/*++
Copyright (c) 1991 Microsoft Corporation
Copyright (c) 1991 Nokia Data Systems AB
Module Name:
dlcque.c
Abstract:
This module provides primitives to manage the dlc command and
event queues.
Contents:
QueueDlcEvent
MakeDlcEvent
IsCommandOnList
SearchAndRemoveCommand
SearchAndRemoveAnyCommand
SearchAndRemoveCommandByHandle
SearchAndRemoveSpecificCommand
QueueDlcCommand
AbortCommand
CancelDlcCommand
PurgeDlcEventQueue
PurgeDlcFlowControlQueue
Author:
Antti Saarenheimo 29-Aug-1991
Environment:
Kernel mode
Revision History:
--*/
#include <dlc.h>
#include "dlcdebug.h"
/*++
Design notes about the DLC event and command queue management
-------------------------------------------------------------
In DLC API the READ command may be given before or after the actual
event has happened. This means, that all DLC events of the READ command
must be queued and also the READ command must be queued to wait for
the set of events it was designated.
For each new DLC (READ) command the driver searches first the event queue
and then queues the command, if the desired event was not found.
The same thing is made also for the events: the dlc command queue
is checked first and then the event is queued (if it was a read event)
or it is dropped away (if the event was not meant for READ and there
was no command waiting for it).
The events are implemented by the event masks. The event is executed
if the result of bit-OR operation for the event masks in the command
and in the event is not zero.
All commands and receive events of a dlc station (direct, sap or link)
are returned as a DLC completion event when the station is closed.
The same operation is done also by the total reset or all sap stations
(and the only direct station).
A READ command may be used to read that command completion from
the event list. The READ command may have been give before, in the
same time linked to the next CCB field of the close/reset command or
after the close/reset command has completed.
DirOpenAdapter command deletes all events (and commands) from the
event queue. The received data and CCBs are not returned back, if
there is not given any READ command for that purpose.
(This has been fixed:
There could be a minor incompatibility with IBM OS/2 DLC API,
the NT DLC driver may not always complete a dlc command with
the READ command linked to commmand's CCB, if there is another
matching DLC command pending)
Here is the solution:
Actually we could make a special
READ command, that is chained to the very end of the command queue
and that can be matched only with a CCB pointer of the completed
DLC command. We could modify the command aborting to support also
this case, and there should be a special CCB input field in the
NT READ for the completed command (do we also need to return
the READ flag or command completion flag?).
----
We need at least these procedures:
MakeDlcEvent(
pFileContext, Event, StationId, pOwnerObject, pEventInformation, SecInfo);
- scans the command queues
- saves the event if it can't find a matching command and
if the command's event masks defines, that the event should be saved
QueueDlcCommand(
pFileContext, Event, StationId, StationIdMask, pIrp, AbortHandle, pfComp );
- scans the event queue for a matching event
- saves the event if can't find a match
AbortCommand(
pFileContext, Event, StationId, StationIdMask, AbortHandle, ppCcbLink );
- aborts a command in the command queue
****** Subprocedures (used by the api functions)
PDLC_COMMAND
SearchPrevCommand(
pQueue, EventMask, StationId, StationIdMask, SearchHandle, pPrevCommand
- returns pointer to the previous element before the matching
dlc command in a queue,
(Macro: SearchPrevEvent
- searches and removes the given event from the event queue and
returns its pointer)
--*/
VOID
QueueDlcEvent(
IN PDLC_FILE_CONTEXT pFileContext,
IN PDLC_PACKET pPacket
)
/*++
Routine Description:
The routine tries first to find a matching event in the command
queues and queues the DLC event if it can't find anything and if
the event belongs to the mask of the queued commands.
There are two event queues, both having a mask for the checked
events. The queue is checked only if the event bits are found
in the mask of the queue.
Arguments:
pFileContext - process specific adapter context
pPacket - Event packet
Return Value:
None
--*/
{
PDLC_COMMAND pDlcCommand;
DIAG_FUNCTION("QueueDlcEvent");
//
// get search mask
//
pPacket->Event.Overlay.StationIdMask = (USHORT)((pPacket->Event.StationId == -1) ? 0 : -1);
//
// DLC commands can be completed with a special READ command,
// that is linked to the CCB pointer of the command.
