Cleanup: track-untrack.c: declare all `int` on the same line

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: Ic566fe9f33d67f7da750c478c6af0b41ec2a968b
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: relayd: hostname check is too restrictive

The check performed by the relay daemon on hostnames is too
restrictive. Since existing session daemons directly use the hostname
returned by gethostname(), the relay daemon must correctly handle FQDN
hostnames, which may contain dots.

This has been observed on the LTTng CI's RHEL8 nodes which report an
FQDN hostname.

The new function 'is_name_path_safe' is used for both session and host
names. It does not check for every problematic path names (reserved
names on Windows, per-platform illegal characters, etc.) Those
restrictions are assumed to be handled when open() and similar
syscalls fail.

However, the objective of this check is to prevent malicious (or at
least unexpected), but legal, names from being used, namely:
  - names that contain a path separator,
  - empty names,
  - hidden names (starting with a dot).

Ideally, illegal names would be automatically escaped in the future.
This is, however, beyond the scope of this fix.

Fixes #1212

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ieeb8b60d22c27b390b51ef7fb52cea0d0ac0f188

Cleanup: remove extra whitespace from include directive

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ic91f07131aced6857ddbcef46f85c3cc3119f98f

Fix: skip start trace for app that are already started.

When using trackers, call to ust_app_global_update
results in a call to ust_app_start_trace even if the ust app
trace was already enabled.

This resulted in error message from the app (-1024) complaining that the
tracing was already active on the app side.

  Error: Error starting tracing for app pid: 329376 (ret: -1024)
  ok 211 - Track command with opts: 0 -u --vpid 329376

A solution to this is to keep the enabled state inside the ua_sess and
skip the start trace if already enabled.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Ie4198245627e9f0426948489bc9ce24d8c813b08
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: keep active session state on redundant start command

Steps to reproduce problem:
  lttng create
  lttng enable-event -u -a
  lttng start
  lttng start
  lttng stop

Yield:

  Session auto-20200106-134455 created.
  Traces will be output to /home/joraj/lttng-traces/auto-20200106-134455
  All UST events are enabled in channel channel0
  Tracing started for session auto-20200106-134455
  Warning: Tracing already started for session auto-20200106-134455
  Warning: Tracing already stopped for session auto-20200106-134455

The "warning" on the "lttng stop" command is invalid.

This was introduced by commit

1f4962443 Fix: sessiond: no rotation performed from null chunk to new chunk

For cases where the session is already active, simply skip all the way to
the end without passing via the error handling path.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Iaf26090191d3eb940fa419848df8911758e0a6e3
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: build failures when `--without-lttng-ust`

The `--without-lttng-ust` configure option makes the build to fail due
to 2 bugs
1. Missing object file for session unit tests causes the following errors:
    CCLD     test_session
  ../../src/bin/lttng-sessiond/kernel.o: In function `kernel_track_id':
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:712: undefined reference to `lttng_tracker_id_lookup_string'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:723: undefined reference to `lttng_tracker_id_get_list'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:729: undefined reference to `lttng_tracker_list_add'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:810: undefined reference to `lttng_tracker_id_set_list'
  ../../src/bin/lttng-sessiond/kernel.o: In function `kernel_untrack_id':
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:826: undefined reference to `lttng_tracker_id_lookup_string'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:836: undefined reference to `lttng_tracker_id_get_list'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:841: undefined reference to `lttng_tracker_list_remove'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:925: undefined reference to `lttng_tracker_id_set_list'
  ../../src/bin/lttng-sessiond/kernel.o: In function `kernel_list_tracker_ids':
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/kernel.c:949: undefined reference to `lttng_tracker_id_get_list'
  ../../src/bin/lttng-sessiond/trace-kernel.o: In function `trace_kernel_create_session':
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:167: undefined reference to `lttng_tracker_list_create'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:171: undefined reference to `lttng_tracker_list_create'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:175: undefined reference to `lttng_tracker_list_create'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:179: undefined reference to `lttng_tracker_list_create'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:183: undefined reference to `lttng_tracker_list_create'
  ../../src/bin/lttng-sessiond/trace-kernel.o:/home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:187: more undefined references to `lttng_tracker_list_create' follow
  ../../src/bin/lttng-sessiond/trace-kernel.o: In function `trace_kernel_create_session':
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:199: undefined reference to `lttng_tracker_list_destroy'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:200: undefined reference to `lttng_tracker_list_destroy'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:201: undefined reference to `lttng_tracker_list_destroy'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:202: undefined reference to `lttng_tracker_list_destroy'
  /home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:203: undefined reference to `lttng_tracker_list_destroy'
  ../../src/bin/lttng-sessiond/trace-kernel.o:/home/frdeso/projets/lttng/tools/src/bin/lttng-sessiond/trace-kernel.c:204: more undefined references to `lttng_tracker_list_destroy' follow
  collect2: error: ld returned 1 exit status
  Makefile:1062: recipe for target 'test_session' failed
  make[1]: *** [test_session] Error 1
  make[1]: Leaving directory '/home/frdeso/projets/lttng/tools/tests/unit'
  Makefile:1166: recipe for target 'all-recursive' failed
  make: *** [all-recursive] Error 1

