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IAMDevMemoryControl::WriteSync (Compact 2013)

3/26/2014

This method used to synchronize with the completed write. This method returns when any data being written to the particular allocator region is fully written into the memory.

Syntax

HRESULT WriteSync( );

Parameters

None.

Return Value

Returns an HRESULT value that depends on the implementation of the interface. Common return values include the following.

Value

Description

E_FAIL

A time-out has occurred without this method confirming that data was written.

S_OK

The data was successfully written into memory.

VFW_E_NOT_COMMITTED

The allocator has not called the IMemAllocator::Commit method.

Remarks

This method guarantees that all prior write operations to allocated memory have succeeded. Subsequent memory write operations require another call to WriteSync.

This method is implementation dependent, and is used (when necessary) to synchronize memory write operations to the memory. The driver of the on-board memory provides the implementation.

The IAMDevMemoryControl interface is typically found on memory that is accessed through a Peripheral Component Interconnect (PCI) bridge. (A PCI is a local bus for personal computers that provides a high-speed data path between the processor and peripheral devices.) Memory behind a PCI bridge must be synchronized after a memory write operation completes, if another device will access that memory from behind the PCI bridge. This is because the host access to the memory is buffered through the PCI bridge FIFO (first in first out), and the host will assume the write is completed before the bridge actually writes the data. A subsequent action by a device behind the bridge, such as a SCSI controller, might read the memory before the write is completed, if the IAMDevMemoryControl::WriteSync method is not called.

Requirements

Header

dshow.h

Library

Strmiids.lib

See Also

Reference

IAMDevMemoryControl Interface