diff --git a/services/oboeservice/AAudioServiceStreamBase.h b/services/oboeservice/AAudioServiceStreamBase.h
index 0ad015e..a1815d0 100644
--- a/services/oboeservice/AAudioServiceStreamBase.h
+++ b/services/oboeservice/AAudioServiceStreamBase.h
@@ -205,22 +205,33 @@
 
     /**
      * Atomically increment the number of active references to the stream by AAudioService.
+     *
+     * This is called under a global lock in AAudioStreamTracker.
+     *
      * @return value after the increment
      */
-    int32_t incrementServiceReferenceCount();
+    int32_t incrementServiceReferenceCount_l();
 
     /**
      * Atomically decrement the number of active references to the stream by AAudioService.
+     * This should only be called after incrementServiceReferenceCount_l().
+     *
+     * This is called under a global lock in AAudioStreamTracker.
+     *
      * @return value after the decrement
      */
-    int32_t decrementServiceReferenceCount();
+    int32_t decrementServiceReferenceCount_l();
 
     bool isCloseNeeded() const {
         return mCloseNeeded.load();
     }
 
-    void setCloseNeeded(bool needed) {
-        mCloseNeeded.store(needed);
+    /**
+     * Mark this stream as needing to be closed.
+     * Once marked for closing, it cannot be unmarked.
+     */
+    void markCloseNeeded() {
+        mCloseNeeded.store(true);
     }
 
     virtual const char *getTypeText() const { return "Base"; }
@@ -290,8 +301,9 @@
     aaudio_handle_t         mHandle = -1;
     bool                    mFlowing = false;
 
-    std::mutex              mCallingCountLock;
-    std::atomic<int32_t>    mCallingCount{0};
+    // This is modified under a global lock in AAudioStreamTracker.
+    int32_t                 mCallingCount = 0;
+
     std::atomic<bool>       mCloseNeeded{false};
 };