surfaceflinger: Generate unique layer names

Add a counter to layer names to make it clear when there are duplicates.

    layer foo#0
    layer foo#1
    layer bar#0
    layer bar#1
    layer bar#2

Bug: b/32543755
Test: Build, install, run game with duplicate layers, see unique names.

Change-Id: I915531d7adbdc506c429b86a685665fb6c56d25e

3 files changed, 58 insertions, 4 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index f82b363cb5..0f6b39713e 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2839,15 +2839,17 @@ status_t SurfaceFlinger::createLayer(
 
     sp<Layer> layer;
 
+    String8 uniqueName = getUniqueLayerName(name);
+
     switch (flags & ISurfaceComposerClient::eFXSurfaceMask) {
         case ISurfaceComposerClient::eFXSurfaceNormal:
             result = createNormalLayer(client,
-                    name, w, h, flags, format,
+                    uniqueName, w, h, flags, format,
                     handle, gbp, &layer);
             break;
         case ISurfaceComposerClient::eFXSurfaceDim:
             result = createDimLayer(client,
-                    name, w, h, flags,
+                    uniqueName, w, h, flags,
                     handle, gbp, &layer);
             break;
         default:
@@ -2871,6 +2873,30 @@ status_t SurfaceFlinger::createLayer(
     return result;
 }
 
+String8 SurfaceFlinger::getUniqueLayerName(const String8& name)
+{
+    bool matchFound = true;
+    uint32_t dupeCounter = 0;
+
+    // Tack on our counter whether there is a hit or not, so everyone gets a tag
+    String8 uniqueName = name + "#" + String8(std::to_string(dupeCounter).c_str());
+
+    // Loop over layers until we're sure there is no matching name
+    while (matchFound) {
+        matchFound = false;
+        mDrawingState.traverseInZOrder([&](Layer* layer) {
+            if (layer->getName() == uniqueName) {
+                matchFound = true;
+                uniqueName = name + "#" + String8(std::to_string(++dupeCounter).c_str());
+            }
+        });
+    }
+
+    ALOGD_IF(dupeCounter > 0, "duplicate layer name: changing %s to %s", name.c_str(), uniqueName.c_str());
+
+    return uniqueName;
+}
+
 status_t SurfaceFlinger::createNormalLayer(const sp<Client>& client,
         const String8& name, uint32_t w, uint32_t h, uint32_t flags, PixelFormat& format,
         sp<IBinder>* handle, sp<IGraphicBufferProducer>* gbp, sp<Layer>* outLayer)
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 581bbfdede..4ecbddd9a2 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -364,6 +364,8 @@ private:
             uint32_t w, uint32_t h, uint32_t flags, sp<IBinder>* outHandle,
             sp<IGraphicBufferProducer>* outGbp, sp<Layer>* outLayer);
 
+    String8 getUniqueLayerName(const String8& name);
+
     // called in response to the window-manager calling
     // ISurfaceComposerClient::destroySurface()
     status_t onLayerRemoved(const sp<Client>& client, const sp<IBinder>& handle);
diff --git a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
index c26847f927..a6c0b9c686 100644
--- a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
+++ b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
@@ -2637,15 +2637,17 @@ status_t SurfaceFlinger::createLayer(
 
     sp<Layer> layer;
 
+    String8 uniqueName = getUniqueLayerName(name);
+
     switch (flags & ISurfaceComposerClient::eFXSurfaceMask) {
         case ISurfaceComposerClient::eFXSurfaceNormal:
             result = createNormalLayer(client,
-                    name, w, h, flags, format,
+                    uniqueName, w, h, flags, format,
                     handle, gbp, &layer);
             break;
         case ISurfaceComposerClient::eFXSurfaceDim:
             result = createDimLayer(client,
-                    name, w, h, flags,
+                    uniqueName, w, h, flags,
                     handle, gbp, &layer);
             break;
         default:
@@ -2669,6 +2671,30 @@ status_t SurfaceFlinger::createLayer(
     return result;
 }
 
+String8 SurfaceFlinger::getUniqueLayerName(const String8& name)
+{
+    bool matchFound = true;
+    uint32_t dupeCounter = 0;
+
+    // Tack on our counter whether there is a hit or not, so everyone gets a tag
+    String8 uniqueName = name + "#" + String8(std::to_string(dupeCounter).c_str());
+
+    // Loop over layers until we're sure there is no matching name
+    while (matchFound) {
+        matchFound = false;
+        mDrawingState.traverseInZOrder([&](Layer* layer) {
+            if (layer->getName() == uniqueName) {
+                matchFound = true;
+                uniqueName = name + "#" + String8(std::to_string(++dupeCounter).c_str());
+            }
+        });
+    }
+
+    ALOGD_IF(dupeCounter > 0, "duplicate layer name: changing %s to %s", name.c_str(), uniqueName.c_str());
+
+    return uniqueName;
+}
+
 status_t SurfaceFlinger::createNormalLayer(const sp<Client>& client,
         const String8& name, uint32_t w, uint32_t h, uint32_t flags, PixelFormat& format,
         sp<IBinder>* handle, sp<IGraphicBufferProducer>* gbp, sp<Layer>* outLayer)