Version 2.5.7

[lttng-ust.git] / README

diff --git a/README b/README
index 9d4603bce79b2ccd7a0a9bb10b1d787757915722..1d731ab76c4d8d8ab1fe787f12d51d4adda7bc8a 100644 (file)
--- a/README
+++ b/README
@@ -1,12 +1,11 @@
 LTTNG USERSPACE TRACER (LTTng-UST)
 ----------------------------
 
-UST web site: http://lttng.org/lttng2.0
+UST web site: http://lttng.org
 
 Updated versions of this package may be found at:
 
-  * Website:  http://lttng.org/lttng2.0
-  * Releases: http://lttng.org/files/lttng-ust
+  * Releases: http://lttng.org/download
   * GitWeb:   http://git.lttng.org (project: lttng-ust)
   * Git:      git://git.lttng.org/lttng-ust.git
 
@@ -22,9 +21,7 @@ PREREQUISITES:
       * Website:  http://lttng.org/urcu
       * Releases: http://lttng.org/files/urcu
       * GitWeb:   http://lttng.org/cgi-bin/gitweb.cgi?p=userspace-rcu.git;a=summary
-      * Git:      git://lttng.org/userspace-rcu.git
-
-  - libuuid (for Linux)
+      * Git:      git://git.urcu.so/userspace-rcu.git
 
 For developers using the git tree:
 
@@ -36,6 +33,8 @@ compile the git repository tree :
   (make sure your system wide "automake" points to a recent version!)
 - GNU Libtool >=2.2
   (for more information, go to http://www.gnu.org/software/autoconf/)
+- Perl (optional)
+  Needed for make check and tests.
 
 If you get the tree from the repository, you will need to use the "bootstrap"
 script in the root of the tree. It calls all the GNU tools needed to prepare the
@@ -53,6 +52,13 @@ INSTALLATION INSTRUCTIONS:
   If compiling from the git repository, run ./bootstrap before running
   the configure script, to generate it.
 
+  Note that configure sets '/usr/local' as the default prefix for files it
+  installs. However, this path is not part of most distributions' default
+  library path which will cause builds depending on liblttng-ust to fail unless
+  '-L/usr/local/lib' is added to LDFLAGS. You may provide a custom prefix to
+  configure by using the --prefix switch. Note that LTTng-UST needs to
+  be a shared library, even if the tracepoint probe provider is statically
+  linked into the application.
 
 USAGE:
 
@@ -73,11 +79,14 @@ USAGE:
     - If building the provider directly into the application,
       link the application with "-llttng-ust".
     - If building a static library for the provider, link the static
-      library with "-lllttng-ust".
+      library with "-llttng-ust".
     - Include the tracepoint provider header into all C files using
       the provider.
-    - Example:
-        tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example.*
+    - Examples:
+      - doc/examples/easy-ust/   sample.c sample_component_provider.h
+        tp.c Makefile
+      - doc/examples/hello-static-lib/   hello.c tp.c ust_test_hello.h
+        Makefile
 
   2) Compile the Tracepoint Provider separately from the application,
      using dynamic linking:
@@ -95,10 +104,18 @@ USAGE:
       needed. Another way is to dlopen the tracepoint probe when needed
       by the application.
     - Example:
-      - tests/demo/   demo.c  tp*.c ust_tests_demo*.h demo-trace
+      - doc/examples/demo   demo.c  tp*.c ust_tests_demo*.h demo-trace Makefile
 
+  - Note about dlclose() usage: it is not safe to use dlclose on a
+    provider shared object that is being actively used for tracing due
+    to a lack of reference counting from lttng-ust to the used shared
+    object.
   - Enable instrumentation and control tracing with the "lttng" command
     from lttng-tools. See lttng-tools doc/quickstart.txt.
+  - Note for C++ support: since LTTng-UST 2.3, both tracepoints and
+    tracepoint probes can be compiled in C++. To compile tracepoint probes
+    in C++, you need g++ >= 4.7 or Clang.
+
 
 ENVIRONMENT VARIABLES:
 
@@ -122,7 +139,7 @@ ENVIRONMENT VARIABLES:
 
 TRACE VIEWER:
 
-  Use babeltrace for viewing traces generated by LTTng UST 2.0.
+  Use babeltrace for viewing traces generated by LTTng UST 2.x.
   See http://lttng.org for download.