commit 17b4e4570fed99881a94730b9ad67b590aa426b9
author Marissa Wall <marissaw@google.com> Wed Dec 26 16:32:34 2018 -0800
committer Marissa Wall <marissaw@google.com> Thu Jan 17 18:47:19 2019 -0800
tree 5646b06239624c1ac06f9246f8fb7bda28d95ba4
parent 5a68a77923216e3f889776d1398880c6532f834a

blast: add desired present time

Add the option to set a desiredPresentTime for a transaction. This
lets the framework know approximately when the transaction should
be presented.

Test: Transaction_test
Bug: 80477568

Change-Id: Ic25617fb93f2c249b3b3c7a8f90f72ec358938f0

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index dc02666..c0059d5 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3498,8 +3498,8 @@
         auto& [applyToken, transactionQueue] = *it;
 
         while (!transactionQueue.empty()) {
-            const auto& [states, displays, flags] = transactionQueue.front();
-            if (composerStateContainsUnsignaledFences(states)) {
+            const auto& [states, displays, flags, desiredPresentTime] = transactionQueue.front();
+            if (!transactionIsReadyToBeApplied(desiredPresentTime, states)) {
                 break;
             }
             applyTransactionState(states, displays, flags, mInputWindowCommands);
@@ -3533,23 +3533,33 @@
     return false;
 }
 
-bool SurfaceFlinger::composerStateContainsUnsignaledFences(const Vector<ComposerState>& states) {
+bool SurfaceFlinger::transactionIsReadyToBeApplied(int64_t desiredPresentTime,
+                                                   const Vector<ComposerState>& states) {
+    const nsecs_t expectedPresentTime = mPrimaryDispSync->expectedPresentTime();
+    // Do not present if the desiredPresentTime has not passed unless it is more than one second
+    // in the future. We ignore timestamps more than 1 second in the future for stability reasons.
+    if (desiredPresentTime >= 0 && desiredPresentTime >= expectedPresentTime &&
+        desiredPresentTime < expectedPresentTime + s2ns(1)) {
+        return false;
+    }
+
     for (const ComposerState& state : states) {
         const layer_state_t& s = state.state;
         if (!(s.what & layer_state_t::eAcquireFenceChanged)) {
             continue;
         }
         if (s.acquireFence && s.acquireFence->getStatus() == Fence::Status::Unsignaled) {
-            return true;
+            return false;
         }
     }
-    return false;
+    return true;
 }
 
 void SurfaceFlinger::setTransactionState(const Vector<ComposerState>& states,
                                          const Vector<DisplayState>& displays, uint32_t flags,
                                          const sp<IBinder>& applyToken,
-                                         const InputWindowCommands& inputWindowCommands) {
+                                         const InputWindowCommands& inputWindowCommands,
+                                         int64_t desiredPresentTime) {
     ATRACE_CALL();
     Mutex::Autolock _l(mStateLock);
 
@@ -3559,8 +3569,8 @@
 
     // If its TransactionQueue already has a pending TransactionState or if it is pending
     if (mTransactionQueues.find(applyToken) != mTransactionQueues.end() ||
-        composerStateContainsUnsignaledFences(states)) {
-        mTransactionQueues[applyToken].emplace(states, displays, flags);
+        !transactionIsReadyToBeApplied(desiredPresentTime, states)) {
+        mTransactionQueues[applyToken].emplace(states, displays, flags, desiredPresentTime);
         setTransactionFlags(eTransactionNeeded);
         return;
     }
@@ -4147,7 +4157,7 @@
     d.width = 0;
     d.height = 0;
     displays.add(d);
-    setTransactionState(state, displays, 0, nullptr, mInputWindowCommands);
+    setTransactionState(state, displays, 0, nullptr, mInputWindowCommands, -1);
 
     const auto display = getDisplayDevice(displayToken);
     if (!display) return;