git-commit-vandalism/trace2/tr2_tgt_perf.c
Emily Shaffer 2f732bf15e tr2: log parent process name
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 <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22 13:35:20 -07:00

568 lines
15 KiB
C

#include "cache.h"
#include "config.h"
#include "run-command.h"
#include "quote.h"
#include "version.h"
#include "json-writer.h"
#include "trace2/tr2_dst.h"
#include "trace2/tr2_sid.h"
#include "trace2/tr2_sysenv.h"
#include "trace2/tr2_tbuf.h"
#include "trace2/tr2_tgt.h"
#include "trace2/tr2_tls.h"
static struct tr2_dst tr2dst_perf = { TR2_SYSENV_PERF, 0, 0, 0, 0 };
/*
* Use TR2_SYSENV_PERF_BRIEF to omit the "<time> <file>:<line>"
* fields from each line written to the builtin performance target.
*
* Unit tests may want to use this to help with testing.
*/
static int tr2env_perf_be_brief;
#define TR2FMT_PERF_FL_WIDTH (28)
#define TR2FMT_PERF_MAX_EVENT_NAME (12)
#define TR2FMT_PERF_REPO_WIDTH (3)
#define TR2FMT_PERF_CATEGORY_WIDTH (12)
#define TR2_INDENT (2)
#define TR2_INDENT_LENGTH(ctx) (((ctx)->nr_open_regions - 1) * TR2_INDENT)
static int fn_init(void)
{
int want = tr2_dst_trace_want(&tr2dst_perf);
int want_brief;
const char *brief;
if (!want)
return want;
brief = tr2_sysenv_get(TR2_SYSENV_PERF_BRIEF);
if (brief && *brief &&
((want_brief = git_parse_maybe_bool(brief)) != -1))
tr2env_perf_be_brief = want_brief;
return want;
}
static void fn_term(void)
{
tr2_dst_trace_disable(&tr2dst_perf);
}
/*
* Format trace line prefix in human-readable classic format for
* the performance target:
* "[<time> [<file>:<line>] <bar>] <nr_parents> <bar>
* <thread_name> <bar> <event_name> <bar> [<repo>] <bar>
* [<elapsed_absolute>] [<elapsed_relative>] <bar>
* [<category>] <bar> [<dots>] "
*/
static void perf_fmt_prepare(const char *event_name,
struct tr2tls_thread_ctx *ctx, const char *file,
int line, const struct repository *repo,
uint64_t *p_us_elapsed_absolute,
uint64_t *p_us_elapsed_relative,
const char *category, struct strbuf *buf)
{
int len;
strbuf_setlen(buf, 0);
if (!tr2env_perf_be_brief) {
struct tr2_tbuf tb_now;
size_t fl_end_col;
tr2_tbuf_local_time(&tb_now);
strbuf_addstr(buf, tb_now.buf);
strbuf_addch(buf, ' ');
fl_end_col = buf->len + TR2FMT_PERF_FL_WIDTH;
if (file && *file) {
struct strbuf buf_fl = STRBUF_INIT;
strbuf_addf(&buf_fl, "%s:%d", file, line);
if (buf_fl.len <= TR2FMT_PERF_FL_WIDTH)
strbuf_addbuf(buf, &buf_fl);
else {
size_t avail = TR2FMT_PERF_FL_WIDTH - 3;
strbuf_addstr(buf, "...");
strbuf_add(buf,
&buf_fl.buf[buf_fl.len - avail],
avail);
}
strbuf_release(&buf_fl);
}
while (buf->len < fl_end_col)
strbuf_addch(buf, ' ');
strbuf_addstr(buf, " | ");
}
strbuf_addf(buf, "d%d | ", tr2_sid_depth());
strbuf_addf(buf, "%-*s | %-*s | ", TR2_MAX_THREAD_NAME,
ctx->thread_name.buf, TR2FMT_PERF_MAX_EVENT_NAME,
event_name);
len = buf->len + TR2FMT_PERF_REPO_WIDTH;
if (repo)
strbuf_addf(buf, "r%d ", repo->trace2_repo_id);
while (buf->len < len)
strbuf_addch(buf, ' ');
strbuf_addstr(buf, " | ");
if (p_us_elapsed_absolute)
strbuf_addf(buf, "%9.6f | ",
((double)(*p_us_elapsed_absolute)) / 1000000.0);
else
strbuf_addf(buf, "%9s | ", " ");
if (p_us_elapsed_relative)
strbuf_addf(buf, "%9.6f | ",
((double)(*p_us_elapsed_relative)) / 1000000.0);
else
strbuf_addf(buf, "%9s | ", " ");
strbuf_addf(buf, "%-*.*s | ", TR2FMT_PERF_CATEGORY_WIDTH,
TR2FMT_PERF_CATEGORY_WIDTH, (category ? category : ""));
if (ctx->nr_open_regions > 0)
strbuf_addchars(buf, '.', TR2_INDENT_LENGTH(ctx));
}
static void perf_io_write_fl(const char *file, int line, const char *event_name,
const struct repository *repo,
uint64_t *p_us_elapsed_absolute,
uint64_t *p_us_elapsed_relative,
const char *category,
const struct strbuf *buf_payload)
{
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
struct strbuf buf_line = STRBUF_INIT;
perf_fmt_prepare(event_name, ctx, file, line, repo,
p_us_elapsed_absolute, p_us_elapsed_relative, category,
&buf_line);
strbuf_addbuf(&buf_line, buf_payload);
tr2_dst_write_line(&tr2dst_perf, &buf_line);
strbuf_release(&buf_line);
}
static void fn_version_fl(const char *file, int line)
{
const char *event_name = "version";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addstr(&buf_payload, git_version_string);
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_start_fl(const char *file, int line,
uint64_t us_elapsed_absolute, const char **argv)
{
const char *event_name = "start";
struct strbuf buf_payload = STRBUF_INIT;
sq_append_quote_argv_pretty(&buf_payload, argv);