2. An extra colon at the end of the `trace_ust_track_id()` stub
function gives this error:
    CC       utils.o
  In file included from ust-app.h:26:0,
                   from lttng-sessiond.h:31,
                   from utils.c:27:
  trace-ust.h:339:1: error: expected identifier or '(' before '{' token
   {
   ^
  trace-ust.h:336:19: warning: 'trace_ust_track_id' declared 'static' but never defined [-Wunused-function]
   static inline int trace_ust_track_id(enum lttng_tracker_type tracker_type,
                     ^~~~~~~~~~~~~~~~~~
  Makefile:729: recipe for target 'utils.o' failed

Both bugs are trivial to fix.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: I66c57d206ad0142db057443374d28bbcf16c02f7
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Sync lttng-ust ABI version in ust-abi-internal.h

Bump LTTNG_UST_ABI_MINOR_VERSION to 1

Increment the minor version of lttng-ust ABI to 1, to take into
account that the "clear" command was added in this release cycle.

This will allow future LTTng-tools versions to check for this
capability.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I472eb11589547a9fa119d061a2c1886371b87f69

Sync lttng-modules ABI version in internal kernel-ioctl.h

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I67eafac24bc8db62831b6bc72497c706ff383a07

Fix: lttng-clear: invalid free of session name

Valgrind reports an invalid free of session_name when it is sourced
from the popt args. Only free it when it comes from the .lttngrc file.

This also caused spurious core dumps when running the tests on
one of my machines.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I194cd36147a1028aad503b4e5d3ea23732a30bc5

Fix: initialize var_data to NULL

Remove a false-positive from scan-build. Initialization of
var_data_len should have been enough but scan build is not smart
enough to understand this.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I90cb449f3092db432967a3f2ea5eedb0728b8678
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tracker: update API documentation

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I71f02c5cbebe7ed8e19aee6bc0d2af7741ed272f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Cleanup: remove struct lttng_handle from tracker.h

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I8b9fd5c86200013cbd60c57505621cb851556b01
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Refactoring: introduce lttng_tracker_ids_serialize

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I0d43b85241b7097ac722724d9fef0ca352422495
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Refactoring: move count to an output parameter

This mimics what is done for lttng_rotation_schedules_get_count.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I576d112de4a9bfa258a78cb52b8da8a5f25adefb
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Refactoring: introduce lttng_tracker_ids data structure

This data structure is opaque to allow for back-end implementation change
in the future.

For now, only the following functions concerning lttng_tracker_ids are public:
    lttng_list_tracker_ids
    lttng_tracker_ids_get_count
    lttng_tracker_ids_get_at_index
    lttng_tracker_ids_destroy

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Iae1c10d0b578b402ab91378dd49f69f605b316b2
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Refactoring: use an opaque lttng_tracker_id type

Move the tracker and tracker id related API to tracker.h and
tracker-internal.h.

The use of an opaque object mimics the new API for rotation and trigger
etc.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I00b876c618d7dcb0dd940189e5250c3f3d64c7e0
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: Initialize ret to zero

For the improbable case that the domain is unknown the return value ret
would not be initialized.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I22ae6b98bbbc4f4fe3e9c28985e2400f7c668525
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Update track/untrack man page

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Ie7092993034f2fb71fc3b1fad0ce5a6f61a31493
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Error early on invalid tracker type for UST domain

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Iea182575c99c1fcf84cb8c313af5904581b5023d
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

ust-app: remove dead code

This code path is not possible since all callsite are fenced with a check
to "has_been_started". Hence, a session cannot be active at the same time.

