{"id":826,"date":"2017-12-20T16:15:49","date_gmt":"2017-12-20T08:15:49","guid":{"rendered":"https:\/\/damogame.cn:15443\/wordpress\/?p=826"},"modified":"2017-12-20T16:19:52","modified_gmt":"2017-12-20T08:19:52","slug":"volatile","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/826","title":{"rendered":"volatile"},"content":{"rendered":"
\n
\u7f16\u8f91<\/a><\/dd>\n<\/dl>\n
\n
volatile\u662f\u4e00\u4e2a\u7c7b\u578b\u4fee\u9970\u7b26<\/a>\uff08type specifier\uff09\uff0c\u5c31\u50cf\u5927\u5bb6\u66f4\u719f\u6089\u7684const\u4e00\u6837\uff0c\u5b83\u662f\u88ab\u8bbe\u8ba1\u7528\u6765\u4fee\u9970\u88ab\u4e0d\u540c\u7ebf\u7a0b\u8bbf\u95ee\u548c\u4fee\u6539\u7684\u53d8\u91cf<\/a>\u3002volatile<\/b>\u7684\u4f5c\u7528\u662f\u4f5c\u4e3a\u6307\u4ee4\u5173\u952e\u5b57<\/a>\uff0c\u786e\u4fdd\u672c\u6761\u6307\u4ee4\u4e0d\u4f1a\u56e0\u7f16\u8bd1\u5668<\/a>\u7684\u4f18\u5316\u800c\u7701\u7565\uff0c\u4e14\u8981\u6c42\u6bcf\u6b21\u76f4\u63a5\u8bfb\u503c\u3002<\/div>\n
volatile\u7684\u53d8\u91cf\u662f\u8bf4\u8fd9\u53d8\u91cf\u53ef\u80fd\u4f1a\u88ab\u610f\u60f3\u4e0d\u5230\u5730\u6539\u53d8\uff0c\u8fd9\u6837\uff0c\u7f16\u8bd1\u5668<\/a>\u5c31\u4e0d\u4f1a\u53bb\u5047\u8bbe\u8fd9\u4e2a\u53d8\u91cf\u7684\u503c\u4e86\u3002<\/div>\n<\/div>\n
<\/div>\n
\n
\n
\u4e2d\u6587\u540d<\/dt>\n
\u6613\u53d8\u578b\u53d8\u91cf<\/dd>\n
\u5916\u6587\u540d<\/dt>\n
volatile<\/dd>\n<\/dl>\n
\n
\u91ca\u00a0\u00a0\u00a0\u00a0\u4e49<\/dt>\n
\u6613\u53d8\u7684<\/dd>\n
\u8bcd\u00a0\u00a0\u00a0\u00a0\u6027<\/dt>\n
\u5f62\u5bb9\u8bcd<\/dd>\n
\u5c5e\u00a0\u00a0\u00a0\u00a0\u6027<\/dt>\n
\u7c7b\u578b\u4fee\u9970\u7b26<\/a><\/dd>\n<\/dl>\n<\/div>\n
\n
\n

\u76ee\u5f55<\/h2>\n
\n
    \n
  1. 1<\/span>\u00a0\u4f5c\u7528<\/a><\/span><\/li>\n
  2. 2<\/span>\u00a0\u4f8b\u5b50<\/a><\/span><\/li>\n
  3. 3<\/span>\u00a0\u4f7f\u7528\u5730\u65b9<\/a><\/span><\/li>\n<\/ol>\n
      \n
    1. 4<\/span>\u00a0\u4ee3\u7801<\/a><\/span><\/li>\n
    2. 5<\/span>\u00a0\u6b63\u786e\u4f7f\u7528<\/a><\/span><\/li>\n
    3. 6<\/span>\u00a0\u4f7f\u7528\u65b9\u6cd5<\/a><\/span><\/li>\n<\/ol>\n
        \n
      1. 7<\/span>\u00a0\u8bcd\u5178\u89e3\u91ca<\/a><\/span><\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u4f5c\u7528<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        \u7b80\u5355\u5730\u8bf4\u5c31\u662f\u9632\u6b62\u7f16\u8bd1\u5668\u5bf9\u4ee3\u7801\u8fdb\u884c\u4f18\u5316\u3002\u6bd4\u5982\u5982\u4e0b\u7a0b\u5e8f\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n<\/td>\n
        		\n
        \n
        XBYTE[2]=0x55;<\/code><\/div>\n
        XBYTE[2]=0x56;<\/code><\/div>\n
        XBYTE[2]=0x57;<\/code><\/div>\n
        XBYTE[2]=0x58;<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5bf9\u5916\u90e8\u786c\u4ef6\u800c\u8a00\uff0c\u4e0a\u8ff0\u56db\u6761\u8bed\u53e5\u5206\u522b\u8868\u793a\u4e0d\u540c\u7684\u64cd\u4f5c\uff0c\u4f1a\u4ea7\u751f\u56db\u79cd\u4e0d\u540c\u7684\u52a8\u4f5c\uff0c\u4f46\u662f\u7f16\u8bd1\u5668\u5374\u4f1a\u5bf9\u4e0a\u8ff0\u56db\u6761\u8bed\u53e5\u8fdb\u884c\u4f18\u5316\uff0c\u8ba4\u4e3a\u53ea\u6709XBYTE[2]=0x58\uff08\u5373\u5ffd\u7565\u524d\u4e09\u6761\u8bed\u53e5\uff0c\u53ea\u4ea7\u751f\u4e00\u6761\u673a\u5668\u4ee3\u7801\uff09\u3002\u5982\u679c\u952e\u5165volatile<\/b>\uff0c\u5219\u7f16\u8bd1\u5668\u4f1a\u9010\u4e00\u5730\u8fdb\u884c\u7f16\u8bd1\u5e76\u4ea7\u751f\u76f8\u5e94\u7684\u673a\u5668\u4ee3\u7801\uff08\u4ea7\u751f\u56db\u6761\u4ee3\u7801\uff09\u3002<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u4f8b\u5b50<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        \u7cbe\u786e\u5730\u8bf4\u5c31\u662f\uff0c\u4f18\u5316\u5668\u5728\u7528\u5230\u8fd9\u4e2a\u53d8\u91cf\u65f6\u5fc5\u987b\u6bcf\u6b21\u90fd\u5c0f\u5fc3\u5730\u91cd\u65b0\u8bfb\u53d6\u8fd9\u4e2a\u53d8\u91cf\u7684\u503c\uff0c\u800c\u4e0d\u662f\u4f7f\u7528\u4fdd\u5b58\u5728\u5bc4\u5b58\u5668<\/a>\u91cc\u7684\u5907\u4efd\u3002\u4e0b\u9762\u662fvolatile\u53d8\u91cf\u7684\u51e0\u4e2a\u4f8b\u5b50\uff1a<\/div>\n
        1\uff09\u5e76\u884c\u8bbe\u5907\u7684\u786c\u4ef6\u5bc4\u5b58\u5668\uff08\u5982\uff1a\u72b6\u6001\u5bc4\u5b58\u5668\uff09<\/div>\n
        2\uff09\u4e00\u4e2a\u4e2d\u65ad\u670d\u52a1\u5b50\u7a0b\u5e8f\u4e2d\u4f1a\u8bbf\u95ee\u5230\u7684\u975e\u81ea\u52a8\u53d8\u91cf\uff08Non-automatic variables)<\/div>\n
        3\uff09\u591a\u7ebf\u7a0b\u5e94\u7528\u4e2d\u88ab\u51e0\u4e2a\u4efb\u52a1\u5171\u4eab\u7684\u53d8\u91cf<\/div>\n
        \u8fd9\u662f\u533a\u5206C\u7a0b\u5e8f\u5458\u548c\u5d4c\u5165\u5f0f\u7cfb\u7edf<\/a>\u7a0b\u5e8f\u5458\u7684\u6700\u57fa\u672c\u7684\u95ee\u9898\uff1a\u5d4c\u5165\u5f0f\u7cfb\u7edf\u7a0b\u5e8f\u5458\u7ecf\u5e38\u540c\u786c\u4ef6\u3001\u4e2d\u65ad\u3001RTOS\u7b49\u7b49\u6253\u4ea4\u9053\uff0c\u6240\u6709\u8fd9\u4e9b\u90fd\u8981\u6c42\u4f7f\u7528volatile\u53d8\u91cf\u3002\u4e0d\u61c2\u5f97volatile\u5185\u5bb9\u5c06\u4f1a\u5e26\u6765\u707e\u96be\u3002<\/div>\n
        \u5047\u8bbe\u88ab\u9762\u8bd5\u8005\u6b63\u786e\u5730\u56de\u7b54\u4e86\u8fd9\u4e2a\u95ee\u9898\uff08\u55ef\uff0c\u6000\u7591\u662f\u5426\u4f1a\u662f\u8fd9\u6837\uff09\uff0c\u6211\u5c06\u7a0d\u5fae\u6df1\u7a76\u4e00\u4e0b\uff0c\u770b\u4e00\u4e0b\u8fd9\u5bb6\u4f19\u662f\u4e0d\u662f\u771f\u6b63\u61c2\u5f97volatile\u5b8c\u5168\u7684\u91cd\u8981\u6027\u3002<\/div>\n
        1\uff09\u4e00\u4e2a\u53c2\u6570\u65e2\u53ef\u4ee5\u662fconst\u8fd8\u53ef\u4ee5\u662fvolatile\u5417\uff1f\u89e3\u91ca\u4e3a\u4ec0\u4e48\u3002<\/div>\n
        2\uff09\u4e00\u4e2a\u6307\u9488\u53ef\u4ee5\u662fvolatile \u5417\uff1f\u89e3\u91ca\u4e3a\u4ec0\u4e48\u3002<\/div>\n
        3\uff09\u4e0b\u9762\u7684\u51fd\u6570\u88ab\u7528\u6765\u8ba1\u7b97\u67d0\u4e2a\u6574\u6570\u7684\u5e73\u65b9\uff0c\u5b83\u80fd\u5b9e\u73b0\u9884\u671f\u8bbe\u8ba1\u76ee\u6807\u5417\uff1f\u5982\u679c\u4e0d\u80fd\uff0c\u8bd5\u56de\u7b54\u5b58\u5728\u4ec0\u4e48\u95ee\u9898\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n<\/td>\n
        		\n
        \n
        int<\/code>\u00a0square(<\/code>volatile<\/code>\u00a0int<\/code>\u00a0*ptr)<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0((*ptr)\u00a0*\u00a0(*ptr));<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u4e0b\u9762\u662f\u7b54\u6848\uff1a<\/div>\n
        1\uff09\u662f\u7684\u3002\u4e00\u4e2a\u4f8b\u5b50\u662f\u53ea\u8bfb\u7684\u72b6\u6001\u5bc4\u5b58\u5668<\/a>\u3002\u5b83\u662fvolatile\u56e0\u4e3a\u5b83\u53ef\u80fd\u88ab\u610f\u60f3\u4e0d\u5230\u5730\u6539\u53d8\u3002\u5b83\u662fconst\u56e0\u4e3a\u7a0b\u5e8f\u4e0d\u5e94\u8be5\u8bd5\u56fe\u53bb\u4fee\u6539\u5b83\u3002<\/div>\n
        2\uff09\u662f\u7684\u3002\u5c3d\u7ba1\u8fd9\u5e76\u4e0d\u5f88\u5e38\u89c1\u3002\u4e00\u4e2a\u4f8b\u5b50\u662f\u5f53\u4e00\u4e2a\u4e2d\u65ad\u670d\u52a1\u5b50\u7a0b\u5e8f\u4fee\u6539\u4e00\u4e2a\u6307\u5411\u4e00\u4e2abuffer\u7684\u6307\u9488<\/a>\u65f6\u3002<\/div>\n
        3\uff09\u8fd9\u6bb5\u4ee3\u7801\u662f\u4e2a\u6076\u4f5c\u5267\u3002\u8fd9\u6bb5\u4ee3\u7801\u7684\u76ee\u7684\u662f\u7528\u6765\u8fd4\u6307\u9488*ptr\u6307\u5411\u503c\u7684\u5e73\u65b9\uff0c\u4f46\u662f\uff0c\u7531\u4e8e*ptr\u6307\u5411\u4e00\u4e2avolatile\u578b\u53c2\u6570\uff0c\u7f16\u8bd1\u5668<\/a>\u5c06\u4ea7\u751f\u7c7b\u4f3c\u4e0b\u9762\u7684\u4ee3\u7801\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n<\/td>\n
        		\n
        \n
        int<\/code>\u00a0square(<\/code>volatile<\/code>\u00a0int<\/code>*\u00a0&ptr)<\/code>\/\/\u8fd9\u91cc\u53c2\u6570\u5e94\u8be5\u7533\u660e\u4e3a\u5f15\u7528\uff0c\u4e0d\u7136\u51fd\u6570\u4f53\u91cc\u53ea\u4f1a\u4f7f\u7528\u526f\u672c\uff0c\u5916\u90e8\u6ca1\u6cd5\u66f4\u6539<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0a,b;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>a\u00a0=\u00a0*ptr;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>b\u00a0=\u00a0*ptr;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0a*b;<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u7531\u4e8e*ptr\u7684\u503c\u53ef\u80fd\u5728\u4e24\u6b21\u53d6\u503c\u8bed\u53e5\u4e4b\u95f4\u53d1\u751f\u6539\u53d8\uff0c\u56e0\u6b64a\u548cb\u53ef\u80fd\u662f\u4e0d\u540c\u7684\u3002\u7ed3\u679c\uff0c\u8fd9\u6bb5\u4ee3\u7801\u53ef\u80fd\u8fd4\u56de\u7684\u4e0d\u662f\u4f60\u6240\u671f\u671b\u7684\u5e73\u65b9\u503c\uff01\u6b63\u786e\u7684\u4ee3\u7801\u5982\u4e0b\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n<\/td>\n
        		\n
        \n
        long<\/code>\u00a0square(<\/code>volatile<\/code>\u00a0int<\/code>*ptr)<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0a;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>a\u00a0=\u00a0*ptr;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0a*a;<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u8bb2\u8bb2\u4e2a\u4eba\u7406\u89e3\uff1a<\/div>\n
