Get a handle to a condition in an entity
#include <ha/ham.h> ham_condition_t *ham_condition_handle( int nd, const char *ename, const char *cname, unsigned flags ); ham_condition_t *ham_condition_handle_node( const char *nodename, const char *ename, const char *cname, unsigned flags );
The ham_condition_handle() function returns a handle to a condition (cname) in an entity (ename).
The handle obtained from this function can be passed to other functions, such as ham_action_restart() or ham_condition_handle_free().
|To get a handle for a global entity, pass NULL for ename.|
The handle returned is opaque — its contents are internal to the library.
If a node (nd) is specified, the handle is to an entity/condition/action combination that refers to a process on that remote node. The ham_condition_handle_node() function is used when a nodename is used to specify a remote HAM instead of a node identifier (nd).
There are no flags defined at this time.
A valid ham_condition_t, or NULL if an error occurred (errno is set).
A call to ham_condition_handle() and a subsequent use of the handle returned in a call such as ham_action_restart() are completely asynchronous. Therefore, a valid action/condition/entity may no longer exist when the handle is used to attach actions at a later time.
In such an event, the ham_action*() functions will return an error (ENOENT) that the condition doesn't exist in the given entity.
ham_action_execute(), ham_action_handle(), ham_action_handle_free(), ham_action_notify_pulse(), ham_action_notify_signal(), ham_action_remove(), ham_action_restart(), ham_action_waitfor(), ham_condition_handle_free(), ham_entity_handle(), ham_entity_handle_free()