xref: /netbsd-src/lib/libkvm/kvm_getlwps.3 (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1.\"	$NetBSD: kvm_getlwps.3,v 1.5 2008/04/30 13:10:51 martin Exp $
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3.\"Copyright (c) 2002 The NetBSD Foundation, Inc.
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6.\"This code is derived from software contributed to The NetBSD Foundation
7.\"by Nathan J. Williams.
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30.Dd February 10, 2004
31.Dt KVM_GETLWPS 3
32.Os
33.Sh NAME
34.Nm kvm_getlwps
35.Nd access state of LWPs belonging to a user process
36.Sh LIBRARY
37.Lb libkvm
38.Sh SYNOPSIS
39.In kvm.h
40.In sys/param.h
41.In sys/sysctl.h
42.\" .Fa kvm_t *kd
43.br
44.Ft struct kinfo_lwp *
45.Fn kvm_getlwps "kvm_t *kd" "int pid" "u_long procaddr" "int *elemsize" "int *cnt"
46.Sh DESCRIPTION
47.Fn kvm_getlwps
48returns the set of LWPs belonging to the process specified by
49.Fa pid
50or
51.Fa procaddr
52in the kernel indicated by
53.Fa kd .
54The number of LWPs found is returned in the reference parameter
55.Fa cnt .
56The LWPs are returned as a contiguous array of
57.Sy kinfo_lwp
58structures.
59This memory is locally allocated, and subsequent calls to
60.Fn kvm_getlwps
61and
62.Fn kvm_close
63will overwrite this storage.
64.Pp
65Only the first
66.Fa elemsize
67bytes of each array entry are returned.
68If the size of the
69.Sy kinfo_lwp
70structure increases in size in a future release of
71.Nx
72the kernel will only return the requested amount of data for
73each array entry and programs that use
74.Fn kvm_getlwps
75will continue to function without the need for recompilation.
76.Pp
77If called against an active kernel, the
78.Fn kvm_getlwps
79function will use the
80.Xr sysctl 3
81interface and return information about the process identified by
82.Fa pid ;
83otherwise the kernel memory device file or swap device will be
84accessed and the process is identified by the location passed in
85.Fa paddr .
86.Sh RETURN VALUES
87.Fn kvm_getlwps
88returns
89.Dv NULL
90on failure.
91.Sh SEE ALSO
92.Xr kvm 3 ,
93.Xr kvm_close 3 ,
94.Xr kvm_geterr 3 ,
95.Xr kvm_getproc2 3 ,
96.Xr kvm_getprocs 3 ,
97.Xr kvm_nlist 3 ,
98.Xr kvm_open 3 ,
99.Xr kvm_openfiles 3 ,
100.Xr kvm_read 3 ,
101.Xr kvm_write 3
102.Sh BUGS
103These routines do not belong in the kvm interface.
104