Проект OpenNet: MAN sysevent_bind_handle (3) Библиотечные вызовы (FreeBSD и Linux)

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sysevent_bind_handle (3)

>> sysevent_bind_handle (3) ( Solaris man: Библиотечные вызовы )

NAME

sysevent_bind_handle, sysevent_unbind_handle - bind or unbind subscriber handle

SYNOPSIS

cc [flag...]  file ... -lsysevent [library ...] 
#include <libsysevent.h>

sysevent_handle_t *sysevent_bind_handle(void (*event_handler)
    (sysevent_t *ev));

void sysevent_unbind_handle(sysevent_handle_t *sysevent_hdl);

PARAMETERS

: pointer to sysevent buffer handle

event_handler

: pointer to an event handling function

sysevent_hdl

: pointer to a sysevent subscriber handle

DESCRIPTION

The sysevent_bind_handle() function allocates memory associated with a subscription handle and binds it to the caller's event_handler. The event_handler is invoked during subsequent system event notifications once a subscription has been made with sysevent_subscribe_event(3SYSEVENT).

The system event is represented by the argument ev and is passed as an argument to the invoked event delivery function, event_handler.

Additional threads are created to service communication between syseventd(1M) and the calling process and to run the event handler routine, event_handler.

The sysevent_unbind_handle() function deallocates memory and other resources associated with a subscription handle and deactivates all system event notifications for the calling process. All event notifications are guaranteed to stop upon return from sysevent_unbind_handle().

RETURN VALUES

The sysevent_bind_handle() function returns a valid sysevent subscriber handle if the handle is successfully allocated. Otherwise, NULL is returned and errno is set to indicate the error.

The sysevent_unbind_handle() function returns no value.

ERRORS

The sysevent_bind_handle() function will fail if:

EACCES

: The calling process has an ID other than the privileged user.

EBUSY

: There are no resources available.

EINVAL

: The pointer to the function event_handler is NULL.

EMFILE

: The process has too many open descriptors.

ENOMEM

: There are insufficient resources to allocate the handle.

ATTRIBUTES

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

ATTRIBUTE TYPE ATTRIBUTE VALUE

Interface Stability Evolving

MT-Level

NOTES

Event notifications are revoked by syseventd when the bound process dies. Event notification is suspended if a signal is caught and handled by the event_handler thread. Event notification is also suspended when the calling process attempts to use fork(2) or fork1(2). Event notifications might be lost during suspension periods.