SF: Store and manage snapshots for virtual displays

Create/destroy VirtualDisplaySnapshot that tracks the virtual display's
lifetime.

For now, VirtualDisplaySnapshots will track a virtual display's
DisplayId and whether or not it's backed by Hal/Gpu. This will be
helpful when moving the cast system of DisplayIds from within
DisplayId.h to SurfaceFlinger.

Bug: 374163881
Flag: EXEMPT refactor
Test: libsurfaceflinger_unittest
Change-Id: Id730e65b24ecd10925282bd72585ac7c5635a4fe

1 files changed, 22 insertions, 3 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 37b35f2f63..824768203b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -647,11 +647,12 @@ void SurfaceFlinger::enableHalVirtualDisplays(bool enable) {
     }
 }
 
-VirtualDisplayId SurfaceFlinger::acquireVirtualDisplay(ui::Size resolution,
-                                                       ui::PixelFormat format) {
+VirtualDisplayId SurfaceFlinger::acquireVirtualDisplay(ui::Size resolution, ui::PixelFormat format,
+                                                       const std::string& uniqueId) {
     if (auto& generator = mVirtualDisplayIdGenerators.hal) {
         if (const auto id = generator->generateId()) {
             if (getHwComposer().allocateVirtualDisplay(*id, resolution, &format)) {
+                acquireVirtualDisplaySnapshot(*id, uniqueId);
                 return *id;
             }
 
@@ -665,6 +666,7 @@ VirtualDisplayId SurfaceFlinger::acquireVirtualDisplay(ui::Size resolution,
 
     const auto id = mVirtualDisplayIdGenerators.gpu.generateId();
     LOG_ALWAYS_FATAL_IF(!id, "Failed to generate ID for GPU virtual display");
+    acquireVirtualDisplaySnapshot(*id, uniqueId);
     return *id;
 }
 
@@ -672,6 +674,7 @@ void SurfaceFlinger::releaseVirtualDisplay(VirtualDisplayId displayId) {
     if (const auto id = HalVirtualDisplayId::tryCast(displayId)) {
         if (auto& generator = mVirtualDisplayIdGenerators.hal) {
             generator->releaseId(*id);
+            releaseVirtualDisplaySnapshot(*id);
         }
         return;
     }
@@ -679,6 +682,14 @@ void SurfaceFlinger::releaseVirtualDisplay(VirtualDisplayId displayId) {
     const auto id = GpuVirtualDisplayId::tryCast(displayId);
     LOG_ALWAYS_FATAL_IF(!id);
     mVirtualDisplayIdGenerators.gpu.releaseId(*id);
+    releaseVirtualDisplaySnapshot(*id);
+}
+
+void SurfaceFlinger::releaseVirtualDisplaySnapshot(VirtualDisplayId displayId) {
+    std::lock_guard lock(mVirtualDisplaysMutex);
+    if (!mVirtualDisplays.erase(displayId)) {
+        ALOGW("%s: Virtual display snapshot was not removed", __func__);
+    }
 }
 
 std::vector<PhysicalDisplayId> SurfaceFlinger::getPhysicalDisplayIdsLocked() const {
@@ -3730,7 +3741,7 @@ void SurfaceFlinger::processDisplayAdded(const wp<IBinder>& displayToken,
     if (const auto& physical = state.physical) {
         builder.setId(physical->id);
     } else {
-        builder.setId(acquireVirtualDisplay(resolution, pixelFormat));
+        builder.setId(acquireVirtualDisplay(resolution, pixelFormat, state.uniqueId));
     }
 
     builder.setPixels(resolution);
@@ -5717,6 +5728,14 @@ void SurfaceFlinger::dumpDisplays(std::string& result) const {
             utils::Dumper::Section section(dumper,
                                            ftl::Concat("Virtual Display ", displayId.value).str());
             display->dump(dumper);
+
+            if (const auto virtualIdOpt = VirtualDisplayId::tryCast(displayId)) {
+                std::lock_guard lock(mVirtualDisplaysMutex);
+                const auto virtualSnapshotIt = mVirtualDisplays.find(virtualIdOpt.value());
+                if (virtualSnapshotIt != mVirtualDisplays.end()) {
+                    virtualSnapshotIt->second.dump(dumper);
+                }
+            }
         }
     }
 }