diff options
Diffstat (limited to 'usr/src/man/man3c/signalfd.3c')
-rw-r--r-- | usr/src/man/man3c/signalfd.3c | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/usr/src/man/man3c/signalfd.3c b/usr/src/man/man3c/signalfd.3c index fecd46e124..070bafc854 100644 --- a/usr/src/man/man3c/signalfd.3c +++ b/usr/src/man/man3c/signalfd.3c @@ -30,14 +30,15 @@ The .Fn signalfd function returns a file descriptor that can be used -for synchronous consumption of signals. The file descriptor can be operated -upon via +for synchronous consumption of signals. +The file descriptor can be operated upon via .Xr read 2 and the facilities that notify of file descriptor activity (e.g. .Xr poll 2 , .Xr port_get 3C , .Xr epoll_wait 3C -). To dispose of the instance +). +To dispose of the instance .Xr close 2 should be called on the file descriptor. .Pp @@ -72,7 +73,8 @@ see description for in .Xr open 2 . .It Sy SFD_NONBLOCK -Instance will be set to be non-blocking. A +Instance will be set to be non-blocking. +A .Xr read 2 on a signalfd instance that has been initialized with .Fa SFD_NONBLOCK , @@ -85,10 +87,10 @@ that are pending. .Pp As with .Xr sigwait 2 , -reading a signal from the file descriptor will consume the signal. The signals -used with signalfd file descriptors are normally first blocked so that their -handler does not run when a signal arrives. If the signal is not blocked the -behavior matches that of +reading a signal from the file descriptor will consume the signal. +The signals used with signalfd file descriptors are normally first blocked so +that their handler does not run when a signal arrives. +If the signal is not blocked the behavior matches that of .Xr sigwait 2 ; if a .Xr read 2 @@ -154,19 +156,21 @@ typedef struct signalfd_siginfo { File descriptor duplication during fork presents a challenge to the .Sy signalfd facility since signal data and events are dependent on the process from which -they are queried. Its use with caching event systems such as +they are queried. +Its use with caching event systems such as .Xr epoll 5 , -.Sy /dev/poll , +.Pa /dev/poll , or .Xr port_create 3C can result in undefined behavior if signalfd and polling descriptors are used -together after being shared across a fork. Such restrictions do not apply if -the child only calls +together after being shared across a fork. +Such restrictions do not apply if the child only calls .Xr close 2 on the descriptors. .Sh RETURN VALUES Upon successful completion, a file descriptor associated with the instance -is returned. Otherwise, -1 is returned and errno is set to indicate the error. +is returned. +Otherwise, -1 is returned and errno is set to indicate the error. When .Va fd is not -1 and there is no error, the value of |