        \u5173\u952e\u5728\u4e8e\u4e24\u4e2a\u5730\u65b9\uff1a<\/div>\n
        \u2488\u7f16\u8bd1\u5668<\/a>\u7684\u4f18\u5316\uff08\u8bf7\u9ad8\u624b\u5e2e\u6211\u770b\u770b\u4e0b\u9762\u7684\u7406\u89e3\uff09<\/div>\n
        \u5728\u672c\u6b21\u7ebf\u7a0b\u5185\uff0c\u5f53\u8bfb\u53d6\u4e00\u4e2a\u53d8\u91cf\u65f6\uff0c\u4e3a\u63d0\u9ad8\u5b58\u53d6\u901f\u5ea6\uff0c\u7f16\u8bd1\u5668\u4f18\u5316\u65f6\u6709\u65f6\u4f1a\u5148\u628a\u53d8\u91cf\u8bfb\u53d6\u5230\u4e00\u4e2a\u5bc4\u5b58\u5668\u4e2d\uff1b\u4ee5\u540e\u518d\u53d6\u53d8\u91cf\u503c\u65f6\uff0c\u5c31\u76f4\u63a5\u4ece\u5bc4\u5b58\u5668\u4e2d\u53d6\u503c\uff1b<\/div>\n
        \u5f53\u53d8\u91cf\u503c\u5728\u672c\u7ebf\u7a0b\u91cc\u6539\u53d8\u65f6\uff0c\u4f1a\u540c\u65f6\u628a\u53d8\u91cf\u7684\u65b0\u503ccopy\u5230\u8be5\u5bc4\u5b58\u5668\u4e2d\uff0c\u4ee5\u4fbf\u4fdd\u6301\u4e00\u81f4<\/div>\n
        \u5f53\u53d8\u91cf\u5728\u56e0\u522b\u7684\u7ebf\u7a0b\u7b49\u800c\u6539\u53d8\u4e86\u503c\uff0c\u8be5\u5bc4\u5b58\u5668\u7684\u503c\u4e0d\u4f1a\u76f8\u5e94\u6539\u53d8\uff0c\u4ece\u800c\u9020\u6210\u5e94\u7528\u7a0b\u5e8f\u8bfb\u53d6\u7684\u503c\u548c\u5b9e\u9645\u7684\u53d8\u91cf\u503c\u4e0d\u4e00\u81f4<\/div>\n
        \u5f53\u8be5\u5bc4\u5b58\u5668<\/a>\u5728\u56e0\u522b\u7684\u7ebf\u7a0b\u7b49\u800c\u6539\u53d8\u4e86\u503c\uff0c\u539f\u53d8\u91cf\u7684\u503c\u4e0d\u4f1a\u6539\u53d8\uff0c\u4ece\u800c\u9020\u6210\u5e94\u7528\u7a0b\u5e8f\u8bfb\u53d6\u7684\u503c\u548c\u5b9e\u9645\u7684\u53d8\u91cf\u503c\u4e0d\u4e00\u81f4<\/div>\n
        \u4e3e\u4e00\u4e2a\u4e0d\u592a\u51c6\u786e\u7684\u4f8b\u5b50\uff1a<\/div>\n
        \u53d1\u85aa\u8d44\u65f6\uff0c\u4f1a\u8ba1\u6bcf\u6b21\u90fd\u628a\u5458\u5de5\u53eb\u6765\u767b\u8bb0\u4ed6\u4eec\u7684\u94f6\u884c\u5361\u53f7\uff1b\u4e00\u6b21\u4f1a\u8ba1\u4e3a\u4e86\u7701\u4e8b\uff0c\u6ca1\u6709\u5373\u65f6\u767b\u8bb0\uff0c\u7528\u4e86\u4ee5\u524d\u767b\u8bb0\u7684\u94f6\u884c\u5361\u53f7\uff1b\u521a\u597d\u4e00\u4e2a\u5458\u5de5\u7684\u94f6\u884c\u5361\u4e22\u4e86\uff0c\u5df2\u6302\u5931\u8be5\u94f6\u884c\u5361\u53f7\uff1b\u4ece\u800c\u9020\u6210\u8be5\u5458\u5de5\u9886\u4e0d\u5230\u5de5\u8d44<\/div>\n
        \u5458\u5de5 \uff0d\uff0d \u539f\u59cb\u53d8\u91cf\u5730\u5740<\/div>\n
        \u94f6\u884c\u5361\u53f7 \uff0d\uff0d \u539f\u59cb\u53d8\u91cf\u5728\u5bc4\u5b58\u5668\u7684\u5907\u4efd<\/div>\n
        \u2489 \u5728\u4ec0\u4e48\u60c5\u51b5\u4e0b\u4f1a\u51fa\u73b0<\/div>\n
        1\uff09\u5e76\u884c\u8bbe\u5907\u7684\u786c\u4ef6\u5bc4\u5b58\u5668<\/div>\n
        2\uff09\u4e00\u4e2a\u4e2d\u65ad\u670d\u52a1\u5b50\u7a0b\u5e8f\u4e2d\u4f1a\u8bbf\u95ee\u5230\u7684\u975e\u81ea\u52a8\u53d8\u91cf\uff08Non-automatic variables)<\/div>\n
        3\uff09\u591a\u7ebf\u7a0b\u5e94\u7528\u4e2d\u88ab\u51e0\u4e2a\u4efb\u52a1\u5171\u4eab\u7684\u53d8\u91cf<\/div>\n
        \u8865\u5145\uff1avolatile\u5e94\u8be5\u89e3\u91ca\u4e3a\u201c\u76f4\u63a5\u5b58\u53d6\u539f\u59cb\u5185\u5b58\u5730\u5740\u201d\u6bd4\u8f83\u5408\u9002\uff0c\u201c\u6613\u53d8\u7684\u201d\u8fd9\u79cd\u89e3\u91ca\u7b80\u76f4\u6709\u70b9\u8bef\u5bfc\u4eba\uff1b<\/div>\n
        \u201c\u6613\u53d8\u201d\u662f\u56e0\u4e3a\u5916\u5728\u56e0\u7d20\u5f15\u8d77\u7684\uff0c\u50cf\u591a\u7ebf\u7a0b\uff0c\u4e2d\u65ad\u7b49\uff0c\u5e76\u4e0d\u662f\u56e0\u4e3a\u7528volatile\u4fee\u9970\u4e86\u7684\u53d8\u91cf\u5c31\u662f\u201c\u6613\u53d8\u201d\u4e86\uff0c\u5047\u5982\u6ca1\u6709\u5916\u56e0\uff0c\u5373\u4f7f\u7528volatile\u5b9a\u4e49\uff0c\u5b83\u4e5f\u4e0d\u4f1a\u53d8\u5316\uff1b<\/div>\n
        \u800c\u7528volatile\u5b9a\u4e49\u4e4b\u540e\uff0c\u5176\u5b9e\u8fd9\u4e2a\u53d8\u91cf\u5c31\u4e0d\u4f1a\u56e0\u5916\u56e0\u800c\u53d8\u5316\u4e86\uff0c\u53ef\u4ee5\u653e\u5fc3\u4f7f\u7528\u4e86\uff1b \u5927\u5bb6\u770b\u770b\u524d\u9762\u90a3\u79cd\u89e3\u91ca\uff08\u6613\u53d8\u7684\uff09\u662f\u4e0d\u662f\u5728\u8bef\u5bfc\u4eba<\/div>\n
        volatile\u5173\u952e\u5b57<\/a>\u662f\u4e00\u79cd\u7c7b\u578b\u4fee\u9970\u7b26<\/a>\uff0c\u7528\u5b83\u58f0\u660e\u7684\u7c7b\u578b\u53d8\u91cf\u8868\u793a\u53ef\u4ee5\u88ab\u67d0\u4e9b\u7f16\u8bd1\u5668<\/a>\u672a\u77e5\u7684\u56e0\u7d20\u66f4\u6539\uff0c\u6bd4\u5982\uff1a\u64cd\u4f5c\u7cfb\u7edf\u3001\u786c\u4ef6\u6216\u8005\u5176\u5b83\u7ebf\u7a0b\u7b49\u3002\u9047\u5230\u8fd9\u4e2a\u5173\u952e\u5b57\u58f0\u660e\u7684\u53d8\u91cf\uff0c\u7f16\u8bd1\u5668\u5bf9\u8bbf\u95ee\u8be5\u53d8\u91cf\u7684\u4ee3\u7801\u5c31\u4e0d\u518d\u8fdb\u884c\u4f18\u5316\uff0c\u4ece\u800c\u53ef\u4ee5\u63d0\u4f9b\u5bf9\u7279\u6b8a\u5730\u5740\u7684\u7a33\u5b9a\u8bbf\u95ee\u3002<\/div>\n
        \u4f7f\u7528\u8be5\u5173\u952e\u5b57\u7684\u4f8b\u5b50\u5982\u4e0b\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n<\/td>\n
        		\n
        \n
        volatile<\/code>\u00a0int<\/code>\u00a0vint;<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5f53\u8981\u6c42\u4f7f\u7528volatile \u58f0\u660e\u7684\u53d8\u91cf\u7684\u503c\u7684\u65f6\u5019\uff0c\u7cfb\u7edf\u603b\u662f\u91cd\u65b0\u4ece\u5b83\u6240\u5728\u7684\u5185\u5b58\u8bfb\u53d6\u6570\u636e\uff0c\u5373\u4f7f\u5b83\u524d\u9762\u7684\u6307\u4ee4\u521a\u521a\u4ece\u8be5\u5904\u8bfb\u53d6\u8fc7\u6570\u636e\u3002\u800c\u4e14\u8bfb\u53d6\u7684\u6570\u636e\u7acb\u523b\u88ab\u4fdd\u5b58\u3002<\/div>\n
        \u4f8b\u5982\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n<\/td>\n
        		\n
        \n
        volatile<\/code>\u00a0int<\/code>\u00a0i=10;<\/code><\/div>\n
        int<\/code>\u00a0a=i;<\/code><\/div>\n
        \/\/...<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \/\/\u5176\u4ed6\u4ee3\u7801\uff0c\u5e76\u672a\u660e\u786e\u544a\u8bc9\u7f16\u8bd1\u5668<\/a>\uff0c\u5bf9i\u8fdb\u884c\u8fc7\u64cd\u4f5c<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n<\/td>\n
        		\n
        \n
        int<\/code>\u00a0b=i;<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        volatile \u6307\u51fa i\u662f\u968f\u65f6\u53ef\u80fd\u53d1\u751f\u53d8\u5316\u7684\uff0c\u6bcf\u6b21\u4f7f\u7528\u5b83\u7684\u65f6\u5019\u5fc5\u987b\u4ecei\u7684\u5730\u5740\u4e2d\u8bfb\u53d6\uff0c\u56e0\u800c\u7f16\u8bd1\u5668\u751f\u6210\u7684\u6c47\u7f16\u4ee3\u7801\u4f1a\u91cd\u65b0\u4ecei\u7684\u5730\u5740\u8bfb\u53d6\u6570\u636e\u653e\u5728b\u4e2d\u3002\u800c\u4f18\u5316\u505a\u6cd5\u662f\uff0c\u7531\u4e8e\u7f16\u8bd1\u5668\u53d1\u73b0\u4e24\u6b21\u4ecei\u8bfb\u6570\u636e\u7684\u4ee3\u7801\u4e4b\u95f4\u7684\u4ee3\u7801\u6ca1\u6709\u5bf9i\u8fdb\u884c\u8fc7\u64cd\u4f5c\uff0c\u5b83\u4f1a\u81ea\u52a8\u628a\u4e0a\u6b21\u8bfb\u7684\u6570\u636e\u653e\u5728b\u4e2d\u3002\u800c\u4e0d\u662f\u91cd\u65b0\u4ecei\u91cc\u9762\u8bfb\u3002\u8fd9\u6837\u4e00\u6765\uff0c\u5982\u679ci\u662f\u4e00\u4e2a\u5bc4\u5b58\u5668\u53d8\u91cf<\/a>\u6216\u8005\u8868\u793a\u4e00\u4e2a\u7aef\u53e3\u6570\u636e\u5c31\u5bb9\u6613\u51fa\u9519\uff0c\u6240\u4ee5\u8bf4volatile\u53ef\u4ee5\u4fdd\u8bc1\u5bf9\u7279\u6b8a\u5730\u5740\u7684\u7a33\u5b9a\u8bbf\u95ee\u3002<\/div>\n
        \u6ce8\u610f\uff0c\u5728vc6\u4e2d\uff0c\u4e00\u822c\u8c03\u8bd5\u6a21\u5f0f\u6ca1\u6709\u8fdb\u884c\u4ee3\u7801\u4f18\u5316\uff0c\u6240\u4ee5\u8fd9\u4e2a\u5173\u952e\u5b57<\/a>\u7684\u4f5c\u7528\u770b\u4e0d\u51fa\u6765\u3002\u4e0b\u9762\u901a\u8fc7\u63d2\u5165\u6c47\u7f16\u4ee3\u7801\uff0c\u6d4b\u8bd5\u6709\u65e0volatile\u5173\u952e\u5b57\uff0c\u5bf9\u7a0b\u5e8f\u6700\u7ec8\u4ee3\u7801\u7684\u5f71\u54cd\uff1a<\/div>\n
        \u9996\u5148\uff0c\u7528classwizard\u5efa\u4e00\u4e2awin32 console\u5de5\u7a0b\uff0c\u63d2\u5165\u4e00\u4e2avoltest.cpp\u6587\u4ef6\uff0c\u8f93\u5165\u4e0b\u9762\u7684\u4ee3\u7801\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n
        14<\/div>\n
        15<\/div>\n
        16<\/div>\n
        17<\/div>\n
        18<\/div>\n
        19<\/div>\n<\/td>\n
        		\n
        \n
        #include<stdio.h><\/code><\/div>\n
        <\/div>\n
        void<\/code>\u00a0main(<\/code>int<\/code>\u00a0argc,<\/code>char<\/code>\u00a0*argv[])<\/code><\/div>\n
        <\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0i\u00a0=\u00a010;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0a\u00a0=\u00a0i;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>printf<\/code>(<\/code>\"i=%d\"<\/code>,a);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>\/\/\u4e0b\u9762\u6c47\u7f16\u8bed\u53e5\u7684\u4f5c\u7528\u5c31\u662f\u6539\u53d8\u5185\u5b58\u4e2di\u7684\u503c\uff0c\u4f46\u662f\u53c8\u4e0d\u8ba9\u7f16\u8bd1\u5668\u77e5\u9053<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>__asm<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>mov\u00a0dword\u00a0ptr[ebp-4],20h<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0b\u00a0=\u00a0i;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>printf<\/code>(<\/code>\"i=%d\"<\/code>,b);<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u7136\u540e\uff0c\u5728\u8c03\u8bd5\u7248\u672c\u6a21\u5f0f\u8fd0\u884c\u7a0b\u5e8f\uff0c\u8f93\u51fa\u7ed3\u679c\u5982\u4e0b\uff1a<\/div>\n
