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SIGEVENT

Section: Linux Programmer's Manual (7)

Updated: 2011-09-09

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NAME

sigevent - structure for notification from asynchronous routines

SYNOPSIS

DESCRIPTION

The sigevent structure is used by various APIs to describe the way a process is to be notified about an event (e.g., completion of an asynchronous request, expiration of a timer, or the arrival of a message).

The definition shown in the SYNOPSIS is approximate: some of the fields in the sigevent structure may be defined as part of a union. Programs should employ only those fields relevant to the value specified in sigev_notify.

The sigev_notify field specifies how notification is to be performed. This field can have one of the following values:

SIGEV_NONE
A "null" notification: don't do anything when the event occurs.:
SIGEV_SIGNAL
Notify the process by sending the signal specified in sigev_signo.If the signal is caught with a signal handler that was registered using the sigaction?(2) SA_SIGINFO flag, then the following fields are set in the siginfo_t structure that is passed as the second argument of the handler:

:

si_code
This field is set to a value that depends on the API delivering the notification.:
si_signo
This field is set to the signal number (i.e., the same value as in sigev_signo).:
si_value
This field is set to the value specified in sigev_value.:
Depending on the API, other fields may also be set in the siginfo_t structure.The same information is also available if the signal is accepted using sigwaitinfo?(2).
SIGEV_THREAD
Notify the process by invoking sigev_notify_function "as if" it were the start function of a new thread. (Among the implementation possibilities here are that each timer notification could result in the creation of a new thread, or that a single thread is created to receive all notifications.) The function is invoked with sigev_value as its sole argument. If sigev_notify_attributes is not NULL, it should point to a pthread_attr_t structure that defines attributes for the new thread (see pthread_attr_init?(3)).:
SIGEV_THREAD_ID (Linux-specific)
Currently used only by POSIX timers; see timer_create?(2).:

CONFORMING TO

POSIX.1-2001.

SEE ALSO

timer_create?(2), aio_fsync?(3), aio_read?(3), aio_write?(3), getaddrinfo_a?(3), lio_listio?(3), mq_notify?(3), aio?(7), pthreads?(7)

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Index

NAME

SYNOPSIS

DESCRIPTION

CONFORMING TO

SEE ALSO

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