// NT DLC must queue that special read command before the
// command that it was linked. We must check here
// if there is a special READ command just for this command
// completion.
// ************** HACK-HACK-HACK **************
// Close/Reset command completions use different
// EventInformation from the other command completions
// and they search the read command by themself =>
// we don't need to care about it.
// If SeconadryInfo == 0
// then this is a Close/Reset command completion
// and we don't search the special read command.
//
// ************** HACK-HACK-HACK **************
//
if (!IsListEmpty(&pFileContext->CommandQueue)) {
pDlcCommand = NULL;
if (pPacket->Event.Event == DLC_COMMAND_COMPLETION
&& pPacket->Event.SecondaryInfo != 0) {
pDlcCommand = SearchAndRemoveCommandByHandle(
&pFileContext->CommandQueue,
(ULONG)-1, // mask for all events
(USHORT)DLC_IGNORE_STATION_ID,
(USHORT)DLC_STATION_MASK_SPECIFIC,
pPacket->Event.pEventInformation
);
}
if (pDlcCommand == NULL) {
pDlcCommand = SearchAndRemoveCommand(&pFileContext->CommandQueue,
pPacket->Event.Event,
pPacket->Event.StationId,
pPacket->Event.Overlay.StationIdMask
);
}
if (pDlcCommand != NULL) {
BOOLEAN DeallocateEvent;
DeallocateEvent = pDlcCommand->Overlay.pfCompletionHandler(
pFileContext,
pPacket->Event.pOwnerObject,
pDlcCommand->pIrp,
(UINT)pPacket->Event.Event,
pPacket->Event.pEventInformation,
pPacket->Event.SecondaryInfo
);
if (DeallocateEvent) {
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, pPacket);
}
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, pDlcCommand);
return;
}
}
//
// queue this event packet if it is to be picked up by a READ
//
if (pPacket->Event.Event & DLC_READ_FLAGS) {
LlcInsertTailList(&pFileContext->EventQueue, pPacket);
}
}
NTSTATUS
MakeDlcEvent(
IN PDLC_FILE_CONTEXT pFileContext,
IN ULONG Event,
IN USHORT StationId,
IN PDLC_OBJECT pDlcObject,
IN PVOID pEventInformation,
IN ULONG SecondaryInfo,
IN BOOLEAN FreeEventInfo
)
/*++
Routine Description:
The routine allocates a event packet, saves the event information
into it and queues (or completes) the event packet.
Arguments:
pFileContext - process specific adapter context
Event - event code
StationId - station id the event is destined
pDlcObject - the optional dlc object used in the event completion
pEventInformation - generic event information
SecondaryInfo - optional misc. data
FreeEventInfo - TRUE if pEventInformation should be deallocated
Return Value:
NTSTATUS:
STATUS_SUCCESS
DLC_STATUS_NO_MEMORY
--*/
{
PDLC_EVENT pDlcEvent;
DIAG_FUNCTION("MakeDlcEvent");
//
// We couldn't find any matching commands for this event and
// this event is a queued event => allocate a packet and
// queue the event.
