libgui: Add support for unlimited slot BufferQueues

BufferQueues can now be of unlimited size, according to the wishes of
the producer.

We add four new methods:

- IGBC::allowUnlimitedSlots, which permits the IGBP to call
  extendSlotCount
- IGBP::extendSlotCount, which increases the total available slot count
  to a fixed number and notifies the consumer via
  ICL::onSlotCountChanged
- ICL::onSlotCountChanged, which notifies the consumer to resize its
  personal slot vector
- IGBC::getReleasedBuffersExtented, which is like getReleasedBuffers but
  with an arbitrary sized bitvector instead of a fixed 64 bit vector

The internal representation of the slots in BufferQueueCore is now a
vector instead of an array, and can grow (but not shrink). The only
consumers of these new APIs are intented to be Surface and ConsumerBase.
Everything else is being migrated away from IGBP/IGBC anyway.

This is part of go/warren-buffers.

Bug: 341359814
Flag: com.android.graphics.libgui.flags.wb_unlimited_slots
Test: new tests, old tests

Change-Id: I0df872b9d6f9273854cc07a88d29b65451e1832a

1 files changed, 90 insertions, 14 deletions

diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index 9855b5bca4..f0125868ae 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -341,9 +341,9 @@ status_t BufferQueueConsumer::detachBuffer(int slot) {
             return BAD_VALUE;
         }
 
-        if (slot < 0 || slot >= BufferQueueDefs::NUM_BUFFER_SLOTS) {
-            BQ_LOGE("detachBuffer: slot index %d out of range [0, %d)",
-                    slot, BufferQueueDefs::NUM_BUFFER_SLOTS);
+        const int totalSlotCount = mCore->getTotalSlotCountLocked();
+        if (slot < 0 || slot >= totalSlotCount) {
+            BQ_LOGE("detachBuffer: slot index %d out of range [0, %d)", slot, totalSlotCount);
             return BAD_VALUE;
         } else if (!mSlots[slot].mBufferState.isAcquired()) {
             BQ_LOGE("detachBuffer: slot %d is not owned by the consumer "
@@ -483,10 +483,13 @@ status_t BufferQueueConsumer::releaseBuffer(int slot, uint64_t frameNumber,
     ATRACE_CALL();
     ATRACE_BUFFER_INDEX(slot);
 
-    if (slot < 0 || slot >= BufferQueueDefs::NUM_BUFFER_SLOTS ||
-            releaseFence == nullptr) {
-        BQ_LOGE("releaseBuffer: slot %d out of range or fence %p NULL", slot,
-                releaseFence.get());
+    const int totalSlotCount = mCore->getTotalSlotCountLocked();
+    if (slot < 0 || slot >= totalSlotCount) {
+        BQ_LOGE("releaseBuffer: slot index %d out of range [0, %d)", slot, totalSlotCount);
+        return BAD_VALUE;
+    }
+    if (releaseFence == nullptr) {
+        BQ_LOGE("releaseBuffer: slot %d fence %p NULL", slot, releaseFence.get());
         return BAD_VALUE;
     }
 
@@ -515,6 +518,13 @@ status_t BufferQueueConsumer::releaseBuffer(int slot, uint64_t frameNumber,
     { // Autolock scope
         std::lock_guard<std::mutex> lock(mCore->mMutex);
 
+        const int totalSlotCount = mCore->getTotalSlotCountLocked();
+        if (slot < 0 || slot >= totalSlotCount || releaseFence == nullptr) {
+            BQ_LOGE("releaseBuffer: slot %d out of range [0, %d) or fence %p NULL", slot,
+                    totalSlotCount, releaseFence.get());
+            return BAD_VALUE;
+        }
+
         // If the frame number has changed because the buffer has been reallocated,
         // we can ignore this releaseBuffer for the old buffer.
         // Ignore this for the shared buffer where the frame number can easily
@@ -661,6 +671,43 @@ status_t BufferQueueConsumer::getReleasedBuffers(uint64_t *outSlotMask) {
     return NO_ERROR;
 }
 
