IProducerListener: Add a listener for consumer detach

Currently consumer side detach cannot be tracked from Producer side.
Add a listener from IProducerListener for consumer side detaching.

Test: m
Bug: 254050314
Change-Id: I80f4aebe276cd8bc961f498b281e771d9b6a9789

3 files changed, 109 insertions, 24 deletions

diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index 5b34ba12c8..b6a47fb4e9 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -318,35 +318,44 @@ status_t BufferQueueConsumer::detachBuffer(int slot) {
     ATRACE_CALL();
     ATRACE_BUFFER_INDEX(slot);
     BQ_LOGV("detachBuffer: slot %d", slot);
-    std::lock_guard<std::mutex> lock(mCore->mMutex);
+    sp<IProducerListener> listener;
+    {
+        std::lock_guard<std::mutex> lock(mCore->mMutex);
 
-    if (mCore->mIsAbandoned) {
-        BQ_LOGE("detachBuffer: BufferQueue has been abandoned");
-        return NO_INIT;
-    }
+        if (mCore->mIsAbandoned) {
+            BQ_LOGE("detachBuffer: BufferQueue has been abandoned");
+            return NO_INIT;
+        }
 
-    if (mCore->mSharedBufferMode || slot == mCore->mSharedBufferSlot) {
-        BQ_LOGE("detachBuffer: detachBuffer not allowed in shared buffer mode");
-        return BAD_VALUE;
-    }
+        if (mCore->mSharedBufferMode || slot == mCore->mSharedBufferSlot) {
+            BQ_LOGE("detachBuffer: detachBuffer not allowed in shared buffer mode");
+            return BAD_VALUE;
+        }
 
-    if (slot < 0 || slot >= BufferQueueDefs::NUM_BUFFER_SLOTS) {
-        BQ_LOGE("detachBuffer: slot index %d out of range [0, %d)",
-                slot, BufferQueueDefs::NUM_BUFFER_SLOTS);
-        return BAD_VALUE;
-    } else if (!mSlots[slot].mBufferState.isAcquired()) {
-        BQ_LOGE("detachBuffer: slot %d is not owned by the consumer "
-                "(state = %s)", slot, mSlots[slot].mBufferState.string());
-        return BAD_VALUE;
-    }
+        if (slot < 0 || slot >= BufferQueueDefs::NUM_BUFFER_SLOTS) {
+            BQ_LOGE("detachBuffer: slot index %d out of range [0, %d)",
+                    slot, BufferQueueDefs::NUM_BUFFER_SLOTS);
+            return BAD_VALUE;
+        } else if (!mSlots[slot].mBufferState.isAcquired()) {
+            BQ_LOGE("detachBuffer: slot %d is not owned by the consumer "
+                    "(state = %s)", slot, mSlots[slot].mBufferState.string());
+            return BAD_VALUE;
+        }
+        if (mCore->mBufferReleasedCbEnabled) {
+            listener = mCore->mConnectedProducerListener;
+        }
 
-    mSlots[slot].mBufferState.detachConsumer();
-    mCore->mActiveBuffers.erase(slot);
-    mCore->mFreeSlots.insert(slot);
-    mCore->clearBufferSlotLocked(slot);
-    mCore->mDequeueCondition.notify_all();
-    VALIDATE_CONSISTENCY();
+        mSlots[slot].mBufferState.detachConsumer();
+        mCore->mActiveBuffers.erase(slot);
+        mCore->mFreeSlots.insert(slot);
+        mCore->clearBufferSlotLocked(slot);
+        mCore->mDequeueCondition.notify_all();
+        VALIDATE_CONSISTENCY();
+    }
 
+    if (listener) {
+        listener->onBufferDetached(slot);
+    }
     return NO_ERROR;
 }
 
diff --git a/libs/gui/include/gui/IProducerListener.h b/libs/gui/include/gui/IProducerListener.h
index f7ffbb99ea..b15f501518 100644
--- a/libs/gui/include/gui/IProducerListener.h
+++ b/libs/gui/include/gui/IProducerListener.h
@@ -49,6 +49,12 @@ public:
     // onBuffersFreed is called from IGraphicBufferConsumer::discardFreeBuffers
     // to notify the producer that certain free buffers are discarded by the consumer.
     virtual void onBuffersDiscarded(const std::vector<int32_t>& slots) = 0; // Asynchronous
+    // onBufferDetached is called from IGraphicBufferConsumer::detachBuffer to
+    // notify the producer that a buffer slot is free and ready to be dequeued.
+    //
+    // This is called without any lock held and can be called concurrently by
+    // multiple threads.
+    virtual void onBufferDetached(int /*slot*/) {} // Asynchronous
 };
 