//
pDlcEvent = ALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool);
if (pDlcEvent == NULL) {
return DLC_STATUS_NO_MEMORY;
}
pDlcEvent->Event = Event;
pDlcEvent->StationId = StationId;
pDlcEvent->pOwnerObject = pDlcObject;
pDlcEvent->SecondaryInfo = SecondaryInfo;
pDlcEvent->pEventInformation = pEventInformation;
pDlcEvent->bFreeEventInfo = FreeEventInfo;
QueueDlcEvent(pFileContext, (PDLC_PACKET)pDlcEvent);
return STATUS_SUCCESS;
}
PDLC_COMMAND
IsCommandOnList(
IN PVOID RequestHandle,
IN PLIST_ENTRY List
)
/*++
Routine Description:
Searches the command queue of a DLC file context for a 'request handle'
which is the address (in user space) of a command CCB, such as a READ
If RequestHandle is located, a pointer to the DLC_COMMAND containing
it is returned, else NULL
Note: Assumes that handles are not shared between processes (it looks
as though the entire driver assumes this) and this function is called
within the context of the process to which the searched handle belongs
Arguments:
RequestHandle - address of CCB to look for
List - address of a list of DLC_COMMAND structures
Return Value:
PDLC_COMMAND
Success - address of located DLC_COMMAND structure containing
RequestHandle (in AbortHandle field)
Failure - NULL
--*/
{
PLIST_ENTRY entry;
if (!IsListEmpty(List)) {
for (entry = List->Flink; entry != List; entry = entry->Flink) {
if (((PDLC_COMMAND)entry)->AbortHandle == RequestHandle) {
return (PDLC_COMMAND)entry;
}
}
}
return NULL;
}
PDLC_COMMAND
SearchAndRemoveCommand(
IN PLIST_ENTRY pQueueBase,
IN ULONG Event,
IN USHORT StationId,
IN USHORT StationIdMask
)
/*++
Routine Description:
The routine searches and removes the given command or event from
command, event or receive command queue.
The station id, its mask, event mask and search handle are used
to define the search.
Arguments:
pQueueBase - address of queue's base pointer
Event - event code
StationId - station id of this command
StationIdMask - station id mask for the event station id
pSearchHandle - additional search key, this is actually an
orginal user mode ccb pointer (vdm or Windows/Nt)
Return Value:
PDLC_COMMAND
--*/
{
PDLC_COMMAND pCmd;
DIAG_FUNCTION("SearchAndRemoveCommand");
//
// Events and commands are both saved to entry lists and this
// procedure is used to search a macthing event for a command
// or vice verse. Commands has a masks, that may defines
// the search for a specific station id, all stations on a sap
// or all station ids.
// the newest element in the list and the next element is the oldest
// The commands are always scanned from the oldest to the newest.
//
if (!IsListEmpty(pQueueBase)) {
for (pCmd = (PDLC_COMMAND)pQueueBase->Flink;
pCmd != (PDLC_COMMAND)pQueueBase;
pCmd = (PDLC_COMMAND)pCmd->LlcPacket.pNext) {
if ((pCmd->Event & Event)
&& (pCmd->StationId & pCmd->StationIdMask & StationIdMask)
== (StationId & pCmd->StationIdMask & StationIdMask)) {
LlcRemoveEntryList(pCmd);
return pCmd;
}
}
}
return NULL;
}
PDLC_COMMAND
SearchAndRemoveAnyCommand(
IN PDLC_FILE_CONTEXT pFileContext,
IN ULONG EventMask,
IN USHORT StationId,
IN USHORT StationIdMask,
IN PVOID pSearchHandle
)
/*++
Routine Description:
The routine searches a dlc command from the normal read command queue
for events and the special receive command queue.
Arguments:
pQueueBase - address of queue's base pointer
Event - event code
StationId - station id of this command
StationIdMask - station id mask for the event station id
pSearchHandle - additional search key, this is actually an
orginal user mode ccb pointer (vdm or Windows/Nt)
Return Value:
PDLC_COMMAND
--*/
{
PDLC_COMMAND pDlcCommand;
DIAG_FUNCTION("SearchAndRemoveAnyCommand");
pDlcCommand = SearchAndRemoveCommandByHandle(&pFileContext->CommandQueue,
EventMask,
StationId,
StationIdMask,
pSearchHandle
);
if (pDlcCommand == NULL) {
pDlcCommand = SearchAndRemoveCommandByHandle(&pFileContext->ReceiveQueue,
EventMask,
StationId,
StationIdMask,
pSearchHandle
);
}
return pDlcCommand;
}
PDLC_COMMAND
SearchAndRemoveCommandByHandle(
IN PLIST_ENTRY pQueueBase,
IN ULONG Event,
IN USHORT StationId,
IN USHORT StationIdMask,
IN PVOID pSearchHandle
)
/*++
Routine Description:
The routine searches and removes the given command or event from
command, event or receive command queue using a search handle.
