VOID
NTAPI
WorkItemRoutine(
IN PVOID Context)
{
PKSIWORKER KsWorker;
KIRQL OldLevel;
PWORK_QUEUE_ITEM WorkItem;
PLIST_ENTRY Entry;
/* get ks worker implementation */
KsWorker = (PKSIWORKER)Context;
/* acquire back the lock */
KeAcquireSpinLock(&KsWorker->Lock, &OldLevel);
do
{
/* sanity check */
ASSERT(!IsListEmpty(&KsWorker->QueuedWorkItems));
/* remove first entry */
Entry = RemoveHeadList(&KsWorker->QueuedWorkItems);
/* get offset to work item */
WorkItem = (PWORK_QUEUE_ITEM)CONTAINING_RECORD(Entry, WORK_QUEUE_ITEM, List);
/* release lock as the callback might call one KsWorker functions */
KeReleaseSpinLock(&KsWorker->Lock, OldLevel);
/* now dispatch the work */
WorkItem->WorkerRoutine(WorkItem->Parameter);
/* acquire back the lock */
KeAcquireSpinLock(&KsWorker->Lock, &OldLevel);
/* decrement queued work item count */
InterlockedDecrement(&KsWorker->QueuedWorkItemCount);
}while(KsWorker->QueuedWorkItemCount);
/* release the lock */
KeReleaseSpinLock(&KsWorker->Lock, OldLevel);
/* signal completion event */
KeSetEvent(&KsWorker->Event, IO_NO_INCREMENT, FALSE);
}
VOID
NTAPI
PopProcessShutDownLists(VOID)
{
PPOP_SHUTDOWN_WAIT_ENTRY ShutDownWaitEntry;
PWORK_QUEUE_ITEM WorkItem;
PLIST_ENTRY ListEntry;
/* First signal the shutdown event */
KeSetEvent(&PopShutdownEvent, IO_NO_INCREMENT, FALSE);
/* Acquire the shutdown list lock */
KeAcquireGuardedMutex(&PopShutdownListMutex);
/* Block any further attempts to register a shutdown event */
PopShutdownListAvailable = FALSE;
/* Release the list lock, since we are exclusively using the lists now */
KeReleaseGuardedMutex(&PopShutdownListMutex);
/* Process the shutdown queue */
while (!IsListEmpty(&PopShutdownQueue))
{
/* Get the head entry */
ListEntry = RemoveHeadList(&PopShutdownQueue);
WorkItem = CONTAINING_RECORD(ListEntry, WORK_QUEUE_ITEM, List);
/* Call the shutdown worker routine */
WorkItem->WorkerRoutine(WorkItem->Parameter);
}
/* Now process the shutdown thread list */
while (PopShutdownThreadList != NULL)
{
/* Get the top entry and remove it from the list */
ShutDownWaitEntry = PopShutdownThreadList;
PopShutdownThreadList = PopShutdownThreadList->NextEntry;
/* Wait for the thread to finish and dereference it */
KeWaitForSingleObject(ShutDownWaitEntry->Thread, 0, 0, 0, 0);
ObfDereferenceObject(ShutDownWaitEntry->Thread);
/* Finally free the entry */
ExFreePoolWithTag(ShutDownWaitEntry, 0);
}
}
/*++
* @name ExpWorkerThreadEntryPoint
*
* The ExpWorkerThreadEntryPoint routine is the entrypoint for any new
* worker thread created by teh system.
*
* @param Context
* Contains the work queue type masked with a flag specifing whether the
* thread is dynamic or not.
*
* @return None.
*
* @remarks A dynamic thread can timeout after 10 minutes of waiting on a queue
* while a static thread will never timeout.
*
* Worker threads must return at IRQL == PASSIVE_LEVEL, must not have
* active impersonation info, and must not have disabled APCs.
*
* NB: We will re-enable APCs for broken threads but all other cases
* will generate a bugcheck.
