git/trace2.c
Jeff Hostetler ee4512ed48 trace2: create new combined trace facility
Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:27:59 -08:00

762 lines
17 KiB
C

#include "cache.h"
#include "config.h"
#include "json-writer.h"
#include "quote.h"
#include "run-command.h"
#include "sigchain.h"
#include "thread-utils.h"
#include "version.h"
#include "trace2/tr2_cfg.h"
#include "trace2/tr2_cmd_name.h"
#include "trace2/tr2_dst.h"
#include "trace2/tr2_sid.h"
#include "trace2/tr2_tgt.h"
#include "trace2/tr2_tls.h"
static int trace2_enabled;
static int tr2_next_child_id; /* modify under lock */
static int tr2_next_exec_id; /* modify under lock */
static int tr2_next_repo_id = 1; /* modify under lock. zero is reserved */
/*
* A table of the builtin TRACE2 targets. Each of these may be independently
* enabled or disabled. Each TRACE2 API method will try to write an event to
* *each* of the enabled targets.
*/
/* clang-format off */
static struct tr2_tgt *tr2_tgt_builtins[] =
{
&tr2_tgt_normal,
&tr2_tgt_perf,
&tr2_tgt_event,
NULL
};
/* clang-format on */
/* clang-format off */
#define for_each_builtin(j, tgt_j) \
for (j = 0, tgt_j = tr2_tgt_builtins[j]; \
tgt_j; \
j++, tgt_j = tr2_tgt_builtins[j])
/* clang-format on */
/* clang-format off */
#define for_each_wanted_builtin(j, tgt_j) \
for_each_builtin(j, tgt_j) \
if (tr2_dst_trace_want(tgt_j->pdst))
/* clang-format on */
/*
* Force (rather than lazily) initialize any of the requested
* builtin TRACE2 targets at startup (and before we've seen an
* actual TRACE2 event call) so we can see if we need to setup
* the TR2 and TLS machinery.
*
* Return the number of builtin targets enabled.
*/
static int tr2_tgt_want_builtins(void)
{
struct tr2_tgt *tgt_j;
int j;
int sum = 0;
for_each_builtin (j, tgt_j)
if (tgt_j->pfn_init())
sum++;
return sum;
}
/*
* Properly terminate each builtin target. Give each target
* a chance to write a summary event and/or flush if necessary
* and then close the fd.
*/
static void tr2_tgt_disable_builtins(void)
{
struct tr2_tgt *tgt_j;
int j;
for_each_builtin (j, tgt_j)
tgt_j->pfn_term();
}
static int tr2main_exit_code;
/*
* Our atexit routine should run after everything has finished.
*
* Note that events generated here might not actually appear if
* we are writing to fd 1 or 2 and our atexit routine runs after
* the pager's atexit routine (since it closes them to shutdown
* the pipes).
*/
static void tr2main_atexit_handler(void)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
/*
* Clear any unbalanced regions so that our atexit message
* does not appear nested. This improves the appearance of
* the trace output if someone calls die(), for example.
*/
tr2tls_pop_unwind_self();
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_atexit)
tgt_j->pfn_atexit(us_elapsed_absolute,
tr2main_exit_code);
tr2_tgt_disable_builtins();
tr2tls_release();
tr2_sid_release();
tr2_cmd_name_release();
tr2_cfg_free_patterns();
trace2_enabled = 0;
}
static void tr2main_signal_handler(int signo)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_signal)
tgt_j->pfn_signal(us_elapsed_absolute, signo);
sigchain_pop(signo);
raise(signo);
}
void trace2_initialize_fl(const char *file, int line)
{
struct tr2_tgt *tgt_j;
int j;
if (trace2_enabled)
return;
if (!tr2_tgt_want_builtins())
return;
trace2_enabled = 1;
tr2_sid_get();
atexit(tr2main_atexit_handler);
sigchain_push(SIGPIPE, tr2main_signal_handler);
tr2tls_init();
/*
* Emit 'version' message on each active builtin target.
*/
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_version_fl)
tgt_j->pfn_version_fl(file, line);
}
int trace2_is_enabled(void)
{
return trace2_enabled;
}
void trace2_cmd_start_fl(const char *file, int line, const char **argv)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_start_fl)
tgt_j->pfn_start_fl(file, line, argv);
}
int trace2_cmd_exit_fl(const char *file, int line, int code)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
code &= 0xff;
if (!trace2_enabled)
return code;
tr2main_exit_code = code;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_exit_fl)
tgt_j->pfn_exit_fl(file, line, us_elapsed_absolute,
code);
return code;
}
void trace2_cmd_error_va_fl(const char *file, int line, const char *fmt,
va_list ap)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
/*
* We expect each target function to treat 'ap' as constant
* and use va_copy (because an 'ap' can only be walked once).
