HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. |  |
NAME |SYNOPSIS |DESCRIPTION |STANDARDS |HISTORY |NOTES |SEE ALSO |COLOPHON | |
sigevent(3type)sigevent(3type)sigevent, sigval - structure for notification from asynchronous routines
#include <signal.h>struct sigevent {int sigev_notify;/* Notification type */int sigev_signo;/* Signal number */union sigval sigev_value;/* Data passed with notification */typeof(void (union sigval)) *sigev_notify_function; /* Notification function (SIGEV_THREAD) */pthread_attr_t *sigev_notify_attributes; /* Notification attributes */ /* Linux only: */pid_t sigev_notify_thread_id; /* ID of thread to signal (SIGEV_THREAD_ID) */};union sigval {/* Data passed with notification */int sival_int;/* Integer value */void *sival_ptr;/* Pointer value */};sigevent Thesigevent 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 thesigevent structure may be defined as part of a union. Programs should employ only those fields relevant to the value specified insigev_notify. Thesigev_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 insigev_signo. If the signal is caught with a signal handler that was registered using thesigaction(2)SA_SIGINFOflag, then the following fields are set in thesiginfo_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 insigev_signo).si_value This field is set to the value specified insigev_value. Depending on the API, other fields may also be set in thesiginfo_t structure. The same information is also available if the signal is accepted usingsigwaitinfo(2).SIGEV_THREAD Notify the process by invokingsigev_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 withsigev_value as its sole argument. Ifsigev_notify_attributes is not NULL, it should point to apthread_attr_t structure that defines attributes for the new thread (seepthread_attr_init(3)).SIGEV_THREAD_ID(Linux-specific) Currently used only by POSIX timers; seetimer_create(2).sigval Data passed with a signal.
POSIX.1-2008.
POSIX.1-2001.<aio.h> and<time.h> definesigevent since POSIX.1-2008.
The following headers also providesigevent:<aio.h>,<mqueue.h>, and<time.h>.
timer_create(2),getaddrinfo_a(3),lio_listio(3),mq_notify(3),pthread_sigqueue(3),sigqueue(3),aiocb(3type),siginfo_t(3type)
This page is part of theman-pages (Linux kernel and C library user-space interface documentation) project. Information about the project can be found at ⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report for this manual page, see ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩. This page was obtained from the tarball man-pages-6.15.tar.gz fetched from ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on 2025-08-11. If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up- to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orgLinux man-pages 6.15 2025-05-17sigevent(3type)Pages that refer to this page:timer_create(2), aio_cancel(3), aio_fsync(3), aio_read(3), aio_write(3), getaddrinfo_a(3), lio_listio(3), mq_notify(3), aio(7), pthreads(7), signal(7)
HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |