libui/libgui: Fix errors in parceling

BufferItem and GraphicBuffer were not parceling correctly, which had
not been noticed because the libgui tests (specifically, one that
tests placing a BufferQueue in a separate process from the IGBP/C)
had not been run recently. This change fixes the errors found in
those classes.

Change-Id: Ie224361a534a79115a3481d83ff97f21d154d4f5

2 files changed, 83 insertions, 54 deletions

diff --git a/libs/gui/BufferItem.cpp b/libs/gui/BufferItem.cpp
index 239da20..5793d40 100644
--- a/libs/gui/BufferItem.cpp
+++ b/libs/gui/BufferItem.cpp
@@ -39,52 +39,66 @@ BufferItem::BufferItem() :
 
 BufferItem::~BufferItem() {}
 
+template <typename T>
+static void addAligned(size_t& size, T /* value */) {
+    size = FlattenableUtils::align<sizeof(T)>(size);
+    size += sizeof(T);
+}
+
 size_t BufferItem::getPodSize() const {
-    size_t c =  sizeof(mCrop) +
-            sizeof(mTransform) +
-            sizeof(mScalingMode) +
-            sizeof(mTimestamp) +
-            sizeof(mIsAutoTimestamp) +
-            sizeof(mDataSpace) +
-            sizeof(mFrameNumber) +
-            sizeof(mSlot) +
-            sizeof(mIsDroppable) +
-            sizeof(mAcquireCalled) +
-            sizeof(mTransformToDisplayInverse);
-    return c;
+    // Must align<8> before writing these fields for this to be correct
+    size_t size = 0;
+    addAligned(size, mCrop);
+    addAligned(size, mTransform);
+    addAligned(size, mScalingMode);
+    addAligned(size, mTimestamp);
+    addAligned(size, mIsAutoTimestamp);
+    addAligned(size, mDataSpace);
+    addAligned(size, mFrameNumber);
+    addAligned(size, mSlot);
+    addAligned(size, mIsDroppable);
+    addAligned(size, mAcquireCalled);
+    addAligned(size, mTransformToDisplayInverse);
+    return size;
 }
 
 size_t BufferItem::getFlattenedSize() const {
-    size_t c = 0;
+    size_t size = sizeof(uint32_t); // Flags
     if (mGraphicBuffer != 0) {
-        c += mGraphicBuffer->getFlattenedSize();
-        FlattenableUtils::align<4>(c);
+        size += mGraphicBuffer->getFlattenedSize();
+        FlattenableUtils::align<4>(size);
     }
     if (mFence != 0) {
-        c += mFence->getFlattenedSize();
-        FlattenableUtils::align<4>(c);
+        size += mFence->getFlattenedSize();
+        FlattenableUtils::align<4>(size);
     }
-    c += mSurfaceDamage.getFlattenedSize();
-    FlattenableUtils::align<4>(c);
-    return sizeof(int32_t) + c + getPodSize();
+    size += mSurfaceDamage.getFlattenedSize();
+    size = FlattenableUtils::align<8>(size);
+    return size + getPodSize();
 }
 
 size_t BufferItem::getFdCount() const {
-    size_t c = 0;
+    size_t count = 0;
     if (mGraphicBuffer != 0) {
-        c += mGraphicBuffer->getFdCount();
+        count += mGraphicBuffer->getFdCount();
     }
     if (mFence != 0) {
-        c += mFence->getFdCount();
+        count += mFence->getFdCount();
     }
-    return c;
+    return count;
+}
+
+template <typename T>
+static void writeAligned(void*& buffer, size_t& size, T value) {
+    size -= FlattenableUtils::align<alignof(T)>(buffer);
+    FlattenableUtils::write(buffer, size, value);
 }
 
 status_t BufferItem::flatten(
         void*& buffer, size_t& size, int*& fds, size_t& count) const {
 
     // make sure we have enough space
-    if (count < BufferItem::getFlattenedSize()) {
+    if (size < BufferItem::getFlattenedSize()) {
         return NO_MEMORY;
     }
 
@@ -107,35 +121,46 @@ status_t BufferItem::flatten(
         size -= FlattenableUtils::align<4>(buffer);
         flags |= 2;
     }
+
     status_t err = mSurfaceDamage.flatten(buffer, size);
     if (err) return err;
-    size -= FlattenableUtils::align<4>(buffer);
+    FlattenableUtils::advance(buffer, size, mSurfaceDamage.getFlattenedSize());
+
+    // Must align<8> so that getPodSize returns the correct value
+    size -= FlattenableUtils::align<8>(buffer);
 
-    // check we have enough space (in case flattening the fence/graphicbuffer lied to us)
+    // Check we still have enough space
     if (size < getPodSize()) {
         return NO_MEMORY;
     }
 
