windows-nt/Source/XPSP1/NT/inetsrv/iis/svcs/ftp/server51/aap.cxx
2020-09-26 16:20:57 +08:00

1064 lines
24 KiB
C++

/**********************************************************************/
/** Microsoft Windows NT **/
/** Copyright(c) Microsoft Corp., 1993 **/
/**********************************************************************/
/*
aap.cxx
This module contains implementation of the Asynchronous Accept Pool
package.
Functions exported by this module:
AapInitialize
AapTerminate
AapAcquire
AapRelease
AapAccept
AapAbort
FILE HISTORY:
KeithMo 01-Mar-1995 Created.
*/
#include "ftpdp.hxx"
//
// Private constants.
//
#define MAX_IDLE_THREADS 10
#define AapLockLists() EnterCriticalSection( &p_AapListLock )
#define AapUnlockLists() LeaveCriticalSection( &p_AapListLock )
//
// Private types.
//
typedef enum _AAP_STATE
{
AapStateFirst = -1, // Must be first aap state!
AapStateIdle, // Idle.
AapStateActive, // Waiting for incoming connection.
AapStateAbort, // Aborting, return to idle.
AapStateShutdown, // Shutting down.
AapStateLast // Must be last aap state!
} AAP_STATE;
#define IS_VALID_AAP_STATE(x) (((x) > AapStateFirst) && ((x) < AapStateLast))
typedef struct _AAP_CONTEXT
{
//
// Structure signature, for safety's sake.
//
DEBUG_SIGNATURE
//
// Links onto a list of idle/active contexts.
//
LIST_ENTRY ContextList;
//
// Current state.
//
AAP_STATE State;
//
// The listening socket.
//
SOCKET ListeningSocket;
//
// An event object for synchronizing with the worker thread.
//
HANDLE EventHandle;
//
// A handle to the worker thread for synchronizing shutdown.
//
HANDLE ThreadHandle;
//
// The callback associated with this context.
//
LPAAP_CALLBACK AapCallback;
//
// A user-definable context.
//
LPVOID UserContext;
} AAP_CONTEXT, * LPAAP_CONTEXT;
#if DBG
#define AAP_SIGNATURE (DWORD)'cPaA'
#define AAP_SIGNATURE_X (DWORD)'paaX'
#define INIT_AAP_SIG(p) ((p)->Signature = AAP_SIGNATURE)
#define KILL_AAP_SIG(p) ((p)->Signature = AAP_SIGNATURE_X)
#define IS_VALID_AAP_CONTEXT(p) (((p) != NULL) && ((p)->Signature == AAP_SIGNATURE))
#else // !DBG
#define INIT_AAP_SIG(p) ((void)(p))
#define KILL_AAP_SIG(p) ((void)(p))
#define IS_VALID_AAP_CONTEXT(p) (((void)(p)), TRUE)
#endif // DBG
//
// Private globals.
//
LIST_ENTRY p_AapIdleList;
LIST_ENTRY p_AapActiveList;
CRITICAL_SECTION p_AapListLock;
DWORD p_AapIdleCount;
//
// Private prototypes.
//
LPAAP_CONTEXT
AappCreateContext(
VOID
);
VOID
AappFreeResources(
LPAAP_CONTEXT AapContext
);
DWORD
AappWorkerThread(
LPVOID Param
);
//
// Public functions.
//
/*******************************************************************
NAME: AapInitialize
SYNOPSIS: Initializes the AAP package.
EXIT: APIERR - 0 if successful, !0 if not.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
APIERR
AapInitialize(
VOID
)
{
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"in AapInitialize\n" ));
}
//
// Initialize the critical section.
//
INITIALIZE_CRITICAL_SECTION( &p_AapListLock );
//
// Initialize the worker lists.
//
InitializeListHead( &p_AapIdleList );
InitializeListHead( &p_AapActiveList );
p_AapIdleCount = 0;
//
// Success!
//
return 0;
} // AapInitialize
/*******************************************************************
NAME: AapTerminate
SYNOPSIS: Terminates the AAP package.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
VOID
AapTerminate(
VOID
)
{
PLIST_ENTRY Entry;
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"in AapTerminate\n" ));
}
//
// Lock the lists.