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_exit_fl(const char *file, int line, uint64_t us_elapsed_absolute,
int code)
{
const char *event_name = "exit";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "code:%d", code);
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_signal(uint64_t us_elapsed_absolute, int signo)
{
const char *event_name = "signal";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "signo:%d", signo);
perf_io_write_fl(__FILE__, __LINE__, event_name, NULL,
&us_elapsed_absolute, NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_atexit(uint64_t us_elapsed_absolute, int code)
{
const char *event_name = "atexit";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "code:%d", code);
perf_io_write_fl(__FILE__, __LINE__, event_name, NULL,
&us_elapsed_absolute, NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void maybe_append_string_va(struct strbuf *buf, const char *fmt,
va_list ap)
{
if (fmt && *fmt) {
va_list copy_ap;
va_copy(copy_ap, ap);
strbuf_vaddf(buf, fmt, copy_ap);
va_end(copy_ap);
return;
}
}
static void fn_error_va_fl(const char *file, int line, const char *fmt,
va_list ap)
{
const char *event_name = "error";
struct strbuf buf_payload = STRBUF_INIT;
maybe_append_string_va(&buf_payload, fmt, ap);
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_command_path_fl(const char *file, int line, const char *pathname)
{
const char *event_name = "cmd_path";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addstr(&buf_payload, pathname);
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_command_ancestry_fl(const char *file, int line, const char **parent_names)
{
const char *event_name = "cmd_ancestry";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addstr(&buf_payload, "ancestry:[");
/* It's not an argv but the rules are basically the same. */
sq_append_quote_argv_pretty(&buf_payload, parent_names);
strbuf_addch(&buf_payload, ']');
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_command_name_fl(const char *file, int line, const char *name,
const char *hierarchy)
{
const char *event_name = "cmd_name";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addstr(&buf_payload, name);
if (hierarchy && *hierarchy)
strbuf_addf(&buf_payload, " (%s)", hierarchy);
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_command_mode_fl(const char *file, int line, const char *mode)
{
const char *event_name = "cmd_mode";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addstr(&buf_payload, mode);
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_alias_fl(const char *file, int line, const char *alias,
const char **argv)
{
const char *event_name = "alias";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "alias:%s argv:[", alias);
sq_append_quote_argv_pretty(&buf_payload, argv);
strbuf_addch(&buf_payload, ']');
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_child_start_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
const struct child_process *cmd)
{
const char *event_name = "child_start";
struct strbuf buf_payload = STRBUF_INIT;
if (cmd->trace2_hook_name) {
strbuf_addf(&buf_payload, "[ch%d] class:hook hook:%s",
cmd->trace2_child_id, cmd->trace2_hook_name);
} else {
const char *child_class =
cmd->trace2_child_class ? cmd->trace2_child_class : "?";
strbuf_addf(&buf_payload, "[ch%d] class:%s",
cmd->trace2_child_id, child_class);
}
if (cmd->dir) {
strbuf_addstr(&buf_payload, " cd:");
sq_quote_buf_pretty(&buf_payload, cmd->dir);
}
strbuf_addstr(&buf_payload, " argv:[");
if (cmd->git_cmd) {
strbuf_addstr(&buf_payload, "git");
if (cmd->argv[0])
strbuf_addch(&buf_payload, ' ');
}
sq_append_quote_argv_pretty(&buf_payload, cmd->argv);
strbuf_addch(&buf_payload, ']');
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_child_exit_fl(const char *file, int line,
uint64_t us_elapsed_absolute, int cid, int pid,
int code, uint64_t us_elapsed_child)
{
const char *event_name = "child_exit";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "[ch%d] pid:%d code:%d", cid, pid, code);
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
&us_elapsed_child, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_thread_start_fl(const char *file, int line,
uint64_t us_elapsed_absolute)
{
const char *event_name = "thread_start";
struct strbuf buf_payload = STRBUF_INIT;
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_thread_exit_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
uint64_t us_elapsed_thread)
{
const char *event_name = "thread_exit";
struct strbuf buf_payload = STRBUF_INIT;