Change-Id: I53785017989ed7afc8755a41428087d988e5ae88
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: Skip uid registry when metadata key value is 0

A value of 0 for the metadata key indicates that the metadata channel
was never created/pushed on the consumer side.

This can occur in scenario where a tracker(s) (vuid/vgid/vpid) is present.
The metadata channel might never be created/pushed since no applications
are actually tracing. Still, the uid registry exists due to the order
in which the sessiond received the client commands (create,
enable-channel, lttng track/untrack).

See included test for a complete reproducer.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Id7ef34ebc48333f47db4bdca907cf81911b60d1d
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: bump MI version to 4.0

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0a44262016cf90e0629be5cb7d8b5976462c62d9
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: test uid/gid/pid/vuid/vgid/vpid trackers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I1b5ee95efc58a3969066e353cb30eeb3fd8eebb9
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: update list/track/untrack commands

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I18e41d0e3c7826596ac0468eb5ef7bcc549c8f98
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: support tracking feature

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I1629562f4c94947f5dd54a0cee6c0f8f7beb19fe
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: add sessiond tracker list implementation

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I28dbeac1f3db2df7e61911249a3250fbc17dc244
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: update lttng-modules tracer ABI

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I27e1e552b13b5a541b43ff250d1d4839e399f1f3
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: introduce new tracker types

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I749915124dbfe7cbe15d889a5dbcb648c17374dc
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trackers: change error code from "pid" to "id"

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0ce03b23350a9f0da9d5f00ac3c6d0e824af9a98
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

format: use AfterCaseLabel: true for switch case

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Ib0bb3c222441e7c6afcf7ea5c5c95bbf8413be57
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: sessiond: check for lttng-modules ABI 2.1 rather than 2.8

The clear patchset introduces a regression that breaks session
rotations when the kernel domain is used. The 2.8 lttng-modules ABI
does not exist yet.

The packet sequence number functionality was introduced in LTTng 2.8,
which introduced the 2.1 kernel tracer ABI.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ief97e7e25f6f0fcb5b5b97b39abb417c1eb327ec

Doc: man page: lttng-relayd LTTNG_RELAYD_DISALLOW_CLEAR env. var.

Describe the LTTNG_RELAYD_DISALLOW_CLEAR environment variable in the
lttng-relayd(8) man page.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3573d0f220f8aa298935e01f62c89035a1966f77
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Doc: lttng-clear(8) man page

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I6d981a1e17a2a3fdd20a4c61b8c2216bc6517f3f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: mi for clear command

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I769825ce10ce08cc1ae127821982d7ec3b1448ca
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: lttng clear command

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I96c837dfd65be76aa8995305e1e17a8b315b22af
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: gen-ust-events: abort() on argument error

Facilitates test transition: quickly identify tests which were not
updated.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Idec886cc565c4cb7f1de89e7f3f765c882f4b988
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: gen-ust-events: add touch and wait sync points before exit.

Allows an app to linger until the wait file is created and signals that
the app is just before the exit.

This is mostly useful for per-pid tracing where trace buffers are
cleaned on application teardown.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I37db4c118ebc759ce97c5de8901cad7b39ac1e01
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: gen-ust-events: use options instead of arguments

Remove argument dependency and ease usage of features individually.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I25769754a1ab271cea9b9ff5519f37371fd877dc
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: live: implement support for clear feature

Implement support for clear feature on live side of relayd.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I2d8996098abbdcd635757425bfcee405daf1bb13
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: implement support for clear feature

Implement support for the clear feature on relayd receiving end.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ice56dea0b7f59a4881f28fef84bcb0406e0afca6
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: viewer-stream: introduce viewer_stream_close_files and viewer_stream_sync_tracefile_array_tail

Introduce the following viewer helpers for clear:

- viewer_stream_close_files: Allow closing currently open viewer files.

- viewer_stream_sync_tracefile_array_tail: Allow updating the current
  tracefile id and the index sent seqcount based on the current content
  of the tracefile array.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I5d2f72868625b00b207c75c202bc514768c35166
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: viewer_session: expose viewer_session_set_trace_chunk_copy symbol

Expose viewer_session_set_trace_chunk_copy() so it can be used from
relayd live.c. Needed for clear feature.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ie5892353a13a80481da52f847e691a984e02000f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trace-chunk: implement no-op and delete release commands

The delete release command is used by clear. The no-op command is used
for implicit session rotations launched by the destroy command.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I49ea666ff77d3e5f6ac4b25977313ea18e10be62
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: document effect of rotated_after_last_stop on clear