//
AapLockLists();
//
// Scan the idle list and blow them away.
//
Entry = p_AapIdleList.Flink;
while( Entry != &p_AapIdleList )
{
LPAAP_CONTEXT AapContext;
AapContext = CONTAINING_RECORD( Entry, AAP_CONTEXT, ContextList );
Entry = Entry->Flink;
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapContext ) );
DBG_ASSERT( AapContext->State == AapStateIdle );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapTerminate: killing idle context @ %08lX\n",
AapContext ));
}
//
// Set the state to closing so the thread will know to exit.
//
AapContext->State = AapStateShutdown;
//
// Signal the event to wake up the thread.
//
DBG_ASSERT( AapContext->EventHandle != NULL );
TCP_REQUIRE( SetEvent( AapContext->EventHandle ) );
}
//
// Scan the active list and blow them away.
//
Entry = p_AapActiveList.Flink;
while( Entry != &p_AapActiveList )
{
LPAAP_CONTEXT AapContext;
SOCKET Socket;
AapContext = CONTAINING_RECORD( Entry, AAP_CONTEXT, ContextList );
Entry = Entry->Flink;
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapContext ) );
DBG_ASSERT( AapContext->State == AapStateActive );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapTerminate: killing active context @ %08lX\n",
AapContext ));
}
//
// Set the state to closing so the thread will know to exit.
//
AapContext->State = AapStateShutdown;
//
// Close the listening socket to wake up the thread.
//
Socket = AapContext->ListeningSocket;
DBG_ASSERT( Socket != INVALID_SOCKET );
AapContext->ListeningSocket = INVALID_SOCKET;
TCP_REQUIRE( closesocket( Socket ) == 0 );
DBG_ASSERT( AapContext->EventHandle != NULL );
TCP_REQUIRE( SetEvent( AapContext->EventHandle ) );
}
//
// Wait for the worker threads to exit. Note that the list
// lock is currently held.
//
for( ; ; )
{
LPAAP_CONTEXT AapContext;
//
// Find a thread to wait on. If both lists are empty,
// then we're done.
//
if( IsListEmpty( &p_AapIdleList ) )
{
if( IsListEmpty( &p_AapActiveList ) )
{
break;
}
AapContext = CONTAINING_RECORD( p_AapActiveList.Flink,
AAP_CONTEXT,
ContextList );
}
else
{
AapContext = CONTAINING_RECORD( p_AapIdleList.Flink,
AAP_CONTEXT,
ContextList );
}
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapContext ) );
DBG_ASSERT( AapContext->State == AapStateShutdown );
//
// Unlock the lists, wait for the thread to exit, then
// relock the lists.
//
AapUnlockLists();
WaitForSingleObject( AapContext->ThreadHandle, INFINITE );
AapLockLists();
//
// Note that worker threads will neither close their thread
// handles nor free their AAP_CONTEXT structures during shutdown.
// This is our responsibility.
//
AappFreeResources( AapContext );
}
DBG_ASSERT( p_AapIdleCount == 0 );
//
// Unlock the lists.
//
AapUnlockLists();
} // AapTerminate
/*******************************************************************
NAME: AapAcquire
SYNOPSIS: Acquires an AAP socket/thread pair for a future
asynchronous accept request.
ENTRY: AapCallback - Pointer to a callback function to be
invoked when the accept() completes.
UserContext - An uninterpreted context value passed
into the callback.
EXIT: AAP_HANDLE - A valid AAP handle if !NULL, NULL if
an error occurred.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
AAP_HANDLE
AapAcquire(
LPAAP_CALLBACK AapCallback,
LPVOID UserContext
)
{
PLIST_ENTRY Entry;
LPAAP_CONTEXT AapContext;
//
// Sanity check.
//
DBG_ASSERT( AapCallback != NULL );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapAcquire: callback @ %08lX, context = %08lX\n",
AapCallback,
UserContext ));
}
//
// See if there's something available on the idle list.