        i = 10<\/div>\n
        i = 32<\/div>\n
        \u7136\u540e\uff0c\u5728release\u7248\u672c\u6a21\u5f0f\u8fd0\u884c\u7a0b\u5e8f\uff0c\u8f93\u51fa\u7ed3\u679c\u5982\u4e0b\uff1a<\/div>\n
        i = 10<\/div>\n
        i = 10<\/div>\n
        \u8f93\u51fa\u7684\u7ed3\u679c\u660e\u663e\u8868\u660e\uff0crelease\u6a21\u5f0f\u4e0b\uff0c\u7f16\u8bd1\u5668<\/a>\u5bf9\u4ee3\u7801\u8fdb\u884c\u4e86\u4f18\u5316\uff0c\u7b2c\u4e8c\u6b21\u6ca1\u6709\u8f93\u51fa\u6b63\u786e\u7684i\u503c\u3002\u4e0b\u9762\uff0c\u6211\u4eec\u628a i\u7684\u58f0\u660e\u52a0\u4e0avolatile\u5173\u952e\u5b57<\/a>\uff0c\u770b\u770b\u6709\u4ec0\u4e48\u53d8\u5316\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n<\/td>\n
        		\n
        \n
        #include<stdio.h><\/code><\/div>\n
        void<\/code>\u00a0main(<\/code>int<\/code>\u00a0argc,<\/code>char<\/code>\u00a0*argv[])<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>volatile<\/code>\u00a0int<\/code>\u00a0i\u00a0=\u00a010;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0a\u00a0=\u00a0i;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>printf<\/code>(<\/code>\"i=%d\"<\/code>,a);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>__asm<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>`\u00a0\u00a0\u00a0\u00a0mov\u00a0dword\u00a0ptr[ebp-4],20h<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0b\u00a0=\u00a0i;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>printf<\/code>(<\/code>\"i=%d\"<\/code>,b);<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5206\u522b\u5728\u8c03\u8bd5\u7248\u672c\u548crelease\u7248\u672c\u8fd0\u884c\u7a0b\u5e8f\uff0c\u8f93\u51fa\u90fd\u662f\uff1a<\/div>\n
        i = 10<\/div>\n
        i = 32<\/div>\n
        \u8fd9\u8bf4\u660e\u8fd9\u4e2a\u5173\u952e\u5b57<\/a>\u53d1\u6325\u4e86\u5b83\u7684\u4f5c\u7528\uff01<\/div>\n
        \uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d\uff0d<\/div>\n
        volatile\u5bf9\u5e94\u7684\u53d8\u91cf\u53ef\u80fd\u5728\u4f60\u7684\u7a0b\u5e8f\u672c\u8eab\u4e0d\u77e5\u9053\u7684\u60c5\u51b5\u4e0b\u53d1\u751f\u6539\u53d8<\/div>\n
        \u6bd4\u5982\u591a\u7ebf\u7a0b\u7684\u7a0b\u5e8f\uff0c\u5171\u540c\u8bbf\u95ee\u7684\u5185\u5b58\u5f53\u4e2d\uff0c\u591a\u4e2a\u7a0b\u5e8f\u90fd\u53ef\u4ee5\u64cd\u7eb5\u8fd9\u4e2a\u53d8\u91cf<\/div>\n
        \u4f60\u81ea\u5df1\u7684\u7a0b\u5e8f\uff0c\u662f\u65e0\u6cd5\u5224\u5b9a\u4f55\u65f6\u8fd9\u4e2a\u53d8\u91cf\u4f1a\u53d1\u751f\u53d8\u5316<\/div>\n
        \u8fd8\u6bd4\u5982\uff0c\u4ed6\u548c\u4e00\u4e2a\u5916\u90e8\u8bbe\u5907\u7684\u67d0\u4e2a\u72b6\u6001\u5bf9\u5e94\uff0c\u5f53\u5916\u90e8\u8bbe\u5907\u53d1\u751f\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u901a\u8fc7\u9a71\u52a8\u7a0b\u5e8f\u548c\u4e2d\u65ad\u4e8b\u4ef6\uff0c\u7cfb\u7edf\u6539\u53d8\u4e86\u8fd9\u4e2a\u53d8\u91cf\u7684\u6570\u503c\uff0c\u800c\u4f60\u7684\u7a0b\u5e8f\u5e76\u4e0d\u77e5\u9053\u3002<\/div>\n
        \u5bf9\u4e8evolatile\u7c7b\u578b\u7684\u53d8\u91cf\uff0c\u7cfb\u7edf\u6bcf\u6b21\u7528\u5230\u4ed6\u7684\u65f6\u5019\u90fd\u662f\u76f4\u63a5\u4ece\u5bf9\u5e94\u7684\u5185\u5b58\u5f53\u4e2d\u63d0\u53d6\uff0c\u800c\u4e0d\u4f1a\u5229\u7528cache\u5f53\u4e2d\u7684\u539f\u6709\u6570\u503c\uff0c\u4ee5\u9002\u5e94\u5b83\u7684\u672a\u77e5\u4f55\u65f6\u4f1a\u53d1\u751f\u7684\u53d8\u5316\uff0c\u7cfb\u7edf\u5bf9\u8fd9\u79cd\u53d8\u91cf\u7684\u5904\u7406\u4e0d\u4f1a\u505a\u4f18\u5316\u2014\u2014\u663e\u7136\u4e5f\u662f\u56e0\u4e3a\u5b83\u7684\u6570\u503c\u968f\u65f6\u90fd\u53ef\u80fd\u53d8\u5316\u7684\u60c5\u51b5\u3002<\/div>\n
        ——————————————————————————–<\/div>\n
        \u5178\u578b\u7684\u4f8b\u5b50<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n<\/td>\n
        		\n
        \n
        for<\/code>(<\/code>int<\/code>\u00a0i=0;\u00a0i<100000;\u00a0i++);<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u8fd9\u4e2a\u8bed\u53e5\u7528\u6765\u6d4b\u8bd5\u7a7a\u5faa\u73af\u7684\u901f\u5ea6\u7684<\/div>\n
        \u4f46\u662f\u7f16\u8bd1\u5668<\/a>\u80af\u5b9a\u8981\u628a\u5b83\u4f18\u5316\u6389\uff0c\u6839\u672c\u5c31\u4e0d\u6267\u884c<\/div>\n
        \u5982\u679c\u4f60\u5199\u6210<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n<\/td>\n
        		\n
        \n
        for<\/code>(<\/code>volatile<\/code>\u00a0int<\/code>\u00a0i=0;\u00a0i<100000;\u00a0i++);<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5b83\u5c31\u4f1a\u6267\u884c\u4e86<\/div>\n
        volatile\u7684\u672c\u610f\u662f\u201c\u6613\u53d8\u7684\u201d<\/div>\n
        \u7531\u4e8e\u8bbf\u95ee\u5bc4\u5b58\u5668<\/a>\u7684\u901f\u5ea6\u8981\u5feb\u8fc7RAM\uff0c\u6240\u4ee5\u7f16\u8bd1\u5668\u4e00\u822c\u90fd\u4f1a\u4f5c\u51cf\u5c11\u5b58\u53d6\u5916\u90e8RAM\u7684\u4f18\u5316\u3002\u6bd4\u5982\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n
        14<\/div>\n
        15<\/div>\n<\/td>\n
        		\n
        \n
        static<\/code>\u00a0int<\/code>\u00a0i\u00a0=\u00a00;<\/code><\/div>\n
        int<\/code>\u00a0main(<\/code>void<\/code>)<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>\/\/...<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>while<\/code>(1)<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>(i)<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>dosomething();<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n
        \/*Interruptserviceroutine.*\/<\/code><\/div>\n
        void<\/code>\u00a0ISR_2(<\/code>void<\/code>)<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>i=1;<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u7a0b\u5e8f\u7684\u672c\u610f\u662f\u5e0c\u671bISR_2\u4e2d\u65ad\u4ea7\u751f\u65f6\uff0c\u5728main\u5f53\u4e2d\u8c03\u7528dosomething\u51fd\u6570\uff0c\u4f46\u662f\uff0c\u7531\u4e8e\u7f16\u8bd1\u5668\u5224\u65ad\u5728main\u51fd\u6570<\/a>\u91cc\u9762\u6ca1\u6709\u4fee\u6539\u8fc7i\uff0c\u56e0\u6b64<\/div>\n
        \u53ef\u80fd\u53ea\u6267\u884c\u4e00\u6b21\u5bf9\u4ecei\u5230\u67d0\u5bc4\u5b58\u5668<\/a>\u7684\u8bfb\u64cd\u4f5c\uff0c\u7136\u540e\u6bcf\u6b21if\u5224\u65ad\u90fd\u53ea\u4f7f\u7528\u8fd9\u4e2a\u5bc4\u5b58\u5668\u91cc\u9762\u7684\u201ci\u526f\u672c\u201d\uff0c\u5bfc\u81f4dosomething\u6c38\u8fdc\u4e5f\u4e0d\u4f1a\u88ab\u8c03\u7528\u3002\u5982\u679c\u5c06\u53d8\u91cf\u52a0\u4e0avolatile\u4fee\u9970\uff0c\u5219\u7f16\u8bd1\u5668<\/a>\u4fdd\u8bc1\u5bf9\u6b64\u53d8\u91cf\u7684\u8bfb\u5199\u64cd\u4f5c\u90fd\u4e0d\u4f1a\u88ab\u4f18\u5316\uff08\u80af\u5b9a\u6267\u884c\uff09\u3002\u6b64\u4f8b\u4e2di\u4e5f\u5e94\u8be5\u5982\u6b64\u8bf4\u660e\u3002<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u4f7f\u7528\u5730\u65b9<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        \u4e00\u822c\u8bf4\u6765\uff0cvolatile\u7528\u5728\u5982\u4e0b\u7684\u51e0\u4e2a\u5730\u65b9\uff1a<\/div>\n
        1\u3001\u4e2d\u65ad\u670d\u52a1\u7a0b\u5e8f<\/a>\u4e2d\u4fee\u6539\u7684\u4f9b\u5176\u5b83\u7a0b\u5e8f\u68c0\u6d4b\u7684\u53d8\u91cf\u9700\u8981\u52a0volatile\uff1b<\/div>\n
        2\u3001\u591a\u4efb\u52a1\u73af\u5883\u4e0b\u5404\u4efb\u52a1\u95f4\u5171\u4eab\u7684\u6807\u5fd7\u5e94\u8be5\u52a0volatile\uff1b<\/div>\n
        3\u3001\u5b58\u50a8\u5668\u6620\u5c04<\/a>\u7684\u786c\u4ef6\u5bc4\u5b58\u5668\u901a\u5e38\u4e5f\u8981\u52a0volatile\u8bf4\u660e\uff0c\u56e0\u4e3a\u6bcf\u6b21\u5bf9\u5b83\u7684\u8bfb\u5199\u90fd\u53ef\u80fd\u6709\u4e0d\u540c\u610f\u4e49\uff1b<\/div>\n
        \u53e6\u5916\uff0c\u4ee5\u4e0a\u8fd9\u51e0\u79cd\u60c5\u51b5\u7ecf\u5e38\u8fd8\u8981\u540c\u65f6\u8003\u8651\u6570\u636e\u7684\u5b8c\u6574\u6027\uff08\u76f8\u4e92\u5173\u8054\u7684\u51e0\u4e2a\u6807\u5fd7\u8bfb\u4e86\u4e00\u534a\u88ab\u6253\u65ad\u4e86\u91cd\u5199\uff09\uff0c\u57281\u4e2d\u53ef\u4ee5\u901a\u8fc7\u5173\u4e2d\u65ad\u6765\u5b9e\u73b0\uff0c2 \u4e2d\u53ef\u4ee5\u7981\u6b62\u4efb\u52a1\u8c03\u5ea6\uff0c3\u4e2d\u5219\u53ea\u80fd\u4f9d\u9760\u786c\u4ef6\u7684\u826f\u597d\u8bbe\u8ba1\u4e86\u3002<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u4ee3\u7801<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        \u4e0b\u9762\u6211\u4eec\u6765\u4e00\u4e2a\u4e2a\u8bf4\u660e\u3002<\/div>\n
        \u8003\u8651\u4e0b\u9762\u7684\u4ee3\u7801\uff1a<\/div>\n
        \u4ee3\u7801\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n
        14<\/div>\n
        15<\/div>\n
        16<\/div>\n
        17<\/div>\n
        18<\/div>\n<\/td>\n
