero, if not successful (invalid handle)
*/
int lookup_handle(HANDLETABLE *lpTable, unsigned int handle, DWORD dwType, OBJECTHDR **lplpObject)
{
int ret = 0;
TRACE("(lpTable=%p, handle=%d, lplpObject=%p)\n", lpTable, handle, lplpObject);
EnterCriticalSection(&lpTable->mutex);
if (!is_valid_handle(lpTable, handle, dwType))
{
*lplpObject = NULL;
goto exit;
}
*lplpObject = lpTable->paEntries[HANDLE2INDEX(handle)].pObject;
ret = 1;
exit:
LeaveCriticalSection(&lpTable->mutex);
return ret;
}
/******************************************************************************
* copy_handle
*
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* Copies a handle. Increments the reference count of the object referenced
* by the handle.
*
* PARAMS
* lpTable [I] Pointer to the handle table, which holds the handle to be copied.
* handle [I] The handle to be copied.
* copy [O] Pointer to a handle variable, where the copied handle is put.
*
* RETURNS
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* non zero, if successful
* zero, if not successful (invalid handle or out of memory)
*/
int copy_handle(HANDLETABLE *lpTable, unsigned int handle, DWORD dwType, unsigned int *copy)
{
OBJECTHDR *pObject;
int ret;
TRACE("(lpTable=%p, handle=%d, copy=%p)\n", lpTable, handle, copy);
EnterCriticalSection(&lpTable->mutex);
if (!lookup_handle(lpTable, handle, dwType, &pObject))
{
*copy = (unsigned int)INVALID_HANDLE_VALUE;
LeaveCriticalSection(&lpTable->mutex);
return 0;
}
ret = alloc_handle(lpTable, pObject, copy);
LeaveCriticalSection(&lpTable->mutex);
return ret;
}
/******************************************************************************
* new_object
*
* Allocates a new object of size cbSize on the current process's heap.
* Initializes the object header using the destructor and dwType params.
* Allocates a handle to the object in the handle table pointed to by lpTable.
* Returns a pointer to the created object in ppObject.
* Returns a handle to the created object.
*
* PARAMS
* lpTable [I] Pointer to the handle table, from which a handle is to be
* allocated.
* cbSize [I] Size of the object to be allocated in bytes.
* dwType [I] Object type; will be copied to the object header.
* destructor [I] Function pointer to a destructor function. Will be called
* once the object's reference count gets zero.
* ppObject [O] Pointer to a pointer variable, where a pointer to the newly
* created object will be stored. You may set this to NULL.
*
* RETURNS
* INVALID_HANDLE_VALUE, if something went wrong.
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* a handle to the new object, if successful.
*/
unsigned int new_object(HANDLETABLE *lpTable, size_t cbSize, DWORD dwType, DESTRUCTOR destructor,
OBJECTHDR **ppObject)
{
OBJECTHDR *pObject;
unsigned int hObject;
if (ppObject)
*ppObject = NULL;
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pObject = HeapAlloc(GetProcessHeap(), 0, cbSize);
if (!pObject)
return (unsigned int)INVALID_HANDLE_VALUE;
pObject->dwType = dwType;
pObject->refcount = 0;
pObject->destructor = destructor;
if (!alloc_handle(lpTable, pObject, &hObject))
HeapFree(GetProcessHeap(), 0, pObject);
else
if (ppObject)
*ppObject = pObject;
return hObject;
}