NAME¶
iv_task_register, iv_task_unregister, iv_task_registered - deal with ivykis
tasks
SYNOPSIS¶
#include <iv.h>
struct iv_task {
void *cookie;
void (*handler)(void *);
};
void IV_TASK_INIT(struct iv_task *task);
void iv_task_register(struct iv_task *task);
void iv_task_unregister(struct iv_task *task);
int iv_task_registered(struct iv_task *task);
DESCRIPTION¶
The functions
iv_task_register and
iv_task_unregister register,
respectively unregister, a task with the current thread's ivykis event loop.
iv_task_registered on a task returns true if that task is currently
registered with ivykis.
A task is like a timer, but with an immediate timeout. When a task is
registered, unless it is unregistered again first, the callback function
specified by
->handler is guaranteed to be called once, in the
thread that the task was registered in, some time after control returns to the
ivykis main loop but before ivykis will sleep for more events, with
->cookie as its first and sole argument. When this happens, the task
is transparently unregistered.
Tasks are mainly used for scheduling code for execution where it is not
appropriate to directly run that code in the calling context (for example,
because the current context might be run as a callback function where the
caller expects certain conditions to remain invariant after the callback
completes).
The application is allowed to change the
->cookie and
->handler members at any time.
A given
struct iv_task can only be registered in one thread at a time,
and a task can only be unregistered in the thread that it was registered from.
There is no limit on the number of tasks registered at once.
See
iv_examples(3) for programming examples.
SEE ALSO¶
ivykis(3),
iv_examples(3)