Java多线程（四）之ConcurrentSkipListMap深入分析 - JAVA

/ 和get操作类似，不同的就是查找的同时在各个level上加入了对应的key
for (;;) {
int j = h.level;
Index q = h;
Index r = q.right;
Index t = idx;
for (;;) {
if (r != null) {
Node n = r.node;
// compare before deletion check avoids needing recheck
int c = key.compareTo(n.key);
if (n.value == null) {
if (!q.unlink(r))
break;
r = q.right;
continue;
}
if (c > 0) {
q = r;
r = r.right;
continue;
}
}

if (j == insertionLevel) {//在该层level中执行插入操作
// Don't insert index if node already deleted
if (t.indexesDeletedNode()) {
findNode(key); // cleans up
return;
}
if (!q.link(r, t))//执行link操作，其实就是inset的实现部分
break; // restart
if (--insertionLevel == 0) {
// need final deletion check before return
if (t.indexesDeletedNode())
findNode(key);
return;
}
}
if (--j >= insertionLevel && j < indexLevel)//key移动到下一层level
t = t.down;
q = q.down;
r = q.right;
}
}
}

Java多线程（四）之ConcurrentSkipListMap深入分析(三)