TNFCTL_PROBE_STATE_GET(3TNF)TNFCTL_PROBE_STATE_GET(3TNF)NAME
tnfctl_probe_state_get, tnfctl_probe_enable, tnfctl_probe_disable,
tnfctl_probe_trace, tnfctl_probe_untrace, tnfctl_probe_connect,
tnfctl_probe_disconnect_all - interfaces to query and to change the
state of a probe
SYNOPSIS
cc [ flag ... ] file ... -ltnfctl [ library ... ]
#include <tnf/tnfctl.h>
tnfctl_errcode_t tnfctl_probe_state_get(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, tnfctl_probe_state_t *state);
tnfctl_errcode_t tnfctl_probe_enable(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, void *ignored);
tnfctl_errcode_t tnfctl_probe_disable(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, void *ignored);
tnfctl_errcode_t tnfctl_probe_trace(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, void *ignored);
tnfctl_errcode_t tnfctl_probe_untrace(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, void *ignored);
tnfctl_errcode_t tnfctl_probe_disconnect_all(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, void *ignored);
tnfctl_errcode_t tnfctl_probe_connect(tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl, const char *lib_base_name,
const char *func_name);
DESCRIPTIONtnfctl_probe_state_get() returns the state of the probe specified by
probe_hndl in the process or kernel specified by hndl. The user will
pass these in to an apply iterator. The caller must also allocate state
and pass in a pointer to it. The semantics of the individual members
of state are:
id
The unique integer assigned to this probe.
This number does not change over the lifetime
of this probe. A probe_hndl can be obtained
by using the calls tnfctl_apply(), tan‐
fctl_apply_ids(), or tnfctl_register_funcs().
attr_string
A string that consists of attribute value
pairs separated by semicolons. For the syn‐
tax of this string, see the syntax of the
detail argument of the TNF_PROBE(3TNF) macro.
The attributes name, slots, keys, file, and
line are defined for every probe. Additional
user-defined attributes can be added by using
the detail argument of the TNF_PROBE(3TNF)
macro. An example of attr_string follows:
"name pageout;slots vnode pages_pageout ;
keys vm pageio io;file vm.c;line 25;"
enabled
B_TRUE if the probe is enabled, or B_FALSE
if the probe is disabled. Probes are disabled
by default. Use tnfctl_probe_enable() or
tnfctl_probe_disable() to change this state.
traced
B_TRUE if the probe is traced, or B_FALSE if
the probe is not traced. Probes in user pro‐
cesses are traced by default. Kernel probes
are untraced by default. Use
tnfctl_probe_trace() or
tnfctl_probe_untrace() to change this state.
new_probe
B_TRUE if this is a new probe brought in
since the last change in libraries. See
dlopen(3C) or dlclose(3C). Otherwise, the
value of new_probe will be B_FALSE. This
field is not meaningful for kernel probe
control.
obj_name
The name of the shared object or executable
in which the probe is located. This string
can be freed, so the client should make a
copy of the string if it needs to be saved
for use by other libtnfctl interfaces. In
kernel mode, this string is always NULL.
func_names
A null-terminated array of pointers to
strings that contain the names of functions
connected to this probe. Whenever an enabled
probe is encountered at runtime, these func‐
tions are executed. This array also will be
freed by the library when the state of the
probe changes. Use tnfctl_probe_connect() or
tnfctl_probe_disconnect_all() to change this
state.
func_addrs
A null-terminated array of pointers to
addresses of functions in the target image
connected to this probe. This array also
will be freed by the library when the state
of the probe changes.
client_registered_data
Data that was registered by the client for
this probe by the creator function in
tnfctl_register_funcs(3TNF).
tnfctl_probe_enable(), tnfctl_probe_disable(), tnfctl_probe_trace(),
tnfctl_probe_untrace(), and tnfctl_probe_disconnect_all() ignore the
last argument. This convenient feature permits these functions to be
used in the probe_op field of tnfctl_probe_apply(3TNF) and
tnfctl_probe_apply_ids(3TNF). tnfctl_probe_enable() enables the probe
specified by probe_hndl. This is the master switch on a probe. A
probe does not perform any action until it is enabled.
