[lttng-docs.git] / contents / using-lttng / instrumenting / prebuilt-ust-helpers / intro.md

---
id: prebuilt-ust-helpers
---

The LTTng-UST package provides a few helpers that one may find
useful in some situations. They all work the same way: you must
preload the appropriate shared object before running the user
application (using the `LD_PRELOAD` environment variable).

The shared objects are normally found in `/usr/lib`.

The current installed helpers are:

  * `liblttng-ust-libc-wrapper.so` and
    `liblttng-ust-pthread-wrapper.so`:
    [C&nbsp;standard library and POSIX threads tracing](#doc-liblttng‑ust‑libc‑pthread-wrapper)
  * `liblttng-ust-cyg-profile.so` and
    `liblttng-ust-cyg-profile-fast.so`:
    [function tracing](#doc-liblttng‑ust‑cyg‑profile)
  * `liblttng-ust-dl.so`:
    [dynamic linker tracing](#doc-liblttng‑ust‑dl)

The following subsections document what helpers instrument exactly
and how to use them.
Commit	Line	Data
5e0cbfb0 PP	1	---
	2	id: prebuilt-ust-helpers
	3	---
	4
	5	The LTTng-UST package provides a few helpers that one may find
	6	useful in some situations. They all work the same way: you must
	7	preload the appropriate shared object before running the user
	8	application (using the `LD_PRELOAD` environment variable).
	9
	10	The shared objects are normally found in `/usr/lib`.
	11
	12	The current installed helpers are:
	13
	14	* `liblttng-ust-libc-wrapper.so` and
	15	`liblttng-ust-pthread-wrapper.so`:
	16	[C standard library and POSIX threads tracing](#doc-liblttng‑ust‑libc‑pthread-wrapper)
	17	* `liblttng-ust-cyg-profile.so` and
	18	`liblttng-ust-cyg-profile-fast.so`:
	19	[function tracing](#doc-liblttng‑ust‑cyg‑profile)
	20	* `liblttng-ust-dl.so`:
	21	[dynamic linker tracing](#doc-liblttng‑ust‑dl)
	22
	23	The following subsections document what helpers instrument exactly
	24	and how to use them.