IAllocatorMXF::GetMessage method (dmusicks.h)

Article
02/22/2024

The GetMessage method serves as the retrieval point for any DirectMusic kernel-mode component that utilizes the port driver's allocator to reuse DMUS_KERNEL_EVENT structures.

Syntax

NTSTATUS GetMessage(
  [out] PDMUS_KERNEL_EVENT *ppDMKEvt
);

Parameters

[out] ppDMKEvt

Output pointer for the MIDI event. This parameter points to a caller-allocated pointer variable into which the method writes a pointer to the event structure being retrieved from the allocator. The structure itself is empty (zeroed by the allocator).

Return value

GetMessage returns S_OK if the call was successful. Otherwise, the method returns an appropriate error code.

Remarks

The miniport driver uses the GetMessage method to retrieve event structures for MIDI rendering and capture. This method retrieves DMUS_KERNEL_EVENT structures from the same pool that IMXF::PutMessage puts them into when it discards them to the allocator.

In the case of a MIDI capture stream, the port driver retrieves capture events from the miniport driver when prompted by the usual Service DPC.

For more information about the allocator, see Allocator.

Requirements

Requirement	Value
Target Platform	Desktop
Header	dmusicks.h (include Dmusicks.h)
IRQL	<=DISPATCH_LEVEL