This search routine is tailored to find the commands belonging
only to the deleted object (this searches only the exact macthes).
The other search routine supports wild cards only for the read
commands and thus it cannot be used here. We just want to remove
only those commands, that read events from the deleted object but not
from elsewhere.
Arguments:
pQueueBase - address of queue's base pointer
Event - event code or mask for the searched events
StationId - station id of this command
StationIdMask - station id mask for the event station id
pSearchHandle - additional search key, this is actually an orginal user
mode ccb pointer (vdm or Windows/Nt)
Return Value:
PDLC_COMMAND
--*/
{
PDLC_COMMAND pCmd;
DIAG_FUNCTION("SearchAndRemoveCommandByHandle");
if (!IsListEmpty(pQueueBase)) {
for (pCmd = (PDLC_COMMAND)pQueueBase->Flink;
pCmd != (PDLC_COMMAND)pQueueBase;
pCmd = (PDLC_COMMAND)pCmd->LlcPacket.pNext) {
//
// The event mask match always!
//
if ((pCmd->Event & Event)
&& (pSearchHandle == DLC_MATCH_ANY_COMMAND
|| pSearchHandle == pCmd->AbortHandle
|| (pCmd->StationId & StationIdMask) == (StationId & StationIdMask))) {
LlcRemoveEntryList(pCmd);
return pCmd;
}
}
}
return NULL;
}
PDLC_COMMAND
SearchAndRemoveSpecificCommand(
IN PLIST_ENTRY pQueueBase,
IN PVOID pSearchHandle
)
/*++
Routine Description:
Searches for a DLC_COMMAND structure having a specific search handle (ie
abort handle or application CCB address). If found, removes the DLC_COMMAND
from the queue, else returns NULL
Arguments:
pQueueBase - address of queue's base pointer
pSearchHandle - additional search key, this is actually an orginal user
mode ccb pointer (vdm or Windows/Nt)
Return Value:
PDLC_COMMAND
--*/
{
DIAG_FUNCTION("SearchAndRemoveSpecificCommand");
if (!IsListEmpty(pQueueBase)) {
PDLC_COMMAND pCmd;
for (pCmd = (PDLC_COMMAND)pQueueBase->Flink;
pCmd != (PDLC_COMMAND)pQueueBase;
pCmd = (PDLC_COMMAND)pCmd->LlcPacket.pNext) {
//
// The event mask match always!
//
if (pSearchHandle == pCmd->AbortHandle) {
LlcRemoveEntryList(pCmd);
return pCmd;
}
}
}
return NULL;
}
NTSTATUS
QueueDlcCommand(
IN PDLC_FILE_CONTEXT pFileContext,
IN ULONG Event,
IN USHORT StationId,
IN USHORT StationIdMask,
IN PIRP pIrp,
IN PVOID AbortHandle,
IN PFCOMPLETION_HANDLER pfCompletionHandler
)
/*++
Routine Description:
The routine tries first to find a matching event in the event
queue and queues the DLC command if it can't find an event.
Arguments:
pFileContext - process specific adapter context
Event - event code
StationId - station id the event is destined
StationIdMask - mask used to define the destination station group
pIrp - the i/o request packet of the related DLC command,
link to the input and output parameters.
AbortHandle - handle used to cancel the command from the queue
pfCompletionHandler - completion handler of the command, called when a
matching event has been found.
Return Value:
NTSTATUS
--*/
{
PDLC_COMMAND pDlcCommand;
PDLC_EVENT pEvent;
DIAG_FUNCTION("QueueDlcCommand");
pEvent = SearchAndRemoveEvent(&pFileContext->EventQueue,
Event,
StationId,
StationIdMask
);
if (pEvent != NULL) {
BOOLEAN DeallocateEvent;
DeallocateEvent = pfCompletionHandler(pFileContext,
pEvent->pOwnerObject,
pIrp,
(UINT)pEvent->Event,
pEvent->pEventInformation,
pEvent->SecondaryInfo
);
if (DeallocateEvent) {
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, pEvent);
}
} else {
//
// We couldn't find any matching command for this event and
// this event is a queued event => allocate a packet and
// queue the event.
