<h2>memory_object_data_unavailable</h2>

<strong>Function</strong> - Instruct kernel to zero-fill pages as requested data does not exist.

<h3>SYNOPSIS</h3>

<strong>kern_return_t memory_object_data_unavailable</strong>

<strong>(memory_object_control_t</strong> <var>memory_control</var>,

<strong>vm_offset_t</strong> <var>offset</var>,

<strong>vm_size_t</strong> <var>size</var><strong>);</strong>

<h3>PARAMETERS</h3>

<dt> <var>memory_control</var>

[in memory-cache-control send right]

The memory cache control port

to be used by the memory manager for cache management requests.

This port is provided by the kernel in a <strong>memory_object_init</strong> or a

<strong>memory_object_create</strong> call.

<dt> <var>offset</var>

[in scalar]

The offset within the memory object, in bytes.

<dt> <var>size</var>

[in scalar]

The number of bytes of data (starting at <var>offset</var>). The number

must convert to an integral number of memory object pages.

<h3>DESCRIPTION</h3>

The <strong>memory_object_data_unavailable</strong> function indicates

that the memory

manager cannot provide the kernel with the data requested for

the given region.

Instead, the kernel should provide the data for this region.

A memory manager can use this call in any of the following situations:

When the object was created by the kernel

(via <strong>memory_object_create</strong>) and

the kernel has not yet provided data for the region (via either

<strong>memory_object_data_initialize</strong> or <strong>memory_object_data_return</strong>).

In this case, the

object is a temporary memory object; the memory manager is the default

memory manager; and the kernel should provide zero-filled pages for the

object.

<p>

When the object is a normal user-created memory object. In this case, the

kernel should provide zero-filled pages for the region.

<h3>RETURN VALUES</h3>

Only generic errors apply.

<h3>RELATED INFORMATION</h3>

Functions:

<a href="memory_object_create.html"><strong>memory_object_create</strong></a>,

<a href="memory_object_data_error.html"><strong>memory_object_data_error</strong></a>,

<a href="memory_object_data_request.html"><strong>memory_object_data_request</strong></a>,

<a href="memory_object_data_supply.html"><strong>memory_object_data_supply</strong></a>.