pool_get_binding

, pool_set_binding

, pool_get_resource_binding

- set and query process to resource pool bindings

Synopsis

cc [ flag… ] file… -lpool [ library… ] 
#include <pool.h>

char *pool_get_binding(pid_t pid);

int pool_set_binding(const char *pool, idtype_t idtype,
     id_t id);

char *pool_get_resource_binding(const char *type, pid_t pid);

Description

The pool_get_binding() function returns the name of the pool on the running system that contains the set of resources to which the given process is bound. If no such pool exists on the system or the search returns more than one pool (since the set of resources is referred to by more than one pool), NULL is returned and the pool error value is set to POE_INVALID_SEARCH.

It is possible that one of the resources to which the given process is bound is not associated with a pool. This could occur if a processor set was created with one of the pset_() functions and the process was then bound to that set. It could also occur if the process was bound to a resource set not currently associated with a pool, since resources can exist that are not associated with a pool.

The pool_set_binding() function binds the processes matching idtype and id to the resources associated with pool on the running system. This function requires the privilege required by the underlying resource types referenced by the pool; generally, this requirement is equivalent to requiring superuser privilege.

The idtype parameter can be of the following types:

P_PID

The id parameter is a pid.

P_TASKID

The id parameter is a taskid.

P_PROJID

The id parameter is a project ID. All currently running processes belonging to the given project will be bound to the pool's resources.

The pool_get_resource_binding() function returns the name of the resource of the supplied type to which the supplied process is bound.

The application must explicity free the memory allocated for the return values for pool_get_binding() and pool_get_resource_binding().

Return Values

Upon successful completion, pool_get_binding() returns the name of the pool to which the process is bound. Otherwise it returns NULL and pool_error(3POOL) returns the pool-specific error value.

Upon successful completion, pool_set_binding() returns PO_SUCCESS. Otherwise, it returns PO_FAIL and pool_error() returns the pool-specific error value.

Upon successful completion, pool_get_resource_binding() returns the name of the resource of the specified type to which the process is bound. Otherwise it returns NULL and pool_error() returns the pool-specific error value.

Errors

The pool_get_binding() function will fail if:

POE_INVALID_CONF

The configuration is invalid.

POE_INVALID_SEARCH

It is not possible to determine the binding for this target due to the overlapping nature of the pools configured for this system, or the pool could not be located.

POE_SYSTEM

A system error has occurred. Check the system error code for more details.

The pool_set_binding() function will fail if:

POE_INVALID_SEARCH

The pool could not be found.

POE_INVALID_CONF

The configuration is invalid.

POE_SYSTEM

A system error has occurred. Check the system error code for more details.

The pool_get_resource_binding() function will fail if:

POE_INVALID_CONF

The configuration is invalid.

POE_INVALID_SEARCH

The target is not bound to a resource of the specified type.

POE_SYSTEM

A system error has occurred. Check the system error code for more details.

Examples

Example 1 Bind the current process to the pool named “target”.

#include <sys/types.h>
#include <pool.h>
#include <unistd.h>
 
...
 
id_t pid = getpid();
 
...
 
if (pool_set_binding("target", P_PID, pid) == PO_FAIL) \{
        (void) fprintf(stderr, "pool binding failed (\%d)\B{}n",
                 pool_error());
\}

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

libpool(3LIB), pool_error(3POOL), attributes(5)