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I81e758aee375f297647bcf9c9a469f867799358a
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: snapshot: set trace chunk to NULL before closing it

Operations are expected to happen in this order with the reworked
trace chunk for clear feature.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3d655714c4b40b8563abdadb8cb74067eb7e4b6e
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: return invalid protocol error on close chunk disallowed clear

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic10283d5a9769f01486d3f6df07f54a8d2856699
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: set has rotated only for explicit rotations

Only set session has_rotated for explicit rotations on the trace chunk
close. This ensures has_rotated can distinguish between clear and
explicit rotate.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I97fac1ac2a6edc233bf1889d693f74f2d7936156
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

trace-chunk: Introduce chunk "path", relayd session "ongoing_rotation", sessiond session "rotated"

This commit introduces new attributes in 3 different structures because
those are used in surrounding areas of the code.

Introduce a trace chunk path attribute which tracks where the chunk
currently keeps its files.

It allows updating the current chunk location with the "rename"
API without having to rely on changing the chunk name override,
which is an attribute we may want to keep using when we archive
the chunk.

Separating the "path" from the "name override" attribute allows
easy manipulation of the chunk output without having to keep the
name override around in the caller code.

Introduce an "ongoing_rotation" relayd session attribute to allow
live viewers to retry while a rotation is ongoing. This ongoing
rotation attribute is introduced in the same commit as the path
chunk attribute because they are used in a surrounding area of the code.

Introduce a "rotated" sessiond session attribute in this commit
because it is used in a surrounding area of the code. This rotated
attribute tracks whether an explicit rotation has been performed
on the session. It is a preparation step for the clear feature,
which will use this to figure out whether it needs to clear the
"root" output path (no rotation prior to clear") or if it needs
to clear to a new path. Before introduction of the clear feature,
a chunk_id of 0 was used to identify this, but because clear will
increment the chunk id without changing the path, we need to track
this explicitly through the "rotated" session flag.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ifdecc66cb4849f3e5f7476ab7db48d8f7532a6d3
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

consumer: add extra debug output

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I9cc81de9c46d5379e288ece625ccfef4fbf8e022
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: add extra debug output

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ie83470b293e10441357302a0d6e2668522d983ed
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: implement clear command

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Iaff1df7693858f5c9b24a6c8d1411fd76cc83714
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: add clear notifier

Add a clear notifier array to reply to clients requesting a clear
command.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I422d87b0122b75be47ae5941fed15f09e87460fe
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: introduce cleared_after_last_stop

Track whether a session was cleared after the last stop, so
additional clear will be effect-less until it is started again.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Icaa86acab20081b436bd55d026ec79a10c56034b
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: implement ust app clear session

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I9205b25cd18035156485df980104dea5c241542f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: implement kernel clear session

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ie47c128fc951b206c7ae50933395e9ade9d0012d
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: implement consumer clear channel

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I1c17a34c23e4c03f94acb99fb822c3bc42faccf5
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

consumer: implement clear channel

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I4eefc1d23b1b781f055790933572c4796375da26
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

common trace-chunk: introduce lttng_trace_chunk_get_name_overridden

While it is possible to query whether the name of a chunk is
overridden through lttng_trace_chunk_get_name(), using it requires
a lot of code to deal with an unused name string when all that is needed
is to check whether the name is overridden.

In preparation for the new "path" handling needed for the clear
feature introduce this lttng_trace_chunk_get_name_overridden()
API to allow checking whether name is overridden in a succint way.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ied8bcbb5202826e68a5d6b54130f29f203948794
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

common: trace-chunk: track all files within a chunk

Track all files added/removed in a chunk. Required by the clear
feature so all files of a prior chunk can be unlinked, even if
they belong to applications which have already closed their
stream with per-pid UST buffers.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I41bf8ac61f9a8ed1e8f206520ef8845a102b1c1e
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: cmd_rotate_session: introduce command argument

Add a command type argument to cmd_rotate_session().

Change the internal session_close_trace_chunk() API to introduce the
LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION command rather than rely on
a NULL pointer, which facilitates passing of command argument across
cmd_rotate_session.

