Call Layer::getLayerDebugInfo from the main threadandroid-9.0.0_r60

Fixes an issue where drawing state could be accessed from a binder
thread. The function also mixed current state with drawing state
incorrectly. The function now only retrieves drawing state.

Bug: 150226608
Test: Steps in bug doesn't repro
Test: atest sffakehwc_test
Merged-In: I04daedcb9a890083cc710bab30b295e14b9872ae
Change-Id: I04daedcb9a890083cc710bab30b295e14b9872ae
(cherry picked from commit 927b3b120839954a575b4e8c498b1b4d4d375afa)

6 files changed, 11 insertions, 18 deletions

diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 81c7f9c57c..ce71d3cd21 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -509,7 +509,7 @@ public:
         return result;
     }
 
-    virtual status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers) const
+    virtual status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers)
     {
         if (!outLayers) {
             return UNEXPECTED_NULL;
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index a672ce4ed8..2ab0d99597 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -225,7 +225,7 @@ public:
      *
      * Requires the ACCESS_SURFACE_FLINGER permission.
      */
-    virtual status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers) const = 0;
+    virtual status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers) = 0;
 };
 
 // ----------------------------------------------------------------------------
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 4effd653b8..a0ecb4c149 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -622,7 +622,7 @@ public:
         return NO_ERROR;
     }
     status_t injectVSync(nsecs_t /*when*/) override { return NO_ERROR; }
-    status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* /*layers*/) const override {
+    status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* /*layers*/) override {
         return NO_ERROR;
     }
 
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 220da1d40e..edd946db0f 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1402,7 +1402,7 @@ LayerDebugInfo Layer::getLayerDebugInfo() const {
     LayerDebugInfo info;
     const Layer::State& ds = getDrawingState();
     info.mName = getName();
-    sp<Layer> parent = getParent();
+    sp<Layer> parent = mDrawingParent.promote();
     info.mParentName = (parent == nullptr ? std::string("none") : parent->getName().string());
     info.mType = String8(getTypeId());
     info.mTransparentRegion = ds.activeTransparentRegion;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 7360306d12..ba203bd176 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1184,7 +1184,7 @@ status_t SurfaceFlinger::injectVSync(nsecs_t when) {
     return NO_ERROR;
 }
 
-status_t SurfaceFlinger::getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers) const
+status_t SurfaceFlinger::getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers)
         NO_THREAD_SAFETY_ANALYSIS {
     IPCThreadState* ipc = IPCThreadState::self();
     const int pid = ipc->getCallingPid();
@@ -1195,20 +1195,13 @@ status_t SurfaceFlinger::getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayer
         return PERMISSION_DENIED;
     }
 
-    // Try to acquire a lock for 1s, fail gracefully
-    const status_t err = mStateLock.timedLock(s2ns(1));
-    const bool locked = (err == NO_ERROR);
-    if (!locked) {
-        ALOGE("LayerDebugInfo: SurfaceFlinger unresponsive (%s [%d]) - exit", strerror(-err), err);
-        return TIMED_OUT;
-    }
-
     outLayers->clear();
-    mCurrentState.traverseInZOrder([&](Layer* layer) {
-        outLayers->push_back(layer->getLayerDebugInfo());
-    });
+    postMessageSync(new LambdaMessage([&]() { 
+            mDrawingState.traverseInZOrder([&](Layer* layer) {
+            outLayers->push_back(layer->getLayerDebugInfo());
+        });
 
-    mStateLock.unlock();
+    }));
     return NO_ERROR;
 }
 
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index c7555c31d2..3fbc1e7da8 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -447,7 +447,7 @@ private:
             HdrCapabilities* outCapabilities) const;
     virtual status_t enableVSyncInjections(bool enable);
     virtual status_t injectVSync(nsecs_t when);
-    virtual status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers) const;
+    virtual status_t getLayerDebugInfo(std::vector<LayerDebugInfo>* outLayers);
 
 
     /* ------------------------------------------------------------------------