*/
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_error_va_fl)
tgt_j->pfn_error_va_fl(file, line, fmt, ap);
}
void trace2_cmd_path_fl(const char *file, int line, const char *pathname)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_command_path_fl)
tgt_j->pfn_command_path_fl(file, line, pathname);
}
void trace2_cmd_name_fl(const char *file, int line, const char *name)
{
struct tr2_tgt *tgt_j;
const char *hierarchy;
int j;
if (!trace2_enabled)
return;
tr2_cmd_name_append_hierarchy(name);
hierarchy = tr2_cmd_name_get_hierarchy();
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_command_name_fl)
tgt_j->pfn_command_name_fl(file, line, name, hierarchy);
}
void trace2_cmd_mode_fl(const char *file, int line, const char *mode)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_command_mode_fl)
tgt_j->pfn_command_mode_fl(file, line, mode);
}
void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
const char **argv)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_alias_fl)
tgt_j->pfn_alias_fl(file, line, alias, argv);
}
void trace2_cmd_list_config_fl(const char *file, int line)
{
if (!trace2_enabled)
return;
tr2_cfg_list_config_fl(file, line);
}
void trace2_cmd_set_config_fl(const char *file, int line, const char *key,
const char *value)
{
if (!trace2_enabled)
return;
tr2_cfg_set_fl(file, line, key, value);
}
void trace2_child_start_fl(const char *file, int line,
struct child_process *cmd)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
cmd->trace2_child_id = tr2tls_locked_increment(&tr2_next_child_id);
cmd->trace2_child_us_start = us_now;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_child_start_fl)
tgt_j->pfn_child_start_fl(file, line,
us_elapsed_absolute, cmd);
}
void trace2_child_exit_fl(const char *file, int line, struct child_process *cmd,
int child_exit_code)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
uint64_t us_elapsed_child;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
if (cmd->trace2_child_us_start)
us_elapsed_child = us_now - cmd->trace2_child_us_start;
else
us_elapsed_child = 0;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_child_exit_fl)
tgt_j->pfn_child_exit_fl(file, line,
us_elapsed_absolute,
cmd->trace2_child_id, cmd->pid,
child_exit_code,
us_elapsed_child);
}
int trace2_exec_fl(const char *file, int line, const char *exe,
const char **argv)
{
struct tr2_tgt *tgt_j;
int j;
int exec_id;
uint64_t us_now;
uint64_t us_elapsed_absolute;
if (!trace2_enabled)
return -1;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
exec_id = tr2tls_locked_increment(&tr2_next_exec_id);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_exec_fl)
tgt_j->pfn_exec_fl(file, line, us_elapsed_absolute,
exec_id, exe, argv);
return exec_id;
}
void trace2_exec_result_fl(const char *file, int line, int exec_id, int code)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_exec_result_fl)
tgt_j->pfn_exec_result_fl(
file, line, us_elapsed_absolute, exec_id, code);
}
void trace2_thread_start_fl(const char *file, int line, const char *thread_name)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
if (!trace2_enabled)
return;
if (tr2tls_is_main_thread()) {
/*
* We should only be called from the new thread's thread-proc,
* so this is technically a bug. But in those cases where the
* main thread also runs the thread-proc function (or when we
* are built with threading disabled), we need to allow it.
*
* Convert this call to a region-enter so the nesting looks
* correct.
*/
trace2_region_enter_printf_fl(file, line, NULL, NULL, NULL,
"thread-proc on main: %s",
thread_name);
return;
}
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
tr2tls_create_self(thread_name);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_thread_start_fl)
tgt_j->pfn_thread_start_fl(file, line,
us_elapsed_absolute);
}
void trace2_thread_exit_fl(const char *file, int line)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
uint64_t us_elapsed_thread;
if (!trace2_enabled)
return;
if (tr2tls_is_main_thread()) {
/*
* We should only be called from the exiting thread's
* thread-proc, so this is technically a bug. But in
* those cases where the main thread also runs the
* thread-proc function (or when we are built with
* threading disabled), we need to allow it.
*
* Convert this call to a region-leave so the nesting
* looks correct.
*/
trace2_region_leave_printf_fl(file, line, NULL, NULL, NULL,
"thread-proc on main");
return;
}
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
/*
* Clear any unbalanced regions and then get the relative time
* for the outer-most region (which we pushed when the thread
* started). This gives us the run time of the thread.
*/
tr2tls_pop_unwind_self();
us_elapsed_thread = tr2tls_region_elasped_self(us_now);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_thread_exit_fl)
tgt_j->pfn_thread_exit_fl(file, line,
us_elapsed_absolute,
us_elapsed_thread);
tr2tls_unset_self();
}
void trace2_def_param_fl(const char *file, int line, const char *param,
const char *value)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_param_fl)
tgt_j->pfn_param_fl(file, line, param, value);
}
void trace2_def_repo_fl(const char *file, int line, struct repository *repo)
{
struct tr2_tgt *tgt_j;
int j;
if (!trace2_enabled)
return;
if (repo->trace2_repo_id)
return;
repo->trace2_repo_id = tr2tls_locked_increment(&tr2_next_repo_id);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_repo_fl)
tgt_j->pfn_repo_fl(file, line, repo);
}
void trace2_region_enter_printf_va_fl(const char *file, int line,
const char *category, const char *label,
const struct repository *repo,
const char *fmt, va_list ap)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
/*
* Print the region-enter message at the current nesting
* (indentation) level and then push a new level.