//
pDlcCommand = (PDLC_COMMAND)ALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool);
if (pDlcCommand == NULL) {
return DLC_STATUS_NO_MEMORY;
}
pDlcCommand->Event = Event;
pDlcCommand->pIrp = pIrp;
pDlcCommand->StationId = StationId;
pDlcCommand->StationIdMask = StationIdMask;
pDlcCommand->AbortHandle = AbortHandle;
pDlcCommand->Overlay.pfCompletionHandler = pfCompletionHandler;
//
// The permanent receive commands, that do not actually read
// anuting (just enable the data receiving) are put to another
// queue to speed up the search of the read commands.
//
if (Event == LLC_RECEIVE_COMMAND_FLAG) {
LlcInsertTailList(&pFileContext->ReceiveQueue, pDlcCommand);
} else {
LlcInsertTailList(&pFileContext->CommandQueue, pDlcCommand);
}
//
// Asynchronous commands returns ALWAYS the pending status.
//
}
return STATUS_PENDING;
}
NTSTATUS
AbortCommand(
IN PDLC_FILE_CONTEXT pFileContext,
IN USHORT StationId,
IN USHORT StationIdMask,
IN PVOID AbortHandle,
IN OUT PVOID *ppCcbLink,
IN UINT CancelStatus,
IN BOOLEAN SuppressCommandCompletion
)
/*++
Routine Description:
The routine searches and cancels a command from a command queue.
The commands must always belong to the defined DLC object.
A NULL value in abort handle selects all matching commands
found in the queue.
Arguments:
pFileContext -
StationId - station id the searched command is destined for
StationIdMask - station id mask used in the search
AbortHandle - handle used to cancel the command from the
queue. The whole command queue will be scanned
if this handle is NULL
ppCcbLink - the canceled commands are linked by their next
CCB pointer fieldsr. The caller must provide
the next CCB address in this parameter
(usually *ppCcbLink == NULL) and the function
will return the address of the last cancelled
CCB field.
CancelStatus - Status for the command to be canceled
SuppressCommandCompletion - the flag is set, if the normal command
completion is suppressed.
Return Value:
- no mathing command was found
STATUS_SUCCESS - the command was canceled
--*/
{
PDLC_COMMAND pDlcCommand;
DIAG_FUNCTION("AbortCommand");
pDlcCommand = SearchAndRemoveAnyCommand(pFileContext,
(ULONG)(-1), // search all commands
StationId,
StationIdMask,
AbortHandle
);
if (pDlcCommand == NULL && AbortHandle == DLC_MATCH_ANY_COMMAND) {
pDlcCommand = pFileContext->pTimerQueue;
if (pDlcCommand != NULL) {
pFileContext->pTimerQueue = (PDLC_COMMAND)pDlcCommand->LlcPacket.pNext;
}
}
if (pDlcCommand != NULL) {
CancelDlcCommand(pFileContext,
pDlcCommand,
ppCcbLink,
CancelStatus,
SuppressCommandCompletion
);
return STATUS_SUCCESS;
} else {
return DLC_STATUS_INVALID_CCB_POINTER;
}
}
VOID
CancelDlcCommand(
IN PDLC_FILE_CONTEXT pFileContext,
IN PDLC_COMMAND pDlcCommand,
IN OUT PVOID *ppCcbLink,
IN UINT CancelStatus,
IN BOOLEAN SuppressCommandCompletion
)
/*++
Routine Description:
The cancels and optionally completes the given DLC command. Called when one
DLC I/O request is used to kill another (e.g. READ.CANCEL, DIR.TIMER.CANCEL)
Arguments:
pFileContext -
pDlcCommand -
ppCcbLink - the canceled commands are linked by their next
CCB pointer fields. The caller must provide
the next CCB address in this parameter
(usually *ppCcbLink == NULL) and the function
will return the address of the last cancelled
CCB field
CancelStatus - Status for the command to be canceled