This introduces the LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE command,
which is required for the clear feature. Its implementation will
follow in a separate commit.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic1d8cbab1f98b93f1f6d27a2c6624ac2780932e2
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: query relayd configuration for availability of clear feature

Query the relayd configuration when connecting to check for availability
of the clear feature.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I5827fdc7f92bc9bc87ccf9d1c567057b2c227e2b
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: Implement get_configuration relayd protocol command

Introduce a "GET_CONFIGURATION" command to the relayd protocol.
This allows checking whether the relay daemon allows the clear
command or not. A 64-bit set of flags are returned, and it can be
extended in the future with a variable length payload.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I33a03d09871f1c0c248d5514451c533ffd773979
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

common: index and trace-chunk file creation/open API change

An API change to the common libraries is required for the following
functions to accomodate the clear feature:

- lttng_trace_chunk_open_file(),
- lttng_index_file_create_from_trace_chunk(),
- lttng_index_file_create_from_trace_chunk_read_only().

An "expect_no_file" boolean is introduced, allowing specific invocation
to consider a ENOENT errno as an expected condition (and not an error).
This is the case for instance for relayd live viewer_stream_rotate(),
which can fail to open files in the new chunk after a clear with per-pid
buffers. Same goes for viewer_get_next_index() and try_open_index().

Change the lttng_index_file_create_from_trace_chunk_read_only and
lttng_index_file_create_from_trace_chunk to allow them to return
a chunk status, which allows the callers to distinguish between
errors and a "no file" status, and deal with the situation accordingly.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3c43edca01629488c4e777078db7ffd2e88dc7ea
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

common: index: remove redundant separator for empty channel string

Tweak _lttng_index_file_create_from_trace_chunk() to correctly deal with
empty channel_path string, removing redundant "/" separators.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I743917c27e334ad12e145959b3ad3f59f62f1a64
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond: refactoring: introduce start/stop_kernel_session

The clear feature will need to stop kernel session as well, so move this
code to its own function rather than duplicate it.

start_kernel_session already exists, but is static. Expose it so it
can be used from a separate compile unit.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I68da1ee2e51105278265866590734c320a9789bd
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond-comm: add clear command support to consumer protocol

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I717012b855bc394bcdb524befb02a5b1ca54621b
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

sessiond-comm: Document feature branch specific commands range

Reserve a range of numbers for customer feature branches.
It is never meant to be used in the master branch.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ib15ffe281c8e040231559e48b76343e67a625f4b
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: tracefile array: Allow head position to skip ahead

The clear feature needs to move the head position ahead (jump)
over sequence numbers.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I08482bd13dd748621968c43de7647f9d19670880
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd tracefile array: add tracefile_array_reset

Required by clear feature.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I58893eb3fffbec5d39e7bf11a6d118fe23ec4496
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

common dynamic-array: Introduce dynamic array clear

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I35d25b054a040c2d23b4b1c1a8137ef59ee3c7d1
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

relayd: environment variable to disable clear command

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I04e5867220315660a373f2e49d5e6f0652a6c37e
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

lttng: Implement lttng clear session command

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Ia51a2bf7aa7d764431eff9a45a91d5348bc9a7e5
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

lttng-ctl: Expose sessiond cmd_clear_session command

Co-developed-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Id9d169daaa1c20912a6c105b4473c3f9f2ba3b49
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

common error: Add errors for clear feature

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ib7f1a99e2c5535941d6d7f9479e00762ae14b6ae
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

ust-consumer: Expose user space clear buffer operation

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I25d15b41b7186242f43339d035650ffe9f3f9936
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

kernel-ctl: Expose kernel clear buffer operation

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I582b922f577635ca66e78680fdfedb523e6dcf67
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Test: rotate_utils.sh: consider chunk archive with ust/ as empty

Now the session daemon needs to create the ust/ subdir to pass it
to the consumer daemon even if there are no active traced applications
in per-pid tracing. Therefore, we need to consider a chunk with a
ust/ empty directory as empty.

Empty local traces have this empty subdir, but remote traces do not.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic0cda7baf6eafa5b0c7b4f0b79e03bc8ea523d93
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Send ust and kernel domain directory handle to consumer

Send a directory handle to ust/ and kernel/ subdirectories of the
chunk to the consumer daemon, and alter the paths sent to consumer
so they do not include the domain subdir.