        		\n
        \n
        classGadget<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>:<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>void<\/code>\u00a0Wait()<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>while<\/code>(!flag_)<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>Sleep\uff081000);<\/code>\/\/sleeps\u00a0for\u00a01000milli\u00a0seconds<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>void<\/code>\u00a0Wakeup()<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>flag_=<\/code>true<\/code>;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/...<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>:<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>bool<\/code>\u00a0flag_;<\/code><\/div>\n
        };<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u4e0a\u9762\u4ee3\u7801\u4e2dGadget::Wait\u7684\u76ee\u7684\u662f\u6bcf\u8fc7\u4e00\u79d2\u949f\u53bb\u68c0\u67e5\u4e00\u4e0bflag_\u6210\u5458\u53d8\u91cf\uff0c\u5f53flag_\u88ab\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u8bbe\u4e3atrue\u65f6\uff0c\u8be5\u51fd\u6570\u624d\u4f1a\u8fd4\u56de\u3002\u81f3\u5c11\u8fd9\u662f\u7a0b\u5e8f\u4f5c\u8005\u7684\u610f\u56fe\uff0c\u7136\u800c\uff0c\u8fd9\u4e2aWait\u51fd\u6570\u662f\u9519\u8bef\u7684\u3002<\/div>\n
        \u5047\u8bbe\u7f16\u8bd1\u5668<\/a>\u53d1\u73b0Sleep\uff081000\uff09\u662f\u8c03\u7528\u4e00\u4e2a\u5916\u90e8\u7684\u5e93\u51fd\u6570\uff0c\u5b83\u4e0d\u4f1a\u6539\u53d8\u6210\u5458\u53d8\u91cfflag_\uff0c\u90a3\u4e48\u7f16\u8bd1\u5668\u5c31\u53ef\u4ee5\u65ad\u5b9a\u5b83\u53ef\u4ee5\u628aflag_\u7f13\u5b58\u5728\u5bc4\u5b58\u5668<\/a>\u4e2d\uff0c\u4ee5\u540e\u53ef\u4ee5\u8bbf\u95ee\u8be5\u5bc4\u5b58\u5668\u6765\u4ee3\u66ff\u8bbf\u95ee\u8f83\u6162\u7684\u4e3b\u677f\u4e0a\u7684\u5185\u5b58\u3002\u8fd9\u5bf9\u4e8e\u5355\u7ebf\u7a0b<\/a>\u4ee3\u7801\u6765\u8bf4\u662f\u4e00\u4e2a\u5f88\u597d\u7684\u4f18\u5316\uff0c\u4f46\u662f\u5728\u73b0\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5b83\u7834\u574f\u4e86\u7a0b\u5e8f\u7684\u6b63\u786e\u6027\uff1a\u5f53\u4f60\u8c03\u7528\u4e86\u67d0\u4e2aGadget\u7684Wait\u51fd\u6570\u540e\uff0c\u5373\u4f7f\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u8c03\u7528\u4e86Wakeup\uff0cWait\u8fd8\u662f\u4f1a\u4e00\u76f4\u5faa\u73af\u4e0b\u53bb\u3002\u8fd9\u662f\u56e0\u4e3aflag_\u7684\u6539\u53d8\u6ca1\u6709\u53cd\u6620\u5230\u7f13\u5b58\u5b83\u7684\u5bc4\u5b58\u5668\u4e2d\u53bb\u3002\u7f16\u8bd1\u5668<\/a>\u7684\u4f18\u5316\u672a\u514d\u6709\u70b9\u592a\u2026\u2026\u4e50\u89c2\u4e86\u3002<\/div>\n
        \u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0c\u628a\u53d8\u91cf\u7f13\u5b58\u5728\u5bc4\u5b58\u5668\u4e2d\u662f\u4e00\u4e2a\u975e\u5e38\u6709\u4ef7\u503c\u7684\u4f18\u5316\u65b9\u6cd5\uff0c\u5982\u679c\u4e0d\u7528\u7684\u8bdd\u5f88\u53ef\u60dc\u3002C\u548cC++\u7ed9\u4f60\u63d0\u4f9b\u4e86\u663e\u5f0f\u7981\u7528\u8fd9\u79cd\u7f13\u5b58\u4f18\u5316\u7684\u673a\u4f1a\u3002\u5982\u679c\u4f60\u58f0\u660e\u53d8\u91cf\u662f\u4f7f\u7528\u4e86volatile\u4fee\u9970\u7b26<\/a>\uff0c\u7f16\u8bd1\u5668\u5c31\u4e0d\u4f1a\u628a\u8fd9\u4e2a\u53d8\u91cf\u7f13\u5b58\u5728\u5bc4\u5b58\u5668\u91cc\u2014\u2014\u6bcf\u6b21\u8bbf\u95ee\u90fd\u5c06\u53bb\u5b58\u53d6\u53d8\u91cf\u5728\u5185\u5b58\u4e2d\u7684\u5b9e\u9645\u4f4d\u7f6e\u3002\u8fd9\u6837\u4f60\u8981\u5bf9Gadget\u7684Wait\/Wakeup\u505a\u7684\u4fee\u6539\u5c31\u662f\u7ed9flag_\u52a0\u4e0a\u6b63\u786e\u7684\u4fee\u9970\uff1a<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n<\/td>\n
        		\n
        \n
        class<\/code>\u00a0Gadget<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>:<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/...as\u00a0above...<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>:<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>volatile<\/code>\u00a0bool<\/code>\u00a0flag_;<\/code><\/div>\n
        };<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5728Java\u4e2d\u8bbe\u7f6e\u53d8\u91cf\u503c\u7684\u64cd\u4f5c\uff0c\u9664\u4e86long\u548cdouble\u7c7b\u578b\u7684\u53d8\u91cf\u5916\u90fd\u662f\u539f\u5b50\u64cd\u4f5c<\/a>\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u5bf9\u4e8e\u53d8\u91cf\u503c\u7684\u7b80\u5355\u8bfb\u5199\u64cd\u4f5c\u6ca1\u6709\u5fc5\u8981\u8fdb\u884c\u540c\u6b65\u3002<\/div>\n
        \u8fd9\u5728JVM 1.2\u4e4b\u524d\uff0cJava\u7684\u5185\u5b58\u6a21\u578b\u5b9e\u73b0\u603b\u662f\u4ece\u4e3b\u5b58\u8bfb\u53d6\u53d8\u91cf\uff0c\u662f\u4e0d\u9700\u8981\u8fdb\u884c\u7279\u522b\u7684\u6ce8\u610f\u7684\u3002\u800c\u968f\u7740JVM\u7684\u6210\u719f\u548c\u4f18\u5316\uff0c\u73b0\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0bvolatile\u5173\u952e\u5b57<\/a>\u7684\u4f7f\u7528\u53d8\u5f97\u975e\u5e38\u91cd\u8981\u3002<\/div>\n
        \u5728\u5f53\u524d\u7684Java\u5185\u5b58\u6a21\u578b\u4e0b\uff0c\u7ebf\u7a0b<\/a>\u53ef\u4ee5\u628a\u53d8\u91cf\u4fdd\u5b58\u5728\u672c\u5730\u5185\u5b58\uff08\u6bd4\u5982\u673a\u5668\u7684\u5bc4\u5b58\u5668\uff09\u4e2d\uff0c\u800c\u4e0d\u662f\u76f4\u63a5\u5728\u4e3b\u5b58\u4e2d\u8fdb\u884c\u8bfb\u5199\u3002\u8fd9\u5c31\u53ef\u80fd\u9020\u6210\u4e00\u4e2a\u7ebf\u7a0b\u5728\u4e3b\u5b58\u4e2d\u4fee\u6539\u4e86\u4e00\u4e2a\u53d8\u91cf\u7684\u503c\uff0c\u800c\u53e6\u5916\u4e00\u4e2a\u7ebf\u7a0b\u8fd8\u7ee7\u7eed\u4f7f\u7528\u5b83\u5728\u5bc4\u5b58\u5668<\/a>\u4e2d\u7684\u53d8\u91cf\u503c\u7684\u62f7\u8d1d\uff0c\u9020\u6210\u6570\u636e\u7684\u4e0d\u4e00\u81f4\u3002<\/div>\n
        \u8981\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u53ea\u9700\u8981\u50cf\u5728\u672c\u7a0b\u5e8f\u4e2d\u7684\u8fd9\u6837\uff0c\u628a\u8be5\u53d8\u91cf\u58f0\u660e\u4e3avolatile\uff08\u4e0d\u7a33\u5b9a\u7684\uff09\u5373\u53ef\uff0c\u8fd9\u5c31\u6307\u793aJVM\uff0c\u8fd9\u4e2a\u53d8\u91cf\u662f\u4e0d\u7a33\u5b9a\u7684\uff0c\u6bcf\u6b21\u4f7f\u7528\u5b83\u90fd\u5230\u4e3b\u5b58\u4e2d\u8fdb\u884c\u8bfb\u53d6\u3002\u4e00\u822c\u8bf4\u6765\uff0c\u591a\u4efb\u52a1\u73af\u5883\u4e0b\u5404\u4efb\u52a1\u95f4\u5171\u4eab\u7684\u6807\u5fd7\u90fd\u5e94\u8be5\u52a0volatile\u4fee\u9970\u3002<\/div>\n
        Volatile\u4fee\u9970\u7684\u6210\u5458\u53d8\u91cf<\/a>\u5728\u6bcf\u6b21\u88ab\u7ebf\u7a0b<\/a>\u8bbf\u95ee\u65f6\uff0c\u90fd\u5f3a\u8feb\u4ece\u5171\u4eab\u5185\u5b58<\/a>\u4e2d\u91cd\u8bfb\u8be5\u6210\u5458\u53d8\u91cf\u7684\u503c\u3002\u800c\u4e14\uff0c\u5f53\u6210\u5458\u53d8\u91cf\u53d1\u751f\u53d8\u5316\u65f6\uff0c\u5f3a\u8feb\u7ebf\u7a0b\u5c06\u53d8\u5316\u503c\u56de\u5199\u5230\u5171\u4eab\u5185\u5b58\u3002\u8fd9\u6837\u5728\u4efb\u4f55\u65f6\u523b\uff0c\u4e24\u4e2a\u4e0d\u540c\u7684\u7ebf\u7a0b\u603b\u662f\u770b\u5230\u67d0\u4e2a\u6210\u5458\u53d8\u91cf\u7684\u540c\u4e00\u4e2a\u503c\u3002<\/div>\n
        Java\u8bed\u8a00<\/a>\u89c4\u8303\u4e2d\u6307\u51fa\uff1a\u4e3a\u4e86\u83b7\u5f97\u6700\u4f73\u901f\u5ea6\uff0c\u5141\u8bb8\u7ebf\u7a0b\u4fdd\u5b58\u5171\u4eab\u6210\u5458\u53d8\u91cf\u7684\u79c1\u6709\u62f7\u8d1d\uff0c\u800c\u4e14\u53ea\u5f53\u7ebf\u7a0b\u8fdb\u5165\u6216\u8005\u79bb\u5f00\u540c\u6b65\u4ee3\u7801\u5757<\/a>\u65f6\u624d\u4e0e\u5171\u4eab\u6210\u5458\u53d8\u91cf\u7684\u539f\u59cb\u503c\u5bf9\u6bd4\u3002<\/div>\n
        \u8fd9\u6837\u5f53\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u4e0e\u67d0\u4e2a\u5bf9\u8c61\u4ea4\u4e92\u65f6\uff0c\u5c31\u5fc5\u987b\u8981\u6ce8\u610f\u5230\u8981\u8ba9\u7ebf\u7a0b\u53ca\u65f6\u7684\u5f97\u5230\u5171\u4eab\u6210\u5458\u53d8\u91cf\u7684\u53d8\u5316\u3002<\/div>\n
        \u800cvolatile\u5173\u952e\u5b57<\/a>\u5c31\u662f\u63d0\u793aJVM\uff1a\u5bf9\u4e8e\u8fd9\u4e2a\u6210\u5458\u53d8\u91cf<\/a>\u4e0d\u80fd\u4fdd\u5b58\u5b83\u7684\u79c1\u6709\u62f7\u8d1d\uff0c\u800c\u5e94\u76f4\u63a5\u4e0e\u5171\u4eab\u6210\u5458\u53d8\u91cf\u4ea4\u4e92\u3002<\/div>\n
        \u4f7f\u7528\u5efa\u8bae\uff1a\u5728\u4e24\u4e2a\u6216\u8005\u66f4\u591a\u7684\u7ebf\u7a0b\u8bbf\u95ee\u7684\u6210\u5458\u53d8\u91cf\u4e0a\u4f7f\u7528volatile\u3002\u5f53\u8981\u8bbf\u95ee\u7684\u53d8\u91cf\u5df2\u5728synchronized\u4ee3\u7801\u5757\u4e2d\uff0c\u6216\u8005\u4e3a\u5e38\u91cf<\/a>\u65f6\uff0c\u4e0d\u5fc5\u4f7f\u7528\u3002<\/div>\n
