1 files changed, 42 insertions, 3 deletions

diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index cf8b13ffa4..821dd37a85 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -139,6 +139,11 @@ void BLASTBufferItemConsumer::onSidebandStreamChanged() {
     }
 }
 
+void BLASTBufferItemConsumer::resizeFrameEventHistory(size_t newSize) {
+    Mutex::Autolock lock(mMutex);
+    mFrameEventHistory.resize(newSize);
+}
+
 BLASTBufferQueue::BLASTBufferQueue(const std::string& name, bool updateDestinationFrame)
       : mSurfaceControl(nullptr),
         mSize(1, 1),
@@ -1069,8 +1074,9 @@ public:
 // can be non-blocking when the producer is in the client process.
 class BBQBufferQueueProducer : public BufferQueueProducer {
 public:
-    BBQBufferQueueProducer(const sp<BufferQueueCore>& core)
-          : BufferQueueProducer(core, false /* consumerIsSurfaceFlinger*/) {}
+    BBQBufferQueueProducer(const sp<BufferQueueCore>& core, wp<BLASTBufferQueue> bbq)
+          : BufferQueueProducer(core, false /* consumerIsSurfaceFlinger*/),
+            mBLASTBufferQueue(std::move(bbq)) {}
 
     status_t connect(const sp<IProducerListener>& listener, int api, bool producerControlledByApp,
                      QueueBufferOutput* output) override {
@@ -1082,6 +1088,26 @@ public:
                                             producerControlledByApp, output);
     }
 
+    // We want to resize the frame history when changing the size of the buffer queue
+    status_t setMaxDequeuedBufferCount(int maxDequeuedBufferCount) override {
+        int maxBufferCount;
+        status_t status = BufferQueueProducer::setMaxDequeuedBufferCount(maxDequeuedBufferCount,
+                                                                         &maxBufferCount);
+        // if we can't determine the max buffer count, then just skip growing the history size
+        if (status == OK) {
+            size_t newFrameHistorySize = maxBufferCount + 2; // +2 because triple buffer rendering
+            // optimize away resizing the frame history unless it will grow
+            if (newFrameHistorySize > FrameEventHistory::INITIAL_MAX_FRAME_HISTORY) {
+                sp<BLASTBufferQueue> bbq = mBLASTBufferQueue.promote();
+                if (bbq != nullptr) {
+                    ALOGV("increasing frame history size to %zu", newFrameHistorySize);
+                    bbq->resizeFrameEventHistory(newFrameHistorySize);
+                }
+            }
+        }
+        return status;
+    }
+
     int query(int what, int* value) override {
         if (what == NATIVE_WINDOW_QUEUES_TO_WINDOW_COMPOSER) {
             *value = 1;
@@ -1089,6 +1115,9 @@ public:
         }
         return BufferQueueProducer::query(what, value);
     }
+
+private:
+    const wp<BLASTBufferQueue> mBLASTBufferQueue;
 };
 
 // Similar to BufferQueue::createBufferQueue but creates an adapter specific bufferqueue producer.
@@ -1103,7 +1132,7 @@ void BLASTBufferQueue::createBufferQueue(sp<IGraphicBufferProducer>* outProducer
     sp<BufferQueueCore> core(new BufferQueueCore());
     LOG_ALWAYS_FATAL_IF(core == nullptr, "BLASTBufferQueue: failed to create BufferQueueCore");
 
-    sp<IGraphicBufferProducer> producer(new BBQBufferQueueProducer(core));
+    sp<IGraphicBufferProducer> producer(new BBQBufferQueueProducer(core, this));
     LOG_ALWAYS_FATAL_IF(producer == nullptr,
                         "BLASTBufferQueue: failed to create BBQBufferQueueProducer");
 
@@ -1116,6 +1145,16 @@ void BLASTBufferQueue::createBufferQueue(sp<IGraphicBufferProducer>* outProducer
     *outConsumer = consumer;
 }
 
+void BLASTBufferQueue::resizeFrameEventHistory(size_t newSize) {
+    // This can be null during creation of the buffer queue, but resizing won't do anything at that
+    // point in time, so just ignore. This can go away once the class relationships and lifetimes of
+    // objects are cleaned up with a major refactor of BufferQueue as a whole.
+    if (mBufferItemConsumer != nullptr) {
+        std::unique_lock _lock{mMutex};
+        mBufferItemConsumer->resizeFrameEventHistory(newSize);
+    }
+}
+
 PixelFormat BLASTBufferQueue::convertBufferFormat(PixelFormat& format) {
     PixelFormat convertedFormat = format;
     switch (format) {