This will facilitate implementation of the clear command when no
rotation has been performed. The clear command will need to move the
ust/ and kernel/ directories to a "deleted" temporary directory while
the consumer is still actively using those directories. Making sure that
the consumer uses a handle on those subdirectories only ensures that the
consumer will not observe any transient state when those directories are
moved.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I2357ad702f810561c4d11405edc3ef204fc6c455
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: consumer: do not flush on transition from NULL chunk

When transitioning from NULL chunk, do not flush streams, because
the consumer has nowhere to store the packets generated by this
flush.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic92c035f6b1377849825527d0c9cc05a6b92ac38
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: consumer: honor "active" flush flag

Honor "active" flush flag in both kernel and ust consumers. A flush
"active" does a flush which will not generate empty packets (no event),
whereas an "inactive" flush will generate empty packets if flushing
a current packet which has no event.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Icc9772ba3ae18e96f24354ac6eb9223f343c3458
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: sessiond cmd.h: include missing lttng-sessiond.h

lttng-sessiond.h declares struct command_ctx which is used in cmd.h
prototypes.

It typically does not generate a compilation error because all
compile units including cmd.h also include lttng-sessiond.h, but
it is cleaner to include dependencies directly in cmd.h.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: If3106291309cd543a886b2aecda7d4f9d4b290b3
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: sessiond: ust-app: per-pid buffers: Create empty ust/ directory

When no applications are running, the toplevel ust/ directory is not
created in a chunk on rotation. Make sure this top level directory
is created.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia272f3182df298302e02b3e096785cb51687b8c9
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: utils: utils_stream_file_path separator

Do not add a separator for empty paths.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Icec7b07d7abab4c010706c8cb4f199229fa04c6f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: consumerd: use packet sequence number for rotation position

Refer to "Fix: relayd: use packet sequence number for rotation position"
for context of this change.

This commit introduces the changes required in the consumerd.

Some notable points related to this commit:

- Internally, the rotate_position (per-stream) is now a 64-bit
  value rather than an unsigned long.
- The scheme to rotate a stream is changed to allow using the
  backward-compatible lttng_consumer_take_snapshot() rather than
  the newer lttng_consumer_get_produced_snapshot(), thus allowing
  backward compatibility of the implicit rotation on destroy with
  pre-2.10 lttng-modules.
- The rotate position used as pivot point for the rotation is
  based on the packet_seq_num of the last packet that has been
  send over the network by consumerd, incremented by the number of
  packets between the sampled produced_pos and the consumed_pos.
  In the worse case scenario where an overwrite mode ring buffer
  overwrites its contents enough to trigger a 4GB overflow on a
  32-bit producer since the last packet was sent (e.g. due to a
  slow network), the difference between produced_pos and
  consumed_pos will be lower that what would have been expected.
  However, because this pivot position is used as a lower bound,
  being smaller than the real value is fine: the data that would
  have been misplaced in the wrong trace chunk were actually
  overwritten, and will therefore never be consumed.
- When interacting with pre-2.8 lttng-modules, the packet sequence
  number is not available. The current approach is to disallow
  rotations performed on sessions which have kernel tracing active
  with a pre-2.8 lttng-modules.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I8600cb5e2e9c05f3dfba0499a5fc4a3bb85dec24
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

align.h: Implement ALIGN_FLOOR macro

Implement the ALIGN_FLOOR macro which aligns the given value to the
previous alignment boundary, or keeps the value as-is if it is already
aligned.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I36d981e8fb705fafa3ff23ba2d82ec1babe73e45
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: relayd: per-pid live: no new metadata vs close

When using lttng-live on a per-pid UST trace, the metadata stream is
closed after an application exits. The live viewer observes that the
stream has no more data when getting the metadata returns 0 bytes.

Internally in the relay daemon, it is assumed that a metadata stream
can be put (and thus removed) as soon as all the metadata has been sent
to the viewer, but this is not quite right. The viewer actually needs to
observe a 0-byte reply after receiving all the metadata in order to
gracefully perceive the metadata stream hang up.

Therefore, add a no_new_metadata_notified flag to the metadata stream
to track whether that 0-byte message has been sent to the viewer since
the last metadata content was sent, and postpone the reclamation of the
metadata stream until it is closed _and_ that 0-byte reply was sent to
the live viewer.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0a05332284299d62b832046e4f9d22b6029c3a3e
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: relayd: use packet sequence number for rotation position

The "network" sequence number (net_seq_num) is a 64-bit sequence number
tagging each packet sent over the network. The net_seq_num increments
monotonically (+1) for each packet sent from consumer daemon to relay
daemon, on a per-stream basis. It is tagged by the consumer daemon when
sending a trace packet to the relay daemon.