        \u7531\u4e8e\u4f7f\u7528volatile\u5c4f\u853d\u6389\u4e86JVM\u4e2d\u5fc5\u8981\u7684\u4ee3\u7801\u4f18\u5316<\/a>\uff0c\u6240\u4ee5\u5728\u6548\u7387\u4e0a\u6bd4\u8f83\u4f4e\uff0c\u56e0\u6b64\u4e00\u5b9a\u5728\u5fc5\u8981\u65f6\u624d\u4f7f\u7528\u6b64\u5173\u952e\u5b57<\/a>\u3002<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u6b63\u786e\u4f7f\u7528<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        Java \u8bed\u8a00\u5305\u542b\u4e24\u79cd\u5185\u5728\u7684\u540c\u6b65\u673a\u5236\uff1a\u540c\u6b65\u5757\uff08\u6216\u65b9\u6cd5\uff09\u548c volatile \u53d8\u91cf\u3002\u8fd9\u4e24\u79cd\u673a\u5236\u7684\u63d0\u51fa\u90fd\u662f\u4e3a\u4e86\u5b9e\u73b0\u4ee3\u7801\u7ebf\u7a0b\u7684\u5b89\u5168\u6027\u3002\u5176\u4e2d Volatile\u53d8\u91cf\u7684\u540c\u6b65\u6027\u8f83\u5dee\uff08\u4f46\u6709\u65f6\u5b83\u66f4\u7b80\u5355\u5e76\u4e14\u5f00\u9500\u66f4\u4f4e\uff09\uff0c\u800c\u4e14\u5176\u4f7f\u7528\u4e5f\u66f4\u5bb9\u6613\u51fa\u9519\u3002\u5728\u8fd9\u671f\u7684Java \u7406\u8bba\u4e0e\u5b9e\u8df5<\/i>\u4e2d\uff0cBrian Goetz \u5c06\u4ecb\u7ecd\u51e0\u79cd\u6b63\u786e\u4f7f\u7528 volatile\u53d8\u91cf\u7684\u6a21\u5f0f\uff0c\u5e76\u9488\u5bf9\u5176\u9002\u7528\u6027\u9650\u5236\u63d0\u51fa\u4e00\u4e9b\u5efa\u8bae\u3002<\/div>\n
        Java \u8bed\u8a00\u4e2d\u7684 volatile\u53d8\u91cf\u53ef\u4ee5\u88ab\u770b\u4f5c\u662f\u4e00\u79cd \u201c\u7a0b\u5ea6\u8f83\u8f7b\u7684 synchronized\u201d\uff1b\u4e0e synchronized \u5757\u76f8\u6bd4\uff0cvolatile \u53d8\u91cf\u6240\u9700\u7684\u7f16\u7801\u8f83\u5c11\uff0c\u5e76\u4e14\u8fd0\u884c\u65f6\u5f00\u9500\u4e5f\u8f83\u5c11\uff0c\u4f46\u662f\u5b83\u6240\u80fd\u5b9e\u73b0\u7684\u529f\u80fd\u4e5f\u4ec5\u662f synchronized \u7684\u4e00\u90e8\u5206\u3002\u672c\u6587\u4ecb\u7ecd\u4e86\u51e0\u79cd\u6709\u6548\u4f7f\u7528 volatile\u53d8\u91cf\u7684\u6a21\u5f0f\uff0c\u5e76\u5f3a\u8c03\u4e86\u51e0\u79cd\u4e0d\u9002\u5408\u4f7f\u7528 volatile \u53d8\u91cf\u7684\u60c5\u5f62\u3002<\/div>\n
        \u9501\u63d0\u4f9b\u4e86\u4e24\u79cd\u4e3b\u8981\u7279\u6027\uff1a\u4e92\u65a5\uff08mutual exclusion\uff09<\/i>\u548c\u53ef\u89c1\u6027\uff08visibility\uff09<\/i>\u3002\u4e92\u65a5\u5373\u4e00\u6b21\u53ea\u5141\u8bb8\u4e00\u4e2a\u7ebf\u7a0b<\/a>\u6301\u6709\u67d0\u4e2a\u7279\u5b9a\u7684\u9501\uff0c\u56e0\u6b64\u53ef\u4f7f\u7528\u8be5\u7279\u6027\u5b9e\u73b0\u5bf9\u5171\u4eab\u6570\u636e\u7684\u534f\u8c03\u8bbf\u95ee\u534f\u8bae\uff0c\u8fd9\u6837\uff0c\u4e00\u6b21\u5c31\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u591f\u4f7f\u7528\u8be5\u5171\u4eab\u6570\u636e\u3002\u53ef\u89c1\u6027\u8981\u66f4\u52a0\u590d\u6742\u4e00\u4e9b\uff0c\u5b83\u5fc5\u987b\u786e\u4fdd\u91ca\u653e\u9501\u4e4b\u524d\u5bf9\u5171\u4eab\u6570\u636e\u505a\u51fa\u7684\u66f4\u6539\u5bf9\u4e8e\u968f\u540e\u83b7\u5f97\u8be5\u9501\u7684\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u662f\u53ef\u89c1\u7684 \u2014\u2014 \u5982\u679c\u6ca1\u6709\u540c\u6b65\u673a\u5236\u63d0\u4f9b\u7684\u8fd9\u79cd\u53ef\u89c1\u6027\u4fdd\u8bc1\uff0c\u7ebf\u7a0b\u770b\u5230\u7684\u5171\u4eab\u53d8\u91cf\u53ef\u80fd\u662f\u4fee\u6539\u524d\u7684\u503c\u6216\u4e0d\u4e00\u81f4\u7684\u503c\uff0c\u8fd9\u5c06\u5f15\u53d1\u8bb8\u591a\u4e25\u91cd\u95ee\u9898\u3002<\/div>\n
        Volatile \u53d8\u91cf<\/b><\/div>\n
        Volatile\u53d8\u91cf\u5177\u6709 synchronized \u7684\u53ef\u89c1\u6027\u7279\u6027\uff0c\u4f46\u662f\u4e0d\u5177\u5907\u539f\u5b50\u7279\u6027\u3002\u8fd9\u5c31\u662f\u8bf4\u7ebf\u7a0b\u80fd\u591f\u81ea\u52a8\u53d1\u73b0 volatile\u53d8\u91cf\u7684\u6700\u65b0\u503c\u3002Volatile\u53d8\u91cf\u53ef\u7528\u4e8e\u63d0\u4f9b\u7ebf\u7a0b\u5b89\u5168<\/a>\uff0c\u4f46\u662f\u53ea\u80fd\u5e94\u7528\u4e8e\u975e\u5e38\u6709\u9650\u7684\u4e00\u7ec4\u7528\u4f8b\uff1a\u591a\u4e2a\u53d8\u91cf\u4e4b\u95f4\u6216\u8005\u67d0\u4e2a\u53d8\u91cf\u7684\u5f53\u524d\u503c\u4e0e\u4fee\u6539\u540e\u503c\u4e4b\u95f4\u6ca1\u6709\u7ea6\u675f\u3002\u56e0\u6b64\uff0c\u5355\u72ec\u4f7f\u7528 volatile \u8fd8\u4e0d\u8db3\u4ee5\u5b9e\u73b0\u8ba1\u6570\u5668\u3001\u4e92\u65a5\u9501<\/a>\u6216\u4efb\u4f55\u5177\u6709\u4e0e\u591a\u4e2a\u53d8\u91cf\u76f8\u5173\u7684\u4e0d\u53d8\u5f0f\uff08Invariants\uff09\u7684\u7c7b\uff08\u4f8b\u5982 \u201cstart <=end\u201d\uff09\u3002<\/div>\n
        \u51fa\u4e8e\u7b80\u6613\u6027\u6216\u53ef\u4f38\u7f29\u6027\u7684\u8003\u8651\uff0c\u60a8\u53ef\u80fd\u503e\u5411\u4e8e\u4f7f\u7528 volatile\u53d8\u91cf\u800c\u4e0d\u662f\u9501\u3002\u5f53\u4f7f\u7528 volatile\u53d8\u91cf\u800c\u975e\u9501\u65f6\uff0c\u67d0\u4e9b\u4e60\u60ef\u7528\u6cd5\uff08idiom\uff09\u66f4\u52a0\u6613\u4e8e\u7f16\u7801\u548c\u9605\u8bfb\u3002\u6b64\u5916\uff0cvolatile\u53d8\u91cf\u4e0d\u4f1a\u50cf\u9501\u90a3\u6837\u9020\u6210\u7ebf\u7a0b\u963b\u585e<\/a>\uff0c\u56e0\u6b64\u4e5f\u5f88\u5c11\u9020\u6210\u53ef\u4f38\u7f29\u6027\u95ee\u9898\u3002\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u8bfb\u64cd\u4f5c\u8fdc\u8fdc\u5927\u4e8e\u5199\u64cd\u4f5c\uff0cvolatile\u53d8\u91cf\u8fd8\u53ef\u4ee5\u63d0\u4f9b\u4f18\u4e8e\u9501\u7684\u6027\u80fd\u4f18\u52bf\u3002<\/div>\n
        \u6b63\u786e\u4f7f\u7528 volatile \u53d8\u91cf\u7684\u6761\u4ef6<\/b><\/div>\n
        \u60a8\u53ea\u80fd\u5728\u6709\u9650\u7684\u4e00\u4e9b\u60c5\u5f62\u4e0b\u4f7f\u7528 volatile\u53d8\u91cf\u66ff\u4ee3\u9501\u3002\u8981\u4f7f volatile\u53d8\u91cf\u63d0\u4f9b\u7406\u60f3\u7684\u7ebf\u7a0b\u5b89\u5168<\/a>\uff0c\u5fc5\u987b\u540c\u65f6\u6ee1\u8db3\u4e0b\u9762\u4e24\u4e2a\u6761\u4ef6\uff1a<\/div>\n
        \u25cf \u5bf9\u53d8\u91cf\u7684\u5199\u64cd\u4f5c\u4e0d\u4f9d\u8d56\u4e8e\u5f53\u524d\u503c\u3002<\/div>\n
        \u25cf \u8be5\u53d8\u91cf\u6ca1\u6709\u5305\u542b\u5728\u5177\u6709\u5176\u4ed6\u53d8\u91cf\u7684\u4e0d\u53d8\u5f0f\u4e2d\u3002<\/div>\n
        \u5b9e\u9645\u4e0a\uff0c\u8fd9\u4e9b\u6761\u4ef6\u8868\u660e\uff0c\u53ef\u4ee5\u88ab\u5199\u5165 volatile\u53d8\u91cf\u7684\u8fd9\u4e9b\u6709\u6548\u503c\u72ec\u7acb\u4e8e\u4efb\u4f55\u7a0b\u5e8f\u7684\u72b6\u6001\uff0c\u5305\u62ec\u53d8\u91cf\u7684\u5f53\u524d\u72b6\u6001\u3002<\/div>\n
        \u7b2c\u4e00\u4e2a\u6761\u4ef6\u7684\u9650\u5236\u4f7f volatile\u53d8\u91cf\u4e0d\u80fd\u7528\u4f5c\u7ebf\u7a0b\u5b89\u5168\u8ba1\u6570\u5668\u3002\u867d\u7136\u589e\u91cf\u64cd\u4f5c\uff08x++\uff09\u770b\u4e0a\u53bb\u7c7b\u4f3c\u4e00\u4e2a\u5355\u72ec\u64cd\u4f5c\uff0c\u5b9e\u9645\u4e0a\u5b83\u662f\u4e00\u4e2a\u7531\u8bfb\u53d6\uff0d\u4fee\u6539\uff0d\u5199\u5165\u64cd\u4f5c\u5e8f\u5217\u7ec4\u6210\u7684\u7ec4\u5408\u64cd\u4f5c\uff0c\u5fc5\u987b\u4ee5\u539f\u5b50\u65b9\u5f0f\u6267\u884c\uff0c\u800c volatile \u4e0d\u80fd\u63d0\u4f9b\u5fc5\u987b\u7684\u539f\u5b50\u7279\u6027\u3002\u5b9e\u73b0\u6b63\u786e\u7684\u64cd\u4f5c\u9700\u8981\u4f7f x \u7684\u503c\u5728\u64cd\u4f5c\u671f\u95f4\u4fdd\u6301\u4e0d\u53d8\uff0c\u800c volatile\u53d8\u91cf\u65e0\u6cd5\u5b9e\u73b0\u8fd9\u70b9\u3002\uff08\u7136\u800c\uff0c\u5982\u679c\u5c06\u503c\u8c03\u6574\u4e3a\u53ea\u4ece\u5355\u4e2a\u7ebf\u7a0b\u5199\u5165\uff0c\u90a3\u4e48\u53ef\u4ee5\u5ffd\u7565\u7b2c\u4e00\u4e2a\u6761\u4ef6\u3002\uff09<\/div>\n
        \u5927\u591a\u6570\u7f16\u7a0b\u60c5\u5f62\u90fd\u4f1a\u4e0e\u8fd9\u4e24\u4e2a\u6761\u4ef6\u7684\u5176\u4e2d\u4e4b\u4e00\u51b2\u7a81\uff0c\u4f7f\u5f97 volatile\u53d8\u91cf\u4e0d\u80fd\u50cf synchronized \u90a3\u6837\u666e\u904d\u9002\u7528\u4e8e\u5b9e\u73b0\u7ebf\u7a0b\u5b89\u5168<\/a>\u3002\u6e05\u5355 1 \u663e\u793a\u4e86\u4e00\u4e2a\u975e\u7ebf\u7a0b\u5b89\u5168\u7684\u6570\u503c\u8303\u56f4\u7c7b\u3002\u5b83\u5305\u542b\u4e86\u4e00\u4e2a\u4e0d\u53d8\u5f0f \u2014\u2014 \u4e0b\u754c\u603b\u662f\u5c0f\u4e8e\u6216\u7b49\u4e8e\u4e0a\u754c\u3002<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u4f7f\u7528\u65b9\u6cd5<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        \u6e05\u5355 1. \u975e<\/b>\u7ebf\u7a0b\u5b89\u5168<\/a>\u7684\u6570\u503c\u8303\u56f4\u7c7b<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n
        14<\/div>\n
        15<\/div>\n
        16<\/div>\n
        17<\/div>\n
        18<\/div>\n<\/td>\n
        		\n
        \n
        @NotThreadSafe<\/code><\/div>\n