-    FlattenableUtils::write(buffer, size, mCrop);
-    FlattenableUtils::write(buffer, size, mTransform);
-    FlattenableUtils::write(buffer, size, mScalingMode);
-    FlattenableUtils::write(buffer, size, mTimestamp);
-    FlattenableUtils::write(buffer, size, mIsAutoTimestamp);
-    FlattenableUtils::write(buffer, size, mDataSpace);
-    FlattenableUtils::write(buffer, size, mFrameNumber);
-    FlattenableUtils::write(buffer, size, mSlot);
-    FlattenableUtils::write(buffer, size, mIsDroppable);
-    FlattenableUtils::write(buffer, size, mAcquireCalled);
-    FlattenableUtils::write(buffer, size, mTransformToDisplayInverse);
+    writeAligned(buffer, size, mCrop);
+    writeAligned(buffer, size, mTransform);
+    writeAligned(buffer, size, mScalingMode);
+    writeAligned(buffer, size, mTimestamp);
+    writeAligned(buffer, size, mIsAutoTimestamp);
+    writeAligned(buffer, size, mDataSpace);
+    writeAligned(buffer, size, mFrameNumber);
+    writeAligned(buffer, size, mSlot);
+    writeAligned(buffer, size, mIsDroppable);
+    writeAligned(buffer, size, mAcquireCalled);
+    writeAligned(buffer, size, mTransformToDisplayInverse);
 
     return NO_ERROR;
 }
 
+template <typename T>
+static void readAligned(const void*& buffer, size_t& size, T& value) {
+    size -= FlattenableUtils::align<alignof(T)>(buffer);
+    FlattenableUtils::read(buffer, size, value);
+}
+
 status_t BufferItem::unflatten(
         void const*& buffer, size_t& size, int const*& fds, size_t& count) {
 
-    if (size < sizeof(uint32_t))
+    if (size < sizeof(uint32_t)) {
         return NO_MEMORY;
+    }
 
     uint32_t flags = 0;
     FlattenableUtils::read(buffer, size, flags);
@@ -153,26 +178,30 @@ status_t BufferItem::unflatten(
         if (err) return err;
         size -= FlattenableUtils::align<4>(buffer);
     }
+
     status_t err = mSurfaceDamage.unflatten(buffer, size);
     if (err) return err;
-    size -= FlattenableUtils::align<4>(buffer);
+    FlattenableUtils::advance(buffer, size, mSurfaceDamage.getFlattenedSize());
+
+    // Must align<8> so that getPodSize returns the correct value
+    size -= FlattenableUtils::align<8>(buffer);
 
-    // check we have enough space
+    // Check we still have enough space
     if (size < getPodSize()) {
         return NO_MEMORY;
     }
 
-    FlattenableUtils::read(buffer, size, mCrop);
-    FlattenableUtils::read(buffer, size, mTransform);
-    FlattenableUtils::read(buffer, size, mScalingMode);
-    FlattenableUtils::read(buffer, size, mTimestamp);
-    FlattenableUtils::read(buffer, size, mIsAutoTimestamp);
-    FlattenableUtils::read(buffer, size, mDataSpace);
-    FlattenableUtils::read(buffer, size, mFrameNumber);
-    FlattenableUtils::read(buffer, size, mSlot);
-    FlattenableUtils::read(buffer, size, mIsDroppable);
-    FlattenableUtils::read(buffer, size, mAcquireCalled);
-    FlattenableUtils::read(buffer, size, mTransformToDisplayInverse);
+    readAligned(buffer, size, mCrop);
+    readAligned(buffer, size, mTransform);
+    readAligned(buffer, size, mScalingMode);
+    readAligned(buffer, size, mTimestamp);
+    readAligned(buffer, size, mIsAutoTimestamp);
+    readAligned(buffer, size, mDataSpace);
+    readAligned(buffer, size, mFrameNumber);
+    readAligned(buffer, size, mSlot);
+    readAligned(buffer, size, mIsDroppable);
+    readAligned(buffer, size, mAcquireCalled);
+    readAligned(buffer, size, mTransformToDisplayInverse);
 
     return NO_ERROR;
 }
diff --git a/libs/ui/GraphicBuffer.cpp b/libs/ui/GraphicBuffer.cpp
index 638ac62..52fa0df 100644
--- a/libs/ui/GraphicBuffer.cpp
+++ b/libs/ui/GraphicBuffer.cpp
@@ -303,7 +303,7 @@ status_t GraphicBuffer::flatten(void*& buffer, size_t& size, int*& fds, size_t&
                 static_cast<size_t>(handle->numInts) * sizeof(int));
     }
 
-    buffer = reinterpret_cast<void*>(static_cast<int*>(buffer) + sizeNeeded);
+    buffer = static_cast<void*>(static_cast<uint8_t*>(buffer) + sizeNeeded);
     size -= sizeNeeded;
     if (handle) {
         fds += handle->numFds;
@@ -385,7 +385,7 @@ status_t GraphicBuffer::unflatten(
         }
     }
 
-    buffer = reinterpret_cast<void const*>(static_cast<int const*>(buffer) + sizeNeeded);
+    buffer = static_cast<void const*>(static_cast<uint8_t const*>(buffer) + sizeNeeded);
     size -= sizeNeeded;
     fds += numFds;
     count -= numFds;