You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
470 lines
12 KiB
470 lines
12 KiB
/*++ BUILD Version: 0000 // Increment this if a change has global effects
|
|
|
|
Copyright (c) 1998 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
handle.c
|
|
|
|
Abstract:
|
|
|
|
Handle table library. Handles are generated as follows :
|
|
|
|
handle =
|
|
Base value +
|
|
(Table entry index << 4) +
|
|
(Handle usage instance & 0xf)
|
|
|
|
A free list is kept in the handle table header, with the oldest free
|
|
entry being at the head of the list & the youngest at the tail.
|
|
The low four bits of the handle values are used for a usage instance
|
|
count, which gets incremented every time a handle is freed (to
|
|
prevent immediate re-use of the same handle value).
|
|
|
|
Author:
|
|
|
|
Dan Knudson (DanKn) 15-Sep-1998
|
|
|
|
Revision History:
|
|
|
|
--*/
|
|
|
|
|
|
#include "windows.h"
|
|
#include "assert.h"
|
|
#include "tlnklist.h"
|
|
#include "tapihndl.h"
|
|
|
|
|
|
#define TABLE_DELTA 64
|
|
|
|
|
|
BOOL
|
|
GrowTable(
|
|
PHANDLETABLEHEADER Header
|
|
)
|
|
/*++
|
|
|
|
Returns: Index of next free table entry if success, -1 if error
|
|
|
|
--*/
|
|
{
|
|
DWORD numEntries = Header->NumEntries, i, numAdditionalEntries;
|
|
PHANDLETABLEENTRY newTable;
|
|
|
|
// First, we need to compute how many entries we can still alloc.
|
|
// To do this, we need to now how many entries can the table accommodate,
|
|
// so that the largest handle value will not exceed MAXDWORD. We get
|
|
// this by reversing the algorithm used to compute handle values based
|
|
// on the table entry's index.
|
|
|
|
numAdditionalEntries = (MAXDWORD - Header->HandleBase) >> 4; // This is the maximum number of entries in the table,
|
|
// so that handle values do not overflow DWORDs.
|
|
numAdditionalEntries -= numEntries; // This is how many entries we can still alloc;
|
|
if (0 == numAdditionalEntries)
|
|
{
|
|
// The table is already as big as it can be...
|
|
return FALSE;
|
|
}
|
|
if (numAdditionalEntries > TABLE_DELTA)
|
|
{
|
|
numAdditionalEntries = TABLE_DELTA; // We only grow the handle table in TABLE_DELTA or
|
|
} // or smaller increments.
|
|
|
|
if (!(newTable = HeapAlloc(
|
|
Header->Heap,
|
|
0,
|
|
(numEntries + numAdditionalEntries) * sizeof (*newTable)
|
|
)))
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
CopyMemory(
|
|
newTable,
|
|
Header->Table,
|
|
numEntries * sizeof(*newTable)
|
|
);
|
|
|
|
for (i = numEntries; i < numEntries + TABLE_DELTA; i++)
|
|
{
|
|
//
|
|
// Init this entry. Note that we set "Instance = i" to stagger
|
|
// the handle values, because we know tapisrv queues events &
|
|
// completion msgs to a specific SPEVentHandlerThread based on
|
|
// handle values.
|
|
//
|
|
|
|
PHANDLETABLEENTRY entry = newTable + i;
|
|
|
|
|
|
InsertHeadList (&Header->FreeList, &entry->ListEntry);
|
|
entry->Handle = 0;
|
|
entry->Instance = i;
|
|
}
|
|
|
|
if (Header->Table)
|
|
{
|
|
HeapFree (Header->Heap, 0, Header->Table);
|
|
}
|
|
|
|
Header->Table = newTable;
|
|
Header->NumEntries += TABLE_DELTA;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
|
|
HANDLE
|
|
CreateHandleTable(
|
|
HANDLE Heap,
|
|
FREECONTEXTCALLBACK FreeContextCallback,
|
|
DWORD MinHandleValue,
|
|
DWORD MaxHandleValue
|
|
/* Right now, MaxHandleValue is not used. If we find that we
|
|
need to use it however, store it in the table header and
|
|
replace MAXDWORD with it in the code at the beginning of
|
|
GrowTable */
|
|
)
|
|
/*++
|
|
|
|
--*/
|
|
{
|
|
PHANDLETABLEHEADER header;
|
|
|
|
|
|
if (!(header = HeapAlloc (Heap, HEAP_ZERO_MEMORY, sizeof (*header))))
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
header->Heap = Heap;
|
|
header->HandleBase = MinHandleValue;
|
|
header->FreeContextCallback = FreeContextCallback;
|
|
|
|
InitializeListHead (&header->FreeList);
|
|
|
|
InitializeCriticalSectionAndSpinCount (&header->Lock, 0x80001000);
|
|
|
|
if (!GrowTable (header))
|
|
{
|
|
DeleteCriticalSection (&header->Lock);
|
|
|
|
HeapFree (Heap, 0, header);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
return ((HANDLE) header);
|
|
}
|
|
|
|
|
|
VOID
|
|
DeleteHandleTable(
|
|
HANDLE HandleTable
|
|
)
|
|
/*++
|
|
|
|
--*/
|
|
{
|
|
PHANDLETABLEHEADER header = (PHANDLETABLEHEADER) HandleTable;
|
|
|
|
|
|
HeapFree (header->Heap, 0, header->Table);
|
|
|
|
DeleteCriticalSection (&header->Lock);
|
|
|
|
HeapFree (header->Heap, 0, header);
|
|
}
|
|
|
|
//
|
|
// Distinct calls of NewObject in the same handle table always return distinct handles.
