question: reset the buffer to empty . this must only be called from the compositor thread . concode_field_sep DisplayPortMetrics[] mMetrics concode_elem_sep long[] mTimestamps concode_elem_sep String LOGTAG concode_elem_sep int mTail concode_elem_sep int BUFFER_SIZE concode_elem_sep int mHead concode_field_sep boolean add concode_elem_sep long findTimeFor
target: void function ( ) { mHead = ( mTail + BUFFER_SIZE - 1 ) % BUFFER_SIZE ; }