commit f0eaf25e9247edf4d124bedaeb863f7abdf35a3e
author Dan Stoza <stoza@google.com> Fri Mar 21 13:05:51 2014 -0700
committer Dan Stoza <stoza@google.com> Mon Mar 31 14:10:07 2014 -0700
tree 15baebb3fa387a1bba3625b3067aa28221cbc8ae
parent 96668903e4d11893ea1f68525713542b0adb5404

BufferQueue: Add producer buffer-released callback

Add a callback to the producer side, onBufferReleased, which will be
called every time the consumer releases a buffer back to the
BufferQueue. This will enable a buffer stream splitter to work
autonomously without having to block on dequeueBuffer.

The binder object used for the callback replaces the generic IBinder
token that was passed into IGraphicBufferProducer::connect to detect
the death of the producer. If a producer does not wish to listen for
buffer release events, it can pass in an instance of the
DummyProducerListener class defined in IProducerListener.h, if it even
cares about death events (BufferQueue doesn't enforce the token being
non-NULL, though perhaps we should).

Change-Id: I23935760673524abeafea2b58dccc3583b368710

libs/gui/BufferQueueProducer.cpp

diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index 9dd90ba..82d931e 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -25,6 +25,7 @@
 #include <gui/BufferQueueProducer.h>
 #include <gui/IConsumerListener.h>
 #include <gui/IGraphicBufferAlloc.h>
+#include <gui/IProducerListener.h>
 
 #include <utils/Log.h>
 #include <utils/Trace.h>
@@ -654,7 +655,7 @@
     return NO_ERROR;
 }
 
-status_t BufferQueueProducer::connect(const sp<android::IBinder> &token,
+status_t BufferQueueProducer::connect(const sp<IProducerListener>& listener,
         int api, bool producerControlledByApp, QueueBufferOutput *output) {
     ATRACE_CALL();
     Mutex::Autolock lock(mCore->mMutex);
@@ -711,16 +712,16 @@
 
             // Set up a death notification so that we can disconnect
             // automatically if the remote producer dies
-            if (token != NULL && token->remoteBinder() != NULL) {
-                status = token->linkToDeath(
+            if (listener != NULL &&
+                    listener->asBinder()->remoteBinder() != NULL) {
+                status = listener->asBinder()->linkToDeath(
                         static_cast<IBinder::DeathRecipient*>(this));
-                if (status == NO_ERROR) {
-                    mCore->mConnectedProducerToken = token;
-                } else {
+                if (status != NO_ERROR) {
                     BQ_LOGE("connect(P): linkToDeath failed: %s (%d)",
                             strerror(-status), status);
                 }
             }
+            mCore->mConnectedProducerListener = listener;
             break;
         default:
             BQ_LOGE("connect(P): unknown API %d", api);
@@ -759,14 +760,15 @@
                     mCore->freeAllBuffersLocked();
 
                     // Remove our death notification callback if we have one
-                    sp<IBinder> token = mCore->mConnectedProducerToken;
-                    if (token != NULL) {
+                    if (mCore->mConnectedProducerListener != NULL) {
+                        sp<IBinder> token =
+                                mCore->mConnectedProducerListener->asBinder();
                         // This can fail if we're here because of the death
                         // notification, but we just ignore it
                         token->unlinkToDeath(
                                 static_cast<IBinder::DeathRecipient*>(this));
                     }
-                    mCore->mConnectedProducerToken = NULL;
+                    mCore->mConnectedProducerListener = NULL;
                     mCore->mConnectedApi = BufferQueueCore::NO_CONNECTED_API;
                     mCore->mSidebandStream.clear();
                     mCore->mDequeueCondition.broadcast();