diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index c8021e4..ce3a90a 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -166,7 +166,7 @@
     } // Autolock scope
 
     // Call back without lock held
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->onBuffersReleased();
     }
 
@@ -221,7 +221,7 @@
     } // Autolock scope
 
     // Call back without lock held
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->onBuffersReleased();
     }
     return NO_ERROR;
@@ -450,11 +450,11 @@
 
         mSlots[found].mBufferState.dequeue();
 
-        if ((buffer == NULL) ||
+        if ((buffer == nullptr) ||
                 buffer->needsReallocation(width, height, format, BQ_LAYER_COUNT, usage))
         {
             mSlots[found].mAcquireCalled = false;
-            mSlots[found].mGraphicBuffer = NULL;
+            mSlots[found].mGraphicBuffer = nullptr;
             mSlots[found].mRequestBufferCalled = false;
             mSlots[found].mEglDisplay = EGL_NO_DISPLAY;
             mSlots[found].mEglFence = EGL_NO_SYNC_KHR;
@@ -472,7 +472,7 @@
         BQ_LOGV("dequeueBuffer: setting buffer age to %" PRIu64,
                 mCore->mBufferAge);
 
-        if (CC_UNLIKELY(mSlots[found].mFence == NULL)) {
+        if (CC_UNLIKELY(mSlots[found].mFence == nullptr)) {
             BQ_LOGE("dequeueBuffer: about to return a NULL fence - "
                     "slot=%d w=%d h=%d format=%u",
                     found, buffer->width, buffer->height, buffer->format);
@@ -613,7 +613,7 @@
         listener = mCore->mConsumerListener;
     }
 
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->onBuffersReleased();
     }
 
@@ -624,10 +624,10 @@
         sp<Fence>* outFence) {
     ATRACE_CALL();
 
-    if (outBuffer == NULL) {
+    if (outBuffer == nullptr) {
         BQ_LOGE("detachNextBuffer: outBuffer must not be NULL");
         return BAD_VALUE;
-    } else if (outFence == NULL) {
+    } else if (outFence == nullptr) {
         BQ_LOGE("detachNextBuffer: outFence must not be NULL");
         return BAD_VALUE;
     }
@@ -671,7 +671,7 @@
         listener = mCore->mConsumerListener;
     }
 
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->onBuffersReleased();
     }
 
@@ -682,10 +682,10 @@
         const sp<android::GraphicBuffer>& buffer) {
     ATRACE_CALL();
 
-    if (outSlot == NULL) {
+    if (outSlot == nullptr) {
         BQ_LOGE("attachBuffer: outSlot must not be NULL");
         return BAD_VALUE;
-    } else if (buffer == NULL) {
+    } else if (buffer == nullptr) {
         BQ_LOGE("attachBuffer: cannot attach NULL buffer");
         return BAD_VALUE;
     }
@@ -767,7 +767,7 @@
     const Region& surfaceDamage = input.getSurfaceDamage();
     const HdrMetadata& hdrMetadata = input.getHdrMetadata();
 
-    if (acquireFence == NULL) {
+    if (acquireFence == nullptr) {
         BQ_LOGE("queueBuffer: fence is NULL");
         return BAD_VALUE;
     }
@@ -973,9 +973,9 @@
             mCallbackCondition.wait(mCallbackMutex);
         }
 
-        if (frameAvailableListener != NULL) {
+        if (frameAvailableListener != nullptr) {
             frameAvailableListener->onFrameAvailable(item);
-        } else if (frameReplacedListener != NULL) {
+        } else if (frameReplacedListener != nullptr) {
             frameReplacedListener->onFrameReplaced(item);
         }
 
@@ -1040,7 +1040,7 @@
         BQ_LOGE("cancelBuffer: slot %d is not owned by the producer "
                 "(state = %s)", slot, mSlots[slot].mBufferState.string());
         return BAD_VALUE;
-    } else if (fence == NULL) {
+    } else if (fence == nullptr) {
         BQ_LOGE("cancelBuffer: fence is NULL");
         return BAD_VALUE;
     }
@@ -1070,7 +1070,7 @@
     ATRACE_CALL();
     Mutex::Autolock lock(mCore->mMutex);
 
-    if (outValue == NULL) {
+    if (outValue == nullptr) {
         BQ_LOGE("query: outValue was NULL");
         return BAD_VALUE;
     }
@@ -1146,12 +1146,12 @@
         return NO_INIT;
     }
 
-    if (mCore->mConsumerListener == NULL) {
+    if (mCore->mConsumerListener == nullptr) {
         BQ_LOGE("connect: BufferQueue has no consumer");
         return NO_INIT;
     }
 
-    if (output == NULL) {
+    if (output == nullptr) {
         BQ_LOGE("connect: output was NULL");
         return BAD_VALUE;
     }
@@ -1189,10 +1189,10 @@
             output->nextFrameNumber = mCore->mFrameCounter + 1;
             output->bufferReplaced = false;
 
-            if (listener != NULL) {
+            if (listener != nullptr) {
                 // Set up a death notification so that we can disconnect
                 // automatically if the remote producer dies
-                if (IInterface::asBinder(listener)->remoteBinder() != NULL) {
+                if (IInterface::asBinder(listener)->remoteBinder() != nullptr) {
                     status = IInterface::asBinder(listener)->linkToDeath(
                             static_cast<IBinder::DeathRecipient*>(this));
                     if (status != NO_ERROR) {
@@ -1269,7 +1269,7 @@
                     mCore->freeAllBuffersLocked();
 
                     // Remove our death notification callback if we have one
-                    if (mCore->mLinkedToDeath != NULL) {
+                    if (mCore->mLinkedToDeath != nullptr) {
                         sp<IBinder> token =
                                 IInterface::asBinder(mCore->mLinkedToDeath);
                         // This can fail if we're here because of the death
@@ -1279,8 +1279,8 @@
                     }
                     mCore->mSharedBufferSlot =
                             BufferQueueCore::INVALID_BUFFER_SLOT;
-                    mCore->mLinkedToDeath = NULL;
-                    mCore->mConnectedProducerListener = NULL;
+                    mCore->mLinkedToDeath = nullptr;
+                    mCore->mConnectedProducerListener = nullptr;
                     mCore->mConnectedApi = BufferQueueCore::NO_CONNECTED_API;
                     mCore->mConnectedPid = -1;
                     mCore->mSidebandStream.clear();
@@ -1303,7 +1303,7 @@
     } // Autolock scope
 
     // Call back without lock held
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->onBuffersReleased();
         listener->onDisconnect();
     }
@@ -1319,7 +1319,7 @@
         listener = mCore->mConsumerListener;
     } // Autolock scope
 
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->onSidebandStreamChanged();
     }
     return NO_ERROR;
@@ -1535,7 +1535,7 @@
         Mutex::Autolock lock(mCore->mMutex);
         listener = mCore->mConsumerListener;
     }
-    if (listener != NULL) {
+    if (listener != nullptr) {
         listener->addAndGetFrameTimestamps(newTimestamps, outDelta);
     }
 }