1 LTTNG USERSPACE TRACER (LTTng-UST)
2 ----------------------------
4 UST web site: http://lttng.org
6 Updated versions of this package may be found at:
8 * Releases: http://lttng.org/download
9 * GitWeb: http://git.lttng.org (project: lttng-ust)
10 * Git: git://git.lttng.org/lttng-ust.git
16 Userspace RCU library, by Mathieu Desnoyers and Paul E. McKenney
18 -> This release depends on liburcu v0.7.2
20 * Debian/Ubuntu package: liburcu-dev
21 * Website: http://lttng.org/urcu
22 * Releases: http://lttng.org/files/urcu
23 * GitWeb: http://lttng.org/cgi-bin/gitweb.cgi?p=userspace-rcu.git;a=summary
24 * Git: git://lttng.org/userspace-rcu.git
26 For developers using the git tree:
28 This source tree is based on the autotools suite from GNU to simplify
29 portability. Here are some things you should have on your system in order to
30 compile the git repository tree :
32 - GNU autotools (automake >=1.10, autoconf >=2.50, autoheader >=2.50)
33 (make sure your system wide "automake" points to a recent version!)
35 (for more information, go to http://www.gnu.org/software/autoconf/)
37 Needed for make check and tests.
39 If you get the tree from the repository, you will need to use the "bootstrap"
40 script in the root of the tree. It calls all the GNU tools needed to prepare the
44 INSTALLATION INSTRUCTIONS:
46 - Download, compile and install liburcu.
47 - In this package's tree, run ./configure.
52 If compiling from the git repository, run ./bootstrap before running
53 the configure script, to generate it.
58 - Create an instrumentation header following the tracepoint examples.
59 See lttng/tracepoint.h, and examples.
61 There are 2 ways to compile the Tracepoint Provider with the
62 application: either statically or dynamically. Please follow
65 1.1) Compile the Tracepoint provider with the application, either
66 directly or through a static library (.a):
67 - Into exactly one object of your application: define
68 "TRACEPOINT_DEFINE" and include the tracepoint provider.
69 - Use "-I." for the compilation unit containing the tracepoint
70 provider include (e.g. tp.c).
71 - Link application with "-ldl" on Linux, with "-lc" on BSD.
72 - If building the provider directly into the application,
73 link the application with "-llttng-ust".
74 - If building a static library for the provider, link the static
75 library with "-llttng-ust".
76 - Include the tracepoint provider header into all C files using
79 - doc/examples/easy-ust/ sample.c sample_component_provider.h
81 - doc/examples/hello-static-lib/ hello.c tp.c ust_test_hello.h
84 2) Compile the Tracepoint Provider separately from the application,
85 using dynamic linking:
86 - Into exactly one object of your application: define
87 "TRACEPOINT_DEFINE" _and_ also define
88 "TRACEPOINT_PROBE_DYNAMIC_LINKAGE", then include the tracepoint
90 - Include the tracepoint provider header into all instrumented C
91 files that use the provider.
92 - Compile the tracepoint provider with "-I.".
93 - Link the tracepoint provider with "-llttng-ust".
94 - Link application with "-ldl" on Linux, "-lc" on BSD.
95 - Set a LD_PRELOAD environment to preload the tracepoint provider
96 shared object before starting the application when tracing is
97 needed. Another way is to dlopen the tracepoint probe when needed
100 - doc/examples/demo demo.c tp*.c ust_tests_demo*.h demo-trace Makefile
102 - Note about dlclose() usage: it is not safe to use dlclose on a
103 provider shared object that is being actively used for tracing due
104 to a lack of reference counting from lttng-ust to the used shared
106 - Enable instrumentation and control tracing with the "lttng" command
107 from lttng-tools. See lttng-tools doc/quickstart.txt.
108 - Note for C++ support: although an application instrumented with
109 tracepoints can be compiled with g++, tracepoint probes should be
110 compiled with gcc (only tested with gcc so far).
113 ENVIRONMENT VARIABLES:
115 - liblttng-ust debug can be activated by setting the environment variable
116 "LTTNG_UST_DEBUG" when launching the application. It can also be enabled
117 at compile-time by compiling libust with -DLTTNG_UST_DEBUG.
119 - The environment variable "LTTNG_UST_REGISTER_TIMEOUT" can be used to
120 specify how long the applications should wait for sessiond
121 "registration done" command before proceeding to execute the main
122 program. The default is 3000ms (3 seconds). The timeout value is
123 specified in milliseconds. The value 0 means "don't wait". The value
124 -1 means "wait forever". Setting this environment variable to 0 is
125 recommended for applications with time constraints on the process
128 - The compilation flag "-DLTTNG_UST_DEBUG_VALGRIND" should be enabled
129 at build time to allow liblttng-ust to be used with valgrind
130 (side-effect: disables per-cpu buffering).
135 Use babeltrace for viewing traces generated by LTTng UST 2.x.
136 See http://lttng.org for download.
141 Maintainer: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
142 Mailing list: lttng-dev@lists.lttng.org
147 This package contains the following elements.
150 The actual userspace tracing library that must be linked to the
151 instrumented programs.
154 The public header files that will be installed on the system.
157 Various test programs
159 - liblttng-ust-libc-wrapper
160 An example library that can be LD_PRELOAD'ed to instrument some
161 calls to libc (currently malloc() and free()) in any program without
162 need to recompile it.
165 A library that is LD_PRELOAD'ed, and that hijacks calls to several system
166 calls in order to trace across these calls. It _has_ to be LD_PRELOAD'ed
167 in order to hijack calls. In contrast, libust may be linked at build time.
170 A library to control tracing in other processes. Used by lttng-tools.
173 A static library shared between libust and lttng-tools, that
174 provides functions that allow these components to communicate together.
177 The ring buffer implementation used within LTTng-UST.
180 An asynchronous signal-safe version of snprintf.
183 A simple library that uses JNI to allow tracing in java programs.
184 See liblttng-ust-java/README for build instructions.