handle.c

来自「一个类似windows」· C语言 代码 · 共 284 行

/*
 * COPYRIGHT:   See COPYING in the top level directory
 * PROJECT:     ReactOS WinSock 2 DLL
 * FILE:        misc/handle.c
 * PURPOSE:     Provider handle management
 * PROGRAMMERS: Casper S. Hornstrup ([e-mail])
 * REVISIONS:
 *   CSH 01/09-2000 Created
 */
#include <ws2_32.h>
#include <handle.h>
#include <catalog.h>

PPROVIDER_HANDLE_BLOCK ProviderHandleTable;
CRITICAL_SECTION ProviderHandleTableLock;

PPROVIDER_HANDLE
GetProviderByHandle(
    PPROVIDER_HANDLE_BLOCK HandleTable,
    HANDLE Handle)
/*
 * FUNCTION: Get the data structure for a handle
 * ARGUMENTS:
 *     HandleTable = Pointer to handle table
 *     Handle      = Handle to get data structure for
 * RETURNS:
 *     Pointer to the data structure identified by the handle on success,
 *     NULL on failure
 */
{
  PPROVIDER_HANDLE_BLOCK Current;
  PLIST_ENTRY CurrentEntry;
  ULONG i;
  
  WS_DbgPrint(MAX_TRACE, ("HandleTable (0x%X)  Handle (0x%X).\n", HandleTable, Handle));

  CurrentEntry = HandleTable->Entry.Flink;
  
  while (CurrentEntry != &HandleTable->Entry) {
    Current = CONTAINING_RECORD(CurrentEntry, PROVIDER_HANDLE_BLOCK, Entry);

	  for (i = 0; i < HANDLE_BLOCK_ENTRIES; i++) {
	    if ((Current->Handles[i].Provider != NULL) && 
        (Current->Handles[i].Handle == Handle)) {
        return &Current->Handles[i];
	    }
    }
	  CurrentEntry = CurrentEntry->Flink;
  }

  return NULL;
}


VOID
CloseAllHandles(
  PPROVIDER_HANDLE_BLOCK HandleTable)
{
  PPROVIDER_HANDLE_BLOCK Current;
  PLIST_ENTRY CurrentEntry;
  PCATALOG_ENTRY Provider;
  ULONG i;
  
  WS_DbgPrint(MAX_TRACE, ("HandleTable (0x%X).\n", HandleTable));

  CurrentEntry = HandleTable->Entry.Flink;

  while (CurrentEntry != &HandleTable->Entry) {
    Current = CONTAINING_RECORD(CurrentEntry, PROVIDER_HANDLE_BLOCK, Entry);

	  for (i = 0; i < HANDLE_BLOCK_ENTRIES; i++) {
      Provider = Current->Handles[i].Provider;
	    if (Provider != NULL) {
        DereferenceProviderByPointer(Provider);
        Current->Handles[i].Handle   = (HANDLE)0;
	      Current->Handles[i].Provider = NULL;
	    }
	  }
	  CurrentEntry = CurrentEntry->Flink;
  }
}


VOID
DeleteHandleTable(
  PPROVIDER_HANDLE_BLOCK HandleTable)
{
  PPROVIDER_HANDLE_BLOCK Current;
  PLIST_ENTRY CurrentEntry;

  CloseAllHandles(HandleTable);
  
  CurrentEntry = RemoveHeadList(&HandleTable->Entry);
  
  while (CurrentEntry != &HandleTable->Entry) {
    Current = CONTAINING_RECORD(
      CurrentEntry,
      PROVIDER_HANDLE_BLOCK,
  	  Entry);

	  HeapFree(GlobalHeap, 0, Current);

	  CurrentEntry = RemoveHeadList(&HandleTable->Entry);
  }
}


PCATALOG_ENTRY
DeleteProviderHandle(PPROVIDER_HANDLE_BLOCK HandleTable,
                     HANDLE Handle)
{
  PPROVIDER_HANDLE Entry;
  PCATALOG_ENTRY Provider;

  WS_DbgPrint(MAX_TRACE, ("HandleTable (0x%X)  Handle (0x%X).\n", HandleTable, Handle));

  Entry = GetProviderByHandle(HandleTable, Handle);
  if (!Entry)
	  return NULL;

  Provider = Entry->Provider;
  Entry->Handle = (HANDLE)0;
  Entry->Provider = NULL;

  return Provider;
}


HANDLE
CreateProviderHandleTable(
  PPROVIDER_HANDLE_BLOCK HandleTable,
  HANDLE Handle,
  PCATALOG_ENTRY Provider)
{
  PPROVIDER_HANDLE_BLOCK NewBlock;
  PLIST_ENTRY CurrentEntry;
  ULONG i;

