replicant-frameworks_native/services/surfaceflinger/DisplayHardware/VSyncBarrier.cpp
Mathias Agopian d0566bc26f Add support for sending VSYNC events to the framework
use gui/DisplayEvent to receive the events. Events are
dispatched through a unix pipe, so the API is compatible
with utils/Looper. see gui/DisplayEvent.h for more info.

Bug: 1475048
Change-Id: Ia720f64d1b950328b47b22c6a86042e481d35f09
2011-11-29 13:10:25 -08:00

82 lines
2.0 KiB
C++

/*
* Copyright (C) 2011 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.
*/
#include <stdint.h>
#include <sys/types.h>
#include <utils/Errors.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/fb.h>
#include "DisplayHardware/VSyncBarrier.h"
#ifndef FBIO_WAITFORVSYNC
#define FBIO_WAITFORVSYNC _IOW('F', 0x20, __u32)
#endif
namespace android {
// ---------------------------------------------------------------------------
VSyncBarrier::VSyncBarrier() : mFd(-EINVAL) {
#if HAS_WAITFORVSYNC
mFd = open("/dev/graphics/fb0", O_RDWR);
if (mFd < 0) {
mFd = -errno;
}
// try to see if FBIO_WAITFORVSYNC is supported
uint32_t crt = 0;
int err = ioctl(mFd, FBIO_WAITFORVSYNC, &crt);
if (err < 0) {
close(mFd);
mFd = -EINVAL;
}
#endif
}
VSyncBarrier::~VSyncBarrier() {
if (mFd >= 0) {
close(mFd);
}
}
status_t VSyncBarrier::initCheck() const {
return mFd < 0 ? mFd : status_t(NO_ERROR);
}
// this must be thread-safe
status_t VSyncBarrier::wait(nsecs_t* timestamp) const {
if (mFd < 0) {
return mFd;
}
int err;
uint32_t crt = 0;
do {
err = ioctl(mFd, FBIO_WAITFORVSYNC, &crt);
} while (err<0 && errno==EINTR);
if (err < 0) {
return -errno;
}
// ideally this would come from the driver
timestamp[0] = systemTime();
return NO_ERROR;
}
// ---------------------------------------------------------------------------
}; // namespace android