        public<\/code>\u00a0class<\/code>\u00a0NumberRange{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>\u00a0int<\/code>\u00a0lower,upper;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0int<\/code>\u00a0getLower(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0lower;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0int<\/code>\u00a0getUpper(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0upper;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0setLower(<\/code>int<\/code>\u00a0value){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>(value\u00a0>\u00a0upper)\u00a0<\/code>throw<\/code>\u00a0new<\/code>\u00a0IllegalArgumentException(...);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>lower\u00a0=\u00a0value;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0setUpper(<\/code>int<\/code>\u00a0value){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>(value\u00a0<\u00a0lower)\u00a0<\/code>throw<\/code>\u00a0new<\/code>\u00a0IllegalArgumentException(...);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>upper\u00a0=\u00a0value;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u8fd9\u79cd\u65b9\u5f0f\u9650\u5236\u4e86\u8303\u56f4\u7684\u72b6\u6001\u53d8\u91cf\uff0c\u56e0\u6b64\u5c06 lower \u548c upper \u5b57\u6bb5\u5b9a\u4e49\u4e3a volatile \u7c7b\u578b\u4e0d\u80fd\u591f\u5145\u5206\u5b9e\u73b0\u7c7b\u7684\u7ebf\u7a0b\u5b89\u5168\uff1b\u4ece\u800c\u4ecd\u7136\u9700\u8981\u4f7f\u7528\u540c\u6b65\u3002\u5426\u5219\uff0c\u5982\u679c\u51d1\u5de7\u4e24\u4e2a\u7ebf\u7a0b\u5728\u540c\u4e00\u65f6\u95f4\u4f7f\u7528\u4e0d\u4e00\u81f4\u7684\u503c\u6267\u884c setLower \u548c setUpper \u7684\u8bdd\uff0c\u5219\u4f1a\u4f7f\u8303\u56f4\u5904\u4e8e\u4e0d\u4e00\u81f4\u7684\u72b6\u6001\u3002\u4f8b\u5982\uff0c\u5982\u679c\u521d\u59cb\u72b6\u6001\u662f (0,5\uff09\uff0c\u540c\u4e00\u65f6\u95f4\u5185\uff0c\u7ebf\u7a0b A \u8c03\u7528 setLower\u2477 \u5e76\u4e14\u7ebf\u7a0b B \u8c03\u7528 setUpper\u2476\uff0c\u663e\u7136\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u4ea4\u53c9\u5b58\u5165\u7684\u503c\u662f\u4e0d\u7b26\u5408\u6761\u4ef6\u7684\uff0c\u90a3\u4e48\u4e24\u4e2a\u7ebf\u7a0b\u90fd\u4f1a\u901a\u8fc7\u7528\u4e8e\u4fdd\u62a4\u4e0d\u53d8\u5f0f\u7684\u68c0\u67e5\uff0c\u4f7f\u5f97\u6700\u540e\u7684\u8303\u56f4\u503c\u662f \uff084,3\uff09 \u2014\u2014 \u4e00\u4e2a\u65e0\u6548\u503c\u3002\u81f3\u4e8e\u9488\u5bf9\u8303\u56f4\u7684\u5176\u4ed6\u64cd\u4f5c\uff0c\u6211\u4eec\u9700\u8981\u4f7f setLower() \u548c setUpper() \u64cd\u4f5c\u539f\u5b50\u5316 \u2014\u2014 \u800c\u5c06\u5b57\u6bb5\u5b9a\u4e49\u4e3a volatile \u7c7b\u578b\u662f\u65e0\u6cd5\u5b9e\u73b0\u8fd9\u4e00\u76ee\u7684\u7684\u3002<\/div>\n
        \u6027\u80fd\u8003\u8651<\/b><\/div>\n
        \u4f7f\u7528 volatile\u53d8\u91cf\u7684\u4e3b\u8981\u539f\u56e0\u662f\u5176\u7b80\u6613\u6027\uff1a\u5728\u67d0\u4e9b\u60c5\u5f62\u4e0b\uff0c\u4f7f\u7528 volatile \u53d8\u91cf\u8981\u6bd4\u4f7f\u7528\u76f8\u5e94\u7684\u9501\u7b80\u5355\u5f97\u591a\u3002\u4f7f\u7528 volatile\u53d8\u91cf\u6b21\u8981\u539f\u56e0\u662f\u5176\u6027\u80fd\uff1a\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0cvolatile \u53d8\u91cf\u540c\u6b65\u673a\u5236\u7684\u6027\u80fd\u8981\u4f18\u4e8e\u9501\u3002<\/div>\n
        \u5f88\u96be\u505a\u51fa\u51c6\u786e\u3001\u5168\u9762\u7684\u8bc4\u4ef7\uff0c\u4f8b\u5982 \u201cX \u603b\u662f\u6bd4 Y \u5feb\u201d\uff0c\u5c24\u5176\u662f\u5bf9 JJVM \u5185\u5728\u7684\u64cd\u4f5c\u800c\u8a00\u3002\uff08\u4f8b\u5982\uff0c\u67d0\u4e9b\u60c5\u51b5\u4e0b JVM \u4e5f\u8bb8\u80fd\u591f\u5b8c\u5168\u5220\u9664\u9501\u673a\u5236\uff0c\u8fd9\u4f7f\u5f97\u6211\u4eec\u96be\u4ee5\u62bd\u8c61\u5730\u6bd4\u8f83 volatile\u548c synchronized \u7684\u5f00\u9500\u3002\uff09\u5c31\u662f\u8bf4\uff0c\u5728\u76ee\u524d\u5927\u591a\u6570\u7684\u5904\u7406\u5668\u67b6\u6784\u4e0a\uff0cvolatile \u8bfb\u64cd\u4f5c\u5f00\u9500\u975e\u5e38\u4f4e \u2014\u2014 \u51e0\u4e4e\u548c\u975e volatile \u8bfb\u64cd\u4f5c\u4e00\u6837\u3002\u800c volatile \u5199\u64cd\u4f5c\u7684\u5f00\u9500\u8981\u6bd4\u975e volatile \u5199\u64cd\u4f5c\u591a\u5f88\u591a\uff0c\u56e0\u4e3a\u8981\u4fdd\u8bc1\u53ef\u89c1\u6027\u9700\u8981\u5b9e\u73b0\u5185\u5b58\u754c\u5b9a\uff08Memory Fence\uff09\uff0c\u5373\u4fbf\u5982\u6b64\uff0cvolatile \u7684\u603b\u5f00\u9500\u4ecd\u7136\u8981\u6bd4\u9501\u83b7\u53d6\u4f4e\u3002<\/div>\n
        volatile \u64cd\u4f5c\u4e0d\u4f1a\u50cf\u9501\u4e00\u6837\u9020\u6210\u963b\u585e\uff0c\u56e0\u6b64\uff0c\u5728\u80fd\u591f\u5b89\u5168\u4f7f\u7528 volatile \u7684\u60c5\u51b5\u4e0b\uff0cvolatile \u53ef\u4ee5\u63d0\u4f9b\u4e00\u4e9b\u4f18\u4e8e\u9501\u7684\u53ef\u4f38\u7f29\u7279\u6027\u3002\u5982\u679c\u8bfb\u64cd\u4f5c\u7684\u6b21\u6570\u8981\u8fdc\u8fdc\u8d85\u8fc7\u5199\u64cd\u4f5c\uff0c\u4e0e\u9501\u76f8\u6bd4\uff0cvolatile\u53d8\u91cf\u901a\u5e38\u80fd\u591f\u51cf\u5c11\u540c\u6b65\u7684\u6027\u80fd\u5f00\u9500\u3002<\/div>\n
        \u6b63\u786e\u4f7f\u7528 volatile \u7684\u6a21\u5f0f<\/b><\/div>\n
        \u5f88\u591a\u5e76\u53d1\u6027\u4e13\u5bb6\u4e8b\u5b9e\u4e0a\u5f80\u5f80\u5f15\u5bfc\u7528\u6237\u8fdc\u79bb volatile\u53d8\u91cf\uff0c\u56e0\u4e3a\u4f7f\u7528\u5b83\u4eec\u8981\u6bd4\u4f7f\u7528\u9501\u66f4\u52a0\u5bb9\u6613\u51fa\u9519\u3002\u7136\u800c\uff0c\u5982\u679c\u8c28\u614e\u5730\u9075\u5faa\u4e00\u4e9b\u826f\u597d\u5b9a\u4e49\u7684\u6a21\u5f0f\uff0c\u5c31\u80fd\u591f\u5728\u5f88\u591a\u573a\u5408\u5185\u5b89\u5168\u5730\u4f7f\u7528 volatile \u53d8\u91cf\u3002\u8981\u59cb\u7ec8\u7262\u8bb0\u4f7f\u7528 volatile \u7684\u9650\u5236 \u2014\u2014 \u53ea\u6709\u5728\u72b6\u6001\u771f\u6b63\u72ec\u7acb\u4e8e\u7a0b\u5e8f\u5185\u5176\u4ed6\u5185\u5bb9\u65f6\u624d\u80fd\u4f7f\u7528 volatile \u2014\u2014 \u8fd9\u6761\u89c4\u5219\u80fd\u591f\u907f\u514d\u5c06\u8fd9\u4e9b\u6a21\u5f0f\u6269\u5c55\u5230\u4e0d\u5b89\u5168\u7684\u7528\u4f8b\u3002<\/div>\n
        \u6a21\u5f0f #1\uff1a\u72b6\u6001\u6807\u5fd7<\/b>\u4e5f\u8bb8\u5b9e\u73b0 volatile \u53d8\u91cf\u7684\u89c4\u8303\u4f7f\u7528\u4ec5\u4ec5\u662f\u4f7f\u7528\u4e00\u4e2a\u5e03\u5c14\u72b6\u6001\u6807\u5fd7\uff0c\u7528\u4e8e\u6307\u793a\u53d1\u751f\u4e86\u4e00\u4e2a\u91cd\u8981\u7684\u4e00\u6b21\u6027\u4e8b\u4ef6\uff0c\u4f8b\u5982\u5b8c\u6210\u521d\u59cb\u5316\u6216\u8bf7\u6c42\u505c\u673a\u3002<\/div>\n
        \u5f88\u591a\u5e94\u7528\u7a0b\u5e8f\u5305\u542b\u4e86\u4e00\u79cd\u63a7\u5236\u7ed3\u6784\uff0c\u5f62\u5f0f\u4e3a \u201c\u5728\u8fd8\u6ca1\u6709\u51c6\u5907\u597d\u505c\u6b62\u7a0b\u5e8f\u65f6\u518d\u6267\u884c\u4e00\u4e9b\u5de5\u4f5c\u201d\uff0c\u5982\u6e05\u5355 2 \u6240\u793a\uff1a<\/div>\n
        \u6e05\u5355 2. \u5c06 volatile<\/b>\u53d8\u91cf\u4f5c\u4e3a\u72b6\u6001\u6807\u5fd7<\/a>\u4f7f\u7528<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n<\/td>\n
        		\n
        \n
        volatile<\/code>\u00a0boolean\u00a0shutdownRequested;<\/code><\/div>\n
        ...<\/code><\/div>\n
        public<\/code>\u00a0void<\/code>\u00a0shutdown()<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>shutdownRequested=<\/code>true<\/code>;<\/code><\/div>\n
        }<\/code><\/div>\n
        public<\/code>\u00a0void<\/code>\u00a0doWork()<\/code><\/div>\n
        {<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>while<\/code>(!shutdownRequested)<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/dostuff<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5f88\u53ef\u80fd\u4f1a\u4ece\u5faa\u73af\u5916\u90e8\u8c03\u7528 shutdown() \u65b9\u6cd5 \u2014\u2014 \u5373\u5728\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u4e2d \u2014\u2014 \u56e0\u6b64\uff0c\u9700\u8981\u6267\u884c\u67d0\u79cd\u540c\u6b65\u6765\u786e\u4fdd\u6b63\u786e\u5b9e\u73b0 shutdownRequested \u53d8\u91cf\u7684\u53ef\u89c1\u6027\u3002\uff08\u53ef\u80fd\u4f1a\u4ece JMX \u4fa6\u542c\u7a0b\u5e8f\u3001GUI \u4e8b\u4ef6\u7ebf\u7a0b\u4e2d\u7684\u64cd\u4f5c\u4fa6\u542c\u7a0b\u5e8f\u3001\u901a\u8fc7 RMI \u3001\u901a\u8fc7\u4e00\u4e2a Web \u670d\u52a1\u7b49\u8c03\u7528\uff09\u3002\u7136\u800c\uff0c\u4f7f\u7528 synchronized \u5757\u7f16\u5199\u5faa\u73af\u8981\u6bd4\u4f7f\u7528\u6e05\u5355 2 \u6240\u793a\u7684 volatile\u72b6\u6001\u6807\u5fd7<\/a>\u7f16\u5199\u9ebb\u70e6\u5f88\u591a\u3002\u7531\u4e8e volatile \u7b80\u5316\u4e86\u7f16\u7801\uff0c\u5e76\u4e14\u72b6\u6001\u6807\u5fd7\u5e76\u4e0d\u4f9d\u8d56\u4e8e\u7a0b\u5e8f\u5185\u4efb\u4f55\u5176\u4ed6\u72b6\u6001\uff0c\u56e0\u6b64\u6b64\u5904\u975e\u5e38\u9002\u5408\u4f7f\u7528 volatile\u3002<\/div>\n
        \u8fd9\u79cd\u7c7b\u578b\u7684\u72b6\u6001\u6807\u8bb0\u7684\u4e00\u4e2a\u516c\u5171\u7279\u6027\u662f\uff1a\u901a\u5e38\u53ea\u6709\u4e00\u79cd\u72b6\u6001\u8f6c\u6362\uff1bshutdownRequested \u6807\u5fd7\u4ece false \u8f6c\u6362\u4e3a true\uff0c\u7136\u540e\u7a0b\u5e8f\u505c\u6b62\u3002\u8fd9\u79cd\u6a21\u5f0f\u53ef\u4ee5\u6269\u5c55\u5230\u6765\u56de\u8f6c\u6362\u7684\u72b6\u6001\u6807\u5fd7\uff0c\u4f46\u662f\u53ea\u6709\u5728\u8f6c\u6362\u5468\u671f\u4e0d\u88ab\u5bdf\u89c9\u7684\u60c5\u51b5\u4e0b\u624d\u80fd\u6269\u5c55\uff08\u4ece false \u5230 true\uff0c\u518d\u8f6c\u6362\u5230 false\uff09\u3002\u6b64\u5916\uff0c\u8fd8\u9700\u8981\u67d0\u4e9b\u539f\u5b50\u72b6\u6001\u8f6c\u6362\u673a\u5236\uff0c\u4f8b\u5982\u539f\u5b50\u53d8\u91cf\u3002<\/div>\n
        \u6a21\u5f0f #2\uff1a\u4e00\u6b21\u6027\u5b89\u5168\u53d1\u5e03\uff08one-time safe publication\uff09<\/b><\/div>\n
