bufferqueues: Entirely remove support for passing GL fences into BQs

There are very few if any real clients (i.e. non goldfish) that use
these fences with bufferqueues. We can simplify the overall API by just
removing it and doing explicit sync (which is what would happen anyway)
where we would have passed them into the bufferqueue.

Bug: 339705065
Flag: com.android.graphics.libgui.flags.bq_gl_fence_cleanup
Test: old tests

Change-Id: I1f3973c78aafe278708f203ef46a2b91b138eba7

1 files changed, 17 insertions, 9 deletions

diff --git a/libs/gui/GLConsumer.cpp b/libs/gui/GLConsumer.cpp
index 168129b1f7..052b8edfaa 100644
--- a/libs/gui/GLConsumer.cpp
+++ b/libs/gui/GLConsumer.cpp
@@ -417,18 +417,18 @@ void GLConsumer::onSlotCountChanged(int slotCount) {
 }
 #endif
 
-status_t GLConsumer::releaseBufferLocked(int buf,
-        sp<GraphicBuffer> graphicBuffer,
-        EGLDisplay display, EGLSyncKHR eglFence) {
+#if !COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(BQ_GL_FENCE_CLEANUP)
+status_t GLConsumer::releaseBufferLocked(int buf, sp<GraphicBuffer> graphicBuffer,
+                                         EGLDisplay display, EGLSyncKHR eglFence) {
     // release the buffer if it hasn't already been discarded by the
     // BufferQueue. This can happen, for example, when the producer of this
     // buffer has reallocated the original buffer slot after this buffer
     // was acquired.
-    status_t err = ConsumerBase::releaseBufferLocked(
-            buf, graphicBuffer, display, eglFence);
+    status_t err = ConsumerBase::releaseBufferLocked(buf, graphicBuffer, display, eglFence);
     mEglSlots[buf].mEglFence = EGL_NO_SYNC_KHR;
     return err;
 }
+#endif
 
 status_t GLConsumer::updateAndReleaseLocked(const BufferItem& item,
         PendingRelease* pendingRelease)
@@ -490,9 +490,14 @@ status_t GLConsumer::updateAndReleaseLocked(const BufferItem& item,
     // release old buffer
     if (mCurrentTexture != BufferQueue::INVALID_BUFFER_SLOT) {
         if (pendingRelease == nullptr) {
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(BQ_GL_FENCE_CLEANUP)
+            status_t status =
+                    releaseBufferLocked(mCurrentTexture, mCurrentTextureImage->graphicBuffer());
+#else
             status_t status = releaseBufferLocked(
                     mCurrentTexture, mCurrentTextureImage->graphicBuffer(),
                     mEglDisplay, mEglSlots[mCurrentTexture].mEglFence);
+#endif
             if (status < NO_ERROR) {
                 GLC_LOGE("updateAndRelease: failed to release buffer: %s (%d)",
                         strerror(-status), status);
@@ -501,10 +506,7 @@ status_t GLConsumer::updateAndReleaseLocked(const BufferItem& item,
             }
         } else {
             pendingRelease->currentTexture = mCurrentTexture;
-            pendingRelease->graphicBuffer =
-                    mCurrentTextureImage->graphicBuffer();
-            pendingRelease->display = mEglDisplay;
-            pendingRelease->fence = mEglSlots[mCurrentTexture].mEglFence;
+            pendingRelease->graphicBuffer = mCurrentTextureImage->graphicBuffer();
             pendingRelease->isPending = true;
         }
     }
@@ -744,6 +746,11 @@ status_t GLConsumer::syncForReleaseLocked(EGLDisplay dpy) {
                 return err;
             }
         } else if (mUseFenceSync && SyncFeatures::getInstance().useFenceSync()) {
+#if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(BQ_GL_FENCE_CLEANUP)
+            // Basically all clients are using native fence syncs. If they aren't, we lose nothing
+            // by waiting here, because the alternative can cause deadlocks (b/339705065).
+            glFinish();
+#else
             EGLSyncKHR fence = mEglSlots[mCurrentTexture].mEglFence;
             if (fence != EGL_NO_SYNC_KHR) {
                 // There is already a fence for the current slot.  We need to
@@ -773,6 +780,7 @@ status_t GLConsumer::syncForReleaseLocked(EGLDisplay dpy) {
             }
             glFlush();
             mEglSlots[mCurrentTexture].mEglFence = fence;
+#endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(BQ_GL_FENCE_CLEANUP)
         }
     }