Fix: Fix self-assign warning on struct ustfork_clone_info init

[lttng-ust.git] / README

diff --git a/README b/README
index b3f4c5b29de5362d478b6abbcfbb94a483894573..78160a30f8210e0cdb9e8e6e8483aa3a6204e117 100644 (file)
--- a/README
+++ b/README
@@ -56,22 +56,45 @@ 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".
+    - 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".
+    - 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:
+
+  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".
     - 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.
 
@@ -90,6 +113,10 @@ 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:
 
@@ -117,7 +144,7 @@ PACKAGE CONTENTS:
   - tests
     Various test programs
 
-  - liblttng-ust-libc
+  - 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.