# hwloc_obj Struct Reference
[Topology Objects]

Structure of a topology object. More...

`#include <hwloc.h>`

## Data Fields
hwloc_obj_type_t | type
| Type of object.
unsigned | os_index
| OS-provided physical index number.
char * | name
| Object description if any.
struct hwloc_obj_memory_s | memory
| Memory attributes.
union hwloc_obj_attr_u * | attr
| Object type-specific Attributes.
unsigned | depth
| Vertical index in the hierarchy.
unsigned | logical_index
| Horizontal index in the whole list of similar objects, could be a "cousin_rank" since it's the rank within the "cousin" list below.
signed | os_level
| OS-provided physical level, -1 if unknown or meaningless.
struct hwloc_obj * | next_cousin
| Next object of same type.
struct hwloc_obj * | prev_cousin
| Previous object of same type.
struct hwloc_obj * | parent
| Parent, `NULL` if root (system object).
unsigned | sibling_rank
| Index in parent's `children`[] array.
struct hwloc_obj * | next_sibling
| Next object below the same parent.
struct hwloc_obj * | prev_sibling
| Previous object below the same parent.
unsigned | arity
| Number of children.
struct hwloc_obj ** | children
| Children, `children`[0 .. arity -1].
struct hwloc_obj * | first_child
| First child.
struct hwloc_obj * | last_child
| Last child.
void * | userdata
| Application-given private data pointer, initialized to `NULL`, use it as you wish.
hwloc_cpuset_t | cpuset
| CPUs covered by this object.
hwloc_cpuset_t | complete_cpuset
| The complete CPU set of logical processors of this object,.
hwloc_cpuset_t | online_cpuset
| The CPU set of online logical processors.
hwloc_cpuset_t | allowed_cpuset
| The CPU set of allowed logical processors.
hwloc_cpuset_t | nodeset
| NUMA nodes covered by this object or containing this object.
hwloc_cpuset_t | complete_nodeset
| The complete NUMA node set of this object,.
hwloc_cpuset_t | allowed_nodeset
| The set of allowed NUMA memory nodes.

## Detailed Description

Structure of a topology object.

Applications mustn't modify any field except userdata .

## Field Documentation

hwloc_cpuset_t hwloc_obj::allowed_cpuset

The CPU set of allowed logical processors.

This includes the CPUs contained in this object which are allowed for binding, i.e. passing them to the hwloc binding functions should not return permission errors. This is usually restricted by administration rules. Some of them may however be offline so binding to them may still not be possible, see online_cpuset.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

hwloc_cpuset_t hwloc_obj::allowed_nodeset

The set of allowed NUMA memory nodes.

This includes the NUMA memory nodes contained in this object which are allowed for memory allocation, i.e. passing them to NUMA node-directed memory allocation should not return permission errors. This is usually restricted by administration rules.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

unsigned hwloc_obj::arity

Number of children.

union hwloc_obj_attr_u* hwloc_obj::attr

Object type-specific Attributes.

struct hwloc_obj** hwloc_obj::children

Children, `children`[0 .. arity -1].

hwloc_cpuset_t hwloc_obj::complete_cpuset

The complete CPU set of logical processors of this object,.

This includes not only the same as the cpuset field, but also the CPUs for which topology information is unknown or incomplete, and the CPUs that are ignored when the HWLOC_TOPOLOGY_FLAG_WHOLE_SYSTEM flag is not set. Thus no corresponding PU object may be found in the topology, because the precise position is undefined. It is however known that it would be somewhere under this object.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

hwloc_cpuset_t hwloc_obj::complete_nodeset

The complete NUMA node set of this object,.

This includes not only the same as the nodeset field, but also the NUMA nodes for which topology information is unknown or incomplete, and the nodes that are ignored when the HWLOC_TOPOLOGY_FLAG_WHOLE_SYSTEM flag is not set. Thus no corresponding NODE object may be found in the topology, because the precise position is undefined. It is however known that it would be somewhere under this object.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

hwloc_cpuset_t hwloc_obj::cpuset

CPUs covered by this object.

This is the set of CPUs for which there are PU objects in the topology under this object, i.e. which are known to be physically contained in this object and known how (the children path between this object and the PU objects).

If the HWLOC_TOPOLOGY_FLAG_WHOLE_SYSTEM configuration flag is set, some of these CPUs may be offline, or not allowed for binding, see online_cpuset and allowed_cpuset.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

unsigned hwloc_obj::depth

Vertical index in the hierarchy.

struct hwloc_obj* hwloc_obj::first_child

First child.

struct hwloc_obj* hwloc_obj::last_child

Last child.

unsigned hwloc_obj::logical_index

Horizontal index in the whole list of similar objects, could be a "cousin_rank" since it's the rank within the "cousin" list below.

struct hwloc_obj_memory_s hwloc_obj::memory

Memory attributes.

char* hwloc_obj::name

Object description if any.

struct hwloc_obj* hwloc_obj::next_cousin

Next object of same type.

struct hwloc_obj* hwloc_obj::next_sibling

Next object below the same parent.

hwloc_cpuset_t hwloc_obj::nodeset

NUMA nodes covered by this object or containing this object.

This is the set of NUMA nodes for which there are NODE objects in the topology under or above this object, i.e. which are known to be physically contained in this object or containing it and known how (the children path between this object and the NODE objects).

If the HWLOC_TOPOLOGY_FLAG_WHOLE_SYSTEM configuration flag is set, some of these nodes may not be allowed for allocation, see allowed_nodeset.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

hwloc_cpuset_t hwloc_obj::online_cpuset

The CPU set of online logical processors.

This includes the CPUs contained in this object that are online, i.e. draw power and can execute threads. It may however not be allowed to bind to them due to administration rules, see allowed_cpuset.

Note:
  Its value must not be changed, hwloc_cpuset_dup must be used instead.

unsigned hwloc_obj::os_index

OS-provided physical index number.

signed hwloc_obj::os_level

OS-provided physical level, -1 if unknown or meaningless.

struct hwloc_obj* hwloc_obj::parent

Parent, `NULL` if root (system object).

struct hwloc_obj* hwloc_obj::prev_cousin

Previous object of same type.

struct hwloc_obj* hwloc_obj::prev_sibling

Previous object below the same parent.

unsigned hwloc_obj::sibling_rank

Index in parent's `children`[] array.

hwloc_obj_type_t hwloc_obj::type

Type of object.

void* hwloc_obj::userdata

Application-given private data pointer, initialized to `NULL`, use it as you wish.

The documentation for this struct was generated from the following file:

- hwloc.h