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 v0.6.6
  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 For developers using the git tree:
  28
  29 This source tree is based on the autotools suite from GNU to simplify
  30 portability. Here are some things you should have on your system in order to
  31 compile the git repository tree :
  32
  33 - GNU autotools (automake >=1.10, autoconf >=2.50, autoheader >=2.50)
  34   (make sure your system wide "automake" points to a recent version!)
  35 - GNU Libtool >=2.2
  36   (for more information, go to http://www.gnu.org/software/autoconf/)
  37
  38 If you get the tree from the repository, you will need to use the "bootstrap"
  39 script in the root of the tree. It calls all the GNU tools needed to prepare the
  40 tree configuration.
  41
  42
  43 INSTALLATION INSTRUCTIONS:
  44
  45   - Download, compile and install liburcu.
  46   - In this package's tree, run ./configure.
  47   - Run make.
  48   - Run make install.
  49   - Run ldconfig.
  50
  51   If compiling from the git repository, run ./bootstrap before running
  52   the configure script, to generate it.
  53
  54
  55 USAGE:
  56
  57   - Create an instrumentation header following the tracepoint examples.
  58     See lttng/tracepoint.h, and examples.
  59
  60   There are 2 ways to compile the Tracepoint Provider with the
  61   application: either statically or dynamically. Please follow
  62   carefully:
  63
  64   1.1) Compile the Tracepoint provider with the application, either
  65        directly or through a static library (.a):
  66     - Into exactly one object of your application: define
  67       "TRACEPOINT_DEFINE" and include the tracepoint provider.
  68     - Use "-I." for the compilation unit containing the tracepoint
  69       provider include (e.g. tp.c).
  70     - Link application with "-ldl" on Linux, with "-lc" on BSD.
  71     - If building the provider directly into the application,
  72       link the application with "-llttng-ust".
  73     - If building a static library for the provider, link the static
  74       library with "-lllttng-ust".
  75     - Include the tracepoint provider header into all C files using
  76       the provider.
  77     - Example:
  78         tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example.*
  79
  80   2) Compile the Tracepoint Provider separately from the application,
  81      using dynamic linking:
  82     - Into exactly one object of your application: define
  83       "TRACEPOINT_DEFINE" _and_ also define
  84       "TRACEPOINT_PROBE_DYNAMIC_LINKAGE", then include the tracepoint
  85       provider header.
  86     - Include the tracepoint provider header into all instrumented C
  87       files that use the provider.
  88     - Compile the tracepoint provider with "-I.".
  89     - Link the tracepoint provider with "-llttng-ust".
  90     - Link application with "-ldl" on Linux, "-lc" on BSD.
  91     - Set a LD_PRELOAD environment to preload the tracepoint provider
  92       shared object before starting the application when tracing is
  93       needed. Another way is to dlopen the tracepoint probe when needed
  94       by the application.
  95     - Example:
  96       - tests/demo/   demo.c  tp*.c ust_tests_demo*.h demo-trace
  97
  98   - Enable instrumentation and control tracing with the "lttng" command
  99     from lttng-tools. See lttng-tools doc/quickstart.txt.
 100
 101 ENVIRONMENT VARIABLES:
 102
 103   - liblttng-ust debug can be activated by setting the environment variable
 104     "LTTNG_UST_DEBUG" when launching the application. It can also be enabled
 105     at compile-time by compiling libust with -DLTTNG_UST_DEBUG.
 106
 107   - The environment variable "LTTNG_UST_REGISTER_TIMEOUT" can be used to
 108     specify how long the applications should wait for sessiond
 109     "registration done" command before proceeding to execute the main
 110     program. The default is 3000ms (3 seconds). The timeout value is
 111     specified in milliseconds. The value 0 means "don't wait". The value
 112     -1 means "wait forever". Setting this environment variable to 0 is
 113     recommended for applications with time constraints on the process
 114     startup time.
 115
 116
 117 TRACE VIEWER:
 118
 119   Use babeltrace for viewing traces generated by LTTng UST 2.0.
 120   See http://lttng.org for download.
 121
 122
 123 CONTACT:
 124
 125   Maintainer: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 126   Mailing list: lttng-dev@lists.lttng.org
 127
 128
 129 PACKAGE CONTENTS:
 130
 131   This package contains the following elements.
 132
 133   - liblttng-ust
 134     The actual userspace tracing library that must be linked to the
 135     instrumented programs.
 136
 137   - include
 138     The public header files that will be installed on the system.
 139
 140   - tests
 141     Various test programs
 142
 143   - liblttng-ust-libc-wrapper
 144     An example library that can be LD_PRELOAD'ed to instrument some
 145     calls to libc (currently malloc() and free()) in any program without
 146     need to recompile it.
 147
 148   - liblttng-ust-fork
 149     A library that is LD_PRELOAD'ed, and that hijacks calls to several system
 150     calls in order to trace across these calls. It _has_ to be LD_PRELOAD'ed
 151     in order to hijack calls. In contrast, libust may be linked at build time.
 152
 153   - liblttng-ust-ctl
 154     A library to control tracing in other processes. Used by lttng-tools.
 155
 156   - liblttng-ust-comm
 157     A static library shared between libust and lttng-tools, that
 158     provides functions that allow these components to communicate together.
 159
 160   - libringbuffer
 161     The ring buffer implementation used within LTTng-UST.
 162
 163   - snprintf
 164     An asynchronous signal-safe version of snprintf.
 165
 166   - liblttng-ust-java
 167     A simple library that uses JNI to allow tracing in java programs.
 168     See liblttng-ust-java/README for build instructions.