简单修改，增加注释

Author: yecllsl

.gitignore

@@ -11,3 +11,5 @@
 
 # Repository wide ignore mac DS_Store files
 .DS_Store
+*.lck
+*.log

src/main/java/lambdasinaction/chap7/ParallelStreams.java

@@ -17,7 +17,7 @@ public static long sequentialSum(long n) {
     }
 
     public static long parallelSum(long n) {
-        return Stream.iterate(1L, i -> i + 1).limit(n).parallel().reduce(Long::sum).get();
+        return Stream.iterate(1L, i -> i + 1).limit(n).parallel().reduce(Long::sum).get();//并行处理流
     }
 
     public static long rangedSum(long n) {

src/main/java/lambdasinaction/chap7/ParallelStreamsHarness.java

@@ -6,7 +6,7 @@
 public class ParallelStreamsHarness {
 
     public static final ForkJoinPool FORK_JOIN_POOL = new ForkJoinPool();
-
+    //测试并行的时间
     public static void main(String[] args) {
         System.out.println("Iterative Sum done in: " + measurePerf(ParallelStreams::iterativeSum, 10_000_000L) + " msecs");
         System.out.println("Sequential Sum done in: " + measurePerf(ParallelStreams::sequentialSum, 10_000_000L) + " msecs");