commit f130ad79e6b2beff56a1fcd4f218872513da1070
author Emilian Peev <epeev@google.com> Thu Oct 11 11:03:07 2018 +0100
committer Emilian Peev <epeev@google.com> Mon Oct 22 15:41:25 2018 +0000
tree f52e7190b3d9df4e0c3d37db64cf7bbfb5b59b3a
parent efd99ec863f5a69f20dfacea3f6f4835962c5362

Camera: Consider the currently acquired input buffers

The maximum acquired count of the input buffer queue during surface
sharing should be set considering the total maximum acquired count of
individual registered outputs and also the current acquired count
of the input buffer queue. The reason the two can be different is
due to the fact that individual outputs can acquire and also block
buffers from the input. The latter portion contains all buffers
which are still queued but not acquired. This can happen in case
some output acquires the maximum amount of buffers possible then
stops consuming entirely and the camera client continues to reference
it in subsequent capture requests.
To handle this, track the number of acquired buffers in the input
queue and expand (or contract) the maximum acquired count only if
possible. The maximum shouldn't change otherwise because the blocked
buffers could still be used by the unresponsive output at some
later point in time.

Bug: 117982710
Test: Camera CTS
Change-Id: Ia4e743efdf59cb0c9baaea492f78c37d0f2c95b3

services/camera/libcameraservice/device3/Camera3StreamSplitter.cpp

diff --git a/services/camera/libcameraservice/device3/Camera3StreamSplitter.cpp b/services/camera/libcameraservice/device3/Camera3StreamSplitter.cpp
index 8bc208d..6d08842 100644
--- a/services/camera/libcameraservice/device3/Camera3StreamSplitter.cpp
+++ b/services/camera/libcameraservice/device3/Camera3StreamSplitter.cpp
@@ -83,8 +83,8 @@
     // from input, and attached to the outputs. In this case, the input queue's
     // dequeueBuffer can still allocate 1 extra buffer before being blocked by
     // the output's attachBuffer().
-    mBufferItemConsumer = new BufferItemConsumer(mConsumer, consumerUsage,
-                                                 mMaxConsumerBuffers+1);
+    mMaxConsumerBuffers++;
+    mBufferItemConsumer = new BufferItemConsumer(mConsumer, consumerUsage, mMaxConsumerBuffers);
     if (mBufferItemConsumer == nullptr) {
         return NO_MEMORY;
     }
@@ -108,6 +108,7 @@
     mHeight = height;
     mFormat = format;
     mProducerUsage = producerUsage;
+    mAcquiredInputBuffers = 0;
 
     SP_LOGV("%s: connected", __FUNCTION__);
     return res;
@@ -147,6 +148,7 @@
 
     mMaxHalBuffers = 0;
     mMaxConsumerBuffers = 0;
+    mAcquiredInputBuffers = 0;
     SP_LOGV("%s: Disconnected", __FUNCTION__);
 }
 
@@ -165,7 +167,9 @@
         return res;
     }
 
-    res = mConsumer->setMaxAcquiredBufferCount(mMaxConsumerBuffers+1);
+    if (mMaxConsumerBuffers > mAcquiredInputBuffers) {
+        res = mConsumer->setMaxAcquiredBufferCount(mMaxConsumerBuffers);
+    }
 
     return res;
 }
@@ -266,10 +270,12 @@
         return res;
     }
 
-    res = mConsumer->setMaxAcquiredBufferCount(mMaxConsumerBuffers+1);
-    if (res != OK) {
-        SP_LOGE("%s: setMaxAcquiredBufferCount failed %d", __FUNCTION__, res);
-        return res;
+    if (mAcquiredInputBuffers < mMaxConsumerBuffers) {
+        res = mConsumer->setMaxAcquiredBufferCount(mMaxConsumerBuffers);
+        if (res != OK) {
+            SP_LOGE("%s: setMaxAcquiredBufferCount failed %d", __FUNCTION__, res);
+            return res;
+        }
     }
 
     return res;
@@ -497,6 +503,7 @@
         return;
     }
 
+    mAcquiredInputBuffers++;
     SP_LOGV("acquired buffer %" PRId64 " from input at slot %d",
             bufferItem.mGraphicBuffer->getId(), bufferItem.mSlot);
 
@@ -599,6 +606,12 @@
         } else {
             SP_LOGE("%s: releaseBuffer returns %d", __FUNCTION__, res);
         }
+    } else {
+        if (mAcquiredInputBuffers == 0) {
+            ALOGW("%s: Acquired input buffer count already at zero!", __FUNCTION__);
+        } else {
+            mAcquiredInputBuffers--;
+        }
     }
 }