Topology Creation and Destruction

## Typedefs

typedef struct hwloc_topology * | hwloc_topology_t

## Functions

int | hwloc_topology_init (hwloc_topology_t *topologyp)
int | hwloc_topology_load (hwloc_topology_t topology)
void | hwloc_topology_destroy (hwloc_topology_t topology)
int | hwloc_topology_dup (hwloc_topology_t *newtopology, hwloc_topology_t oldtopology)
int | hwloc_topology_abi_check (hwloc_topology_t topology)
void | hwloc_topology_check (hwloc_topology_t topology)

## Detailed Description

## Typedef Documentation

## hwloc_topology_t

typedef struct hwloc_topology* hwloc_topology_t

Topology context.

To be initialized with hwloc_topology_init() and built with hwloc_topology_load().

## Function Documentation

## hwloc_topology_abi_check()

int hwloc_topology_abi_check | ( | hwloc_topology_t | topology | ) |

Verify that the topology is compatible with the current hwloc library.

This is useful when using the same topology structure (in memory) in different libraries that may use different hwloc installations (for instance if one library embeds a specific version of hwloc, while another library uses a default system-wide hwloc installation).

If all libraries/programs use the same hwloc installation, this function always returns success.

Returns
  `0` on success.
  `-1` with `errno` set to `EINVAL` if incompatible.

Note
  If sharing between processes with hwloc_shmem_topology_write(), the relevant check is already performed inside hwloc_shmem_topology_adopt().

## hwloc_topology_check()

void hwloc_topology_check | ( | hwloc_topology_t | topology | ) |

Run internal checks on a topology structure.

The program aborts if an inconsistency is detected in the given topology.

Parameters

  topology | is the topology to be checked

Note
  This routine is only useful to developers.
  The input topology should have been previously loaded with hwloc_topology_load().

## hwloc_topology_destroy()

void hwloc_topology_destroy | ( | hwloc_topology_t | topology | ) |

Terminate and free a topology context.

Parameters

  topology | is the topology to be freed

## hwloc_topology_dup()

int hwloc_topology_dup | ( | hwloc_topology_t * | newtopology,
|  | hwloc_topology_t | oldtopology
| ) |  |

Duplicate a topology.

The entire topology structure as well as its objects are duplicated into a new one.

This is useful for keeping a backup while modifying a topology.

Note
  Object userdata is not duplicated since hwloc does not know what it point to. The objects of both old and new topologies will point to the same userdata.

## hwloc_topology_init()

int hwloc_topology_init | ( | hwloc_topology_t * | topologyp | ) |

Allocate a topology context.

Parameters

  [out] | topologyp | is assigned a pointer to the new allocated context.

Returns
  0 on success, -1 on error.

## hwloc_topology_load()

int hwloc_topology_load | ( | hwloc_topology_t | topology | ) |

Build the actual topology.

Build the actual topology once initialized with hwloc_topology_init() and tuned with Topology Detection Configuration and Query and Changing the Source of Topology Discovery routines. No other routine may be called earlier using this topology context.

Parameters

  topology | is the topology to be loaded with objects.

Returns
  0 on success, -1 on error.

Note
  On failure, the topology is reinitialized. It should be either destroyed with hwloc_topology_destroy() or configured and loaded again.
  This function may be called only once per topology.
  The binding of the current thread or process may temporarily change during this call but it will be restored before it returns.

See also
  Topology Detection Configuration and Query and Changing the Source of Topology Discovery