Add mutex

Change-Id: I81072031e74a5cca8384e4e8bce4babf2187d8bb

1 files changed, 1 insertions, 0 deletions

diff --git a/services/surfaceflinger/DispSync.cpp b/services/surfaceflinger/DispSync.cpp
index fd4682225b..2ee7570365 100644
--- a/services/surfaceflinger/DispSync.cpp
+++ b/services/surfaceflinger/DispSync.cpp
@@ -509,6 +509,7 @@ void DispSync::resetErrorLocked() {
 }
 
 nsecs_t DispSync::computeNextRefresh(int periodOffset) const {
+    Mutex::Autolock lock(mMutex);
     nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
     return (((now - mPhase) / mPeriod) + periodOffset + 1) * mPeriod + mPhase;
 }