CCodec: fix input surface throttling

There were no throttling in place for video encoders set up with
input surfaces. Throttle based on the number of output buffers
notified to the client.

Bug: 310807188
Test: atest android.hardware.camera2.cts.RecordingTest
Test: atest android.mediav2.cts.CodecEncoderSurfaceTest
Change-Id: Ifec1d16ed25f8100ae1f1eb06a490c955c0c4961
diff --git a/media/codec2/sfplugin/C2NodeImpl.cpp b/media/codec2/sfplugin/C2NodeImpl.cpp
index 6f53e0f..585072d 100644
--- a/media/codec2/sfplugin/C2NodeImpl.cpp
+++ b/media/codec2/sfplugin/C2NodeImpl.cpp
@@ -25,6 +25,7 @@
 #include <C2Debug.h>
 #include <C2PlatformSupport.h>
 
+#include <android_media_codec.h>
 #include <android/fdsan.h>
 #include <media/stagefright/foundation/ColorUtils.h>
 #include <ui/Fence.h>
@@ -373,7 +374,10 @@
     }
     work->worklets.clear();
     work->worklets.emplace_back(new C2Worklet);
-    mBufferIdsInUse.lock()->emplace(work->input.ordinal.frameIndex.peeku(), buffer);
+    {
+        Mutexed<BuffersTracker>::Locked buffers(mBuffersTracker);
+        buffers->mIdsInUse.emplace(work->input.ordinal.frameIndex.peeku(), buffer);
+    }
     mQueueThread->queue(comp, fenceFd, std::move(work), std::move(fd0), std::move(fd1));
 
     return OK;
@@ -405,29 +409,74 @@
 }
 
 void C2NodeImpl::onInputBufferDone(c2_cntr64_t index) {
-    if (mAidlHal) {
-        if (!mAidlBufferSource) {
-            ALOGD("Buffer source not set (index=%llu)", index.peekull());
-            return;
-        }
-    } else {
-        if (!mBufferSource) {
-            ALOGD("Buffer source not set (index=%llu)", index.peekull());
-            return;
-        }
-    }
-
-    int32_t bufferId = 0;
-    {
-        decltype(mBufferIdsInUse)::Locked bufferIds(mBufferIdsInUse);
-        auto it = bufferIds->find(index.peeku());
-        if (it == bufferIds->end()) {
+    if (android::media::codec::provider_->input_surface_throttle()) {
+        Mutexed<BuffersTracker>::Locked buffers(mBuffersTracker);
+        auto it = buffers->mIdsInUse.find(index.peeku());
+        if (it == buffers->mIdsInUse.end()) {
             ALOGV("Untracked input index %llu (maybe already removed)", index.peekull());
             return;
         }
-        bufferId = it->second;
-        (void)bufferIds->erase(it);
+        int32_t bufferId = it->second;
+        (void)buffers->mIdsInUse.erase(it);
+        buffers->mAvailableIds.push_back(bufferId);
+    } else {
+        if (!hasBufferSource()) {
+            return;
+        }
+        int32_t bufferId = 0;
+        {
+            Mutexed<BuffersTracker>::Locked buffers(mBuffersTracker);
+            auto it = buffers->mIdsInUse.find(index.peeku());
+            if (it == buffers->mIdsInUse.end()) {
+                ALOGV("Untracked input index %llu (maybe already removed)", index.peekull());
+                return;
+            }
+            bufferId = it->second;
+            (void)buffers->mIdsInUse.erase(it);
+        }
+        notifyInputBufferEmptied(bufferId);
     }
+}
+
+void C2NodeImpl::onInputBufferEmptied() {
+    if (!android::media::codec::provider_->input_surface_throttle()) {
+        ALOGE("onInputBufferEmptied should not be called "
+              "when input_surface_throttle is false");
+        return;
+    }
+    if (!hasBufferSource()) {
+        return;
+    }
+    int32_t bufferId = 0;
+    {
+        Mutexed<BuffersTracker>::Locked buffers(mBuffersTracker);
+        if (buffers->mAvailableIds.empty()) {
+            ALOGV("The codec is ready to take more input buffers "
+                    "but no input buffers are ready yet.");
+            return;
+        }
+        bufferId = buffers->mAvailableIds.front();
+        buffers->mAvailableIds.pop_front();
+    }
+    notifyInputBufferEmptied(bufferId);
+}
+
+bool C2NodeImpl::hasBufferSource() {
+    if (mAidlHal) {
+        if (!mAidlBufferSource) {
+            ALOGD("Buffer source not set");
+            return false;
+        }
+    } else {
+        if (!mBufferSource) {
+            ALOGD("Buffer source not set");
+            return false;
+        }
+    }
+    return true;
+}
+
+void C2NodeImpl::notifyInputBufferEmptied(int32_t bufferId) {
     if (mAidlHal) {
         ::ndk::ScopedFileDescriptor nullFence;
         (void)mAidlBufferSource->onInputBufferEmptied(bufferId, nullFence);