        \u7f3a\u4e4f\u540c\u6b65\u4f1a\u5bfc\u81f4\u65e0\u6cd5\u5b9e\u73b0\u53ef\u89c1\u6027\uff0c\u8fd9\u4f7f\u5f97\u786e\u5b9a\u4f55\u65f6\u5199\u5165\u5bf9\u8c61\u5f15\u7528\u800c\u4e0d\u662f\u539f\u8bed<\/a>\u503c\u53d8\u5f97\u66f4\u52a0\u56f0\u96be\u3002\u5728\u7f3a\u4e4f\u540c\u6b65\u7684\u60c5\u51b5\u4e0b\uff0c\u53ef\u80fd\u4f1a\u9047\u5230\u67d0\u4e2a\u5bf9\u8c61\u5f15\u7528\u7684\u66f4\u65b0\u503c\uff08\u7531\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5199\u5165\uff09\u548c\u8be5\u5bf9\u8c61\u72b6\u6001\u7684\u65e7\u503c\u540c\u65f6\u5b58\u5728\u3002\uff08\u8fd9\u5c31\u662f\u9020\u6210\u8457\u540d\u7684\u53cc\u91cd\u68c0\u67e5\u9501\u5b9a\uff08double-checked-locking\uff09\u95ee\u9898\u7684\u6839\u6e90\uff0c\u5176\u4e2d\u5bf9\u8c61\u5f15\u7528\u5728\u6ca1\u6709\u540c\u6b65\u7684\u60c5\u51b5\u4e0b\u8fdb\u884c\u8bfb\u64cd\u4f5c\uff0c\u4ea7\u751f\u7684\u95ee\u9898\u662f\u60a8\u53ef\u80fd\u4f1a\u770b\u5230\u4e00\u4e2a\u66f4\u65b0\u7684\u5f15\u7528\uff0c\u4f46\u662f\u4ecd\u7136\u4f1a\u901a\u8fc7\u8be5\u5f15\u7528\u770b\u5230\u4e0d\u5b8c\u5168\u6784\u9020\u7684\u5bf9\u8c61\uff09\u3002<\/div>\n
        \u5b9e\u73b0\u5b89\u5168\u53d1\u5e03\u5bf9\u8c61\u7684\u4e00\u79cd\u6280\u672f\u5c31\u662f\u5c06\u5bf9\u8c61\u5f15\u7528\u5b9a\u4e49\u4e3a volatile \u7c7b\u578b\u3002\u6e05\u5355 3 \u5c55\u793a\u4e86\u4e00\u4e2a\u793a\u4f8b\uff0c\u5176\u4e2d\u540e\u53f0\u7ebf\u7a0b\u5728\u542f\u52a8\u9636\u6bb5\u4ece\u6570\u636e\u5e93\u52a0\u8f7d\u4e00\u4e9b\u6570\u636e\u3002\u5176\u4ed6\u4ee3\u7801\u5728\u80fd\u591f\u5229\u7528\u8fd9\u4e9b\u6570\u636e\u65f6\uff0c\u5728\u4f7f\u7528\u4e4b\u524d\u5c06\u68c0\u67e5\u8fd9\u4e9b\u6570\u636e\u662f\u5426\u66fe\u7ecf\u53d1\u5e03\u8fc7\u3002<\/div>\n
        \u6e05\u5355 3. \u5c06 volatile<\/b>\u53d8\u91cf\u7528\u4e8e\u4e00\u6b21\u6027\u5b89\u5168\u53d1\u5e03<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n
        14<\/div>\n
        15<\/div>\n
        16<\/div>\n
        17<\/div>\n<\/td>\n
        		\n
        \n
        public<\/code>\u00a0class<\/code>\u00a0BackgroundFloobleLoader{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0volatile<\/code>\u00a0Flooble\u00a0theFlooble;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0initInBackground(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/dolotsofstuff<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>theFlooble\u00a0=\u00a0newFlooble();<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/this\u00a0is\u00a0the\u00a0only\u00a0write\u00a0to\u00a0theFlooble<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n
        public<\/code>\u00a0class<\/code>\u00a0SomeOtherClass{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0doWork(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>while<\/code>(<\/code>true<\/code>){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/dosomestuff...<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/usetheFlooble,butonlyifitisready<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>(floobleLoader.theFlooble!=<\/code>null<\/code>)doSomething(floobleLoader.theFlooble);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u5982\u679c theFlooble \u5f15\u7528\u4e0d\u662f volatile \u7c7b\u578b\uff0cdoWork() \u4e2d\u7684\u4ee3\u7801\u5728\u89e3\u9664\u5bf9 theFlooble \u7684\u5f15\u7528\u65f6\uff0c\u5c06\u4f1a\u5f97\u5230\u4e00\u4e2a\u4e0d\u5b8c\u5168\u6784\u9020\u7684 Flooble\u3002<\/div>\n
        \u8be5\u6a21\u5f0f\u7684\u4e00\u4e2a\u5fc5\u8981\u6761\u4ef6\u662f\uff1a\u88ab\u53d1\u5e03\u7684\u5bf9\u8c61\u5fc5\u987b\u662f\u7ebf\u7a0b\u5b89\u5168<\/a>\u7684\uff0c\u6216\u8005\u662f\u6709\u6548\u7684\u4e0d\u53ef\u53d8\u5bf9\u8c61\uff08\u6709\u6548\u4e0d\u53ef\u53d8\u610f\u5473\u7740\u5bf9\u8c61\u7684\u72b6\u6001\u5728\u53d1\u5e03\u4e4b\u540e\u6c38\u8fdc\u4e0d\u4f1a\u88ab\u4fee\u6539\uff09\u3002volatile \u7c7b\u578b\u7684\u5f15\u7528\u53ef\u4ee5\u786e\u4fdd\u5bf9\u8c61\u7684\u53d1\u5e03\u5f62\u5f0f\u7684\u53ef\u89c1\u6027\uff0c\u4f46\u662f\u5982\u679c\u5bf9\u8c61\u7684\u72b6\u6001\u5728\u53d1\u5e03\u540e\u5c06\u53d1\u751f\u66f4\u6539\uff0c\u90a3\u4e48\u5c31\u9700\u8981\u989d\u5916\u7684\u540c\u6b65\u3002<\/div>\n
        \u6a21\u5f0f #3\uff1a\u72ec\u7acb\u89c2\u5bdf\uff08independent observation\uff09<\/b><\/div>\n
        \u5b89\u5168\u4f7f\u7528 volatile \u7684\u53e6\u4e00\u79cd\u7b80\u5355\u6a21\u5f0f\u662f\uff1a\u5b9a\u671f \u201c\u53d1\u5e03\u201d \u89c2\u5bdf\u7ed3\u679c\u4f9b\u7a0b\u5e8f\u5185\u90e8\u4f7f\u7528\u3002\u4f8b\u5982\uff0c\u5047\u8bbe\u6709\u4e00\u79cd\u73af\u5883\u4f20\u611f\u5668\u80fd\u591f\u611f\u89c9\u73af\u5883\u6e29\u5ea6\u3002\u4e00\u4e2a\u540e\u53f0\u7ebf\u7a0b\u53ef\u80fd\u4f1a\u6bcf\u9694\u51e0\u79d2\u8bfb\u53d6\u4e00\u6b21\u8be5\u4f20\u611f\u5668\uff0c\u5e76\u66f4\u65b0\u5305\u542b\u5f53\u524d\u6587\u6863\u7684 volatile \u53d8\u91cf\u3002\u7136\u540e\uff0c\u5176\u4ed6\u7ebf\u7a0b<\/a>\u53ef\u4ee5\u8bfb\u53d6\u8fd9\u4e2a\u53d8\u91cf\uff0c\u4ece\u800c\u968f\u65f6\u80fd\u591f\u770b\u5230\u6700\u65b0\u7684\u6e29\u5ea6\u503c\u3002<\/div>\n
        \u4f7f\u7528\u8be5\u6a21\u5f0f\u7684\u53e6\u4e00\u79cd\u5e94\u7528\u7a0b\u5e8f\u5c31\u662f\u6536\u96c6\u7a0b\u5e8f\u7684\u7edf\u8ba1\u4fe1\u606f\u3002\u6e05\u5355 4 \u5c55\u793a\u4e86\u8eab\u4efd\u9a8c\u8bc1<\/a>\u673a\u5236\u5982\u4f55\u8bb0\u5fc6\u6700\u8fd1\u4e00\u6b21\u767b\u5f55\u7684\u7528\u6237\u7684\u540d\u5b57\u3002\u5c06\u53cd\u590d\u4f7f\u7528 lastUser \u5f15\u7528\u6765\u53d1\u5e03\u503c\uff0c\u4ee5\u4f9b\u7a0b\u5e8f\u7684\u5176\u4ed6\u90e8\u5206\u4f7f\u7528\u3002<\/div>\n
        \u6e05\u5355 4. \u5c06 volatile\u53d8\u91cf\u7528\u4e8e\u591a\u4e2a\u72ec\u7acb\u89c2\u5bdf\u7ed3\u679c\u7684\u53d1\u5e03<\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n<\/td>\n
        		\n
        \n
        public<\/code>\u00a0class<\/code>\u00a0UserManager{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0volatile<\/code>\u00a0String\u00a0lastUser;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0boolean<\/code>\u00a0authenticate(String\u00a0user,\u00a0String\u00a0password){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>boolean<\/code>\u00a0valid\u00a0=\u00a0passwordIsValid(user,\u00a0password);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>(valid){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>User\u00a0u\u00a0=\u00a0<\/code>new<\/code>\u00a0User();<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>activeUsers.add(u);<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>lastUser\u00a0=\u00a0user;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0valid;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u8be5\u6a21\u5f0f\u662f\u524d\u9762\u6a21\u5f0f\u7684\u6269\u5c55\uff1b\u5c06\u67d0\u4e2a\u503c\u53d1\u5e03\u4ee5\u5728\u7a0b\u5e8f\u5185\u7684\u5176\u4ed6\u5730\u65b9\u4f7f\u7528\uff0c\u4f46\u662f\u4e0e\u4e00\u6b21\u6027\u4e8b\u4ef6\u7684\u53d1\u5e03\u4e0d\u540c\uff0c\u8fd9\u662f\u4e00\u7cfb\u5217\u72ec\u7acb\u4e8b\u4ef6\u3002\u8fd9\u4e2a\u6a21\u5f0f\u8981\u6c42\u88ab\u53d1\u5e03\u7684\u503c\u662f\u6709\u6548\u4e0d\u53ef\u53d8\u7684 \u2014\u2014 \u5373\u503c\u7684\u72b6\u6001\u5728\u53d1\u5e03\u540e\u4e0d\u4f1a\u66f4\u6539\u3002\u4f7f\u7528\u8be5\u503c\u7684\u4ee3\u7801\u9700\u8981\u6e05\u695a\u8be5\u503c\u53ef\u80fd\u968f\u65f6\u53d1\u751f\u53d8\u5316\u3002<\/div>\n
        \u6a21\u5f0f #4\uff1a\u201cvolatile bean\u201d \u6a21\u5f0f<\/b><\/div>\n
        volatile bean \u6a21\u5f0f\u9002\u7528\u4e8e\u5c06 JavaBeans \u4f5c\u4e3a\u201c\u8363\u8a89\u7ed3\u6784\u201d\u4f7f\u7528\u7684\u6846\u67b6\u3002\u5728 volatile bean \u6a21\u5f0f\u4e2d\uff0cJavaBean \u88ab\u7528\u4f5c\u4e00\u7ec4\u5177\u6709 getter \u548c\/\u6216 setter \u65b9\u6cd5 \u7684\u72ec\u7acb\u5c5e\u6027\u7684\u5bb9\u5668\u3002volatile bean \u6a21\u5f0f\u7684\u57fa\u672c\u539f\u7406\u662f\uff1a\u5f88\u591a\u6846\u67b6\u4e3a\u6613\u53d8\u6570\u636e\u7684\u6301\u6709\u8005\uff08\u4f8b\u5982 HttpSession\uff09\u63d0\u4f9b\u4e86\u5bb9\u5668\uff0c\u4f46\u662f\u653e\u5165\u8fd9\u4e9b\u5bb9\u5668\u4e2d\u7684\u5bf9\u8c61\u5fc5\u987b\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002<\/div>\n
        \u5728 volatile bean \u6a21\u5f0f\u4e2d\uff0cJavaBean \u7684\u6240\u6709\u6570\u636e\u6210\u5458<\/a>\u90fd\u662f volatile \u7c7b\u578b\u7684\uff0c\u5e76\u4e14 getter \u548c setter \u65b9\u6cd5\u5fc5\u987b\u975e\u5e38\u666e\u901a \u2014\u2014 \u9664\u4e86\u83b7\u53d6\u6216\u8bbe\u7f6e\u76f8\u5e94\u7684\u5c5e\u6027\u5916\uff0c\u4e0d\u80fd\u5305\u542b\u4efb\u4f55\u903b\u8f91\u3002\u6b64\u5916\uff0c\u5bf9\u4e8e\u5bf9\u8c61\u5f15\u7528<\/a>\u7684\u6570\u636e\u6210\u5458\uff0c\u5f15\u7528\u7684\u5bf9\u8c61\u5fc5\u987b\u662f\u6709\u6548\u4e0d\u53ef\u53d8\u7684\u3002\uff08\u8fd9\u5c06\u7981\u6b62\u5177\u6709\u6570\u7ec4<\/a>\u503c\u7684\u5c5e\u6027\uff0c\u56e0\u4e3a\u5f53\u6570\u7ec4\u5f15\u7528\u88ab\u58f0\u660e\u4e3a volatile \u65f6\uff0c\u53ea\u6709\u5f15\u7528\u800c\u4e0d\u662f\u6570\u7ec4\u672c\u8eab\u5177\u6709 volatile \u8bed\u4e49\uff09\u3002\u5bf9\u4e8e\u4efb\u4f55 volatile\u53d8\u91cf\uff0c\u4e0d\u53d8\u5f0f\u6216\u7ea6\u675f\u90fd\u4e0d\u80fd\u5305\u542b JavaBean \u5c5e\u6027\u3002\u6e05\u5355 5 \u4e2d\u7684\u793a\u4f8b\u5c55\u793a\u4e86\u9075\u5b88 volatile bean \u6a21\u5f0f\u7684 JavaBean\uff1a<\/div>\n