//
AapLockLists();
if( !IsListEmpty( &p_AapIdleList ) )
{
Entry = RemoveHeadList( &p_AapIdleList );
AapContext = CONTAINING_RECORD( Entry, AAP_CONTEXT, ContextList );
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapContext ) );
DBG_ASSERT( AapContext->State == AapStateIdle );
DBG_ASSERT( p_AapIdleCount > 0 );
p_AapIdleCount--;
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapAcquire: got idle context @ %08lX\n",
AapContext ));
}
}
else
{
//
// Create a new one.
//
AapContext = AappCreateContext();
}
if( AapContext != NULL )
{
//
// Initialize it.
//
AapContext->AapCallback = AapCallback;
AapContext->UserContext = UserContext;
AapContext->State = AapStateActive;
//
// Put it on the active list.
//
InsertHeadList( &p_AapActiveList, &AapContext->ContextList );
}
//
// Unlock the lists & return the (potentially NULL) context.
//
AapUnlockLists();
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapAcquire: returning context @ %08lX\n",
AapContext ));
}
return AapContext;
} // AapAcquire
/*******************************************************************
NAME: AapRelease
SYNOPSIS: Releases an open AAP handle and makes the associated
socket/thread pair available for use.
ENTRY: AapHandle - A valid AAP handle returned by AapAcquire().
After this API completes, the handle is no longer
valid.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
VOID
AapRelease(
AAP_HANDLE AapHandle
)
{
//
// Sanity check.
//
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapHandle ) );
DBG_ASSERT( AapHandle->State == AapStateActive );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapRelease: releasing context @ %08lX\n",
AapHandle ));
}
//
// Lock the lists.
//
AapLockLists();
//
// let it decide how to handle this.
//
AapHandle->State = AapStateAbort;
DBG_ASSERT( AapHandle->EventHandle != NULL );
TCP_REQUIRE( SetEvent( AapHandle->EventHandle ) );
//
// Unlock the lists.
//
AapUnlockLists();
} // AapRelease
/*******************************************************************
NAME: AapAccept
SYNOPSIS: Initiates an accept(). The callback associated with
the AAP handle will be invoked when the accept()
completes.
ENTRY: AapHandle - A valid AAP handle returned by AapAcquire().
EXIT: APIERR - 0 if successful, !0 if not.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
APIERR
AapAccept(
AAP_HANDLE AapHandle
)
{
//
// Sanity check.
//
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapHandle ) );
DBG_ASSERT( AapHandle->State == AapStateActive );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapAccept: context @ %08lX\n",
AapHandle ));
}
//
// Release the worker thread.
//
TCP_REQUIRE( SetEvent( AapHandle->EventHandle ) );
return 0;
} // AapAccept
/*******************************************************************
NAME: AapAbort
SYNOPSIS: Aborts a pending accept().
ENTRY: AapHandle - A valid AAP handle returned by AapAcquire().
EXIT: APIERR - 0 if successful, !0 if not.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
APIERR
AapAbort(
AAP_HANDLE AapHandle
)
{
//
// Sanity check.
//
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapHandle ) );
DBG_ASSERT( AapHandle->State == AapStateActive );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AapAbort: context @ %08lX\n",
AapHandle ));
}
//
// Just zap the listening handle. The worker thread will clean
// up after itself.
//
TCP_REQUIRE( closesocket( AapHandle->ListeningSocket ) == 0 );
return 0;
} // AapAbort
//
// Private functions.
//
/*******************************************************************
NAME: AappCreateContext
SYNOPSIS: Creates a new AAP context, including the associated
thread, socket, and synchronization objects.
RETURNS: LPAAP_CONTEXT - The newly created context if successful,
NULL otherwise.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
LPAAP_CONTEXT
AappCreateContext(
VOID
)
{
LPAAP_CONTEXT AapContext;
SOCKADDR_IN LocalAddress;
DWORD ThreadId;
//
// Create the context structure.