The LTTng kernel and user-space ring buffer "consumed position"
(consumed_pos) and "produced position" (produced_pos) are free-running
counters counting the number of bytes consumed and produced so far by
each stream. Because those counters are updated atomically, they are
limited to a size of 32-bit on 32-bit architectures.

The "packet" sequence number (packet_seq_num) is a sequence number
found in the packet header starting from LTTng 2.8. It is a 64-bit
sequence number assigned by the lttng-modules and lttng-ust ring
buffers. It increments monotonically (+1) for each packet produced
within a given ring buffer (stream).

Using produced_pos as rotation position and comparing it to the
net_seq_num has a few issues:

1) It breaks on 32-bit producers after generating more than 4GB of
   data per stream, due to overflow. The net_seq_num is a 64-bit
   counter, which does not overflow, but the produced_pos overflows
   after 4GB on 32-bit architectures. This can lead to never-completing
   rotations.

2) It breaks scenarios where ring buffers are configured in
   overwrite mode, and streaming to a relay daemon. Indeed, when
   the ring buffer moves the consumed_pos ahead, actually overwriting
   data within the ring buffer, it introduces an offset between the
   produced_pos and the net_seq_num. Therefore, if producers are
   generating a low- (or no-) throughput in some streams, the
   rotation may never complete, even on 64-bit architectures.

The solution proposed for this issue is to use the packet_seq_num as
rotation position rather than the net_seq_num. It takes care of
the two problematic scenarios, since the counter is always 64-bit
(even on 32-bit architectures), and because the counter is managed
by the producer, which therefore tracks progress of the ring buffer
overwrites.

This commit introduces changes required at the relayd side. A
separate commit introduces the changes required in the consumerd.

In relayd, one major restriction is the fact that the packet_seq_num
is not sent over the data socket, only through the control socket
receiving the indexes.

Therefore, in order to figure out the pivot position for the data
socket for a given stream, the associated index first needs to be
received. At that point, the corresponding net_seq_num is known,
which provides the pivot position for the data stream. Given that
the data and index sockets provide no ordering guarantees with
respect to their arrival, we handle the fact that data might have
been saved to disk in the wrong (previous) trace chunk by moving
it to the next trace chunk when the pivot position is known.

In order to allow "jumps" in the sequence numbers produced by
overwrite mode buffers, try_rotate_stream_index(), which previously
asserted that each sequence number was received in sequence, now
uses the packet_seq_num pivot position as a lower (inclusive) bound.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I755329e313f0980655a164b7bdb57e4f3d8e944a
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: relayd stream.c: LTTNG_OPTIONAL_GET address confusion

The lack of proper care around use of macro arguments in LTTNG_OPTIONAL_GET
allowed this code to compile, but caused the following issue (manually
replacing "optional" argument with the a

Using LTTNG_OPTIONAL_GET(&stream->ongoing_rotation)->next_trace_chunk

with:

 #define LTTNG_OPTIONAL_GET(optional)                   \
         ({                                             \
               assert(optional.is_set);                 \
               optional.value;                          \
         })

translates to:

         ({
               assert(&stream->ongoing_rotation.is_set);
               &stream->ongoing_rotation.value;
         })->next_trace_chunk

The issue here is the assert(), which just checks that the address
is not NULL, when it should actually check that the value is set.

The prior commit fixing optional.h to add proper parentheses to the
macro rightfully fails to compile this code. Fix the erroneous user.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I0dd45fb60573cae6ae3e831e24266aff4406f57f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: optional.h macro missing parentheses and guards

The are a few coding style issues with optional.h which leads to
unexpected effects when the macros are used in the caller code.

All macro parameters need to be surrounded by () (except when used near
commas, which is the C operator with least precedence).

All macros that emit code need to be surrounded by do { } while (0) so
not to emit extra ; or omit ;, which can cause subtle issues when used
with if/else statements.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Iba6fde7c267f4d8c9ec1a89147045f0bcda3a67a
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: use of strnlen breaks build on Solaris 10

The new uuid helper library makes use of strnlen directly, which
doesn't exist on Solaris 10. Using the compat version solves this.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie491da37f968fac417e265b5641fdf0dd3298813

dynamic-array: fix documentation of lttng_dynamic_pointer_array_get_pointer

The documentation of this function says that mutating the array
invalidates the return pointer.  This is not true, since the returned
pointer is the element itself, not a pointer to the array.

