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#include <nnwt/thread.h>
#include "../liana/common.h"
#include "clock.h"
#define RUNNING 0.0
#define PAUSED -DBL_MAX
// @TODO:
// Stop throwing away precision before we need to.
// Assume calc_tick_offset() could give a negative result at any point.
// Use a tick offset to set local buffer latency in a way that makes more sense.
void camu_clock_init(struct camu_clock *clock, void (*callback)(void *, u8), void *userdata)
{
clock->callback = callback;
clock->userdata = userdata;
}
static f64 calc_tick_offset(f64 tick, u64 now, u64 target)
{
if (now > target) {
return tick - (now - target) / 1000000.0;
} else {
return tick + (target - now) / 1000000.0;
}
}
static void offset_tick(struct camu_clock *clock, f64 diff)
{
diff += atomic_load(f64)(&clock->tick, AL_ATOMIC_ACQUIRE);
atomic_store(f64)(&clock->tick, diff, AL_ATOMIC_RELEASE);
}
void camu_clock_set(struct camu_clock *clock, f64 base)
{
clock->base = base;
atomic_store(f64)(&clock->tick, -1.0, AL_ATOMIC_RELAXED);
atomic_store(f64)(&clock->pause, PAUSED, AL_ATOMIC_RELAXED);
clock->paused_at = 0.0;
atomic_store(f64)(&clock->last_pts, base, AL_ATOMIC_RELAXED);
}
void camu_clock_seek(struct camu_clock *clock, f64 base, u64 target)
{
clock->base = base;
atomic_store(f64)(&clock->last_pts, base, AL_ATOMIC_RELAXED);
if (clock->paused_at == -1.0) {
// We are safe to directly edit the tick here.
if (target == 0) {
atomic_store(f64)(&clock->tick, -1.0, AL_ATOMIC_RELAXED);
} else {
f64 tick = nn_get_tick();
tick = calc_tick_offset(tick, nn_get_timestamp(), target);
atomic_store(f64)(&clock->tick, tick, AL_ATOMIC_RELAXED);
}
} else {
// Don't touch clock->pause here for the sake of sync. This means,
// theoretically, the sink could still rely on a CLOCK_PAUSED callback
// from an entry even after it was seeked. That would ultimately maintain sync but
// the clock would report the old position in get_pts() before triggering CLOCK_PAUSED.
// Likely confusing an entry's buffers and causing excessive catchup or delay.
// We mitigate this sink-side by immediately switching to a potential target in
// CLIENT_REMOVE_BUFFERS, which is always called before an entry is seeked.
clock->paused_at = 0.0;
}
}
// Seek to 0 but include the time it took to perform the seek.
void camu_clock_loop(struct camu_clock *clock, f64 last_pts)
{
clock->base = 0.0;
offset_tick(clock, last_pts - clock->base);
}
// If late, pause immediately and on resume() there will be a long delay.
void camu_clock_pause(struct camu_clock *clock, u64 target)
{
al_assert(clock->paused_at == -1.0);
f64 now = nn_get_tick(), tick = now;
if (target > 0) {
tick = calc_tick_offset(tick, nn_get_timestamp(), target);
}
atomic_store(f64)(&clock->pause, (tick > now) ? tick : -tick, AL_ATOMIC_RELAXED);
clock->paused_at = tick;
}
// If late, this will be a catchup.
void camu_clock_resume(struct camu_clock *clock, u64 target)
{
al_assert(clock->paused_at != -1.0);
f64 tick = nn_get_tick();
if (target > 0) {
tick = calc_tick_offset(tick, nn_get_timestamp(), target);
}
if (clock->paused_at == 0.0) {
if (target == 0) {
// target = 0 can never be synced.
atomic_store(f64)(&clock->tick, -1.0, AL_ATOMIC_RELAXED);
} else {
atomic_store(f64)(&clock->tick, tick, AL_ATOMIC_RELAXED);
}
} else {
f64 pause = atomic_load(f64)(&clock->pause, AL_ATOMIC_ACQUIRE);
offset_tick(clock, tick - ((pause != PAUSED) ? -pause : clock->paused_at));
}
atomic_store(f64)(&clock->pause, RUNNING, AL_ATOMIC_RELEASE);
clock->paused_at = -1.0;
}
bool camu_clock_is_paused(struct camu_clock *clock)
{
return atomic_load(f64)(&clock->pause, AL_ATOMIC_RELAXED) < 0.0;
}
f64 camu_clock_get_base_pts(struct camu_clock *clock)
{
return clock->base;
}
f64 camu_clock_get_pts(struct camu_clock *clock, f64 latency, bool allow_set)
{
f64 pause = atomic_load(f64)(&clock->pause, AL_ATOMIC_RELAXED);
if (pause < 0.0) return CAMU_PTS_PAUSED;
f64 current = nn_get_tick();
f64 tick = atomic_load(f64)(&clock->tick, AL_ATOMIC_RELAXED);
if (tick == -1.0) {
if (allow_set) {
tick = atomic_compare_and_swap(f64)(&clock->tick, -1.0, current);
if (tick == -1.0) tick = current;
} else {
return CAMU_PTS_PAUSED;
}
}
f64 pts = clock->base + (current - tick);
bool signal_pause = false;
if (pause > 0.0 && current > pause) { // pause > 0.0 = RUNNING or armed for pause.
f64 paused_at = -current;
pause = atomic_compare_and_swap(f64)(&clock->pause, pause, paused_at);
if (pause != paused_at) {
clock->callback(clock->userdata, CAMU_CLOCK_PAUSED);
signal_pause = true;
}
}
if (allow_set) {
atomic_store(f64)(&clock->last_pts, pts, AL_ATOMIC_RELAXED);
}
return signal_pause ? CAMU_PTS_SIGNAL_PAUSE : pts + latency;
}
f64 camu_clock_get_last_pts(struct camu_clock *clock)
{
return atomic_load(f64)(&clock->last_pts, AL_ATOMIC_RELAXED);
}
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