Fix: add internal mutex for timer

[lttng-ust.git] / README

diff --git a/README b/README
index 114e3b25fd347176a9322ba2575a42c2c7a0654d..dadcd1f5ac5f91975d904cf6d6644c460fe1c0e0 100644 (file)
--- a/README
+++ b/README
@@ -1,14 +1,13 @@
-LTTNG USERSPACE TRACER (UST)
+LTTNG USERSPACE TRACER (LTTng-UST)
 ----------------------------
 
-UST web site and manual: http://lttng.org/ust
+UST web site: http://lttng.org
 
 Updated versions of this package may be found at:
 
-  * Website:  http://lttng.org/ust
-  * Releases: http://lttng.org/files/ust/releases
-  * GitWeb:   http://git.lttng.org (project: ust)
-  * Git:      git://git.lttng.org/ust.git
+  * Releases: http://lttng.org/download
+  * GitWeb:   http://git.lttng.org (project: lttng-ust)
+  * Git:      git://git.lttng.org/lttng-ust.git
 
 
 PREREQUISITES:
@@ -16,7 +15,7 @@ PREREQUISITES:
   - liburcu
     Userspace RCU library, by Mathieu Desnoyers and Paul E. McKenney
 
-    -> This release depends on liburcu v0.6.6
+    -> This release depends on liburcu v0.7.2
 
       * Debian/Ubuntu package: liburcu-dev
       * Website:  http://lttng.org/urcu
@@ -34,6 +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
@@ -56,24 +57,51 @@ USAGE:
 
   - Create an instrumentation header following the tracepoint examples.
     See lttng/tracepoint.h, and examples.
-  - Either compile the Tracepoint probes with the application:
+
+  There are 2 ways to compile the Tracepoint Provider with the
+  application: either statically or dynamically. Please follow
+  carefully:
+
+  1.1) Compile the Tracepoint provider with the application, either
+       directly or through a static library (.a):
+    - Into exactly one object of your application: define
+      "TRACEPOINT_DEFINE" and include the tracepoint provider.
     - Use "-I." for the compilation unit containing the tracepoint
       provider include (e.g. tp.c).
-    - Link application with "-ldl -llttng-ust".
+    - Link application with "-ldl" on Linux, with "-lc" on BSD.
+    - 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 "-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
-  - Or compile the Tracepoint probes separately from the application,
-    using dynamic linking:
+      - tests/hello/  hello.c tp.c ust_tests_hello.h Makefile.example.*
+
+  2) Compile the Tracepoint Provider separately from the application,
+     using dynamic linking:
+    - Into exactly one object of your application: define
+      "TRACEPOINT_DEFINE" _and_ also define
+      "TRACEPOINT_PROBE_DYNAMIC_LINKAGE", then include the tracepoint
+      provider header.
+    - Include the tracepoint provider header into all instrumented C
+      files that use the provider.
     - Compile the tracepoint provider with "-I.".
     - Link the tracepoint provider with "-llttng-ust".
-    - Link application with "-ldl".
+    - Link application with "-ldl" on Linux, "-lc" on BSD.
     - Set a LD_PRELOAD environment to preload the tracepoint provider
       shared object before starting the application when tracing is
-      needed.
+      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
+
   - Enable instrumentation and control tracing with the "lttng" command
     from lttng-tools. See lttng-tools doc/quickstart.txt.
+  - 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.
 
 ENVIRONMENT VARIABLES:
 
@@ -90,17 +118,21 @@ ENVIRONMENT VARIABLES:
     recommended for applications with time constraints on the process
     startup time.
 
+  - The compilation flag "-DLTTNG_UST_DEBUG_VALGRIND" should be enabled
+    at build time to allow liblttng-ust to be used with valgrind
+    (side-effect: disables per-cpu buffering).
+
 
 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.
 
 
 CONTACT:
 
   Maintainer: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
-  Mailing list: ltt-dev@lists.casi.polymtl.ca
+  Mailing list: lttng-dev@lists.lttng.org
 
 
 PACKAGE CONTENTS:
@@ -117,9 +149,10 @@ PACKAGE CONTENTS:
   - tests
     Various test programs
 
-  - liblttng-ust-malloc
-    An example library that can be LD_PRELOAD'ed to instrument calls to malloc()
-    in any program without need to recompile it.
+  - liblttng-ust-libc-wrapper
+    An example library that can be LD_PRELOAD'ed to instrument some
+    calls to libc (currently malloc() and free()) in any program without
+    need to recompile it.
 
   - liblttng-ust-fork
     A library that is LD_PRELOAD'ed, and that hijacks calls to several system