[lttng-dev] [PATCH lttng-tools v2 0/5] Support probes with the same name but different event payload

[Francis Deslauriers]

This patch set allows for multiple probes with the same name to be
hooked on the same callsite. Right now, the Session Daemon only
considers the name and signature of the events to determine if two
events are identical. This could lead to trace corruptions when two
probes would have the same name and signature but really different
binary trace layouts.

We now compare probes by doing a deep compare of every field. If two
events are _exactly_ the same and have the same metadata then the same
event ID will be used, if they are different a new event ID is created.

When used with its corresponding UST patch set[1], it allows for dynamic
library upgrade scenarios during tracing. The user can now dlopen a new
version of a provider library and dlclose an old version without
restarting the process.

This patch set also includes regression tests for both the deep
comparaison and the newly added dlclose capability.

[1]: https://github.com/frdeso/lttng-ust/tree/dlclose-support

Francis Deslauriers (5):
  Fix: probes should be compared strictly by events metadata
  Fix: calling ht_{hash, match}_enum with wrong argument
  Tests: allow the use of regular expressions to match events
  Tests: add function to validate the number of an event name in
    metadata
  Tests: add duplicated providers tests

 configure.ac                                    |   1 +
 src/bin/lttng-sessiond/Makefile.am              |   3 +-
 src/bin/lttng-sessiond/ust-field-utils.c        | 289 ++++++++++++++++++++++++
 src/bin/lttng-sessiond/ust-field-utils.h        |  29 +++
 src/bin/lttng-sessiond/ust-registry.c           |  46 +++-
 tests/fast_regression                           |   1 +
 tests/regression/ust/multi-lib/Makefile.am      | 114 ++++++++++
 tests/regression/ust/multi-lib/README           |  21 ++
 tests/regression/ust/multi-lib/callsites.c      |  34 +++
 tests/regression/ust/multi-lib/callsites.h      |  21 ++
 tests/regression/ust/multi-lib/multi-lib-test.c | 251 ++++++++++++++++++++
 tests/regression/ust/multi-lib/probes.c         |  18 ++
 tests/regression/ust/multi-lib/probes.h         | 195 ++++++++++++++++
 tests/regression/ust/multi-lib/test_multi_lib   | 262 +++++++++++++++++++++
 tests/unit/Makefile.am                          |   1 +
 tests/utils/utils.sh                            |  27 ++-
 16 files changed, 1299 insertions(+), 14 deletions(-)
 create mode 100644 src/bin/lttng-sessiond/ust-field-utils.c
 create mode 100644 src/bin/lttng-sessiond/ust-field-utils.h
 create mode 100644 tests/regression/ust/multi-lib/Makefile.am
 create mode 100644 tests/regression/ust/multi-lib/README
 create mode 100644 tests/regression/ust/multi-lib/callsites.c
 create mode 100644 tests/regression/ust/multi-lib/callsites.h
 create mode 100644 tests/regression/ust/multi-lib/multi-lib-test.c
 create mode 100644 tests/regression/ust/multi-lib/probes.c
 create mode 100644 tests/regression/ust/multi-lib/probes.h
 create mode 100755 tests/regression/ust/multi-lib/test_multi_lib

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2.7.4