|
|
// All NewObject calls in tapisrv use the same handle table, so the handles are known to be distinct,
|
|
// even between different types of objects (i.e. HCALL vs. HLINE)
|
|
// This will need to remain true if the NewObject() implementation changes in the future,
|
|
// as various TAPI operations use this assumption.
|
|
//
|
|
|
|
DWORD
|
|
NewObject(
|
|
HANDLE HandleTable,
|
|
LPVOID Context,
|
|
LPVOID Context2
|
|
)
|
|
/*++
|
|
|
|
--*/
|
|
{
|
|
DWORD handle;
|
|
PHANDLETABLEENTRY entry;
|
|
PHANDLETABLEHEADER header = (PHANDLETABLEHEADER) HandleTable;
|
|
|
|
|
|
if (header && Context)
|
|
{
|
|
EnterCriticalSection (&header->Lock);
|
|
|
|
if (IsListEmpty (&header->FreeList))
|
|
{
|
|
if (!GrowTable (header))
|
|
{
|
|
LeaveCriticalSection (&header->Lock);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
entry = (PHANDLETABLEENTRY) RemoveHeadList (&header->FreeList);
|
|
|
|
entry->Context.C = Context;
|
|
entry->Context.C2 = Context2;
|
|
entry->Handle =
|
|
header->HandleBase +
|
|
(((DWORD)(entry - header->Table)) << 4) + // (entry_index << 4) is guraranteed
|
|
// to fit in a DWORD (see comments at the
|
|
// start of GrowTable).
|
|
(entry->Instance & 0xf);
|
|
entry->ReferenceCount = 1;
|
|
|
|
handle = entry->Handle;
|
|
|
|
LeaveCriticalSection (&header->Lock);
|
|
}
|
|
else
|
|
{
|
|
handle = 0;
|
|
}
|
|
|
|
return handle;
|
|
}
|
|
|
|
|
|
|
|
LPVOID
|
|
ReferenceObject(
|
|
HANDLE HandleTable,
|
|
DWORD Handle,
|
|
DWORD Key
|
|
)
|
|
/*++
|
|
|
|
--*/
|
|
{
|
|
LPVOID context = 0;
|
|
DWORD index;
|
|
PHANDLETABLEENTRY entry;
|
|
PHANDLETABLEHEADER header = (PHANDLETABLEHEADER) HandleTable;
|
|
|
|
|
|
if (header && Handle >= header->HandleBase)
|
|
{
|
|
index = (Handle - header->HandleBase) >> 4;
|
|
|
|
if (index < header->NumEntries)
|
|
{
|
|
EnterCriticalSection (&header->Lock);
|
|
|
|
entry = header->Table + index;
|
|
|
|
if (entry->Handle == Handle && entry->ReferenceCount != 0)
|
|
{
|
|
context = entry->Context.C;
|
|
|
|
if (Key)
|
|
{
|
|
try
|
|
{
|
|
if (*((LPDWORD) context) == Key)
|
|
{
|
|
entry->ReferenceCount++;
|
|
}
|
|
else
|
|
{
|
|
context = 0;
|
|
}
|
|
}
|
|
except (EXCEPTION_EXECUTE_HANDLER)
|
|
{
|
|
context = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
entry->ReferenceCount++;
|
|
}
|
|
}
|
|
|
|
LeaveCriticalSection (&header->Lock);
|
|
}
|
|
}
|
|
|
|
return context;
|
|
}
|
|
|
|
|
|
LPVOID
|
|
ReferenceObjectEx(
|
|
HANDLE HandleTable,
|
|
DWORD Handle,
|
|
DWORD Key,
|
|
LPVOID *Context2
|
|
)
|
|
/*++
|
|
|
|
--*/
|
|
{
|
|
LPVOID context = 0;
|
|
DWORD index;
|
|
PHANDLETABLEENTRY entry;
|
|
PHANDLETABLEHEADER header = (PHANDLETABLEHEADER) HandleTable;
|
|
|
|
|
|
if (header && Handle >= header->HandleBase)
|
|
{
|
|