*
* We expect each target function to treat 'ap' as constant
* and use va_copy.
*/
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_region_enter_printf_va_fl)
tgt_j->pfn_region_enter_printf_va_fl(
file, line, us_elapsed_absolute, category,
label, repo, fmt, ap);
tr2tls_push_self(us_now);
}
void trace2_region_enter_fl(const char *file, int line, const char *category,
const char *label, const struct repository *repo)
{
trace2_region_enter_printf_va_fl(file, line, category, label, repo,
NULL, NULL);
}
void trace2_region_enter_printf_fl(const char *file, int line,
const char *category, const char *label,
const struct repository *repo,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
trace2_region_enter_printf_va_fl(file, line, category, label, repo, fmt,
ap);
va_end(ap);
}
#ifndef HAVE_VARIADIC_MACROS
void trace2_region_enter_printf(const char *category, const char *label,
const struct repository *repo, const char *fmt,
...)
{
va_list ap;
va_start(ap, fmt);
trace2_region_enter_printf_va_fl(NULL, 0, category, label, repo, fmt,
ap);
va_end(ap);
}
#endif
void trace2_region_leave_printf_va_fl(const char *file, int line,
const char *category, const char *label,
const struct repository *repo,
const char *fmt, va_list ap)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
uint64_t us_elapsed_region;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
/*
* Get the elapsed time in the current region before we
* pop it off the stack. Pop the stack. And then print
* the perf message at the new (shallower) level so that
* it lines up with the corresponding push/enter.
*/
us_elapsed_region = tr2tls_region_elasped_self(us_now);
tr2tls_pop_self();
/*
* We expect each target function to treat 'ap' as constant
* and use va_copy.
*/
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_region_leave_printf_va_fl)
tgt_j->pfn_region_leave_printf_va_fl(
file, line, us_elapsed_absolute,
us_elapsed_region, category, label, repo, fmt,
ap);
}
void trace2_region_leave_fl(const char *file, int line, const char *category,
const char *label, const struct repository *repo)
{
trace2_region_leave_printf_va_fl(file, line, category, label, repo,
NULL, NULL);
}
void trace2_region_leave_printf_fl(const char *file, int line,
const char *category, const char *label,
const struct repository *repo,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
trace2_region_leave_printf_va_fl(file, line, category, label, repo, fmt,
ap);
va_end(ap);
}
#ifndef HAVE_VARIADIC_MACROS
void trace2_region_leave_printf(const char *category, const char *label,
const struct repository *repo, const char *fmt,
...)
{
va_list ap;
va_start(ap, fmt);
trace2_region_leave_printf_va_fl(NULL, 0, category, label, repo, fmt,
ap);
va_end(ap);
}
#endif
void trace2_data_string_fl(const char *file, int line, const char *category,
const struct repository *repo, const char *key,
const char *value)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
uint64_t us_elapsed_region;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
us_elapsed_region = tr2tls_region_elasped_self(us_now);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_data_fl)
tgt_j->pfn_data_fl(file, line, us_elapsed_absolute,
us_elapsed_region, category, repo,
key, value);
}
void trace2_data_intmax_fl(const char *file, int line, const char *category,
const struct repository *repo, const char *key,
intmax_t value)
{
struct strbuf buf_string = STRBUF_INIT;
if (!trace2_enabled)
return;
strbuf_addf(&buf_string, "%" PRIdMAX, value);
trace2_data_string_fl(file, line, category, repo, key, buf_string.buf);
strbuf_release(&buf_string);
}
void trace2_data_json_fl(const char *file, int line, const char *category,
const struct repository *repo, const char *key,
const struct json_writer *value)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
uint64_t us_elapsed_region;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
us_elapsed_region = tr2tls_region_elasped_self(us_now);
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_data_fl)
tgt_j->pfn_data_json_fl(file, line, us_elapsed_absolute,
us_elapsed_region, category,
repo, key, value);
}
void trace2_printf_va_fl(const char *file, int line, const char *fmt,
va_list ap)
{
struct tr2_tgt *tgt_j;
int j;
uint64_t us_now;
uint64_t us_elapsed_absolute;
if (!trace2_enabled)
return;
us_now = getnanotime() / 1000;
us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
/*
* We expect each target function to treat 'ap' as constant
* and use va_copy.
*/
for_each_wanted_builtin (j, tgt_j)
if (tgt_j->pfn_printf_va_fl)
tgt_j->pfn_printf_va_fl(file, line, us_elapsed_absolute,
fmt, ap);
}
void trace2_printf_fl(const char *file, int line, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
trace2_printf_va_fl(file, line, fmt, ap);
va_end(ap);
}
#ifndef HAVE_VARIADIC_MACROS
void trace2_printf(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
trace2_printf_va_fl(NULL, 0, fmt, ap);
va_end(ap);
}
#endif