{"id":37416,"date":"2023-12-11T14:41:22","date_gmt":"2023-12-11T06:41:22","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=37416"},"modified":"2023-12-11T14:41:22","modified_gmt":"2023-12-11T06:41:22","slug":"concurrenthashmap%e7%ba%bf%e7%a8%8b%e5%ae%89%e5%85%a8%e7%9a%84%e5%85%b7%e4%bd%93%e5%ae%9e%e7%8e%b0%e6%96%b9%e5%bc%8f-%e5%ba%95%e5%b1%82%e5%85%b7%e4%bd%93%e5%ae%9e%e7%8e%b0%e5%8e%9f%e7%90%86%e9%87%8d","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/12\/11\/concurrenthashmap%e7%ba%bf%e7%a8%8b%e5%ae%89%e5%85%a8%e7%9a%84%e5%85%b7%e4%bd%93%e5%ae%9e%e7%8e%b0%e6%96%b9%e5%bc%8f-%e5%ba%95%e5%b1%82%e5%85%b7%e4%bd%93%e5%ae%9e%e7%8e%b0%e5%8e%9f%e7%90%86%e9%87%8d\/","title":{"rendered":"ConcurrentHashMap\u7ebf\u7a0b\u5b89\u5168\u7684\u5177\u4f53\u5b9e\u73b0\u65b9\u5f0f? \u5e95\u5c42\u5177\u4f53\u5b9e\u73b0\u539f\u7406?\u91cd\u8981"},"content":{"rendered":"

“`”<\/p>\n

<h3>JDK1.7\u7684ConcurrentHashMap\uff1a<\/h3><\/p>\n

<img src=""http:\/\/res.mianshigee.com\/upload\/article\/20200214\/ea291c1d-d0fd-4653-a8d8-95369a40eefb.jpg"" style=""width: 100%;""><br><\/p>\n

\u9996\u5148\u5c06\u6570\u636e\u5206\u4e3a\u4e00\u6bb5\u4e00\u6bb5\u7684\u5b58\u50a8\uff0c\u7136\u540e\u7ed9\u6bcf\u4e00\u6bb5\u6570\u636e\u914d\u4e00\u628a\u9501\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u5360\u7528\u9501\u8bbf\u95ee\u5176\u4e2d\u4e00\u4e2a\u6bb5\u6570\u636e\u65f6\uff0c\u5176\u4ed6\u6bb5\u7684\u6570\u636e\u4e5f\u80fd\u88ab\u5176\u4ed6\u7ebf\u7a0b\u8bbf\u95ee\u3002<\/p>\n

<strong>ConcurrentHashMap \u662f\u7531 Segment \u6570\u7ec4\u7ed3\u6784\u548c HashEntry \u6570\u7ec4\u7ed3\u6784\u7ec4\u6210<\/strong>\u3002<\/p>\n

Segment \u5b9e\u73b0\u4e86 ReentrantLock,\u6240\u4ee5 Segment \u662f\u4e00\u79cd\u53ef\u91cd\u5165\u9501\uff0c\u626e\u6f14\u9501\u7684\u89d2\u8272\u3002HashEntry \u7528\u4e8e\u5b58\u50a8\u952e\u503c\u5bf9\u6570\u636e\u3002<\/p>\n

<code>javastatic class Segment<k,v> extends ReentrantLock implements Serializable {}<\/k,v><\/code><\/p>\n

\u4e00\u4e2a ConcurrentHashMap \u91cc\u5305\u542b\u4e00\u4e2a Segment \u6570\u7ec4\u3002Segment \u7684\u7ed3\u6784\u548cHashMap\u7c7b\u4f3c\uff0c\u662f\u4e00\u79cd\u6570\u7ec4\u548c\u94fe\u8868\u7ed3\u6784\uff0c\u4e00\u4e2a Segment \u5305\u542b\u4e00\u4e2a HashEntry \u6570\u7ec4\uff0c\u6bcf\u4e2a HashEntry \u662f\u4e00\u4e2a\u94fe\u8868\u7ed3\u6784\u7684\u5143\u7d20\uff0c\u6bcf\u4e2a Segment \u5b88\u62a4\u7740\u4e00\u4e2aHashEntry\u6570\u7ec4\u91cc\u7684\u5143\u7d20\uff0c\u5f53\u5bf9 HashEntry \u6570\u7ec4\u7684\u6570\u636e\u8fdb\u884c\u4fee\u6539\u65f6\uff0c\u5fc5\u987b\u9996\u5148\u83b7\u5f97\u5bf9\u5e94\u7684 Segment\u7684\u9501\u3002<\/p><\/p>\n

<h3>JDK1.8\u7684ConcurrentHashMap<\/h3><\/p>\n

<img src=""http:\/\/res.mianshigee.com\/upload\/article\/20200214\/f8dfe001-2a78-46aa-ae56-d82676f8b907.jpg"" style=""width: 100%;""><br><\/p>\n

ConcurrentHashMap\u53d6\u6d88\u4e86Segment\u5206\u6bb5\u9501\uff0c\u91c7\u7528CAS\u548csynchronized\u6765\u4fdd\u8bc1\u5e76\u53d1\u5b89\u5168\u3002\u6570\u636e\u7ed3\u6784\u8ddfHashMap1.8\u7684\u7ed3\u6784\u7c7b\u4f3c\uff0c\u6570\u7ec4+\u94fe\u8868\/\u7ea2\u9ed1\u4e8c\u53c9\u6811\u3002Java 8\u5728\u94fe\u8868\u957f\u5ea6\u8d85\u8fc7\u4e00\u5b9a\u9608\u503c\uff088\uff09\u65f6\u5c06\u94fe\u8868\uff08\u5bfb\u5740\u65f6\u95f4\u590d\u6742\u5ea6\u4e3aO(N)\uff09\u8f6c\u6362\u4e3a\u7ea2\u9ed1\u6811\uff08\u5bfb\u5740\u65f6\u95f4\u590d\u6742\u5ea6\u4e3aO(log(N))\uff09<\/p>\n

synchronized\u53ea\u9501\u5b9a\u5f53\u524d\u94fe\u8868\u6216\u7ea2\u9ed1\u4e8c\u53c9\u6811\u7684\u9996\u8282\u70b9\uff0c\u8fd9\u6837\u53ea\u8981hash\u4e0d\u51b2\u7a81\uff0c\u5c31\u4e0d\u4f1a\u4ea7\u751f\u5e76\u53d1\uff0c\u6548\u7387\u53c8\u63d0\u5347N\u500d\u3002<\/p>\n

<pre><code> "“`
\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"

“`” <h3>JDK1.7\u7684ConcurrentHashMap\uff1a< […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-37416","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/37416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=37416"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/37416\/revisions"}],"predecessor-version":[{"id":37417,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/37416\/revisions\/37417"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=37416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=37416"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=37416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}