git/trace2, branch v2.34.2

Merge branch 'js/trace2-raise-format-version'

2021-11-12T23:29:25Z

When we added a new event type to trace2 event stream, we forgot to raise the format version number, which has been corrected. * js/trace2-raise-format-version: trace2: increment event format version

trace2: increment event format version

2021-11-11T23:01:04Z

In 64bc752 (trace2: add trace2_child_ready() to report on background children, 2021-09-20), we added a new "child_ready" event. In Documentation/technical/api-trace2.txt, we promise that adding a new event type will result in incrementing the trace2 event format version number, but this was not done. Correct this in code & docs. Signed-off-by: Josh Steadmon Signed-off-by: Junio C Hamano

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

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: stop leaking "thread_name" memory

2021-09-07T18:07:59Z

Fix a memory leak introduced in ee4512ed481 (trace2: create new combined trace facility, 2019-02-22), we were doing a free() of other memory allocated in tr2tls_create_self(), but not the "thread_name" "struct strbuf". Signed-off-by: Ævar Arnfjörð Bjarmason Acked-by: Taylor Blau Signed-off-by: Junio C Hamano

Merge branch 'es/trace2-log-parent-process-name'

2021-08-24T22:32:40Z

trace2 logs learned to show parent process name to see in what context Git was invoked. * es/trace2-log-parent-process-name: tr2: log parent process name tr2: make process info collection platform-generic

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

Merge branch 'ab/trace2-squelch-gcc-warning'

2021-06-14T04:33:28Z

Workaround compiler warnings. * ab/trace2-squelch-gcc-warning: trace2: refactor to avoid gcc warning under -O3

trace2: refactor to avoid gcc warning under -O3

2021-05-20T21:56:11Z

Refactor tr2_dst_try_uds_connect() to avoid a gcc warning[1] that appears under -O3 (but not -O2). This makes the build pass under DEVELOPER=1 without needing a DEVOPTS=no-error. This can be reproduced with GCC Debian 8.3.0-6, but not e.g. with clang 7.0.1-8+deb10u2. We've had this warning since ee4512ed481 (trace2: create new combined trace facility, 2019-02-22). As noted in [2] this warning happens because the compiler doesn't assume that errno must be non-zero after a failed syscall. Let's work around by using the well-established "saved_errno" pattern, along with returning -1 ourselves instead of "errno". The caller can thus rely on our "errno" on failure. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61846 for a related bug report against GCC. 1. trace2/tr2_dst.c: In function ‘tr2_dst_get_trace_fd.part.5’: trace2/tr2_dst.c:296:10: warning: ‘fd’ may be used uninitialized in this function [-Wmaybe-uninitialized] dst->fd = fd; ~~~~~~~~^~~~ trace2/tr2_dst.c:229:6: note: ‘fd’ was declared here int fd; ^~ 2. https://lore.kernel.org/git/20200404142131.GA679473@coredump.intra.peff.net/ Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Jeff King 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