*
*--*/
VOID
NTAPI
ExpWorkerThreadEntryPoint(IN PVOID Context)
{
PWORK_QUEUE_ITEM WorkItem;
PLIST_ENTRY QueueEntry;
WORK_QUEUE_TYPE WorkQueueType;
PEX_WORK_QUEUE WorkQueue;
LARGE_INTEGER Timeout;
PLARGE_INTEGER TimeoutPointer = NULL;
PETHREAD Thread = PsGetCurrentThread();
KPROCESSOR_MODE WaitMode;
EX_QUEUE_WORKER_INFO OldValue, NewValue;
/* Check if this is a dyamic thread */
if ((ULONG_PTR)Context & EX_DYNAMIC_WORK_THREAD)
{
/* It is, which means we will eventually time out after 10 minutes */
Timeout.QuadPart = Int32x32To64(10, -10000000 * 60);
TimeoutPointer = &Timeout;
}
/* Get Queue Type and Worker Queue */
WorkQueueType = (WORK_QUEUE_TYPE)((ULONG_PTR)Context &
~EX_DYNAMIC_WORK_THREAD);
WorkQueue = &ExWorkerQueue[WorkQueueType];
/* Select the wait mode */
WaitMode = (UCHAR)WorkQueue->Info.WaitMode;
/* Nobody should have initialized this yet, do it now */
ASSERT(Thread->ExWorkerCanWaitUser == 0);
if (WaitMode == UserMode) Thread->ExWorkerCanWaitUser = TRUE;
/* If we shouldn't swap, disable that feature */
if (!ExpWorkersCanSwap) KeSetKernelStackSwapEnable(FALSE);
/* Set the worker flags */
do
{
/* Check if the queue is being disabled */
if (WorkQueue->Info.QueueDisabled)
{
/* Re-enable stack swapping and kill us */
KeSetKernelStackSwapEnable(TRUE);
PsTerminateSystemThread(STATUS_SYSTEM_SHUTDOWN);
}
/* Increase the worker count */
OldValue = WorkQueue->Info;
NewValue = OldValue;
NewValue.WorkerCount++;
}
while (InterlockedCompareExchange((PLONG)&WorkQueue->Info,
*(PLONG)&NewValue,
*(PLONG)&OldValue) != *(PLONG)&OldValue);
/* Success, you are now officially a worker thread! */
Thread->ActiveExWorker = TRUE;
/* Loop forever */
ProcessLoop:
for (;;)
{
/* Wait for Something to Happen on the Queue */
QueueEntry = KeRemoveQueue(&WorkQueue->WorkerQueue,
WaitMode,
TimeoutPointer);
/* Check if we timed out and quit this loop in that case */
if ((NTSTATUS)(ULONG_PTR)QueueEntry == STATUS_TIMEOUT) break;
/* Increment Processed Work Items */
InterlockedIncrement((PLONG)&WorkQueue->WorkItemsProcessed);
/* Get the Work Item */
WorkItem = CONTAINING_RECORD(QueueEntry, WORK_QUEUE_ITEM, List);
/* Make sure nobody is trying to play smart with us */
ASSERT((ULONG_PTR)WorkItem->WorkerRoutine > MmUserProbeAddress);
/* Call the Worker Routine */
WorkItem->WorkerRoutine(WorkItem->Parameter);
/* Make sure APCs are not disabled */
if (Thread->Tcb.SpecialApcDisable)
{
/* We're nice and do it behind your back */
DPRINT1("Warning: Broken Worker Thread: %p %lx %p came back "
"with APCs disabled!\n",
WorkItem->WorkerRoutine,
WorkItem->Parameter,
WorkItem);
Thread->Tcb.SpecialApcDisable = 0;
}
/* Make sure it returned at right IRQL */
if (KeGetCurrentIrql() != PASSIVE_LEVEL)
{
/* It didn't, bugcheck! */
KeBugCheckEx(WORKER_THREAD_RETURNED_AT_BAD_IRQL,
(ULONG_PTR)WorkItem->WorkerRoutine,
KeGetCurrentIrql(),
(ULONG_PTR)WorkItem->Parameter,
(ULONG_PTR)WorkItem);
}
/* Make sure it returned with Impersionation Disabled */
if (Thread->ActiveImpersonationInfo)
{
/* It didn't, bugcheck! */
KeBugCheckEx(IMPERSONATING_WORKER_THREAD,
(ULONG_PTR)WorkItem->WorkerRoutine,
(ULONG_PTR)WorkItem->Parameter,
(ULONG_PTR)WorkItem,
0);
}
}
/* This is a dynamic thread. Terminate it unless IRPs are pending */
if (!IsListEmpty(&Thread->IrpList)) goto ProcessLoop;
/* Don't terminate it if the queue is disabled either */
if (WorkQueue->Info.QueueDisabled) goto ProcessLoop;
/* Set the worker flags */
do
{
/* Decrease the worker count */
OldValue = WorkQueue->Info;
NewValue = OldValue;
NewValue.WorkerCount--;
}
while (InterlockedCompareExchange((PLONG)&WorkQueue->Info,
*(PLONG)&NewValue,
*(PLONG)&OldValue) != *(PLONG)&OldValue);
/* Decrement dynamic thread count */
InterlockedDecrement(&WorkQueue->DynamicThreadCount);
/* We're not a worker thread anymore */
Thread->ActiveExWorker = FALSE;
/* Re-enable the stack swap */
KeSetKernelStackSwapEnable(TRUE);
return;
}
/*
* @implemented
*/
VOID
NTAPI
FsRtlWorkerThread(IN PVOID StartContext)
{
KIRQL Irql;
PLIST_ENTRY Entry;
PWORK_QUEUE_ITEM WorkItem;
ULONG QueueId = (ULONG)StartContext;
/* Set our priority according to the queue we're dealing with */
KeSetPriorityThread(&PsGetCurrentThread()->Tcb, LOW_REALTIME_PRIORITY + QueueId);
/* Loop for events */
for (;;)
{
/* Look for next event */
Entry = KeRemoveQueue(&FsRtlWorkerQueues[QueueId], KernelMode, NULL);
WorkItem = CONTAINING_RECORD(Entry, WORK_QUEUE_ITEM, List);
/* Call its routine (here: FsRtlStackOverflowRead) */
WorkItem->WorkerRoutine(WorkItem->Parameter);
/* Check we're still at passive level or bugcheck */
Irql = KeGetCurrentIrql();
if (Irql != PASSIVE_LEVEL)
{
KeBugCheckEx(IRQL_NOT_LESS_OR_EQUAL, (ULONG_PTR)WorkItem->WorkerRoutine,
(ULONG_PTR)Irql, (ULONG_PTR)WorkItem->WorkerRoutine,
(ULONG_PTR)WorkItem);
}
}
}