index = (Handle - header->HandleBase) >> 4;
|
|
|
|
if (index < header->NumEntries)
|
|
{
|
|
EnterCriticalSection (&header->Lock);
|
|
|
|
entry = header->Table + index;
|
|
|
|
if (entry->Handle == Handle && entry->ReferenceCount != 0)
|
|
{
|
|
context = entry->Context.C;
|
|
*Context2 = entry->Context.C2;
|
|
|
|
if (Key)
|
|
{
|
|
try
|
|
{
|
|
if (*((LPDWORD) context) == Key)
|
|
{
|
|
entry->ReferenceCount++;
|
|
}
|
|
else
|
|
{
|
|
context = 0;
|
|
}
|
|
}
|
|
except (EXCEPTION_EXECUTE_HANDLER)
|
|
{
|
|
context = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
entry->ReferenceCount++;
|
|
}
|
|
}
|
|
|
|
LeaveCriticalSection (&header->Lock);
|
|
}
|
|
}
|
|
|
|
return context;
|
|
}
|
|
|
|
|
|
VOID
|
|
DereferenceObject(
|
|
HANDLE HandleTable,
|
|
DWORD Handle,
|
|
DWORD DereferenceCount
|
|
)
|
|
/*++
|
|
|
|
--*/
|
|
{
|
|
LPVOID context, context2;
|
|
DWORD index;
|
|
PHANDLETABLEENTRY entry;
|
|
PHANDLETABLEHEADER header = (PHANDLETABLEHEADER) HandleTable;
|
|
|
|
|
|
if (header && Handle >= header->HandleBase)
|
|
{
|
|
index = (Handle - header->HandleBase) >> 4;
|
|
|
|
if (index < header->NumEntries)
|
|
{
|
|
EnterCriticalSection (&header->Lock);
|
|
|
|
entry = header->Table + index;
|
|
|
|
if (entry->Handle == Handle && entry->ReferenceCount != 0)
|
|
{
|
|
assert (DereferenceCount >= entry->ReferenceCount);
|
|
|
|
entry->ReferenceCount -= DereferenceCount;
|
|
|
|
if (entry->ReferenceCount == 0)
|
|
{
|
|
entry->Instance = entry->Handle + 1;
|
|
|
|
entry->Handle = 0;
|
|
|
|
context = entry->Context.C;
|
|
context2 = entry->Context.C2;
|
|
|
|
InsertTailList (&header->FreeList, &entry->ListEntry);
|
|
|
|
LeaveCriticalSection (&header->Lock);
|
|
|
|
(*header->FreeContextCallback)(context, context2);
|
|
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// assert
|
|
}
|
|
|
|
LeaveCriticalSection (&header->Lock);
|
|
}
|
|
else
|
|
{
|
|
// assert
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
ReleaseAllHandles(
|
|
HANDLE HandleTable,
|
|
PVOID Context2
|
|
)
|
|
{
|
|
DWORD index;
|
|
LPVOID context, context2;
|
|
PHANDLETABLEENTRY entry;
|
|
PHANDLETABLEHEADER header = (PHANDLETABLEHEADER) HandleTable;
|
|
|
|
|
|
if (header && NULL != Context2)
|
|
{
|
|
EnterCriticalSection (&header->Lock);
|
|
|
|
for (index = 0, entry = header->Table;
|
|
index < header->NumEntries;
|
|
index++, entry++)
|
|
{
|
|
if (0 != entry->Handle &&
|
|
entry->Context.C2 == Context2)
|
|
{
|
|
entry->Instance = entry->Handle + 1;
|
|
|
|
entry->Handle = 0;
|
|
|
|
context = entry->Context.C;
|
|
context2 = entry->Context.C2;
|
|
|
|
InsertTailList (&header->FreeList, &entry->ListEntry);
|
|
|
|
(*header->FreeContextCallback)(context, context2);
|
|
}
|
|
}
|
|
|
|
LeaveCriticalSection (&header->Lock);
|
|
}
|
|
}
|