tnfctl_probe_disable() disables the probe specified by probe_hndl.
tnfctl_probe_trace() turns on tracing for the probe specified by
probe_hndl. Probes emit a trace record only if the probe is traced.
tnfctl_probe_untrace() turns off tracing for the probe specified by
probe_hndl. This is useful if you want to connect probe functions to a
probe without tracing it.
tnfctl_probe_connect() connects the function func_name which exists in
the library lib_base_name, to the probe specified by probe_hndl.
tnfctl_probe_connect() returns an error code if used on a kernel tnfctl
handle. lib_base_name is the base name (not a path) of the library. If
it is NULL, and multiple functions in the target process match
func_name, one of the matching functions is chosen arbitrarily. A probe
function is a function that is in the target's address space and is
written to a certain specification. The specification is not cur‐
rently published.
tnf_probe_debug() is one function exported by libtnfprobe.so.1 and is
the debug function that prex(1) uses. When the debug function is exe‐
cuted, it prints out the probe arguments and the value of the
sunw%debug attribute of the probe to stderr.
tnfctl_probe_disconnect_all() disconnects all probe functions from the
probe specified by probe_hndl.
Note that no libtnfctl call returns a probe handle (tnfctl_probe_t),
yet each of the routines described here takes a probe_hndl as an argu‐
ment. These routines may be used by passing them to one of the
tnfctl_probe_apply(3TNF) iterators as the "op" argument. Alterna‐
tively, probe handles may be obtained and saved by a user's "op" func‐
tion, and they can be passed later as the probe_hndl argument when
using any of the functions described here.
RETURN VALUEStnfctl_probe_state_get(), tnfctl_probe_enable(), tnfctl_probe_dis‐
able(), tnfctl_probe_trace(), tnfctl_probe_untrace(), tnfctl_probe_dis‐
connect_all() and tnfctl_probe_connect() return TNFCTL_ERR_NONE upon
success.
ERRORS
The following error codes apply to tnfctl_probe_state_get():
TNFCTL_ERR_INVALIDPROBE
probe_hndl is no longer valid. The library
that the probe was in could have been dynam‐
ically closed by dlclose(3C).
The following error codes apply to tnfctl_probe_enable(),
tnfctl_probe_disable(), tnfctl_probe_trace(), tnfctl_probe_untrace(),
and tnfctl_probe_disconnect_all()
TNFCTL_ERR_INVALIDPROBE
probe_hndl is no longer valid. The library
that the probe was in could have been dynam‐
ically closed by dlclose(3C).
TNFCTL_ERR_BUFBROKEN
Cannot do probe operations because tracing
is broken in the target.
TNFCTL_ERR_NOBUF
Cannot do probe operations until a buffer is
allocated. See tnfctl_buffer_alloc(3TNF).
This error code does not apply to kernel
probe control.
The following error codes apply to tnfctl_probe_connect():
TNFCTL_ERR_INVALIDPROBE
probe_hndl is no longer valid. The library
that the probe was in could have been dynam‐
ically closed by dlclose(3C).
TNFCTL_ERR_BADARG
The handle is a kernel handle, or func_name
could not be found.
TNFCTL_ERR_BUFBROKEN
Cannot do probe operations because tracing
is broken in the target.
TNFCTL_ERR_NOBUF
Cannot do probe operations until a buffer is
allocated. See tnfctl_buffer_alloc(3TNF).
ATTRIBUTES
See attributes(5) for description of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│MT Level │ MT-Safe │
└───────────────┴─────────────────┘
SEE ALSOprex(1), TNF_PROBE(3TNF), libtnfctl(3TNF), tnfctl_check_libs(3TNF),
tnfctl_continue(3TNF), tnfctl_probe_apply(3TNF),
tnfctl_probe_apply_ids(3TNF), tracing(3TNF), tnf_kernel_probes(4),
attributes(5)
Mar 1, 2004 TNFCTL_PROBE_STATE_GET(3TNF)
