- 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
+ - tests/hello/ hello.c tp.c ust_tests_hello.h Makefile.example
2) Compile the Tracepoint Provider separately from the application,
using dynamic linking:
- 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
+ - doc/examples/demo demo.c tp*.c ust_tests_demo*.h demo-trace
- - Note about dlopen() usage: due to locking side-effects due to the
- way libc lazily resolves Thread-Local Storage (TLS) symbols when a
- library is dlopen'd, linking the tracepoint probe or liblttng-ust
- with dlopen() is discouraged. They should be linked with the
- application using "\-llibname" or loaded with LD_PRELOAD.
+ - 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: although an application instrumented with
.SH "SEE ALSO"
.PP
-lttng-gen-tp(1), lttng(1), babeltrace(1), lttng-sessiond(8)
+lttng-gen-tp(1), lttng(1), babeltrace(1), lttng-ust-cyg-profile(3),
+lttng-sessiond(8)
.PP
.SH "BUGS"
.PP
-No knows bugs at this point.
+No known bugs at this point.
If you encounter any issues or usability problem, please report it on
our mailing list <lttng-dev@lists.lttng.org> to help improve this