// Host lifecycle: graceful exit (SIGTERM; on iOS the App termination callback calls dm_host_shutdown).
// Pause audio, suspend graphics (wait for in-flight NVN calls to end and drain GPU work), then _exit(0); a 1.5 s fallback goes straight to _exit(0).
// The default action also exits in about 0.08 s (exit code 143); the value of this function is stopping background threads in order, exit code 0, and giving the iOS lifecycle callback an entry.
#include "hle.h"
#include <dispatch/dispatch.h>
#include <stdatomic.h>
#include <signal.h>
#include <unistd.h>
void hlecount_flush(void); void dm_rec_finish(void);
void dm_host_shutdown_then(const char *why, void (*then)(void *), void *arg) {
    static _Atomic int once; if (atomic_exchange(&once, 1)) return;
    uint64_t t0 = now_ns(); LOG("received %s: graceful exit", why);
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1500 * NSEC_PER_MSEC), dispatch_get_global_queue(QOS_CLASS_USER_INTERACTIVE, 0), ^{
        LOG("[RED] graceful exit not done in 1.5 seconds, exiting at once"); if (then) then(arg); _exit(0); });
    hlecount_flush();                               // DM_HLECOUNT: _exit does not run atexit, write a copy here
    dm_rec_finish();                                // DM_REC: the held state and the buffered steps (hle_hid.c)
    dm_cheats_exit();                               // a clean exit: no safe mode for the cheats at the next launch (atexit does not run either)
    dm_audio_suspend(1);
    dm_gfx_suspend(1);
    LOG("graceful exit done (%.3f s)", (now_ns() - t0) / 1e9);
    if (then) then(arg);
    _exit(0);
}
void dm_host_shutdown(const char *why) { dm_host_shutdown_then(why, NULL, NULL); }
void dm_term_install(void) {
    signal(SIGTERM, SIG_IGN);                       // do not take the default action: hand over to the GCD signal source to wrap up on an ordinary thread
    static dispatch_source_t src;
    src = dispatch_source_create(DISPATCH_SOURCE_TYPE_SIGNAL, SIGTERM, 0, dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0));
    dispatch_source_set_event_handler(src, ^{ dm_host_shutdown("SIGTERM"); });
    dispatch_resume(src);
}