README

   1 LTTNG USERSPACE TRACER (UST)
   2 ----------------------------
   3
   4 UST web site and manual: http://lttng.org/ust
   5
   6 Updated versions of this package may be found at:
   7
   8   * Website:  http://lttng.org/ust
   9   * Releases: http://lttng.org/files/ust/releases
  10   * GitWeb:   http://git.lttng.org (project: ust)
  11   * Git:      git://git.lttng.org/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   - Either compile the Tracepoint probes with the application:
  60     - Use "-I." for the compilation unit containing the tracepoint
  61       provider include (e.g. tp.c).
  62     - Link application with "-ldl -llttng-ust".
  63     - Example:
  64         tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example
  65   - Or compile the Tracepoint probes separately from the application,
  66     using dynamic linking:
  67     - Compile the tracepoint provider with "-I.".
  68     - Link the tracepoint provider with "-llttng-ust".
  69     - Link application with "-ldl".
  70     - Set a LD_PRELOAD environment to preload the tracepoint provider
  71       shared object before starting the application when tracing is
  72       needed.
  73     - Example:
  74       - tests/demo/   demo.c  tp*.c ust_tests_demo*.h demo-trace
  75   - Enable instrumentation and control tracing with the "lttng" command
  76     from lttng-tools. See lttng-tools doc/quickstart.txt.
  77
  78 ENVIRONMENT VARIABLES:
  79
  80   - liblttng-ust debug can be activated by setting the environment variable
  81     "LTTNG_UST_DEBUG" when launching the application. It can also be enabled
  82     at compile-time by compiling libust with -DLTTNG_UST_DEBUG.
  83
  84   - The environment variable "LTTNG_UST_REGISTER_TIMEOUT" can be used to
  85     specify how long the applications should wait for sessiond
  86     "registration done" command before proceeding to execute the main
  87     program. The default is 3000ms (3 seconds). The timeout value is
  88     specified in milliseconds. The value 0 means "don't wait". The value
  89     -1 means "wait forever". Setting this environment variable to 0 is
  90     recommended for applications with time constraints on the process
  91     startup time.
  92
  93
  94 TRACE VIEWER:
  95
  96   Use babeltrace for viewing traces generated by LTTng UST 2.0.
  97   See http://lttng.org for download.
  98
  99
 100 CONTACT:
 101
 102   Maintainer: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 103   Mailing list: ltt-dev@lists.casi.polymtl.ca
 104
 105
 106 PACKAGE CONTENTS:
 107
 108   This package contains the following elements.
 109
 110   - liblttng-ust
 111     The actual userspace tracing library that must be linked to the
 112     instrumented programs.
 113
 114   - include
 115     The public header files that will be installed on the system.
 116
 117   - tests
 118     Various test programs
 119
 120   - liblttng-ust-libc
 121     An example library that can be LD_PRELOAD'ed to instrument some
 122     calls to libc (currently malloc() and free()) in any program without
 123     need to recompile it.
 124
 125   - liblttng-ust-fork
 126     A library that is LD_PRELOAD'ed, and that hijacks calls to several system
 127     calls in order to trace across these calls. It _has_ to be LD_PRELOAD'ed
 128     in order to hijack calls. In contrast, libust may be linked at build time.
 129
 130   - liblttng-ust-ctl
 131     A library to control tracing in other processes. Used by lttng-tools.
 132
 133   - liblttng-ust-comm
 134     A static library shared between libust and lttng-tools, that
 135     provides functions that allow these components to communicate together.
 136
 137   - libringbuffer
 138     The ring buffer implementation used within LTTng-UST.
 139
 140   - snprintf
 141     An asynchronous signal-safe version of snprintf.
 142
 143   - liblttng-ust-java
 144     A simple library that uses JNI to allow tracing in java programs.
 145     See liblttng-ust-java/README for build instructions.