VideoPortWaitForSingleObject function (video.h)

Artikel
10/21/2021

The VideoPortWaitForSingleObject function puts the current thread into a wait state until the given dispatch object is set to the signaled state, or (optionally) until the wait times out.

Syntax

VIDEOPORT_API VP_STATUS VideoPortWaitForSingleObject(
  [in] IN PVOID          HwDeviceExtension,
  [in] IN PVOID          Object,
  [in] IN PLARGE_INTEGER Timeout
);

Parameters

[in] HwDeviceExtension

Pointer to the miniport driver's device extension.

[in] Object

Pointer to the event object.

[in] Timeout

(Optional) Pointer to a time-out value that specifies the absolute or relative time at which the wait is to be completed. A negative value specifies a wait interval relative to the current time. The value should be expressed in units of 100 nanoseconds. Absolute expiration times track any changes in the system time; relative expiration times are not affected by system time changes.

Return value

VideoPortWaitForSingleObject returns one of the following values:

Return code	Description
ERROR_INVALID_PARAMETER	One of the parameters is invalid or the call attempted to wait for a mapped user event.
NO_ERROR	The event object specified in the pObject parameter satisfied the wait.
WAIT_TIMEOUT	A time-out occurred before the event object was set to the signaled state. This value can be returned when the specified set of wait conditions cannot be immediately met and Timeout is set to zero.

Remarks

The miniport driver should not attempt to wait for a mapped user event.

Callers of VideoPortWaitForSingleObject must be running at IRQL <= DISPATCH_LEVEL. Usually, the caller will be running at IRQL = PASSIVE_LEVEL and in a nonarbitrary thread context. A call to this function while running at IRQL = DISPATCH_LEVEL is valid if and only if the caller specifies a Timeout value of zero. That is, a miniport driver must not wait for a nonzero interval at IRQL = DISPATCH_LEVEL.

Requirements

Requirement	Value
Minimum supported client	Available in Windows XP and later versions of the Windows operating systems.
Target Platform	Desktop
Header	video.h (include Video.h)
Library	Videoprt.lib
DLL	Videoprt.sys
IRQL	<= DISPATCH_LEVEL (see Remarks section)

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