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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "hwc-vsync-worker"
#include "VSyncWorker.h"
#include <xf86drm.h>
#include <xf86drmMode.h>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include "drm/ResourceManager.h"
#include "utils/log.h"
namespace android {
auto VSyncWorker::CreateInstance(DrmDisplayPipeline *pipe,
VSyncWorkerCallbacks &callbacks)
-> std::shared_ptr<VSyncWorker> {
auto vsw = std::shared_ptr<VSyncWorker>(new VSyncWorker());
vsw->callbacks_ = callbacks;
if (pipe != nullptr) {
vsw->high_crtc_ = pipe->crtc->Get()->GetIndexInResArray()
<< DRM_VBLANK_HIGH_CRTC_SHIFT;
vsw->drm_fd_ = pipe->device->GetFd();
}
std::thread(&VSyncWorker::ThreadFn, vsw.get(), vsw).detach();
return vsw;
}
void VSyncWorker::VSyncControl(bool enabled) {
{
const std::lock_guard<std::mutex> lock(mutex_);
enabled_ = enabled;
last_timestamp_ = -1;
}
cv_.notify_all();
}
void VSyncWorker::StopThread() {
{
const std::lock_guard<std::mutex> lock(mutex_);
thread_exit_ = true;
enabled_ = false;
callbacks_ = {};
}
cv_.notify_all();
}
/*
* Returns the timestamp of the next vsync in phase with last_timestamp_.
* For example:
* last_timestamp_ = 137
* frame_ns = 50
* current = 683
*
* ret = (50 * ((683 - 137)/50 + 1)) + 137
* ret = 687
*
* Thus, we must sleep until timestamp 687 to maintain phase with the last
* timestamp.
*/
int64_t VSyncWorker::GetPhasedVSync(int64_t frame_ns, int64_t current) const {
if (last_timestamp_ < 0)
return current + frame_ns;
return frame_ns * ((current - last_timestamp_) / frame_ns + 1) +
last_timestamp_;
}
static const int64_t kOneSecondNs = 1LL * 1000 * 1000 * 1000;
int VSyncWorker::SyntheticWaitVBlank(int64_t *timestamp) {
auto time_now = ResourceManager::GetTimeMonotonicNs();
// Default to 60Hz refresh rate
constexpr uint32_t kDefaultVSPeriodNs = 16666666;
auto period_ns = kDefaultVSPeriodNs;
if (callbacks_.get_vperiod_ns && callbacks_.get_vperiod_ns() != 0)
period_ns = callbacks_.get_vperiod_ns();
auto phased_timestamp = GetPhasedVSync(period_ns, time_now);
struct timespec vsync {};
vsync.tv_sec = int(phased_timestamp / kOneSecondNs);
vsync.tv_nsec = int(phased_timestamp - (vsync.tv_sec * kOneSecondNs));
int ret = 0;
do {
ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &vsync, nullptr);
} while (ret == EINTR);
if (ret != 0)
return ret;
*timestamp = phased_timestamp;
return 0;
}
void VSyncWorker::ThreadFn(const std::shared_ptr<VSyncWorker> &vsw) {
int ret = 0;
for (;;) {
{
std::unique_lock<std::mutex> lock(vsw->mutex_);
if (thread_exit_)
break;
if (!enabled_)
vsw->cv_.wait(lock);
if (!enabled_)
continue;
}
ret = -EAGAIN;
int64_t timestamp = 0;
drmVBlank vblank{};
if (drm_fd_) {
vblank.request.type = (drmVBlankSeqType)(DRM_VBLANK_RELATIVE |
(high_crtc_ &
DRM_VBLANK_HIGH_CRTC_MASK));
vblank.request.sequence = 1;
ret = drmWaitVBlank(*drm_fd_, &vblank);
if (ret == -EINTR)
continue;
}
if (ret != 0) {
ret = SyntheticWaitVBlank(×tamp);
if (ret != 0)
continue;
} else {
constexpr int kUsToNsMul = 1000;
timestamp = (int64_t)vblank.reply.tval_sec * kOneSecondNs +
(int64_t)vblank.reply.tval_usec * kUsToNsMul;
}
decltype(callbacks_.out_event) callback;
{
const std::lock_guard<std::mutex> lock(mutex_);
if (!enabled_)
continue;
callback = callbacks_.out_event;
}
if (callback)
callback(timestamp);
last_timestamp_ = timestamp;
}
ALOGI("VSyncWorker thread exit");
}
} // namespace android
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