SurfaceFlinger::getNewTexture: Don't deadlock on main thread

This codepath may be invoked on the main thread via the
RefreshRateOverlay surface creation codepath. In such case it will
trigger a deadlock as we wait on the main thread to complete while
blocking the main thread. This can be observed by running
RefreshRateOverlayTests with ~5 iterations. It seems safest to just
avoid this deadlock.

Bug: 184991996
Test: Existing tests pass
Change-Id: I3c5c495b8e93761813157840c9878c73bcdee579

1 files changed, 7 insertions, 3 deletions

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 02579c6bde..82661eca68 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -693,12 +693,16 @@ uint32_t SurfaceFlinger::getNewTexture() {
 
     // The pool was empty, so we need to get a new texture name directly using a
     // blocking call to the main thread
-    return schedule([this] {
+    auto genTextures = [this] {
                uint32_t name = 0;
                getRenderEngine().genTextures(1, &name);
                return name;
-           })
-            .get();
+    };
+    if (std::this_thread::get_id() == mMainThreadId) {
+        return genTextures();
+    } else {
+        return schedule(genTextures).get();
+    }
 }
 
 void SurfaceFlinger::deleteTextureAsync(uint32_t texture) {