SuppressCommandCompletion - if set, normal command completion is suppressed
Return Value:
None
--*/
{
PVOID pOldCcbLink;
DIAG_FUNCTION("CancelDlcCommand");
//
// We must return the current CCB link to be linked to the next cancelled
// CCB command (or to the CCB pointer of cancelling command). But first
// save the previous CCB link before we read a new one
//
pOldCcbLink = *ppCcbLink;
*ppCcbLink = ((PNT_DLC_PARMS)pDlcCommand->pIrp->AssociatedIrp.SystemBuffer)->Async.Ccb.pCcbAddress;
//
// Check if we must suppress any kind of command completion indications to
// the applications. I/O system should not care, if its event handle is
// removed
//
if (SuppressCommandCompletion) {
pDlcCommand->pIrp->UserEvent = NULL;
}
CompleteAsyncCommand(pFileContext, CancelStatus, pDlcCommand->pIrp, pOldCcbLink, FALSE);
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, pDlcCommand);
}
VOID
PurgeDlcEventQueue(
IN PDLC_FILE_CONTEXT pFileContext
)
/*++
Routine Description:
Deletes all events from a FILE_CONTEXT event queue. Called when the
FILE_CONTEXT is being deleted and before we deallocate the packet pool from
which the events were allocated
Arguments:
pFileContext - pointer to FILE_CONTEXT owning the queue
Return Value:
None.
--*/
{
PDLC_EVENT p;
while (!IsListEmpty(&pFileContext->EventQueue)) {
p = (PDLC_EVENT)RemoveHeadList(&pFileContext->EventQueue);
if (p->bFreeEventInfo && p->pEventInformation) {
#if DBG
DbgPrint("PurgeDlcEventQueue: deallocating pEventInformation: %x\n", p->pEventInformation);
#endif
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, p->pEventInformation);
}
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, p);
}
}
VOID
PurgeDlcFlowControlQueue(
IN PDLC_FILE_CONTEXT pFileContext
)
/*++
Routine Description:
Deletes all packets from the flow control queue. Called when the FILE_CONTEXT
is being deleted and before we deallocate the packet pool from which flow
control packets were allocated
Arguments:
pFileContext - pointer to FILE_CONTEXT owning the queue
Return Value:
None.
--*/
{
PDLC_RESET_LOCAL_BUSY_CMD p;
while (!IsListEmpty(&pFileContext->FlowControlQueue)) {
p = (PDLC_RESET_LOCAL_BUSY_CMD)RemoveHeadList(&pFileContext->FlowControlQueue);
DEALLOCATE_PACKET_DLC_PKT(pFileContext->hPacketPool, p);
}
}
/*
//
// Internal consistency check to hunt a bougus event in the event queue.
//
//extern BOOLEAN EventCheckDisabled;
//
int
CheckEventQueue(
PDLC_FILE_CONTEXT pFileContext
)
{
static PDLC_FILE_CONTEXT pOldFileContext = NULL;
if (pFileContext == NULL)
{
pFileContext = pOldFileContext;
}
else
{
pOldFileContext = pFileContext;
}
if (pFileContext == NULL)
return 0;
if (!IsListEmpty( &pFileContext->EventQueue ) &&
pFileContext->EventQueue.Flink == pFileContext->EventQueue.Blink &&
&pFileContext->EventQueue != pFileContext->EventQueue.Flink->Flink)
{
FooDebugBreak();
}
return 0;
}
int
FooDebugBreak()
{
INT i;
return i++;
}
*/
// PDLC_EVENT pEvent;
//
// if (EventCheckDisabled || pFileContext->AdapterNumber != 0 ||
// pFileContext->EventQueue == NULL)
// return;
//
// pEvent = (PDLC_EVENT)pFileContext->pEventQueue->LlcPacket.pNext;
// for (;;)
// {
// if (pEvent->Event == LLC_STATUS_CHANGE &&
// pEvent->pOwnerObject == NULL)
// DebugBreak();
// if (pEvent == pFileContext->pEventQueue)
// break;
// pEvent = (PDLC_EVENT)pEvent->LlcPacket.pNext;
// }
//}
//