xref: /minix3/lib/libkvm/kvm_getlwps.3 (revision 9da227510d14c35cccbd92c6a9e316b4079c4911)
1.\"	$NetBSD: kvm_getlwps.3,v 1.6 2009/03/10 23:49:07 joerg Exp $
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6.\"This code is derived from software contributed to The NetBSD Foundation
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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.Ft struct kinfo_lwp *
44.Fn kvm_getlwps "kvm_t *kd" "int pid" "u_long procaddr" "int *elemsize" "int *cnt"
45.Sh DESCRIPTION
46.Fn kvm_getlwps
47returns the set of LWPs belonging to the process specified by
48.Fa pid
49or
50.Fa procaddr
51in the kernel indicated by
52.Fa kd .
53The number of LWPs found is returned in the reference parameter
54.Fa cnt .
55The LWPs are returned as a contiguous array of
56.Sy kinfo_lwp
57structures.
58This memory is locally allocated, and subsequent calls to
59.Fn kvm_getlwps
60and
61.Fn kvm_close
62will overwrite this storage.
63.Pp
64Only the first
65.Fa elemsize
66bytes of each array entry are returned.
67If the size of the
68.Sy kinfo_lwp
69structure increases in size in a future release of
70.Nx
71the kernel will only return the requested amount of data for
72each array entry and programs that use
73.Fn kvm_getlwps
74will continue to function without the need for recompilation.
75.Pp
76If called against an active kernel, the
77.Fn kvm_getlwps
78function will use the
79.Xr sysctl 3
80interface and return information about the process identified by
81.Fa pid ;
82otherwise the kernel memory device file or swap device will be
83accessed and the process is identified by the location passed in
84.Fa paddr .
85.Sh RETURN VALUES
86.Fn kvm_getlwps
87returns
88.Dv NULL
89on failure.
90.Sh SEE ALSO
91.Xr kvm 3 ,
92.Xr kvm_close 3 ,
93.Xr kvm_geterr 3 ,
94.Xr kvm_getproc2 3 ,
95.Xr kvm_getprocs 3 ,
96.Xr kvm_nlist 3 ,
97.Xr kvm_open 3 ,
98.Xr kvm_openfiles 3 ,
99.Xr kvm_read 3 ,
100.Xr kvm_write 3
101.Sh BUGS
102These routines do not belong in the kvm interface.
103