[RELEASE] LTTng-UST 2.11.0-rc1 (Linux user-space tracer)

[Mathieu Desnoyers]

Hi,

Here is the first release candidate of LTTng-UST 2.11 Linux
user-space tracer.

This release is named after a modern Saison beer from MontrÃal's Oshlag
microbrewery. It is a refreshing, zesty, rice beer with hints of fruit and
spices. Some even say it makes for a great Somaek when mixed with Chamisul
Soju, not that we've tried!

Lafontaine is also a tongue-in-cheek reference to a water leak that
affected EfficiOS's offices during the development of this release.

The most notable features of this new release that apply to lttng-ust
are:

  - Introduce the LTTNG_UST_ALLOW_BLOCKING environment variable,
  - Take NUMA configuration into account for UST buffer allocation,
  - Support unloading of probe providers (dlclose),
  - Session rotation,
  - Support for arrays and bitwise binary operators in filters.

The new LTTNG_UST_ALLOW_BLOCKING env. var. can be used with the
'--blocking-timeout' channel parameter to allow tracing to block
the application (or wait for a specified timeout) when buffers are
full. This is useful when dealing with very high throughput tracing
workloads. See lttng-ust(3) and lttng-enable-channel(1) for details.

See the lttng-tools release tag for more information about session
rotation, as well as support for arrays and bitwise binary operators
in filters at: https://github.com/lttng/lttng-tools/releases/tag/v2.11.0-rc1

Project website: http://lttng.org
Documentation: http://lttng.org/docs
Download link: http://lttng.org/download

Changelog:
2018-09-06 (Fight Procrastination Day) lttng-ust 2.11.0-rc1
        * Fix: add missing stdbool.h include
        * Move symbol preventing unloading of probe providers
        * Fix: Remove unused line from liblttng-ust-fd makefile
        * Fix: add liblttng-ust dependency to liblttng-ust-fd
        * Fix: use LIBDL/LIBC_DL to select either libdl or libc
        * Fix: lttng filter validator ERANGE error handling
        * Filter: implement dynamic typing for load object
        * Filter: add FILTER_OP_RETURN_S64 instruction
        * Perform bitwise ops on unsigned types
        * Filter: catch shift undefined behavior
        * Filter: implement bitwise lshift, rshift, not
        * Filter: index array, sequences, implement bitwise binary operators
        * Fix: AM_CONDITIONAL should be outside AS_IF block
        * Fix: build jni libs with openjdk >= 10
        * Fix: ustfork: save and restore errno in syscall wrappers
        * Fix: cache the result of getpid() internally
        * Fix: reset cached vpid context on fork
        * Fix: build example SO when PIE is enabled
        * Fix: string comparison on incorrect length in context provider
        * Support unloading of probe providers
        * Rename lttng_ust_enum_get to lttng_ust_enum_get_from_desc
        * dlopen() liblttng-ust.so from constructor to prevent unloading
        * Add probe provider unregister function
        * Cleanup: Move version numbers in separate variables in configure script
        * Remove duplicate provider name checks
        * Fix: remove for() loop initial declarations
        * Use ust_lock during sock_info operations for atomicity against fork
        * Force tracked fd to be bigger than STDERR_FILENO
        * Fix: numa: dynamically check that numa is available
        * Fix: specify SONAME in python-lttngust LoadLibrary
        * Fix: ensure fd tracker is initialized when called from constructors
        * Fix: fd of an elf object must be registered to the fd tracker
        * Cleanup: clock description for metadata was moved to lttng-sessiond
        * Fix: liblttng-ust-fd.so: override fclose symbol
        * Revert "Use initial-exec TLS model"
        * Revert "Fix: typo: DECLARE_URCU_TLS_IE -> DEFINE_URCU_TLS_IE"
        * configure.ac: add --disable-examples option to not build/install examples
        * Disable NUMA by default on 32bit arm
        * Update Makefile.am output about libnuma not found
        * Update readme to document opt dep on numa
        * numa support: allow disabling numa support
        * Update README to document dependency on libnuma
        * Take NUMA configuration into account for UST buffer allocation
        * Fix: typo: DECLARE_URCU_TLS_IE -> DEFINE_URCU_TLS_IE
        * Use initial-exec TLS model
        * lttng-gen-tp: formatting
        * Fix: lttng-gen-tp: only replace file extension
        * Fix: move fsync after ftruncate
        * Fix: sync buffer file metadata on buffer allocation
        * lttng-ust(3): reword and fix style of `LTTNG_UST_ALLOW_BLOCKING` variable
        * lttng-ust(3): specify "If set" instead of "if set to 1" for some variables
        * Fix: doc/man: use a single XSL file and match local names
        * Fix: Expand the shmobj size for the sequence number
        * Introduce LTTNG_UST_ALLOW_BLOCKING env. var.
        * Fix: lttng-ust-elf.c: define NT_GNU_BUILD_ID if not defined
        * Calculate context length outside of retry loop
        * Fix: Quote CMAKE variable assignment in Makefile
        * Rework configure script
        * Fix: Typo in doc/examples/Makefile.am
        * Fix: Don't override user variables within the build system
        * Move m4 scripts to m4 dir
        * doc: remove duplicate LTTNG_UST_BLOCKING_RETRY_TIMEOUT man page entry

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com