| UID | title | description | old-location | tech.root | ms.date | keywords | ms.keywords | req.header | req.include-header | req.target-type | req.target-min-winverclnt | req.target-min-winversvr | req.kmdf-ver | req.umdf-ver | req.ddi-compliance | req.unicode-ansi | req.idl | req.max-support | req.namespace | req.assembly | req.type-library | req.lib | req.dll | req.irql | targetos | req.typenames | f1_keywords | topic_type | api_type | api_location | api_name | ||||||||
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NF:video.VideoPortAcquireSpinLockAtDpcLevel |
VideoPortAcquireSpinLockAtDpcLevel function (video.h) |
The VideoPortAcquireSpinLockAtDpcLevel function acquires a spin lock when the caller is already running at IRQL = DISPATCH_LEVEL. |
display\videoportacquirespinlockatdpclevel.htm |
display |
05/10/2018 |
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VideoPortAcquireSpinLockAtDpcLevel, VideoPortAcquireSpinLockAtDpcLevel function [Display Devices], VideoPort_Functions_fc52bdfd-6f1a-4f5c-93e6-321d2488bcd5.xml, display.videoportacquirespinlockatdpclevel, video/VideoPortAcquireSpinLockAtDpcLevel |
video.h |
Video.h |
Desktop |
Available in Windows XP and later versions of the Windows operating systems. |
Videoprt.lib |
Videoprt.sys |
DISPATCH_LEVEL (see Remarks section) |
Windows |
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The VideoPortAcquireSpinLockAtDpcLevel function acquires a spin lock when the caller is already running at IRQL = DISPATCH_LEVEL.
Pointer to the miniport driver's device extension.
Pointer to a memory location that contains the spin lock.
None
Miniport drivers call VideoPortAcquireSpinLockAtDpcLevel instead of VideoPortAcquireSpinLock for better driver performance if and only if they are already running at IRQL = DISPATCH_LEVEL.
If a miniport driver is running at IRQL < DISPATCH_LEVEL, it should call VideoPortAcquireSpinLock to have IRQL raised by that routine. VideoPortAcquireSpinLockAtDpcLevel requires the caller to be running already at IRQL = DISPATCH_LEVEL, so no raise is necessary.
The caller should release the spin lock with VideoPortReleaseSpinLockFromDpcLevel as quickly as possible.