//
AapContext = (LPAAP_CONTEXT)TCP_ALLOC( sizeof(AAP_CONTEXT) );
if( AapContext == NULL )
{
DBGERROR(( DBG_CONTEXT,
"AappCreateContext: allocation failure\n" ));
goto FatalExit0;
}
RtlZeroMemory( AapContext, sizeof(AAP_CONTEXT) );
INIT_AAP_SIG( AapContext );
//
// Create the listening socket.
//
AapContext->ListeningSocket = socket( AF_INET, SOCK_STREAM, 0 );
if( AapContext->ListeningSocket == INVALID_SOCKET)
{
DBGERROR(( DBG_CONTEXT,
"AappCreateContext: socket() failure %d\n",
WSAGetLastError() ));
goto FatalExit1;
}
LocalAddress.sin_family = AF_INET;
LocalAddress.sin_port = 0;
LocalAddress.sin_addr.s_addr = 0;
if( bind( AapContext->ListeningSocket,
(LPSOCKADDR)&LocalAddress,
sizeof(LocalAddress) ) != 0 )
{
DBGERROR(( DBG_CONTEXT,
"AappCreateContext: bind() failure %d\n",
WSAGetLastError() ));
goto FatalExit2;
}
if( listen( AapContext->ListeningSocket, 2 ) != 0 )
{
DBGERROR(( DBG_CONTEXT,
"AappCreateContext: listen() failure %d\n",
WSAGetLastError() ));
goto FatalExit2;
}
//
// Create the event object.
//
AapContext->EventHandle = CreateEvent( NULL, // lpEventAttributes
FALSE, // bManualReset
FALSE, // bInitialState
NULL ); // lpName
if( AapContext->EventHandle == NULL )
{
DBGWARN(( DBG_CONTEXT,
"AappCreateContext: CreateEvent() failure %d\n",
GetLastError() ));
goto FatalExit2;
}
//
// Create the worker thread.
//
AapContext->ThreadHandle = CreateThread( NULL, // lpsa
0, // cbStack
AappWorkerThread, // lpStartAddr
AapContext, // lpvThreadParm
0, // fdwCreate
&ThreadId ); // lpIDThread
if( AapContext->ThreadHandle == NULL )
{
DBGPRINTF(( DBG_CONTEXT,
"AappCreateContext: CreateThread() failure %d\n",
GetLastError() ));
goto FatalExit3;
}
//
// Success!
//
return AapContext;
//
// Cleanup from various levels of fatal error.
//
FatalExit3:
CloseHandle( AapContext->EventHandle );
FatalExit2:
closesocket( AapContext->ListeningSocket );
FatalExit1:
TCP_FREE( AapContext );
FatalExit0:
return NULL;
} // AappCreateContext
/*******************************************************************
NAME: AappFreeResources
SYNOPSIS: Frees the system resources associated with a given
AAP_CONTEXT structure, then frees the structure
itself.
NOTE: This routine MUST be called with the list lock
held!
ENTRY: AapContext - The AAP_CONTEXT structure to free.
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
VOID
AappFreeResources(
LPAAP_CONTEXT AapContext
)
{
//
// Sanity check.
//
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapContext ) );
IF_DEBUG( AAP )
{
DBGWARN(( DBG_CONTEXT,
"AappFreeResource: context @ %08lX\n",
AapContext ));
}
//
// Close the thread handle if open.
//
if( AapContext->ThreadHandle != NULL )
{
CloseHandle( AapContext->ThreadHandle );
}
//
// Remove this structure from the list.
//
RemoveEntryList( &AapContext->ContextList );
//
// Free the structure.
//
KILL_AAP_SIG( AapContext );
TCP_FREE( AapContext );
} // AappFreeResources
/*******************************************************************
NAME: AappWorkerThread
SYNOPSIS: Worker thread for accept()ing incoming connections.
ENTRY: Param - Actually the LPAAP_CONTEXT structure for this
thread.
RETURNS: DWORD - Thread exit code (ignored).
HISTORY:
KeithMo 01-Mar-1995 Created.
