git/trace2, branch v2.22.2

Merge branch 'sg/trace2-rename'

2019-05-30T17:50:45Z

Rename environment variables that are used to control the "trace2" mechanism to a more readable name. * sg/trace2-rename: trace2: document the supported values of GIT_TRACE2* env variables trace2: rename environment variables to GIT_TRACE2*

Merge branch 'jh/trace2'

2019-05-30T17:50:45Z

* jh/trace2: trace2: fix tracing when NO_PTHREADS is defined

trace2: fix tracing when NO_PTHREADS is defined

2019-05-28T17:52:34Z

Teach trace2 TLS code to not rely on pthread_getspecific() when NO_PTHREADS is defined. Instead, always assume the context data of the main thread. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano

trace2: rename environment variables to GIT_TRACE2*

2019-05-28T17:20:34Z

For an environment variable that is supposed to be set by users, the GIT_TR2* env vars are just too unclear, inconsistent, and ugly. Most of the established GIT_* environment variables don't use abbreviations, and in case of the few that do (GIT_DIR, GIT_COMMON_DIR, GIT_DIFF_OPTS) it's quite obvious what the abbreviations (DIR and OPTS) stand for. But what does TR stand for? Track, traditional, trailer, transaction, transfer, transformation, transition, translation, transplant, transport, traversal, tree, trigger, truncate, trust, or ...?! The trace2 facility, as the '2' suffix in its name suggests, is supposed to eventually supercede Git's original trace facility. It's reasonable to expect that the corresponding environment variables follow suit, and after the original GIT_TRACE variables they are called GIT_TRACE2; there is no such thing is 'GIT_TR'. All trace2-specific config variables are, very sensibly, in the 'trace2' section, not in 'tr2'. OTOH, we don't gain anything at all by omitting the last three characters of "trace" from the names of these environment variables. So let's rename all GIT_TR2* environment variables to GIT_TRACE2*, before they make their way into a stable release. Signed-off-by: SZEDER Gábor Signed-off-by: Junio C Hamano

Merge branch 'jh/trace2-sid-fix'

2019-05-13T14:50:31Z

Polishing of the new trace2 facility continues. The system-level configuration can specify site-wide trace2 settings, which can be overridden with per-user configuration and environment variables. * jh/trace2-sid-fix: trace2: fixup access problem on /etc/gitconfig in read_very_early_config trace2: update docs to describe system/global config settings trace2: make SIDs more unique trace2: clarify UTC datetime formatting trace2: report peak memory usage of the process trace2: use system/global config for default trace2 settings config: add read_very_early_config() trace2: find exec-dir before trace2 initialization trace2: add absolute elapsed time to start event trace2: refactor setting process starting time config: initialize opts structure in repo_read_config()

Merge branch 'js/trace2-to-directory'

2019-05-08T15:37:24Z

The trace2 tracing facility learned to auto-generate a filename when told to log to a directory. * js/trace2-to-directory: trace2: write to directory targets

trace2: make SIDs more unique

2019-04-16T04:37:07Z

Update SID component construction to use the current UTC datetime and a portion of the SHA1 of the hostname. Use an simplified date/time format to make it easier to use the SID component as a logfile filename. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano

trace2: clarify UTC datetime formatting

2019-04-16T04:37:07Z

Update tr2_tbuf_utc_datetime to generate extended UTC format. Update tr2_tgt_event target to use extended format in 'time' columns. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano

trace2: use system/global config for default trace2 settings

2019-04-16T04:37:06Z

Teach git to read the system and global config files for default Trace2 settings. This allows system-wide Trace2 settings to be installed and inherited to make it easier to manage a collection of systems. The original GIT_TR2* environment variables are loaded afterwards and can be used to override the system settings. Only the system and global config files are used. Repo and worktree local config files are ignored. Likewise, the "-c" command line arguments are also ignored. These limits are for performance reasons. (1) For users not using Trace2, there should be minimal overhead to detect that Trace2 is not enabled. In particular, Trace2 should not allocate lots of otherwise unused data strucutres. (2) For accurate performance measurements, Trace2 should be initialized as early in the git process as possible, and before most of the normal git process initialization (which involves discovering the .git directory and reading a hierarchy of config files). Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano

trace2: add absolute elapsed time to start event

2019-04-16T04:37:06Z

Add elapsed process time to "start" event to measure the performance of early process startup. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano