git/trace2.h, branch v2.35.2

Merge branch 'jh/builtin-fsmonitor-part1'

2021-10-13T22:15:58Z

Built-in fsmonitor (part 1). * jh/builtin-fsmonitor-part1: t/helper/simple-ipc: convert test-simple-ipc to use start_bg_command run-command: create start_bg_command simple-ipc/ipc-win32: add Windows ACL to named pipe simple-ipc/ipc-win32: add trace2 debugging simple-ipc: move definition of ipc_active_state outside of ifdef simple-ipc: preparations for supporting binary messages. trace2: add trace2_child_ready() to report on background children

Merge branch 'en/typofixes'

2021-09-28T20:06:53Z

Typofixes. * en/typofixes: merge-ort: fix completely wrong comment trace2.h: fix trivial comment typo

trace2.h: fix trivial comment typo

2021-09-20T18:25:01Z

Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

trace2: add trace2_child_ready() to report on background children

2021-09-20T15:57:58Z

Create "child_ready" event to capture the state of a child process created in the background. When a child command is started a "child_start" event is generated in the Trace2 log. For normal synchronous children, a "child_exit" event is later generated when the child exits or is terminated. The two events include information, such as the "child_id" and "pid", to allow post analysis to match-up the command line and exit status. When a child is started in the background (and may outlive the parent process), it is not possible for the parent to emit a "child_exit" event. Create a new "child_ready" event to indicate whether the child was successfully started. Also include the "child_id" and "pid" to allow similar post processing. This will be used in a later commit with the new "start_bg_command()". Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano

tr2: log parent process name

2021-07-22T20:35:20Z

It can be useful to tell who invoked Git - was it invoked manually by a user via CLI or script? By an IDE? In some cases - like 'repo' tool - we can influence the source code and set the GIT_TRACE2_PARENT_SID environment variable from the caller process. In 'repo''s case, that parent SID is manipulated to include the string "repo", which means we can positively identify when Git was invoked by 'repo' tool. However, identifying parents that way requires both that we know which tools invoke Git and that we have the ability to modify the source code of those tools. It cannot scale to keep up with the various IDEs and wrappers which use Git, most of which we don't know about. Learning which tools and wrappers invoke Git, and how, would give us insight to decide where to improve Git's usability and performance. Unfortunately, there's no cross-platform reliable way to gather the name of the parent process. If procfs is present, we can use that; otherwise we will need to discover the name another way. However, the process ID should be sufficient to look up the process name on most platforms, so that code may be shareable. Git for Windows gathers similar information and logs it as a "data_json" event. However, since "data_json" has a variable format, it is difficult to parse effectively in some languages; instead, let's pursue a dedicated "cmd_ancestry" event to record information about the ancestry of the current process and a consistent, parseable way. Git for Windows also gathers information about more than one generation of parent. In Linux further ancestry info can be gathered with procfs, but it's unwieldy to do so. In the interest of later moving Git for Windows ancestry logging to the 'cmd_ancestry' event, and in the interest of later adding more ancestry to the Linux implementation - or of adding this functionality to other platforms which have an easier time walking the process tree - let's make 'cmd_ancestry' accept an array of parentage. Signed-off-by: Emily Shaffer Signed-off-by: Junio C Hamano

tr2: make process info collection platform-generic

2021-07-22T20:35:20Z

To pave the way for non-Windows platforms to define trace2_collect_process_info(), reorganize the stub-or-definition schema to something which doesn't directly reference Windows. Platforms which want to collect parent process information in the future should: 1. Add an implementation to compat/ (e.g. compat/somearch/procinfo.c) 2. Add that object to COMPAT_OBJS to config.mak.uname (e.g. COMPAT_OBJS += compat/somearch/procinfo.o) 3. Define HAVE_PLATFORM_PROCINFO in config.mak.uname In the Windows case, this definition lives in compat/win32/trace2_win32_process_info.c, which is already conditionally added to COMPAT_OBJS; so let's add HAVE_PLATFORM_PROCINFO to hint to the build that compat/stub/procinfo.c should not be used. Signed-off-by: Emily Shaffer Helped-by: Jonathan Nieder Signed-off-by: Junio C Hamano

trace2: add a public function for getting the SID

2020-11-12T02:26:52Z

Add a public wrapper, trace2_session_id(), around tr2_sid_get(), which is intended to be private trace2 implementation. Signed-off-by: Josh Steadmon Signed-off-by: Junio C Hamano

trace2: teach Git to log environment variables

2020-03-23T20:14:53Z

Via trace2, Git can already log interesting config parameters (see the trace2_cmd_list_config() function). However, this can grant an incomplete picture because many config parameters also allow overrides via environment variables. To allow for more complete logs, we add a new trace2_cmd_list_env_vars() function and supporting implementation, modeled after the pre-existing config param logging implementation. Signed-off-by: Josh Steadmon Acked-by: Jeff Hostetler Signed-off-by: Junio C Hamano

trace2: move doc to trace2.h

2019-11-18T06:21:29Z

Move the functions documentation from Documentation/technical/api-trace2.txt to trace2.h as it's easier for the developers to find the usage information beside the code instead of looking for it in another doc file. Only the functions documentation section is removed from Documentation/technical/api-trace2.txt as the file is full of details that seemed more appropriate to be in a separate doc file as it is, with a link to the doc file added in the trace2.h. Also the functions doc is removed to avoid having redundandt info which will be hard to keep syncronized with the documentation in the header file. Signed-off-by: Heba Waly 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