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+status_t BufferQueueConsumer::getReleasedBuffersExtended(std::vector<bool>* outSlotMask) {
+    ATRACE_CALL();
+
+    if (outSlotMask == nullptr) {
+        BQ_LOGE("getReleasedBuffersExtended: outSlotMask may not be NULL");
+        return BAD_VALUE;
+    }
+
+    std::lock_guard<std::mutex> lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        BQ_LOGE("getReleasedBuffersExtended: BufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    const int totalSlotCount = mCore->getTotalSlotCountLocked();
+    outSlotMask->resize(totalSlotCount);
+    for (int s = 0; s < totalSlotCount; ++s) {
+        (*outSlotMask)[s] = !mSlots[s].mAcquireCalled;
+    }
+
+    // Remove from the mask queued buffers for which acquire has been called,
+    // since the consumer will not receive their buffer addresses and so must
+    // retain their cached information
+    BufferQueueCore::Fifo::iterator current(mCore->mQueue.begin());
+    while (current != mCore->mQueue.end()) {
+        if (current->mAcquireCalled) {
+            (*outSlotMask)[current->mSlot] = false;
+        }
+        ++current;
+    }
+
+    return NO_ERROR;
+}
+#endif
+
 status_t BufferQueueConsumer::setDefaultBufferSize(uint32_t width,
         uint32_t height) {
     ATRACE_CALL();
@@ -679,6 +726,28 @@ status_t BufferQueueConsumer::setDefaultBufferSize(uint32_t width,
     return NO_ERROR;
 }
 
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+status_t BufferQueueConsumer::allowUnlimitedSlots(bool allowUnlimitedSlots) {
+    ATRACE_CALL();
+    BQ_LOGV("allowUnlimitedSlots: %d", allowUnlimitedSlots);
+    std::lock_guard<std::mutex> lock(mCore->mMutex);
+
+    if (mCore->mIsAbandoned) {
+        BQ_LOGE("allowUnlimitedSlots: BufferQueue has been abandoned");
+        return NO_INIT;
+    }
+
+    if (mCore->mConnectedApi != BufferQueueCore::NO_CONNECTED_API) {
+        BQ_LOGE("allowUnlimitedSlots: BufferQueue already connected");
+        return INVALID_OPERATION;
+    }
+
+    mCore->mAllowExtendedSlotCount = allowUnlimitedSlots;
+
+    return OK;
+}
+#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+
 status_t BufferQueueConsumer::setMaxBufferCount(int bufferCount) {
     ATRACE_CALL();
 
@@ -718,16 +787,23 @@ status_t BufferQueueConsumer::setMaxAcquiredBufferCount(
         int maxAcquiredBuffers) {
     ATRACE_FORMAT("%s(%d)", __func__, maxAcquiredBuffers);
 
-    if (maxAcquiredBuffers < 1 ||
-            maxAcquiredBuffers > BufferQueueCore::MAX_MAX_ACQUIRED_BUFFERS) {
-        BQ_LOGE("setMaxAcquiredBufferCount: invalid count %d",
-                maxAcquiredBuffers);
-        return BAD_VALUE;
-    }
-
     sp<IConsumerListener> listener;
     { // Autolock scope
         std::unique_lock<std::mutex> lock(mCore->mMutex);
+
+        // We reserve two slots in order to guarantee that the producer and
+        // consumer can run asynchronously.
+        int maxMaxAcquiredBuffers =
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_UNLIMITED_SLOTS)
+                mCore->getTotalSlotCountLocked() - 2;
+#else
+                BufferQueueCore::MAX_MAX_ACQUIRED_BUFFERS;
+#endif
+        if (maxAcquiredBuffers < 1 || maxAcquiredBuffers > maxMaxAcquiredBuffers) {
+            BQ_LOGE("setMaxAcquiredBufferCount: invalid count %d", maxAcquiredBuffers);
+            return BAD_VALUE;
+        }
+
         mCore->waitWhileAllocatingLocked(lock);
 
         if (mCore->mIsAbandoned) {