Change-Id: I8b8978cddb2d1d6ce0b42ed313e9843ca418c96c
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: make dist fails on sdt-probe test with autotools v1.16+

The 'dist' target fails when building with autotools 1.16.1 as the
behaviour of BUILT_SOURCES has changed in 1.16 [1].

BUILT_SOURCES are now built as part of the 'dist' target which causes
it to fail on machines that don't have dtrace installed.

The following error is produced: DTRACE foobar_provider.h /bin/sh: -s:
  command not found

The BUILT_SOURCES is skipped for build configurations where the build
of the test helper 'userspace-probe-sdt-binary' is disabled.

The resulting artifact, foobar_provider.h, is not part of the
distributed tarball (marked as nodist), so this doesn't have any
adverse effect.

[1] https://www.mail-archive.com/automake@gnu.org/msg20156.html

Signed-off-by: Michael Jeanson <michael.jeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibba4689775a8b002e8a959079b1f3c8db9917c5f

Fix: tests: metadata presence on relayd is not deterministic

There is no synchronization point guaranteeing the presence of metadata on
lttng-relayd side when the live metadata request is done. It must be
present at some point in the future but might not be at the moment we
perform the request.

Add a retry phase to this step. It must succeed in the future.

Not sure how this test was never marked as flaky.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: I033005c6a228013e699c74d8e8faafcb3272dd98
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Fix: move testpoint after state update

This prevent failure and hang for the long_regression test suite.

Otherwise the sessiond error out before the test completion due to an
invalid thread state.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Change-Id: Ie4bf3bea6f84f49f5eceb413ae75a7e6fff08a8f
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

Make lttng_directory_handle reference countable

Currently, the lttng_directory_handle API assumes that the caller has
exclusive ownership of the lttng_directory_handle. Directory handles
are passed by reference and populated by an "init" method and
finalized using the "fini" method.

In order to allow multiple references to a path or directory file
descriptor in follow-up patches, the API is moved to a model where
directory handles are dynamically allocated and released using the
"put" method.

No change in behaviour is intended by this change beyond adapting the
API.

The objective of the change is to make it easier to implement copy
operations of trace chunks that are configured to use an fd-tracker
and reduce the number of open file descriptors when
lttng_directory_handles are copied.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ibc8e97ea9e949adafef44533c30b61e3a9fa1f7d

Clean-up: apply clang-format to the newly added fd-tracker

The fd-tracker code was just merged but clang-format found some
changes to apply. Since there is no need to backport to this code
yet, clean it up as much as possible now.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ia0bec41e0531c9f5d611d742e96a984de3f06784

Fix build: fd-tracker is not part of librelayd

The fd-tracker library is not part of the internal librelayd; it is
its own stand-alone library.

Add an autoconf conditional to build libfd-tracker by default
and require it when building the relay daemon.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I40934eeaa62e61f5da4508c1f2c91daaa9e57829

Add git-review config

Add .gitreview for contributors wishing to use gerrit for patch
reviews.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I74c017eeac05c9092be145265e6ce060dddcd791

doc: fix typo in lttng-enable-event man page

Change-Id: I81ce8f5d4eb3857ace5b1bc3a3ed3c62751dc503
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

tests: make functions static in test_notification.c

Fixes:

      CC       test_notification.o
    /home/smarchi/src/lttng-tools/tests/unit/test_notification.c:50:6: error: no previous declaration for ‘test_condition_buffer_usage’ [-Werror=missing-declarations]
     void test_condition_buffer_usage(struct lttng_condition *buffer_usage_condition)
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
    /home/smarchi/src/lttng-tools/tests/unit/test_notification.c:265:6: error: no previous declaration for ‘test_condition_buffer_usage_low’ [-Werror=missing-declarations]
     void test_condition_buffer_usage_low(void)
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    /home/smarchi/src/lttng-tools/tests/unit/test_notification.c:280:6: error: no previous declaration for ‘test_condition_buffer_usage_high’ [-Werror=missing-declarations]
     void test_condition_buffer_usage_high(void)
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    /home/smarchi/src/lttng-tools/tests/unit/test_notification.c:295:6: error: no previous declaration for ‘test_action’ [-Werror=missing-declarations]
     void test_action(void)
          ^~~~~~~~~~~
    /home/smarchi/src/lttng-tools/tests/unit/test_notification.c:305:6: error: no previous declaration for ‘test_trigger’ [-Werror=missing-declarations]
     void test_trigger(void)
          ^~~~~~~~~~~~

Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I4df29ec42436798005e740d5b6fb34973ea22350
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>