libgui: Add generation numbers to BufferQueue

This change allows producers to set a generation number on a
BufferQueue. This number will be embedded in any new GraphicBuffers
created in that BufferQueue, and attempts to attach buffers which have
a different generation number will fail.

It also plumbs the setGenerationNumber method through Surface, with the
additional effect that any buffers attached to the Surface after
setting a new generation number will automatically be updated with the
new number (as opposed to failing, as would happen on through IGBP).

Bug: 20923096
Change-Id: I32bf726b035f99c3e5834beaf76afb9f01adcbc2

2 files changed, 6 insertions, 0 deletions

diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index 11cbdc6..ee8d41c 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -530,6 +530,11 @@ status_t VirtualDisplaySurface::allowAllocation(bool /* allow */) {
     return INVALID_OPERATION;
 }
 
+status_t VirtualDisplaySurface::setGenerationNumber(uint32_t /* generation */) {
+    ALOGE("setGenerationNumber not supported on VirtualDisplaySurface");
+    return INVALID_OPERATION;
+}
+
 void VirtualDisplaySurface::updateQueueBufferOutput(
         const QueueBufferOutput& qbo) {
     uint32_t w, h, transformHint, numPendingBuffers;
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index 97af980..ff02290 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -116,6 +116,7 @@ private:
     virtual void allocateBuffers(bool async, uint32_t width, uint32_t height,
             PixelFormat format, uint32_t usage);
     virtual status_t allowAllocation(bool allow);
+    virtual status_t setGenerationNumber(uint32_t generationNumber);
 
     //
     // Utility methods