Improve the VSYNC api a bit.

- add the ability to set the vsync delivery rate, when the rate is
set to N>1 (ie: receive every N vsync), SF process' is woken up for
all of vsync, but clients only see the every N events.

- add the concept of one-shot vsync events, with a call-back
to request the next one. currently the call-back is a binder IPC.

Change-Id: I09f71df0b0ba0d88ed997645e2e2497d553c9a1b

1 files changed, 20 insertions, 0 deletions

diff --git a/libs/gui/DisplayEventReceiver.cpp b/libs/gui/DisplayEventReceiver.cpp
index 3b29a11..fee1feb 100644
--- a/libs/gui/DisplayEventReceiver.cpp
+++ b/libs/gui/DisplayEventReceiver.cpp
@@ -58,6 +58,26 @@ int DisplayEventReceiver::getFd() const {
     return mDataChannel->getFd();
 }
 
+status_t DisplayEventReceiver::setVsyncRate(uint32_t count) {
+    if (int32_t(count) < 0)
+        return BAD_VALUE;
+
+    if (mEventConnection != NULL) {
+        mEventConnection->setVsyncRate(count);
+        return NO_ERROR;
+    }
+    return NO_INIT;
+}
+
+status_t DisplayEventReceiver::requestNextVsync() {
+    if (mEventConnection != NULL) {
+        mEventConnection->requestNextVsync();
+        return NO_ERROR;
+    }
+    return NO_INIT;
+}
+
+
 ssize_t DisplayEventReceiver::getEvents(DisplayEventReceiver::Event* events,
         size_t count) {
     ssize_t size = mDataChannel->read(events, sizeof(events[0])*count);