contents/using-lttng/instrumenting/prebuilt-ust-helpers/intro.md

   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&nbsp;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.