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
&us_elapsed_thread, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_exec_fl(const char *file, int line, uint64_t us_elapsed_absolute,
int exec_id, const char *exe, const char **argv)
{
const char *event_name = "exec";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "id:%d ", exec_id);
strbuf_addstr(&buf_payload, "argv:[");
if (exe) {
strbuf_addstr(&buf_payload, exe);
if (argv[0])
strbuf_addch(&buf_payload, ' ');
}
sq_append_quote_argv_pretty(&buf_payload, argv);
strbuf_addch(&buf_payload, ']');
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_exec_result_fl(const char *file, int line,
uint64_t us_elapsed_absolute, int exec_id,
int code)
{
const char *event_name = "exec_result";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "id:%d code:%d", exec_id, code);
if (code > 0)
strbuf_addf(&buf_payload, " err:%s", strerror(code));
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_param_fl(const char *file, int line, const char *param,
const char *value)
{
const char *event_name = "def_param";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "%s:%s", param, value);
perf_io_write_fl(file, line, event_name, NULL, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_repo_fl(const char *file, int line,
const struct repository *repo)
{
const char *event_name = "def_repo";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addstr(&buf_payload, "worktree:");
sq_quote_buf_pretty(&buf_payload, repo->worktree);
perf_io_write_fl(file, line, event_name, repo, NULL, NULL, NULL,
&buf_payload);
strbuf_release(&buf_payload);
}
static void fn_region_enter_printf_va_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
const char *category,
const char *label,
const struct repository *repo,
const char *fmt, va_list ap)
{
const char *event_name = "region_enter";
struct strbuf buf_payload = STRBUF_INIT;
if (label)
strbuf_addf(&buf_payload, "label:%s", label);
if (fmt && *fmt) {
strbuf_addch(&buf_payload, ' ');
maybe_append_string_va(&buf_payload, fmt, ap);
}
perf_io_write_fl(file, line, event_name, repo, &us_elapsed_absolute,
NULL, category, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_region_leave_printf_va_fl(
const char *file, int line, uint64_t us_elapsed_absolute,
uint64_t us_elapsed_region, const char *category, const char *label,
const struct repository *repo, const char *fmt, va_list ap)
{
const char *event_name = "region_leave";
struct strbuf buf_payload = STRBUF_INIT;
if (label)
strbuf_addf(&buf_payload, "label:%s", label);
if (fmt && *fmt) {
strbuf_addch(&buf_payload, ' ' );
maybe_append_string_va(&buf_payload, fmt, ap);
}
perf_io_write_fl(file, line, event_name, repo, &us_elapsed_absolute,
&us_elapsed_region, category, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
uint64_t us_elapsed_region, const char *category,
const struct repository *repo, const char *key,
const char *value)
{
const char *event_name = "data";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "%s:%s", key, value);
perf_io_write_fl(file, line, event_name, repo, &us_elapsed_absolute,
&us_elapsed_region, category, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_data_json_fl(const char *file, int line,
uint64_t us_elapsed_absolute,
uint64_t us_elapsed_region, const char *category,
const struct repository *repo, const char *key,
const struct json_writer *value)
{
const char *event_name = "data_json";
struct strbuf buf_payload = STRBUF_INIT;
strbuf_addf(&buf_payload, "%s:%s", key, value->json.buf);
perf_io_write_fl(file, line, event_name, repo, &us_elapsed_absolute,
&us_elapsed_region, category, &buf_payload);
strbuf_release(&buf_payload);
}
static void fn_printf_va_fl(const char *file, int line,
uint64_t us_elapsed_absolute, const char *fmt,
va_list ap)
{
const char *event_name = "printf";
struct strbuf buf_payload = STRBUF_INIT;
maybe_append_string_va(&buf_payload, fmt, ap);
perf_io_write_fl(file, line, event_name, NULL, &us_elapsed_absolute,
NULL, NULL, &buf_payload);
strbuf_release(&buf_payload);
}
struct tr2_tgt tr2_tgt_perf = {
&tr2dst_perf,
fn_init,
fn_term,
fn_version_fl,
fn_start_fl,
fn_exit_fl,
fn_signal,
fn_atexit,
fn_error_va_fl,
fn_command_path_fl,
fn_command_ancestry_fl,
fn_command_name_fl,
fn_command_mode_fl,
fn_alias_fl,
fn_child_start_fl,
fn_child_exit_fl,
fn_thread_start_fl,
fn_thread_exit_fl,
fn_exec_fl,
fn_exec_result_fl,
fn_param_fl,
fn_repo_fl,
fn_region_enter_printf_va_fl,
fn_region_leave_printf_va_fl,
fn_data_fl,
fn_data_json_fl,
fn_printf_va_fl,
};