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
diff --git a/services/surfaceflinger/DisplayHardware/VSyncBarrier.cpp b/services/surfaceflinger/DisplayHardware/VSyncBarrier.cpp
new file mode 100644
index 0000000..187da20
--- /dev/null
+++ b/services/surfaceflinger/DisplayHardware/VSyncBarrier.cpp
@@ -0,0 +1,81 @@
+/*
+ * 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