'\" te
.\" Copyright (c) 2006, Sun Microsystems, Inc.,
.\" All Rights Reserved
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.TH PROC_SIGNAL 9F "Jan 16, 2006"
.SH NAME
proc_signal, proc_ref, proc_unref \- send a signal to a process
.SH SYNOPSIS
.nf
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/signal.h>



\fBvoid *\fR\fBproc_ref\fR(void)
.fi

.LP
.nf
\fBvoid\fR\fBproc_unref\fR(\fBvoid\fR \fI*pref\fR);
.fi

.LP
.nf
\fBint\fR \fBproc_signal\fR(\fBvoid\fR \fI*pref\fR, \fBint\fR \fIsig\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
.ne 2
.na
\fB\fIpref\fR\fR
.ad
.RS 8n
A handle for the process to be signalled.
.RE

.sp
.ne 2
.na
\fB\fIsig\fR\fR
.ad
.RS 8n
Signal number to be sent to the process.
.RE

.SH DESCRIPTION
This set of routines allows a driver to send a signal to a process. The routine
\fBproc_ref()\fR is used to retrieve an unambiguous reference to the process
for signalling purposes. The return value can be used as a unique handle on the
process, even if the process dies. Because system resources are committed to a
process reference, \fBproc_unref()\fR should be used to remove it as soon as it
is no longer needed.\fBproc_signal()\fR is used to send signal \fIsig\fR to the
referenced process. The following set of signals may be sent to a process from
a driver:
.sp
.ne 2
.na
\fB\fBSIGHUP\fR\fR
.ad
.RS 12n
The device has been disconnected.
.RE

.sp
.ne 2
.na
\fB\fBSIGINT\fR\fR
.ad
.RS 12n
The interrupt character has been received.
.RE

.sp
.ne 2
.na
\fB\fBSIGQUIT\fR\fR
.ad
.RS 12n
The quit character has been received.
.RE

.sp
.ne 2
.na
\fB\fBSIGPOLL\fR\fR
.ad
.RS 12n
A pollable event has occurred.
.RE

.sp
.ne 2
.na
\fB\fBSIGKILL\fR\fR
.ad
.RS 12n
Kill the process (cannot be caught or ignored).
.RE

.sp
.ne 2
.na
\fB\fBSIGWINCH\fR\fR
.ad
.RS 12n
Window size change.
.RE

.sp
.ne 2
.na
\fB\fBSIGURG\fR\fR
.ad
.RS 12n
Urgent data are available.
.RE

.sp
.LP
See \fBsignal.h\fR(3HEAD) for more details on the meaning of these signals.
.sp
.LP
If the process has exited at the time the signal was sent, \fBproc_signal()\fR
returns an error code; the caller should remove the reference on the process by
calling \fBproc_unref()\fR.
.sp
.LP
The driver writer must ensure that for each call made to \fBproc_ref()\fR,
there is exactly one corresponding call to \fBproc_unref()\fR.
.SH RETURN VALUES
The \fBproc_ref()\fR returns the following:
.sp
.ne 2
.na
\fB\fIpref\fR\fR
.ad
.RS 8n
An opaque handle used to refer to the current process.
.RE

.sp
.LP
The \fBproc_signal()\fR returns the following:
.sp
.ne 2
.na
\fB\fB0\fR\fR
.ad
.RS 6n
The process existed before the signal was sent.
.RE

.sp
.ne 2
.na
\fB\fB-1\fR\fR
.ad
.RS 6n
The process no longer exists; no signal was sent.
.RE

.SH CONTEXT
The \fBproc_unref()\fR and \fBproc_signal()\fR functions can be called from
user, interrupt, or kernel context. The \fBproc_ref()\fR function should be
called only from user context.
.SH SEE ALSO
.BR signal.h (3HEAD),
.BR putnextctl1 (9F)
.sp
.LP
\fIWriting Device Drivers\fR