/* The signal handler, called on every SIGXCPU */
static void signal_handler(int sig) {
int saved_errno;
saved_errno = errno;
pa_assert(sig == SIGXCPU);
if (phase == PHASE_IDLE) {
pa_usec_t now, elapsed;
#ifdef PRINT_CPU_LOAD
char t[256];
#endif
now = pa_rtclock_now();
elapsed = now - last_time;
#ifdef PRINT_CPU_LOAD
pa_snprintf(t, sizeof(t), "Using %0.1f%% CPU\n", ((double) CPUTIME_INTERVAL_SOFT * (double) PA_USEC_PER_SEC) / (double) elapsed * 100.0);
write_err(t);
#endif
if (((double) CPUTIME_INTERVAL_SOFT * (double) PA_USEC_PER_SEC) >= ((double) elapsed * (double) CPUTIME_PERCENT / 100.0)) {
static const char c = 'X';
write_err("Soft CPU time limit exhausted, terminating.\n");
/* Try a soft cleanup */
(void) write(the_pipe[1], &c, sizeof(c));
phase = PHASE_SOFT;
reset_cpu_time(CPUTIME_INTERVAL_HARD);
} else {
/* Everything's fine */
reset_cpu_time(CPUTIME_INTERVAL_SOFT);
last_time = now;
}
} else if (phase == PHASE_SOFT) {
write_err("Hard CPU time limit exhausted, terminating forcibly.\n");
abort(); /* Forced exit */
}
errno = saved_errno;
}
/* Initializes CPU load limiter */
int pa_cpu_limit_init(pa_mainloop_api *m) {
struct sigaction sa;
pa_assert(m);
pa_assert(!api);
pa_assert(!io_event);
pa_assert(the_pipe[0] == -1);
pa_assert(the_pipe[1] == -1);
pa_assert(!installed);
time(&last_time);
/* Prepare the main loop pipe */
if (pipe(the_pipe) < 0) {
pa_log("pipe() failed: %s", pa_cstrerror(errno));
return -1;
}
pa_make_fd_nonblock(the_pipe[0]);
pa_make_fd_nonblock(the_pipe[1]);
pa_make_fd_cloexec(the_pipe[0]);
pa_make_fd_cloexec(the_pipe[1]);
api = m;
io_event = api->io_new(m, the_pipe[0], PA_IO_EVENT_INPUT, callback, NULL);
phase = PHASE_IDLE;
/* Install signal handler for SIGXCPU */
memset(&sa, 0, sizeof(sa));
sa.sa_handler = signal_handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if (sigaction(SIGXCPU, &sa, &sigaction_prev) < 0) {
pa_cpu_limit_done();
return -1;
}
installed = 1;
reset_cpu_time(CPUTIME_INTERVAL_SOFT);
return 0;
}