 #ifndef NO_BINDER
diff --git a/libs/gui/tests/BufferQueue_test.cpp b/libs/gui/tests/BufferQueue_test.cpp
index 2f1fd3e78f..185ff83a86 100644
--- a/libs/gui/tests/BufferQueue_test.cpp
+++ b/libs/gui/tests/BufferQueue_test.cpp
@@ -1151,6 +1151,76 @@ TEST_F(BufferQueueTest, TestBufferReplacedInQueueBuffer) {
     ASSERT_EQ(true, output.bufferReplaced);
 }
 
+struct BufferDetachedListener : public BnProducerListener {
+public:
+    BufferDetachedListener() = default;
+    virtual ~BufferDetachedListener() = default;
+
+    virtual void onBufferReleased() {}
+    virtual bool needsReleaseNotify() { return true; }
+    virtual void onBufferDetached(int slot) {
+        mDetachedSlots.push_back(slot);
+    }
+    const std::vector<int>& getDetachedSlots() const { return mDetachedSlots; }
+private:
+    std::vector<int> mDetachedSlots;
+};
+
+TEST_F(BufferQueueTest, TestConsumerDetachProducerListener) {
+    createBufferQueue();
+    sp<MockConsumer> mc(new MockConsumer);
+    ASSERT_EQ(OK, mConsumer->consumerConnect(mc, true));
+    IGraphicBufferProducer::QueueBufferOutput output;
+    sp<BufferDetachedListener> pl(new BufferDetachedListener);
+    ASSERT_EQ(OK, mProducer->connect(pl, NATIVE_WINDOW_API_CPU, true, &output));
+    ASSERT_EQ(OK, mProducer->setDequeueTimeout(0));
+    ASSERT_EQ(OK, mConsumer->setMaxAcquiredBufferCount(1));
+
+    sp<Fence> fence = Fence::NO_FENCE;
+    sp<GraphicBuffer> buffer = nullptr;
+    IGraphicBufferProducer::QueueBufferInput input(0ull, true,
+        HAL_DATASPACE_UNKNOWN, Rect::INVALID_RECT,
+        NATIVE_WINDOW_SCALING_MODE_FREEZE, 0, Fence::NO_FENCE);
+
+    int slots[2] = {};
+    status_t result = OK;
+    ASSERT_EQ(OK, mProducer->setMaxDequeuedBufferCount(2));
+
+    result = mProducer->dequeueBuffer(&slots[0], &fence, 0, 0, 0,
+                                      GRALLOC_USAGE_SW_READ_RARELY, nullptr, nullptr);
+    ASSERT_EQ(IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION, result);
+    ASSERT_EQ(OK, mProducer->requestBuffer(slots[0], &buffer));
+
+    result = mProducer->dequeueBuffer(&slots[1], &fence, 0, 0, 0,
+                                      GRALLOC_USAGE_SW_READ_RARELY, nullptr, nullptr);
+    ASSERT_EQ(IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION, result);
+    ASSERT_EQ(OK, mProducer->requestBuffer(slots[1], &buffer));
+
+    // Queue & detach one from two dequeued buffes.
+    ASSERT_EQ(OK, mProducer->queueBuffer(slots[1], input, &output));
+    BufferItem item{};
+    ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+    ASSERT_EQ(OK, mConsumer->detachBuffer(item.mSlot));
+
+    // Check whether the slot from IProducerListener is same to the detached slot.
+    ASSERT_EQ(pl->getDetachedSlots().size(), 1);
+    ASSERT_EQ(pl->getDetachedSlots()[0], slots[1]);
+
+    // Dequeue another buffer.
+    int slot;
+    result = mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0,
+                                      GRALLOC_USAGE_SW_READ_RARELY, nullptr, nullptr);
+    ASSERT_EQ(IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION, result);
+    ASSERT_EQ(OK, mProducer->requestBuffer(slot, &buffer));
+
+    // Dequeue should fail here, since we dequeued 3 buffers and one buffer was
+    // detached from consumer(Two buffers are dequeued, and the current max
+    // dequeued buffer count is two).
+    result = mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0,
+                                      GRALLOC_USAGE_SW_READ_RARELY, nullptr, nullptr);
+    ASSERT_TRUE(result == WOULD_BLOCK || result == TIMED_OUT || result == INVALID_OPERATION);
+}
+
 TEST_F(BufferQueueTest, TestStaleBufferHandleSentAfterDisconnect) {
     createBufferQueue();
     sp<MockConsumer> mc(new MockConsumer);