1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-05-12 14:06:08 +02:00
git/common-main.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

55 lines
1.3 KiB
C

#include "cache.h"
#include "exec-cmd.h"
#include "attr.h"
/*
* Many parts of Git have subprograms communicate via pipe, expect the
* upstream of a pipe to die with SIGPIPE when the downstream of a
* pipe does not need to read all that is written. Some third-party
* programs that ignore or block SIGPIPE for their own reason forget
* to restore SIGPIPE handling to the default before spawning Git and
* break this carefully orchestrated machinery.
*
* Restore the way SIGPIPE is handled to default, which is what we
* expect.
*/
static void restore_sigpipe_to_default(void)
{
sigset_t unblock;
sigemptyset(&unblock);
sigaddset(&unblock, SIGPIPE);
sigprocmask(SIG_UNBLOCK, &unblock, NULL);
signal(SIGPIPE, SIG_DFL);
}
int main(int argc, const char **argv)
{
int result;
/*
* Always open file descriptors 0/1/2 to avoid clobbering files
* in die(). It also avoids messing up when the pipes are dup'ed
* onto stdin/stdout/stderr in the child processes we spawn.
*/
sanitize_stdfds();
restore_sigpipe_to_default();
trace2_initialize();
trace2_cmd_start(argv);
git_resolve_executable_dir(argv[0]);
git_setup_gettext();
initialize_the_repository();
attr_start();
result = cmd_main(argc, argv);
trace2_cmd_exit(result);
return result;
}