TNFCTL_PROBE_APPLY(3TNF)TNFCTL_PROBE_APPLY(3TNF)NAME
tnfctl_probe_apply, tnfctl_probe_apply_ids - iterate over probes
SYNOPSIS
cc [ flag ... ] file ... -ltnfctl [ library ... ]
#include <tnf/tnfctl.h>
tnfctl_errcode_t tnfctl_probe_apply(tnfctl_handle_t *hndl,
tnfctl_probe_op_t probe_op, void *clientdata);
tnfctl_errcode_t tnfctl_probe_apply_ids(tnfctl_handle_t *hndl,
ulong_t probe_count, ulong_t *probe_ids,
tnfctl_probe_op_t probe_op, void *clientdata);
DESCRIPTIONtnfctl_probe_apply() is used to iterate over the probes controlled by
hndl. For every probe, the probe_op function is called:
typedef tnfctl_errcode_t (*tnfctl_probe_op_t)(
tnfctl_handle_t *hndl,
tnfctl_probe_t *probe_hndl,
void *clientdata);
Several predefined functions are available for use as probe_op. These
functions are described in tnfctl_probe_state_get(3TNF).
The clientdata supplied in tnfctl_probe_apply() is passed in as the
last argument of probe_op. The probe_hndl in the probe operation func‐
tion can be used to query or change the state of the probe. See
tnfctl_probe_state_get(3TNF). The probe_op function should return
TNFCTL_ERR_NONE upon success. It can also return an error code, which
will cause tnfctl_probe_apply() to stop processing the rest of the
probes and return with the same error code. Note that there are five
(5) error codes reserved that the client can use for its own seman‐
tics. See ERRORS.
The lifetime of probe_hndl is the same as the lifetime of hndl. It is
good until hndl is closed by tnfctl_close(3TNF). Do not confuse a
probe_hndl with hndl. The probe_hndl refers to a particular probe,
while hndl refers to a process or the kernel. If probe_hndl is used in
another libtnfctl(3TNF) interface, and it references a probe in a
library that has been dynamically closed (see dlclose(3C)), then the
error code TNFCTL_ERR_INVALIDPROBE will be returned by that interface.
tnfctl_probe_apply_ids() is very similar to tnfctl_probe_apply(). The
difference is that probe_op is called only for probes that match a
probe id specified in the array of integers referenced by probe_ids.
The number of probe ids in the array should be specified in
probe_count. Use tnfctl_probe_state_get() to get the probe_id that
corresponds to the probe_handl.
RETURN VALUEStnfctl_probe_apply() and tnfctl_probe_apply_ids() return
TNFCTL_ERR_NONE upon success.
ERRORS
The following errors apply to both tnfctl_probe_apply() and
tnfctl_probe_apply_ids():
TNFCTL_ERR_INTERNAL
An internal error occurred.
TNFCTL_ERR_USR1
Error code reserved for user.
TNFCTL_ERR_USR2
Error code reserved for user.
TNFCTL_ERR_USR3
Error code reserved for user.
TNFCTL_ERR_USR4
Error code reserved for user.
TNFCTL_ERR_USR5
Error code reserved for user.
tnfctl_probe_apply() and tnfctl_probe_apply_ids() also return any
error returned by the callback function probe_op.
The following errors apply only to tnfctl_probe_apply_ids():
TNFCTL_ERR_INVALIDPROBE
The probe handle is no longer valid. For
example, the probe is in a library that has
been closed by dlclose(3C).
EXAMPLES
Example 1 Enabling Probes
To enable all probes:
tnfctl_probe_apply(hndl, tnfctl_probe_enable, NULL);
Example 2 Disabling Probes
To disable the probes that match a certain pattern in the probe
attribute string:
/* To disable all probes that contain the string "vm" */
tnfctl_probe_apply(hndl, select_disable, "vm");
static tnfctl_errcode_t
select_disable(tnfctl_handle_t *hndl, tnfctl_probe_t *probe_hndl,
void *client_data)
{
char *pattern = client_data;
tnfctl_probe_state_t probe_state;
tnfctl_probe_state_get(hndl, probe_hndl, &probe_state);
if (strstr(probe_state.attr_string, pattern)) {
tnfctl_probe_disable(hndl, probe_hndl, NULL);
}
}
Note that these examples do not have any error handling code.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│MT-Level │ MT-Safe │
└───────────────┴─────────────────┘
SEE ALSOprex(1), TNF_PROBE(3TNF), dlclose(3C), dlopen(3C), libtnfctl(3TNF),
tnfctl_close(3TNF), tnfctl_probe_state_get(3TNF), tracing(3TNF),
tnf_kernel_probes(4), attributes(5)
Linker and Libraries Guide
Mar 1, 2004 TNFCTL_PROBE_APPLY(3TNF)
