aboutsummaryrefslogtreecommitdiff
path: root/src/swapchain_monitor.cc
blob: 492e83eb3e99daa429a1c8ccd7527e4a62ffac80 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
#include "swapchain_monitor.hh"
#include "device_context.hh"
#include "helper.hh"

#include <chrono>
#include <vulkan/vulkan_core.h>

#include <functional>
#include <mutex>

namespace low_latency {

SwapchainMonitor::SwapchainMonitor(const DeviceContext& device,
                                   const bool was_low_latency_requested)
    : device(device), was_low_latency_requested(was_low_latency_requested) {}

SwapchainMonitor::~SwapchainMonitor() {}

void SwapchainMonitor::update_params(
    const bool was_low_latency_requested,
    const std::chrono::microseconds present_delay) {

    const auto lock = std::scoped_lock{this->mutex};

    this->was_low_latency_requested = was_low_latency_requested;
    this->present_delay = present_delay;
}

void SwapchainMonitor::prune_submissions() {
    // If our submissions grow too large, we should delete them from our
    // tracking. It would be nice if this was handled elegantly by some custom
    // container and we didn't have to call this manually each time we insert.
    // Also this exact logic is repeated in QueueContext's Submission.
    if (std::size(this->in_flight_submissions) >
        this->MAX_TRACKED_IN_FLIGHT_SUBMISSIONS) {

        this->in_flight_submissions.pop_front();
    }
}

ReflexSwapchainMonitor::ReflexSwapchainMonitor(
    const DeviceContext& device, const bool was_low_latency_requested)
    : SwapchainMonitor(device, was_low_latency_requested),
      monitor_worker(
          std::bind_front(&ReflexSwapchainMonitor::do_monitor, this)) {}

ReflexSwapchainMonitor::~ReflexSwapchainMonitor() {}

void ReflexSwapchainMonitor::WakeupSemaphore::signal(
    const DeviceContext& device) const {

    const auto ssi =
        VkSemaphoreSignalInfo{.sType = VK_STRUCTURE_TYPE_SEMAPHORE_SIGNAL_INFO,
                              .semaphore = this->timeline_semaphore,
                              .value = this->value};
    THROW_NOT_VKSUCCESS(device.vtable.SignalSemaphore(device.device, &ssi));
}

void ReflexSwapchainMonitor::do_monitor(const std::stop_token stoken) {
    for (;;) {
        auto lock = std::unique_lock{this->mutex};
        this->cv.wait(lock, stoken,
                      [&]() { return !this->semaphore_submissions.empty(); });

        if (stoken.stop_requested()) {
            // Small chance an application might need outstanding semaphores
            // to be signalled if it's closing to avoid a hang.
            break;
        }

        // Grab the most recent semaphore we want to signal off the queue.
        const auto semaphore_submission =
            std::move(this->semaphore_submissions.back());
        this->semaphore_submissions.clear();

        lock.unlock();
        // Wait for work to finish and signal its associated semaphore.
        semaphore_submission.submissions->await_completed();
        semaphore_submission.wakeup_semaphore.signal(this->device);
    }
}

void ReflexSwapchainMonitor::notify_semaphore(
    const VkSemaphore& timeline_semaphore, const std::uint64_t& value) {

    auto lock = std::unique_lock{this->mutex};

    const auto wakeup_semaphore = WakeupSemaphore{
        .timeline_semaphore = timeline_semaphore, .value = value};

    if (!this->was_low_latency_requested ||
        this->in_flight_submissions.empty()) {

        wakeup_semaphore.signal(this->device);
        return;
    }

    if (this->in_flight_submissions.back()->has_completed()) {
        this->in_flight_submissions.clear();
        wakeup_semaphore.signal(this->device);
        return;
    }

    this->semaphore_submissions.emplace_back(SemaphoreSubmissions{
        .wakeup_semaphore = wakeup_semaphore,
        .submissions = std::move(this->in_flight_submissions.back()),
    });
    this->in_flight_submissions.clear();

    lock.unlock();
    this->cv.notify_one();
}

void ReflexSwapchainMonitor::notify_present(
    std::unique_ptr<QueueContext::Submissions> submissions) {

    const auto lock = std::scoped_lock{this->mutex};
    if (!this->was_low_latency_requested) {
        return;
    }

    this->in_flight_submissions.emplace_back(std::move(submissions));
    this->prune_submissions();
}

AntiLagSwapchainMonitor::AntiLagSwapchainMonitor(
    const DeviceContext& device, const bool was_low_latency_requested)
    : SwapchainMonitor(device, was_low_latency_requested) {}

AntiLagSwapchainMonitor::~AntiLagSwapchainMonitor() {}
void AntiLagSwapchainMonitor::notify_present(
    std::unique_ptr<QueueContext::Submissions> submissions) {

    const auto lock = std::scoped_lock{this->mutex};
    if (!this->was_low_latency_requested) {
        return;
    }

    this->in_flight_submissions.emplace_back(std::move(submissions));
    this->prune_submissions();
}

void AntiLagSwapchainMonitor::await_submissions() {

    auto lock = std::unique_lock{this->mutex};
    if (this->in_flight_submissions.empty()) {
        return;
    }

    const auto last = std::move(this->in_flight_submissions.back());
    this->in_flight_submissions.clear();
    lock.unlock();

    last->await_completed();
}

} // namespace low_latency