MuBacktrace*
get_backtrace(int skip)
{
MuBacktrace* trace, **out;
void* buffer[100];
int num_frames;
int i;
char** symbols;
num_frames = backtrace(buffer, sizeof(buffer) / sizeof(*buffer));
symbols = backtrace_symbols(buffer, num_frames);
out = &trace;
for (i = skip; i < num_frames; i++)
{
*out = calloc(1, sizeof(MuBacktrace));
fill_backtrace(*out, symbols[i]);
out = &(*out)->up;
}
*out = NULL;
return trace;
}
int
main(int argc, char *argv[])
{
bool need_exit = false;
ptrace_context ptrace_ctx;
program_params params;
struct itimerval itv;
struct proc_timer proc_time;
calltree_node *root = NULL;
g_progname = argv[0];
if (!parse_args(¶ms, argc, argv))
usage();
print_message("Reading symbols (list of function)");
init_fndescr(params.pid);
if (params.just_print_symbols) {
print_symbols();
free_fndescr();
exit(0);
}
if (!reset_process_time(&proc_time, params.pid, params.prof_method)) {
free_fndescr();
errx(2, "Failed to retrieve process time");
}
print_message("Attaching to process: %d", params.pid);
memset(&ptrace_ctx, 0, sizeof(ptrace_ctx));
if (!trace_init(params.pid, &ptrace_ctx))
err(1, "Failed to initialize unwind internals");
signal(SIGCHLD, on_sigchld);
if (ptrace(PTRACE_ATTACH, params.pid, 0, 0) == -1) {
int saved_errno = errno;
warn("ptrace(PTRACE_ATTACH) failed");
if (saved_errno == EPERM) {
printf("You have to see NOTES section of `man crxprof' for workarounds.\n");
}
exit(2);
}
if (do_wait(&ptrace_ctx, true) != WR_STOPPED)
err(1, "Error occured while stopping the process");
if (ptrace(PTRACE_CONT, params.pid, 0, 0) < 0)
err(1, "Error occured while stopping the process 2");
/* interval timer for snapshots */
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = params.us_sleep;
itv.it_value = itv.it_interval;
signal(SIGALRM, on_sigalarm);
if (setitimer(ITIMER_REAL, &itv, NULL) == -1)
err(1, "setitimer failed");
print_message("Starting profile (interval %dms)", params.us_sleep / 1000);
print_message("Press ^C once to show profile, twice to quit");
signal(SIGINT, on_sigint);
/* drop first meter since it contains our preparations */
(void)get_process_dt(&proc_time);
while(!need_exit)
{
waitres_t wres = WR_NOTHING;
sleep(1);
if (timer_alarmed) {
uint64_t proc_dt = get_process_dt(&proc_time);
bool need_prof = (params.prof_method == PROF_REALTIME);
if (params.prof_method == PROF_CPUTIME) {
char st = get_procstate(&ptrace_ctx);
if (st == 'R')
need_prof = true;
}
if (need_prof) {
kill(params.pid, SIGSTOP);
wres = do_wait(&ptrace_ctx, true);
if (wres == WR_STOPPED) {
int signo_cont = (ptrace_ctx.stop_signal == SIGSTOP) ? 0 : ptrace_ctx.stop_signal;
if (!get_backtrace(&ptrace_ctx))
err(2, "failed to get backtrace of process");
/* continue tracee ASAP */
if (ptrace_verbose(PTRACE_CONT, params.pid, 0, signo_cont) < 0)
err(1, "ptrace(PTRACE_CONT) failed");
ptrace_ctx.nsnaps++;
if (fill_backtrace(proc_dt, &ptrace_ctx.stk, &root))
ptrace_ctx.nsnaps_accounted++;
}
}
}
if (wres != WR_FINISHED && wres != WR_NEED_DETACH) {
wres = discard_wait(&ptrace_ctx);
}
if (sigint_caught_twice) {
need_exit = true;
} else if (sigint_caught || wres == WR_FINISHED || wres == WR_NEED_DETACH) {
if (root) {
print_message("%" PRIu64 " snapshot interrputs got (%" PRIu64 " dropped)",
ptrace_ctx.nsnaps, ptrace_ctx.nsnaps - ptrace_ctx.nsnaps_accounted);
visualize_profile(root, ¶ms.vprops);
if (params.dumpfile)
dump_profile(root, params.dumpfile);
} else
print_message("No symbolic snapshot caught yet!");
sigint_caught = false;
}
if (wres == WR_FINISHED || wres == WR_NEED_DETACH) {
if (wres == WR_NEED_DETACH)
(void)ptrace_verbose(PTRACE_DETACH, params.pid, 0, ptrace_ctx.stop_signal);
need_exit = true;
}
}
free_fndescr();
trace_free(&ptrace_ctx);
if (root)
calltree_destroy(root);
return 0;
}
