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Diffstat (limited to 'general/SimpleMediaSource/SimpleMediaSourceDriver/Queue.c')
| -rw-r--r-- | general/SimpleMediaSource/SimpleMediaSourceDriver/Queue.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/general/SimpleMediaSource/SimpleMediaSourceDriver/Queue.c b/general/SimpleMediaSource/SimpleMediaSourceDriver/Queue.c new file mode 100644 index 00000000..6ea51781 --- /dev/null +++ b/general/SimpleMediaSource/SimpleMediaSourceDriver/Queue.c @@ -0,0 +1,193 @@ +/*++ + +Module Name: + + queue.c + +Abstract: + + This file contains the queue entry points and callbacks. + +Environment: + + User-mode Driver Framework 2 + +--*/ + +#include "driver.h" +#include "queue.tmh" + +NTSTATUS +SimpleMediaSourceDriverQueueInitialize( + _In_ WDFDEVICE Device + ) +/*++ + +Routine Description: + + The I/O dispatch callbacks for the frameworks device object + are configured in this function. + + A single default I/O Queue is configured for parallel request + processing, and a driver context memory allocation is created + to hold our structure QUEUE_CONTEXT. + +Arguments: + + Device - Handle to a framework device object. + +Return Value: + + VOID + +--*/ +{ + WDFQUEUE queue; + NTSTATUS status; + WDF_IO_QUEUE_CONFIG queueConfig; + + // + // Configure a default queue so that requests that are not + // configure-fowarded using WdfDeviceConfigureRequestDispatching to goto + // other queues get dispatched here. + // + WDF_IO_QUEUE_CONFIG_INIT_DEFAULT_QUEUE( + &queueConfig, + WdfIoQueueDispatchParallel + ); + + queueConfig.EvtIoDeviceControl = SimpleMediaSourceDriverEvtIoDeviceControl; + queueConfig.EvtIoStop = SimpleMediaSourceDriverEvtIoStop; + + status = WdfIoQueueCreate( + Device, + &queueConfig, + WDF_NO_OBJECT_ATTRIBUTES, + &queue + ); + + if(!NT_SUCCESS(status)) { + TraceEvents(TRACE_LEVEL_ERROR, TRACE_QUEUE, "WdfIoQueueCreate failed %!STATUS!", status); + return status; + } + + return status; +} + +VOID +SimpleMediaSourceDriverEvtIoDeviceControl( + _In_ WDFQUEUE Queue, + _In_ WDFREQUEST Request, + _In_ size_t OutputBufferLength, + _In_ size_t InputBufferLength, + _In_ ULONG IoControlCode + ) +/*++ + +Routine Description: + + This event is invoked when the framework receives IRP_MJ_DEVICE_CONTROL request. + +Arguments: + + Queue - Handle to the framework queue object that is associated with the + I/O request. + + Request - Handle to a framework request object. + + OutputBufferLength - Size of the output buffer in bytes + + InputBufferLength - Size of the input buffer in bytes + + IoControlCode - I/O control code. + +Return Value: + + VOID + +--*/ +{ + TraceEvents(TRACE_LEVEL_INFORMATION, + TRACE_QUEUE, + "%!FUNC! Queue 0x%p, Request 0x%p OutputBufferLength %d InputBufferLength %d IoControlCode %d", + Queue, Request, (int) OutputBufferLength, (int) InputBufferLength, IoControlCode); + + WdfRequestComplete(Request, STATUS_SUCCESS); + + return; +} + +VOID +SimpleMediaSourceDriverEvtIoStop( + _In_ WDFQUEUE Queue, + _In_ WDFREQUEST Request, + _In_ ULONG ActionFlags +) +/*++ + +Routine Description: + + This event is invoked for a power-managed queue before the device leaves the working state (D0). + +Arguments: + + Queue - Handle to the framework queue object that is associated with the + I/O request. + + Request - Handle to a framework request object. + + ActionFlags - A bitwise OR of one or more WDF_REQUEST_STOP_ACTION_FLAGS-typed flags + that identify the reason that the callback function is being called + and whether the request is cancelable. + +Return Value: + + VOID + +--*/ +{ + TraceEvents(TRACE_LEVEL_INFORMATION, + TRACE_QUEUE, + "%!FUNC! Queue 0x%p, Request 0x%p ActionFlags %d", + Queue, Request, ActionFlags); + + // + // In most cases, the EvtIoStop callback function completes, cancels, or postpones + // further processing of the I/O request. + // + // Typically, the driver uses the following rules: + // + // - If the driver owns the I/O request, it calls WdfRequestUnmarkCancelable + // (if the request is cancelable) and either calls WdfRequestStopAcknowledge + // with a Requeue value of TRUE, or it calls WdfRequestComplete with a + // completion status value of STATUS_SUCCESS or STATUS_CANCELLED. + // + // Before it can call these methods safely, the driver must make sure that + // its implementation of EvtIoStop has exclusive access to the request. + // + // In order to do that, the driver must synchronize access to the request + // to prevent other threads from manipulating the request concurrently. + // The synchronization method you choose will depend on your driver's design. + // + // For example, if the request is held in a shared context, the EvtIoStop callback + // might acquire an internal driver lock, take the request from the shared context, + // and then release the lock. At this point, the EvtIoStop callback owns the request + // and can safely complete or requeue the request. + // + // - If the driver has forwarded the I/O request to an I/O target, it either calls + // WdfRequestCancelSentRequest to attempt to cancel the request, or it postpones + // further processing of the request and calls WdfRequestStopAcknowledge with + // a Requeue value of FALSE. + // + // A driver might choose to take no action in EvtIoStop for requests that are + // guaranteed to complete in a small amount of time. + // + // In this case, the framework waits until the specified request is complete + // before moving the device (or system) to a lower power state or removing the device. + // Potentially, this inaction can prevent a system from entering its hibernation state + // or another low system power state. In extreme cases, it can cause the system + // to crash with bugcheck code 9F. + // + + return; +} |