README

   1 LTTNG USERSPACE TRACER (LTTng-UST)
   2 ----------------------------
   3
   4 UST web site: http://lttng.org/lttng2.0
   5
   6 Updated versions of this package may be found at:
   7
   8   * Website:  http://lttng.org/lttng2.0
   9   * Releases: http://lttng.org/files/lttng-ust
  10   * GitWeb:   http://git.lttng.org (project: lttng-ust)
  11   * Git:      git://git.lttng.org/lttng-ust.git
  12
  13
  14 PREREQUISITES:
  15
  16   - liburcu
  17     Userspace RCU library, by Mathieu Desnoyers and Paul E. McKenney
  18
  19     -> This release depends on liburcu v0.7.2
  20
  21       * Debian/Ubuntu package: liburcu-dev
  22       * Website:  http://lttng.org/urcu
  23       * Releases: http://lttng.org/files/urcu
  24       * GitWeb:   http://lttng.org/cgi-bin/gitweb.cgi?p=userspace-rcu.git;a=summary
  25       * Git:      git://lttng.org/userspace-rcu.git
  26
  27   - libuuid (for Linux)
  28
  29 For developers using the git tree:
  30
  31 This source tree is based on the autotools suite from GNU to simplify
  32 portability. Here are some things you should have on your system in order to
  33 compile the git repository tree :
  34
  35 - GNU autotools (automake >=1.10, autoconf >=2.50, autoheader >=2.50)
  36   (make sure your system wide "automake" points to a recent version!)
  37 - GNU Libtool >=2.2
  38   (for more information, go to http://www.gnu.org/software/autoconf/)
  39
  40 If you get the tree from the repository, you will need to use the "bootstrap"
  41 script in the root of the tree. It calls all the GNU tools needed to prepare the
  42 tree configuration.
  43
  44
  45 INSTALLATION INSTRUCTIONS:
  46
  47   - Download, compile and install liburcu.
  48   - In this package's tree, run ./configure.
  49   - Run make.
  50   - Run make install.
  51   - Run ldconfig.
  52
  53   If compiling from the git repository, run ./bootstrap before running
  54   the configure script, to generate it.
  55
  56
  57 USAGE:
  58
  59   - Create an instrumentation header following the tracepoint examples.
  60     See lttng/tracepoint.h, and examples.
  61
  62   There are 2 ways to compile the Tracepoint Provider with the
  63   application: either statically or dynamically. Please follow
  64   carefully:
  65
  66   1.1) Compile the Tracepoint provider with the application, either
  67        directly or through a static library (.a):
  68     - Into exactly one object of your application: define
  69       "TRACEPOINT_DEFINE" and include the tracepoint provider.
  70     - Use "-I." for the compilation unit containing the tracepoint
  71       provider include (e.g. tp.c).
  72     - Link application with "-ldl" on Linux, with "-lc" on BSD.
  73     - If building the provider directly into the application,
  74       link the application with "-llttng-ust".
  75     - If building a static library for the provider, link the static
  76       library with "-lllttng-ust".
  77     - Include the tracepoint provider header into all C files using
  78       the provider.
  79     - Example:
  80         tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example.*
  81
  82   2) Compile the Tracepoint Provider separately from the application,
  83      using dynamic linking:
  84     - Into exactly one object of your application: define
  85       "TRACEPOINT_DEFINE" _and_ also define
  86       "TRACEPOINT_PROBE_DYNAMIC_LINKAGE", then include the tracepoint
  87       provider header.
  88     - Include the tracepoint provider header into all instrumented C
  89       files that use the provider.
  90     - Compile the tracepoint provider with "-I.".
  91     - Link the tracepoint provider with "-llttng-ust".
  92     - Link application with "-ldl" on Linux, "-lc" on BSD.
  93     - Set a LD_PRELOAD environment to preload the tracepoint provider
  94       shared object before starting the application when tracing is
  95       needed. Another way is to dlopen the tracepoint probe when needed
  96       by the application.
  97     - Example:
  98       - tests/demo/   demo.c  tp*.c ust_tests_demo*.h demo-trace
  99
 100   - Enable instrumentation and control tracing with the "lttng" command
 101     from lttng-tools. See lttng-tools doc/quickstart.txt.
 102
 103 ENVIRONMENT VARIABLES:
 104
 105   - liblttng-ust debug can be activated by setting the environment variable
 106     "LTTNG_UST_DEBUG" when launching the application. It can also be enabled
 107     at compile-time by compiling libust with -DLTTNG_UST_DEBUG.
 108
 109   - The environment variable "LTTNG_UST_REGISTER_TIMEOUT" can be used to
 110     specify how long the applications should wait for sessiond
 111     "registration done" command before proceeding to execute the main
 112     program. The default is 3000ms (3 seconds). The timeout value is
 113     specified in milliseconds. The value 0 means "don't wait". The value
 114     -1 means "wait forever". Setting this environment variable to 0 is
 115     recommended for applications with time constraints on the process
 116     startup time.
 117
 118   - The compilation flag "-DLTTNG_UST_DEBUG_VALGRIND" should be enabled
 119     at build time to allow liblttng-ust to be used with valgrind
 120     (side-effect: disables per-cpu buffering).
 121
 122
 123 TRACE VIEWER:
 124
 125   Use babeltrace for viewing traces generated by LTTng UST 2.0.
 126   See http://lttng.org for download.
 127
 128
 129 CONTACT:
 130
 131   Maintainer: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 132   Mailing list: lttng-dev@lists.lttng.org
 133
 134
 135 PACKAGE CONTENTS:
 136
 137   This package contains the following elements.
 138
 139   - liblttng-ust
 140     The actual userspace tracing library that must be linked to the
 141     instrumented programs.
 142
 143   - include
 144     The public header files that will be installed on the system.
 145
 146   - tests
 147     Various test programs
 148
 149   - liblttng-ust-libc-wrapper
 150     An example library that can be LD_PRELOAD'ed to instrument some
 151     calls to libc (currently malloc() and free()) in any program without
 152     need to recompile it.
 153
 154   - liblttng-ust-fork
 155     A library that is LD_PRELOAD'ed, and that hijacks calls to several system
 156     calls in order to trace across these calls. It _has_ to be LD_PRELOAD'ed
 157     in order to hijack calls. In contrast, libust may be linked at build time.
 158
 159   - liblttng-ust-ctl
 160     A library to control tracing in other processes. Used by lttng-tools.
 161
 162   - liblttng-ust-comm
 163     A static library shared between libust and lttng-tools, that
 164     provides functions that allow these components to communicate together.
 165
 166   - libringbuffer
 167     The ring buffer implementation used within LTTng-UST.
 168
 169   - snprintf
 170     An asynchronous signal-safe version of snprintf.
 171
 172   - liblttng-ust-java
 173     A simple library that uses JNI to allow tracing in java programs.
 174     See liblttng-ust-java/README for build instructions.