Introduce ASurfaceTransaction_setOnCommit api

Introduce a new callback for SurfaceControl transactions that
fire after we commit a transaction in SurfaceFlinger. This
will help some clients pace when they should apply the next
transaction so it get applied on the next vsync. If they wait for
the existing transaction complete callback, there may not be
enough time between when the client applies the transaction
and surface flinger waking up and apply it on the new vsync.
This would mean the update would arrive a frame late.

Bug: 185843251
Test: atest ASurfaceControlTest
Change-Id: If0d5d01a1d5c2029eb81667356e666d7297376d4

2 files changed, 38 insertions, 1 deletions

diff --git a/native/android/libandroid.map.txt b/native/android/libandroid.map.txt
index 9729524b47b2..de6db1ae7d23 100644
--- a/native/android/libandroid.map.txt
+++ b/native/android/libandroid.map.txt
@@ -259,6 +259,7 @@ LIBANDROID {
     ASurfaceTransaction_setHdrMetadata_cta861_3; # introduced=29
     ASurfaceTransaction_setHdrMetadata_smpte2086; # introduced=29
     ASurfaceTransaction_setOnComplete; # introduced=29
+    ASurfaceTransaction_setOnCommit; # introduced=31
     ASurfaceTransaction_setPosition; # introduced=31
     ASurfaceTransaction_setCrop; # introduced=31
     ASurfaceTransaction_setBufferTransform; # introduced=31
diff --git a/native/android/surface_control.cpp b/native/android/surface_control.cpp
index 3d14c425ed4d..087837a5c70f 100644
--- a/native/android/surface_control.cpp
+++ b/native/android/surface_control.cpp
@@ -260,6 +260,7 @@ struct ASurfaceTransactionStats {
     std::unordered_map<ASurfaceControl*, ASurfaceControlStats> aSurfaceControlStats;
     int64_t latchTime;
     sp<Fence> presentFence;
+    bool transactionCompleted;
 };
 
 int64_t ASurfaceTransactionStats_getLatchTime(ASurfaceTransactionStats* aSurfaceTransactionStats) {
@@ -269,6 +270,9 @@ int64_t ASurfaceTransactionStats_getLatchTime(ASurfaceTransactionStats* aSurface
 
 int ASurfaceTransactionStats_getPresentFenceFd(ASurfaceTransactionStats* aSurfaceTransactionStats) {
     CHECK_NOT_NULL(aSurfaceTransactionStats);
+    LOG_ALWAYS_FATAL_IF(!aSurfaceTransactionStats->transactionCompleted,
+                        "ASurfaceTransactionStats queried from an incomplete transaction callback");
+
     auto& presentFence = aSurfaceTransactionStats->presentFence;
     return (presentFence) ? presentFence->dup() : -1;
 }
@@ -313,6 +317,8 @@ int ASurfaceTransactionStats_getPreviousReleaseFenceFd(
             ASurfaceTransactionStats* aSurfaceTransactionStats, ASurfaceControl* aSurfaceControl) {
     CHECK_NOT_NULL(aSurfaceTransactionStats);
     CHECK_NOT_NULL(aSurfaceControl);
+    LOG_ALWAYS_FATAL_IF(!aSurfaceTransactionStats->transactionCompleted,
+                        "ASurfaceTransactionStats queried from an incomplete transaction callback");
 
     const auto& aSurfaceControlStats =
             aSurfaceTransactionStats->aSurfaceControlStats.find(aSurfaceControl);
@@ -334,7 +340,6 @@ void ASurfaceTransactionStats_releaseASurfaceControls(ASurfaceControl** aSurface
 void ASurfaceTransaction_setOnComplete(ASurfaceTransaction* aSurfaceTransaction, void* context,
                                        ASurfaceTransaction_OnComplete func) {
     CHECK_NOT_NULL(aSurfaceTransaction);
-    CHECK_NOT_NULL(context);
     CHECK_NOT_NULL(func);
 
     TransactionCompletedCallbackTakesContext callback = [func](void* callback_context,
@@ -345,6 +350,7 @@ void ASurfaceTransaction_setOnComplete(ASurfaceTransaction* aSurfaceTransaction,
 
         aSurfaceTransactionStats.latchTime = latchTime;
         aSurfaceTransactionStats.presentFence = presentFence;
+        aSurfaceTransactionStats.transactionCompleted = true;
 
         auto& aSurfaceControlStats = aSurfaceTransactionStats.aSurfaceControlStats;
 
@@ -695,3 +701,33 @@ void ASurfaceTransaction_setEnableBackPressure(ASurfaceTransaction* aSurfaceTran
                       layer_state_t::eEnableBackpressure : 0;
     transaction->setFlags(surfaceControl, flags, layer_state_t::eEnableBackpressure);
 }
+
+void ASurfaceTransaction_setOnCommit(ASurfaceTransaction* aSurfaceTransaction, void* context,
+                                     ASurfaceTransaction_OnCommit func) {
+    CHECK_NOT_NULL(aSurfaceTransaction);
+    CHECK_NOT_NULL(func);
+
+    TransactionCompletedCallbackTakesContext callback =
+            [func](void* callback_context, nsecs_t latchTime, const sp<Fence>& /* presentFence */,
+                   const std::vector<SurfaceControlStats>& surfaceControlStats) {
+                ASurfaceTransactionStats aSurfaceTransactionStats;
+                aSurfaceTransactionStats.latchTime = latchTime;
+                aSurfaceTransactionStats.transactionCompleted = false;
+
+                auto& aSurfaceControlStats = aSurfaceTransactionStats.aSurfaceControlStats;
+                for (const auto&
+                             [surfaceControl, latchTime, acquireTime, presentFence,
+                              previousReleaseFence, transformHint,
+                              frameEvents] : surfaceControlStats) {
+                    ASurfaceControl* aSurfaceControl =
+                            reinterpret_cast<ASurfaceControl*>(surfaceControl.get());
+                    aSurfaceControlStats[aSurfaceControl].acquireTime = acquireTime;
+                }
+
+                (*func)(callback_context, &aSurfaceTransactionStats);
+            };
+
+    Transaction* transaction = ASurfaceTransaction_to_Transaction(aSurfaceTransaction);
+
+    transaction->addTransactionCommittedCallback(callback, context);
+}
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