********************************************************************/
DWORD
AappWorkerThread(
LPVOID Param
)
{
LPAAP_CONTEXT AapContext;
AAP_STATE AapState;
LPAAP_CALLBACK AapCallback;
LPVOID UserContext;
DWORD WaitResult;
BOOL CallbackResult;
SOCKET ListeningSocket;
SOCKET AcceptedSocket;
SOCKERR SocketStatus;
INT RemoteAddressLength;
SOCKADDR_IN RemoteAddress;
//
// Grab the context structure.
//
AapContext = (LPAAP_CONTEXT)Param;
DBG_ASSERT( IS_VALID_AAP_CONTEXT( AapContext ) );
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AappWorkerThread: starting, context @ %08lX\n",
AapContext ));
}
//
// Capture some fields from the structure.
//
AapCallback = AapContext->AapCallback;
UserContext = AapContext->UserContext;
ListeningSocket = AapContext->ListeningSocket;
//
// Loop forever, or at least until we're told to shutdown.
//
for( ; ; )
{
//
// Wait for a request.
//
WaitResult = WaitForSingleObject( AapContext->EventHandle,
INFINITE );
if( WaitResult != WAIT_OBJECT_0 )
{
DBGWARN(( DBG_CONTEXT,
"AappWorkerThread: wait failure %lu : %d\n",
WaitResult,
GetLastError() ));
break;
}
//
// Check our state.
//
AapLockLists();
AapState = AapContext->State;
AapUnlockLists();
if( AapState == AapStateShutdown )
{
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AappWorkerThread: context @ %08lX state == %d, exiting\n",
AapContext,
AapState ));
}
break;
}
for( ; ; )
{
//
// Wait for an incoming connection.
//
RemoteAddressLength = sizeof(RemoteAddress);
AcceptedSocket = accept( ListeningSocket,
(LPSOCKADDR)&RemoteAddress,
&RemoteAddressLength );
SocketStatus = ( AcceptedSocket == INVALID_SOCKET )
? WSAGetLastError()
: 0;
IF_DEBUG( AAP )
{
if( SocketStatus != 0 )
{
DBGERROR(( DBG_CONTEXT,
"AappWorkerThread: accept() failure %d\n",
SocketStatus ));
}
}
//
// Invoke the callback.
//
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AappWorkerThread: context @ %08lX calling %08lX[%08lX]\n",
AapContext,
AapCallback,
UserContext ));
}
CallbackResult = AapCallback( UserContext,
SocketStatus,
AcceptedSocket,
(LPSOCKADDR)&RemoteAddress,
RemoteAddressLength );
//
// If the callback returned FALSE (indicating that it wants no
// further callbacks) OR if the accept() failed for any reason,
// then exit the accept() loop.
//
if( !CallbackResult || ( SocketStatus != 0 ) )
{
break;
}
}
//
// If we hit a socket error, then bail.
//
if( SocketStatus != 0 )
{
IF_DEBUG( AAP )
{
DBGWARN(( DBG_CONTEXT,
"AappWorkerThread: context @ %08lX, exiting\n",
AapContext ));
}
break;
}
//
// If we haven't exhausted the idle thread quota, then add
// ourselves to the idle list. Otherwise, exit the main
// processing loop & terminate this thread.
//
AapLockLists();
if( ( AapContext->State == AapStateShutdown ) ||
( p_AapIdleCount >= MAX_IDLE_THREADS ) )
{
AapUnlockLists();
break;
}
RemoveEntryList( &AapContext->ContextList );
AapContext->State = AapStateIdle;
InsertHeadList( &p_AapIdleList, &AapContext->ContextList );
p_AapIdleCount++;
IF_DEBUG( AAP )
{
DBGPRINTF(( DBG_CONTEXT,
"AappWorkerThread: context @ %08lX put on idle list\n",
AapContext ));
}
AapUnlockLists();
}
//
// We only make it this far if it's time to die.
//
AapLockLists();
if( AapContext->State != AapStateShutdown )
{
TCP_REQUIRE( CloseHandle( AapContext->EventHandle ) );
TCP_REQUIRE( CloseHandle( AapContext->ThreadHandle ) );
TCP_REQUIRE( closesocket( AapContext->ListeningSocket ) == 0 );
AappFreeResources( AapContext );
}
AapUnlockLists();
return 0;
} // AappWorkerThread