libgui: Add unlimited slot support to Surfaces and Consumers

Surfaces can now use `setMaxDequeuedBufferCount` with any value when the
consumer supports it to give themselves an essentially unlimited number
of buffers to use.

ConsumerBase and its libgui children have been updated to allow for
unlimited buffer slots by default (meaning all users opt into this
automatically), and their implementations have been updated to track the
new variable slot limit.

This is part of go/warren-buffers.

Bug: 341359185
Flag: com.android.graphics.libgui.flags.wb_unlimited_slots
Test: new tests, old tests
Change-Id: I374aa204a2e42a17d95c6e0ffaef2c2caaa9c963
diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index e41f9bb..ec23365 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -38,6 +38,7 @@
 #include <utils/NativeHandle.h>
 #include <utils/Trace.h>
 
+#include <ui/BufferQueueDefs.h>
 #include <ui/DynamicDisplayInfo.h>
 #include <ui/Fence.h>
 #include <ui/GraphicBuffer.h>
@@ -98,7 +99,10 @@
       : mGraphicBufferProducer(bufferProducer),
 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
         mSurfaceDeathListener(nullptr),
-#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
+#endif
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+        mSlots(NUM_BUFFER_SLOTS),
+#endif
         mCrop(Rect::EMPTY_RECT),
         mBufferAge(0),
         mGenerationNumber(0),
@@ -192,7 +196,7 @@
 status_t Surface::allowAllocation(bool allowAllocation) {
     return mGraphicBufferProducer->allowAllocation(allowAllocation);
 }
-#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
+#endif
 
 status_t Surface::setGenerationNumber(uint32_t generation) {
     status_t result = mGraphicBufferProducer->setGenerationNumber(generation);
@@ -658,7 +662,11 @@
         return result;
     }
 
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+    if (buf < 0 || buf >= (int)mSlots.size()) {
+#else
     if (buf < 0 || buf >= NUM_BUFFER_SLOTS) {
+#endif
         ALOGE("dequeueBuffer: IGraphicBufferProducer returned invalid slot number %d", buf);
         android_errorWriteLog(0x534e4554, "36991414"); // SafetyNet logging
         return FAILED_TRANSACTION;
@@ -757,7 +765,11 @@
     Mutex::Autolock lock(mMutex);
 
     uint64_t bufferId = buffer->getId();
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+    for (int slot = 0; slot < (int)mSlots.size(); ++slot) {
+#else
     for (int slot = 0; slot < Surface::NUM_BUFFER_SLOTS; ++slot) {
+#endif
         auto& bufferSlot = mSlots[slot];
         if (bufferSlot.buffer != nullptr && bufferSlot.buffer->getId() == bufferId) {
             bufferSlot.buffer = nullptr;
@@ -840,7 +852,11 @@
             return output.result;
         }
 
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+        if (output.slot < 0 || output.slot >= (int)mSlots.size()) {
+#else
         if (output.slot < 0 || output.slot >= NUM_BUFFER_SLOTS) {
+#endif
             mGraphicBufferProducer->cancelBuffers(cancelBufferInputs, &cancelBufferOutputs);
             ALOGE("%s: IGraphicBufferProducer returned invalid slot number %d",
                     __FUNCTION__, output.slot);
@@ -1027,7 +1043,11 @@
         return BAD_VALUE;
     }
 
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+    for (int i = 0; i < (int)mSlots.size(); i++) {
+#else
     for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
+#endif
         if (mSlots[i].buffer != nullptr &&
                 mSlots[i].buffer->handle == buffer->handle) {
             return i;
@@ -2094,6 +2114,9 @@
         mDefaultHeight = output.height;
         mNextFrameNumber = output.nextFrameNumber;
         mMaxBufferCount = output.maxBufferCount;
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+        mIsSlotExpansionAllowed = output.isSlotExpansionAllowed;
+#endif
 
         // Ignore transform hint if sticky transform is set or transform to display inverse flag is
         // set. Transform hint should be ignored if the client is expected to always submit buffers
@@ -2190,7 +2213,11 @@
         *outFence = Fence::NO_FENCE;
     }
 
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+    for (int i = 0; i < (int)mSlots.size(); i++) {
+#else
     for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
+#endif
         if (mSlots[i].buffer != nullptr &&
                 mSlots[i].buffer->getId() == buffer->getId()) {
             if (mReportRemovedBuffers) {
@@ -2292,8 +2319,35 @@
     ALOGV("Surface::setMaxDequeuedBufferCount");
     Mutex::Autolock lock(mMutex);
 
-    status_t err = mGraphicBufferProducer->setMaxDequeuedBufferCount(
-            maxDequeuedBuffers);
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+    if (maxDequeuedBuffers > BufferQueueDefs::NUM_BUFFER_SLOTS && !mIsSlotExpansionAllowed) {
+        return BAD_VALUE;
+    }
+
+    int minUndequeuedBuffers = 0;
+    status_t err = mGraphicBufferProducer->query(NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS,
+                                                 &minUndequeuedBuffers);
+    if (err != OK) {
+        ALOGE("IGraphicBufferProducer::query(NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS) returned %s",
+              strerror(-err));
+        return err;
+    }
+
+    if (maxDequeuedBuffers > (int)mSlots.size()) {
+        int newSlotCount = minUndequeuedBuffers + maxDequeuedBuffers;
+        err = mGraphicBufferProducer->extendSlotCount(newSlotCount);
+        if (err != OK) {
+            ALOGE("IGraphicBufferProducer::extendSlotCount(%d) returned %s", newSlotCount,
+                  strerror(-err));
+            return err;
+        }
+
+        mSlots.resize(newSlotCount);
+    }
+    err = mGraphicBufferProducer->setMaxDequeuedBufferCount(maxDequeuedBuffers);
+#else
+    status_t err = mGraphicBufferProducer->setMaxDequeuedBufferCount(maxDequeuedBuffers);
+#endif
     ALOGE_IF(err, "IGraphicBufferProducer::setMaxDequeuedBufferCount(%d) "
             "returned %s", maxDequeuedBuffers, strerror(-err));
 
@@ -2501,7 +2555,11 @@
         ALOGE("%s: %zu buffers were freed while being dequeued!",
                 __FUNCTION__, mDequeuedSlots.size());
     }
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+    for (int i = 0; i < (int)mSlots.size(); i++) {
+#else
     for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
+#endif
         mSlots[i].buffer = nullptr;
     }
 }
@@ -2510,7 +2568,11 @@
         std::vector<sp<GraphicBuffer>>* outBuffers) {
     ALOGV("Surface::getAndFlushBuffersFromSlots");
     for (int32_t i : slots) {
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+        if (i < 0 || i >= (int)mSlots.size()) {
+#else
         if (i < 0 || i >= NUM_BUFFER_SLOTS) {
+#endif
             ALOGE("%s: Invalid slotIndex: %d", __FUNCTION__, i);
             return BAD_VALUE;
         }
@@ -2670,7 +2732,11 @@
             newDirtyRegion.set(bounds);
             mDirtyRegion.clear();
             Mutex::Autolock lock(mMutex);
-            for (size_t i=0 ; i<NUM_BUFFER_SLOTS ; i++) {
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+            for (int i = 0; i < (int)mSlots.size(); i++) {
+#else
+            for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
+#endif
                 mSlots[i].dirtyRegion.clear();
             }
         }