  WS_DbgPrint(MAX_TRACE, ("HandleTable (0x%X)  Handle (0x%X)  Provider (0x%X).\n",
    HandleTable, Handle, Provider));

  /* Scan through the currently allocated handle blocks looking for a free slot */
  CurrentEntry = HandleTable->Entry.Flink;
  while (CurrentEntry != &HandleTable->Entry) {
    PPROVIDER_HANDLE_BLOCK Block = CONTAINING_RECORD(
      CurrentEntry, PROVIDER_HANDLE_BLOCK, Entry);

    for (i = 0; i < HANDLE_BLOCK_ENTRIES; i++) {
      WS_DbgPrint(MAX_TRACE, ("Considering slot %ld containing 0x%X.\n",
        i, Block->Handles[i].Provider));
	    if (Block->Handles[i].Provider == NULL) {
        Block->Handles[i].Handle   = Handle;
	      Block->Handles[i].Provider = Provider;
  	    return Handle;
	    }
	  }
	  CurrentEntry = CurrentEntry->Flink;
  }

  /* Add a new handle block to the end of the list */
  NewBlock = (PPROVIDER_HANDLE_BLOCK)HeapAlloc(
      GlobalHeap, 0, sizeof(PROVIDER_HANDLE_BLOCK));

  WS_DbgPrint(MID_TRACE,("using table entry %x\n", NewBlock));

  if (!NewBlock)
      return (HANDLE)0;

  ZeroMemory(NewBlock, sizeof(PROVIDER_HANDLE_BLOCK));
  InsertTailList(&HandleTable->Entry, &NewBlock->Entry);

  NewBlock->Handles[0].Handle   = Handle;
  NewBlock->Handles[0].Provider = Provider;

  return Handle;
}


HANDLE
CreateProviderHandle(
  HANDLE Handle,
  PCATALOG_ENTRY Provider)
{
  HANDLE h;

  EnterCriticalSection(&ProviderHandleTableLock);

  h = CreateProviderHandleTable(ProviderHandleTable, Handle, Provider);

  LeaveCriticalSection(&ProviderHandleTableLock);

  if (h != NULL)
    ReferenceProviderByPointer(Provider);

  return h;
}

    
BOOL
ReferenceProviderByHandle(
  HANDLE Handle,
  PCATALOG_ENTRY* Provider)
/*
 * FUNCTION: Increments the reference count for a provider and returns a pointer to it
 * ARGUMENTS:
 *     Handle   = Handle for the provider
 *     Provider = Address of buffer to place pointer to provider
 * RETURNS:
 *     TRUE if handle was valid, FALSE if not
 */
{
  PPROVIDER_HANDLE ProviderHandle;

  WS_DbgPrint(MID_TRACE, ("Handle (0x%X)  Provider (0x%X).\n", Handle, Provider));

  EnterCriticalSection(&ProviderHandleTableLock);

  ProviderHandle = GetProviderByHandle(ProviderHandleTable, Handle);

  WS_DbgPrint(MID_TRACE, ("ProviderHanddle is %x\n", ProviderHandle));

  LeaveCriticalSection(&ProviderHandleTableLock);

  if (ProviderHandle) {
    ReferenceProviderByPointer(ProviderHandle->Provider);
    *Provider = ProviderHandle->Provider;
  }

  return (ProviderHandle != NULL);
}


BOOL
CloseProviderHandle(
  HANDLE Handle)
{
  PCATALOG_ENTRY Provider;
  
  WS_DbgPrint(MAX_TRACE, ("Handle (0x%X).\n", Handle));

  EnterCriticalSection(&ProviderHandleTableLock);

  Provider = DeleteProviderHandle(ProviderHandleTable, Handle);
  if (!Provider)
    return FALSE;

  LeaveCriticalSection(&ProviderHandleTableLock);

  DereferenceProviderByPointer(Provider);

  return TRUE;
}


BOOL
InitProviderHandleTable(VOID)
{
  ProviderHandleTable = (PPROVIDER_HANDLE_BLOCK)
    HeapAlloc(GlobalHeap, 0, sizeof(PROVIDER_HANDLE_BLOCK));
  if (!ProviderHandleTable)
    return FALSE;

  WS_DbgPrint(MID_TRACE,("Called\n"));

  ZeroMemory(ProviderHandleTable, sizeof(PROVIDER_HANDLE_BLOCK));

  InitializeListHead(&ProviderHandleTable->Entry);

  InitializeCriticalSection(&ProviderHandleTableLock);

  return TRUE;
}


VOID
FreeProviderHandleTable(VOID)
{
  DeleteHandleTable(ProviderHandleTable);

  DeleteCriticalSection(&ProviderHandleTableLock);
}

/* EOF */