| 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. |