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.Dd $Mdocdate: November 12 2018 $ .Dt SIGIO_INIT 9 .Os .Sh NAME .Nm sigio_init , .Nm sigio_free , .Nm sigio_copy , .Nm sigio_setown , .Nm sigio_getown .Nd asynchronous IO signal API .Sh SYNOPSIS n sys/sigio.h .Ft void .Fn "sigio_init" "struct sigio_ref *sir" .Ft void .Fn "sigio_free" "struct sigio_ref *sir" .Ft void .Fn "sigio_copy" "struct sigio_ref *dst" "struct sigio_ref *src" .Ft int .Fn "sigio_setown" "struct sigio_ref *sir" "pid_t pgid" .Ft pid_t .Fn "sigio_getown" "struct sigio_ref *sir" .Sh DESCRIPTION The asynchronous IO signal API provides means to manage signal registrations. It allows associating a process or process group with a signal source. The association is revoked automatically when the process or process group is deleted.
p .Fn sigio_init initializes the sigio reference .Fa sir .
p .Fn sigio_free clears any process or process group associated with reference .Fa sir .
p .Fn sigio_copy copies registration from reference .Fa src to reference .Fa dst .
p .Fn sigio_setown associates the reference .Fa sir with a process or process group. If .Fa pgid is positive, the ID is taken as a process ID. If .Fa pgid is negative, the ID is taken as a process group ID. The reference .Fa sir is cleared if .Fa pgid is zero.
p When .Fn sigio_setown is called, the invoking process' credentials are stored in the reference. These credentials are checked when the reference is used with .Xr pgsigio 9 .
p .Fn sigio_getown returns the ID of the process or process group associated with the reference .Fa sir . .Sh CONTEXT .Fn sigio_init , .Fn sigio_free , .Fn sigio_copy , .Fn sigio_setown and .Fn sigio_getown can be called during autoconf, or from process context. .Sh RETURN VALUES The .Fn sigio_setown returns 0 on success. Otherwise, the following error values are returned: l -tag -width [EPERM] t Bq Er EPERM The invoking process belongs to another session than the process or process group .Fa pgid . t Bq Er ESRCH The process or process group .Fa pgid does not exist. t Bq Er ESRCH The process .Fa pgid is exiting. .El
p The function .Fn sigio_getown returns the ID of the process or process group associated with reference .Fa sir , or zero if no signal target has been registered. .Sh SEE ALSO .Xr pgsigio 9 .Sh HISTORY The sigio routines were adapted from .Fx and first appeared in .Ox 6.5 .