memory_object_data_error

Function - An error prevents the supply of previously requested data.

SYNOPSIS

kern_return_t   memory_object_data_error
                (memory_object_control_t         memory_control,
                 vm_offset_t                             offset,
                 vm_size_t                                 size,
                 kern_return_t                           reason);

PARAMETERS

memory_control

[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 memory_object_create call.

offset

[in scalar] The offset within the memory object, in bytes.

size

[in scalar] The number of bytes of data (starting at offset). The number must convert to an integral number of memory object pages.

reason

[in scalar] Reason for the error.

DESCRIPTION

The memory_object_data_error function indicates that the memory manager cannot provide the kernel with the data requested for the given region, specifying a reason for the error.

When the kernel issues a memory_object_data_request call, the memory manager can respond with a memory_object_data_error call to indicate that the page cannot be retrieved, and that a memory failure exception should be raised in any client threads that are waiting for the page. Clients are permitted to catch these exceptions and retry their page faults. As a result, this call can be used to report transient errors as well as permanent ones. A memory manager can use this call for both hardware errors (for example, disk failures) and software errors (for example, accessing data that does not exist or is protected).

NOTES

If reason has a system code of err_kern, the kernel will substitute an error value of KERN_MEMORY_ERROR.

RETURN VALUES

Only generic errors apply.

RELATED INFORMATION

Functions: memory_object_data_request, memory_object_data_supply, memory_object_data_unavailable.