diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 7363464..12205af 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -606,6 +606,8 @@
         auto vrFlingerRequestDisplayCallback = [this] (bool requestDisplay) {
             ALOGI("VR request display mode: requestDisplay=%d", requestDisplay);
             mVrFlingerRequestsDisplay = requestDisplay;
+            ConditionalLock _l(mStateLock,
+                    std::this_thread::get_id() != mMainThreadId);
             signalTransaction();
         };
         mVrFlinger = dvr::VrFlinger::Create(mHwc->getComposer(),
@@ -693,6 +695,8 @@
         FrameEvent::DEQUEUE_READY,
         FrameEvent::RELEASE,
     };
+    ConditionalLock _l(mStateLock,
+            std::this_thread::get_id() != mMainThreadId);
     if (!getHwComposer().hasCapability(
             HWC2::Capability::PresentFenceIsNotReliable)) {
         outSupported->push_back(FrameEvent::DISPLAY_PRESENT);
@@ -740,6 +744,8 @@
 
     configs->clear();
 
+    ConditionalLock _l(mStateLock,
+            std::this_thread::get_id() != mMainThreadId);
     for (const auto& hwConfig : getHwComposer().getConfigs(type)) {
         DisplayInfo info = DisplayInfo();
 
@@ -763,7 +769,7 @@
             info.density = density;
 
             // TODO: this needs to go away (currently needed only by webkit)
-            sp<const DisplayDevice> hw(getDefaultDisplayDevice());
+            sp<const DisplayDevice> hw(getDefaultDisplayDeviceLocked());
             info.orientation = hw->getOrientation();
         } else {
             // TODO: where should this value come from?
@@ -906,7 +912,12 @@
         return type;
     }
 
-    std::vector<android_color_mode_t> modes = getHwComposer().getColorModes(type);
+    std::vector<android_color_mode_t> modes;
+    {
+        ConditionalLock _l(mStateLock,
+                std::this_thread::get_id() != mMainThreadId);
+        modes = getHwComposer().getColorModes(type);
+    }
     outColorModes->clear();
     std::copy(modes.cbegin(), modes.cend(), std::back_inserter(*outColorModes));
 
@@ -1287,7 +1298,7 @@
     if (sequenceId != mComposerSequenceId) {
         return;
     }
-    repaintEverything();
+    repaintEverythingLocked();
 }
 
 void SurfaceFlinger::setVsyncEnabled(int disp, int enabled) {
@@ -3291,7 +3302,7 @@
 
         mVisibleRegionsDirty = true;
         mHasPoweredOff = true;
-        repaintEverything();
+        repaintEverythingLocked();
 
         struct sched_param param = {0};
         param.sched_priority = 1;
@@ -3935,6 +3946,7 @@
                 return NO_ERROR;
             }
             case 1005:{ // force transaction
+                Mutex::Autolock _l(mStateLock);
                 setTransactionFlags(
                         eTransactionNeeded|
                         eDisplayTransactionNeeded|
@@ -4071,11 +4083,17 @@
     return err;
 }
 
-void SurfaceFlinger::repaintEverything() {
+void SurfaceFlinger::repaintEverythingLocked() {
     android_atomic_or(1, &mRepaintEverything);
     signalTransaction();
 }
 
+void SurfaceFlinger::repaintEverything() {
+    ConditionalLock _l(mStateLock,
+            std::this_thread::get_id() != mMainThreadId);
+    repaintEverythingLocked();
+}
+
 // Checks that the requested width and height are valid and updates them to the display dimensions
 // if they are set to 0
 static status_t updateDimensionsLocked(const sp<const DisplayDevice>& displayDevice,