Merge "VideoFramePool: Only accept one request at the same time" into rvc-dev am: 842849a0ac am: 4a28554a31

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/v4l2_codec2/+/12497569

Change-Id: Idcf18ea6f99a38b6a080c8be62de22ad4f158560

3 files changed, 24 insertions, 33 deletions

diff --git a/components/V4L2Decoder.cpp b/components/V4L2Decoder.cpp
index 0a58e20..26f1365 100644
--- a/components/V4L2Decoder.cpp
+++ b/components/V4L2Decoder.cpp
@@ -502,17 +502,15 @@ void V4L2Decoder::tryFetchVideoFrame() {
 
     if (mState == State::Idle) return;
 
-    if (mVideoFramePool->hasPendingRequests()) {
-        ALOGV("Previous callback is running, ignore.");
-        return;
-    }
-
     if (mOutputQueue->FreeBuffersCount() == 0) {
         ALOGD("No free V4L2 output buffers, ignore.");
         return;
     }
 
-    mVideoFramePool->getVideoFrame(::base::BindOnce(&V4L2Decoder::onVideoFrameReady, mWeakThis));
+    if (!mVideoFramePool->getVideoFrame(
+                ::base::BindOnce(&V4L2Decoder::onVideoFrameReady, mWeakThis))) {
+        ALOGV("%s(): Previous callback is running, ignore.", __func__);
+    }
 }
 
 void V4L2Decoder::onVideoFrameReady(
diff --git a/components/VideoFramePool.cpp b/components/VideoFramePool.cpp
index 0fdd260..22b622d 100644
--- a/components/VideoFramePool.cpp
+++ b/components/VideoFramePool.cpp
@@ -122,23 +122,21 @@ void VideoFramePool::destroyTask() {
     mFetchWeakThisFactory.InvalidateWeakPtrs();
 }
 
-void VideoFramePool::getVideoFrame(GetVideoFrameCB cb) {
+bool VideoFramePool::getVideoFrame(GetVideoFrameCB cb) {
     ALOGV("%s()", __func__);
     ALOG_ASSERT(mClientTaskRunner->RunsTasksInCurrentSequence());
 
-    ++mNumPendingRequests;
-    mFetchTaskRunner->PostTask(FROM_HERE, ::base::BindOnce(&VideoFramePool::getVideoFrameTask,
-                                                           mFetchWeakThis, std::move(cb)));
-}
-
-bool VideoFramePool::hasPendingRequests() const {
-    ALOGV("%s()", __func__);
-    ALOG_ASSERT(mClientTaskRunner->RunsTasksInCurrentSequence());
+    if (mOutputCb) {
+        return false;
+    }
 
-    return mNumPendingRequests > 0;
+    mOutputCb = std::move(cb);
+    mFetchTaskRunner->PostTask(
+            FROM_HERE, ::base::BindOnce(&VideoFramePool::getVideoFrameTask, mFetchWeakThis));
+    return true;
 }
 
-void VideoFramePool::getVideoFrameTask(GetVideoFrameCB cb) {
+void VideoFramePool::getVideoFrameTask() {
     ALOGV("%s()", __func__);
     ALOG_ASSERT(mFetchTaskRunner->RunsTasksInCurrentSequence());
     // Initial delay: 64us
@@ -184,25 +182,21 @@ void VideoFramePool::getVideoFrameTask(GetVideoFrameCB cb) {
 
     mClientTaskRunner->PostTask(
             FROM_HERE, ::base::BindOnce(&VideoFramePool::onVideoFrameReady, mClientWeakThis,
-                                        std::move(cb), std::move(frameWithBlockId)));
+                                        std::move(frameWithBlockId)));
 }
 
-void VideoFramePool::onVideoFrameReady(GetVideoFrameCB cb,
-                                       std::optional<FrameWithBlockId> frameWithBlockId) {
+void VideoFramePool::onVideoFrameReady(std::optional<FrameWithBlockId> frameWithBlockId) {
     ALOGV("%s()", __func__);
     ALOG_ASSERT(mClientTaskRunner->RunsTasksInCurrentSequence());
 
-    --mNumPendingRequests;
-
     if (!frameWithBlockId) {
         ALOGE("Failed to get GraphicBlock, abandoning all pending requests.");
         mClientWeakThisFactory.InvalidateWeakPtrs();
         mClientWeakThis = mClientWeakThisFactory.GetWeakPtr();
-
-        mNumPendingRequests = 0;
     }
 
-    std::move(cb).Run(std::move(frameWithBlockId));
+    ALOG_ASSERT(mOutputCb);
+    std::move(mOutputCb).Run(std::move(frameWithBlockId));
 }
 
 }  // namespace android
diff --git a/components/include/v4l2_codec2/components/VideoFramePool.h b/components/include/v4l2_codec2/components/VideoFramePool.h
index ca26004..c05c4ff 100644
--- a/components/include/v4l2_codec2/components/VideoFramePool.h
+++ b/components/include/v4l2_codec2/components/VideoFramePool.h
@@ -37,11 +37,10 @@ public:
     ~VideoFramePool();
 
     // Get a VideoFrame instance, which will be passed via |cb|.
-    // If any error occurs, then pass nullptr.
-    void getVideoFrame(GetVideoFrameCB cb);
-
-    // Return true if any callback of getting VideoFrame instance is pending.
-    bool hasPendingRequests() const;
+    // If any error occurs, then nullptr will be passed via |cb|.
+    // Return false if the previous callback has not been called, and |cb| will
+    // be dropped directly.
+    bool getVideoFrame(GetVideoFrameCB cb);
 
 private:
     // |blockPool| is the C2BlockPool that we fetch graphic blocks from.
@@ -55,8 +54,8 @@ private:
     bool initialize();
     void destroyTask();
 
-    void getVideoFrameTask(GetVideoFrameCB cb);
-    void onVideoFrameReady(GetVideoFrameCB cb, std::optional<FrameWithBlockId> frameWithBlockId);
+    void getVideoFrameTask();
+    void onVideoFrameReady(std::optional<FrameWithBlockId> frameWithBlockId);
 
     // Extracts buffer ID from graphic block.
     // |block| is the graphic block allocated by |blockPool|.
@@ -72,7 +71,7 @@ private:
     const HalPixelFormat mPixelFormat;
     const C2MemoryUsage mMemoryUsage;
 
-    size_t mNumPendingRequests = 0;
+    GetVideoFrameCB mOutputCb;
 
     scoped_refptr<::base::SequencedTaskRunner> mClientTaskRunner;
     ::base::Thread mFetchThread{"VideoFramePoolFetchThread"};