        \u6e05\u5355 5. \u9075\u5b88 volatile bean \u6a21\u5f0f\u7684 Person \u5bf9\u8c61<\/b><\/div>\n
        <\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n
        14<\/div>\n
        15<\/div>\n
        16<\/div>\n
        17<\/div>\n
        18<\/div>\n
        19<\/div>\n
        20<\/div>\n
        21<\/div>\n
        22<\/div>\n
        23<\/div>\n
        24<\/div>\n<\/td>\n
        		\n
        \n
        @ThreadSafe<\/code><\/div>\n
        public<\/code>\u00a0class<\/code>\u00a0Person{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>\u00a0volatile<\/code>\u00a0String\u00a0firstName;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>\u00a0volatile<\/code>\u00a0String\u00a0lastName;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>\u00a0volatile<\/code>\u00a0intage;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0String\u00a0getFirstName(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0firstName;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0String\u00a0getLastName(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0lastName;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0int<\/code>\u00a0getAge(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0age;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0setFirstName(String\u00a0firstName){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>this<\/code>.firstName\u00a0=\u00a0firstName;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0setLastName(String\u00a0lastName){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>this<\/code>.lastName\u00a0=\u00a0lastName;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0void<\/code>\u00a0setAge(<\/code>int<\/code>\u00a0age){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>this<\/code>.age\u00a0=\u00a0age;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        volatile \u7684\u9ad8\u7ea7\u6a21\u5f0f<\/b><\/div>\n
        \u524d\u9762\u51e0\u8282\u4ecb\u7ecd\u7684\u6a21\u5f0f\u6db5\u76d6\u4e86\u5927\u90e8\u5206\u7684\u57fa\u672c\u7528\u4f8b\uff0c\u5728\u8fd9\u4e9b\u6a21\u5f0f\u4e2d\u4f7f\u7528 volatile \u975e\u5e38\u6709\u7528\u5e76\u4e14\u7b80\u5355\u3002\u8fd9\u4e00\u8282\u5c06\u4ecb\u7ecd\u4e00\u79cd\u66f4\u52a0\u9ad8\u7ea7\u7684\u6a21\u5f0f\uff0c\u5728\u8be5\u6a21\u5f0f\u4e2d\uff0cvolatile \u5c06\u63d0\u4f9b\u6027\u80fd\u6216\u53ef\u4f38\u7f29\u6027\u4f18\u52bf\u3002<\/div>\n
        volatile \u5e94\u7528\u7684\u7684\u9ad8\u7ea7\u6a21\u5f0f\u975e\u5e38\u8106\u5f31\u3002\u56e0\u6b64\uff0c\u5fc5\u987b\u5bf9\u5047\u8bbe\u7684\u6761\u4ef6\u4ed4\u7ec6\u8bc1\u660e\uff0c\u5e76\u4e14\u8fd9\u4e9b\u6a21\u5f0f\u88ab\u4e25\u683c\u5730\u5c01\u88c5\u4e86\u8d77\u6765\uff0c\u56e0\u4e3a\u5373\u4f7f\u975e\u5e38\u5c0f\u7684\u66f4\u6539\u4e5f\u4f1a\u635f\u574f\u60a8\u7684\u4ee3\u7801\uff01\u540c\u6837\uff0c\u4f7f\u7528\u66f4\u9ad8\u7ea7\u7684 volatile \u7528\u4f8b\u7684\u539f\u56e0\u662f\u5b83\u80fd\u591f\u63d0\u5347\u6027\u80fd\uff0c\u786e\u4fdd\u5728\u5f00\u59cb\u5e94\u7528\u9ad8\u7ea7\u6a21\u5f0f\u4e4b\u524d\uff0c\u771f\u6b63\u786e\u5b9a\u9700\u8981\u5b9e\u73b0\u8fd9\u79cd\u6027\u80fd\u83b7\u76ca\u3002\u9700\u8981\u5bf9\u8fd9\u4e9b\u6a21\u5f0f\u8fdb\u884c\u6743\u8861\uff0c\u653e\u5f03\u53ef\u8bfb\u6027\u6216\u53ef\u7ef4\u62a4\u6027\u6765\u6362\u53d6\u53ef\u80fd\u7684\u6027\u80fd\u6536\u76ca \u2014\u2014 \u5982\u679c\u60a8\u4e0d\u9700\u8981\u63d0\u5347\u6027\u80fd\uff08\u6216\u8005\u4e0d\u80fd\u591f\u901a\u8fc7\u4e00\u4e2a\u4e25\u683c\u7684\u6d4b\u8bd5\u7a0b\u5e8f<\/a>\u8bc1\u660e\u60a8\u9700\u8981\u5b83\uff09\uff0c\u90a3\u4e48\u8fd9\u5f88\u53ef\u80fd\u662f\u4e00\u6b21\u7cdf\u7cd5\u7684\u4ea4\u6613\uff0c\u56e0\u4e3a\u60a8\u5f88\u53ef\u80fd\u4f1a\u5f97\u4e0d\u507f\u5931\uff0c\u6362\u6765\u7684\u4e1c\u897f\u8981\u6bd4\u653e\u5f03\u7684\u4e1c\u897f\u4ef7\u503c\u66f4\u4f4e\u3002<\/div>\n
        \u6a21\u5f0f #5\uff1a\u5f00\u9500\u8f83\u4f4e\u7684\u8bfb\uff0d\u5199\u9501\u7b56\u7565<\/b><\/div>\n
        \u76ee\u524d\u4e3a\u6b62\uff0c\u60a8\u5e94\u8be5\u4e86\u89e3\u4e86 volatile \u7684\u529f\u80fd\u8fd8\u4e0d\u8db3\u4ee5\u5b9e\u73b0\u8ba1\u6570\u5668\u3002\u56e0\u4e3a ++x \u5b9e\u9645\u4e0a\u662f\u4e09\u79cd\u64cd\u4f5c\uff08\u8bfb\u3001\u6dfb\u52a0\u3001\u5b58\u50a8\uff09\u7684\u7b80\u5355\u7ec4\u5408\uff0c\u5982\u679c\u591a\u4e2a\u7ebf\u7a0b\u51d1\u5de7\u8bd5\u56fe\u540c\u65f6\u5bf9 volatile \u8ba1\u6570\u5668\u6267\u884c\u589e\u91cf\u64cd\u4f5c\uff0c\u90a3\u4e48\u5b83\u7684\u66f4\u65b0\u503c\u6709\u53ef\u80fd\u4f1a\u4e22\u5931\u3002<\/div>\n
        \u7136\u800c\uff0c\u5982\u679c\u8bfb\u64cd\u4f5c\u8fdc\u8fdc\u8d85\u8fc7\u5199\u64cd\u4f5c\uff0c\u60a8\u53ef\u4ee5\u7ed3\u5408\u4f7f\u7528\u5185\u90e8\u9501\u548c volatile\u53d8\u91cf\u6765\u51cf\u5c11\u516c\u5171\u4ee3\u7801\u8def\u5f84\u7684\u5f00\u9500\u3002\u6e05\u5355 6 \u4e2d\u663e\u793a\u7684\u7ebf\u7a0b\u5b89\u5168<\/a>\u7684\u8ba1\u6570\u5668\u4f7f\u7528 synchronized \u786e\u4fdd\u589e\u91cf\u64cd\u4f5c\u662f\u539f\u5b50\u7684\uff0c\u5e76\u4f7f\u7528 volatile \u4fdd\u8bc1\u5f53\u524d\u7ed3\u679c\u7684\u53ef\u89c1\u6027\u3002\u5982\u679c\u66f4\u65b0\u4e0d\u9891\u7e41\u7684\u8bdd\uff0c\u8be5\u65b9\u6cd5\u53ef\u5b9e\u73b0\u66f4\u597d\u7684\u6027\u80fd\uff0c\u56e0\u4e3a\u8bfb\u8def\u5f84\u7684\u5f00\u9500\u4ec5\u4ec5\u6d89\u53ca volatile \u8bfb\u64cd\u4f5c\uff0c\u8fd9\u901a\u5e38\u8981\u4f18\u4e8e\u4e00\u4e2a\u65e0\u7ade\u4e89\u7684\u9501\u83b7\u53d6\u7684\u5f00\u9500\u3002<\/div>\n
        \u6e05\u5355 6. \u7ed3\u5408\u4f7f\u7528 volatile \u548c synchronized \u5b9e\u73b0 \u201c\u5f00\u9500\u8f83\u4f4e\u7684\u8bfb\uff0d\u5199\u9501\u201d<\/b><\/div>\n
        \n
        \n\n\n\n
        \n
        1<\/div>\n
        2<\/div>\n
        3<\/div>\n
        4<\/div>\n
        5<\/div>\n
        6<\/div>\n
        7<\/div>\n
        8<\/div>\n
        9<\/div>\n
        10<\/div>\n
        11<\/div>\n
        12<\/div>\n
        13<\/div>\n<\/td>\n
        		\n
        \n
        @ThreadSafe<\/code><\/div>\n
        public<\/code>\u00a0class<\/code>\u00a0CheesyCounter{<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>\/\/Employs\u00a0the\u00a0cheap\u00a0read-write\u00a0lock\u00a0trick<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>\/\/All\u00a0mutative\u00a0operations\u00a0MUST\u00a0be\u00a0done\u00a0with\u00a0the\u00a0'this'\u00a0lock\u00a0held<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>@GuardedBy<\/code>(<\/code>\"this\"<\/code>)<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>private<\/code>\u00a0volatile<\/code>\u00a0int<\/code>\u00a0value;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0int<\/code>\u00a0getValue(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0value;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>public<\/code>\u00a0synchronized<\/code>\u00a0int<\/code>\u00a0increment(){<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a0value++;<\/code><\/div>\n
        \u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
        }<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n
        \u4e4b\u6240\u4ee5\u5c06\u8fd9\u79cd\u6280\u672f\u79f0\u4e4b\u4e3a \u201c\u5f00\u9500\u8f83\u4f4e\u7684\u8bfb\uff0d\u5199\u9501\u201d \u662f\u56e0\u4e3a\u60a8\u4f7f\u7528\u4e86\u4e0d\u540c\u7684\u540c\u6b65\u673a\u5236\u8fdb\u884c\u8bfb\u5199\u64cd\u4f5c\u3002\u56e0\u4e3a\u672c\u4f8b\u4e2d\u7684\u5199\u64cd\u4f5c\u8fdd\u53cd\u4e86\u4f7f\u7528 volatile \u7684\u7b2c\u4e00\u4e2a\u6761\u4ef6\uff0c\u56e0\u6b64\u4e0d\u80fd\u4f7f\u7528 volatile \u5b89\u5168\u5730\u5b9e\u73b0\u8ba1\u6570\u5668 \u2014\u2014 \u60a8\u5fc5\u987b\u4f7f\u7528\u9501\u3002\u7136\u800c\uff0c\u60a8\u53ef\u4ee5\u5728\u8bfb\u64cd\u4f5c\u4e2d\u4f7f\u7528 volatile \u786e\u4fdd\u5f53\u524d\u503c\u7684\u53ef\u89c1\u6027<\/i>\uff0c\u56e0\u6b64\u53ef\u4ee5\u4f7f\u7528\u9501\u8fdb\u884c\u6240\u6709\u53d8\u5316\u7684\u64cd\u4f5c\uff0c\u4f7f\u7528 volatile \u8fdb\u884c\u53ea\u8bfb\u64cd\u4f5c\u3002\u5176\u4e2d\uff0c\u9501\u4e00\u6b21\u53ea\u5141\u8bb8\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u503c\uff0cvolatile \u5141\u8bb8\u591a\u4e2a\u7ebf\u7a0b\u6267\u884c\u8bfb\u64cd\u4f5c\uff0c\u56e0\u6b64\u5f53\u4f7f\u7528 volatile \u4fdd\u8bc1\u8bfb\u4ee3\u7801\u8def\u5f84\u65f6\uff0c\u8981\u6bd4\u4f7f\u7528\u9501\u6267\u884c\u5168\u90e8\u4ee3\u7801\u8def\u5f84\u83b7\u5f97\u66f4\u9ad8\u7684\u5171\u4eab\u5ea6 \u2014\u2014 \u5c31\u50cf\u8bfb\uff0d\u5199\u64cd\u4f5c\u4e00\u6837\u3002\u7136\u800c\uff0c\u8981\u968f\u65f6\u7262\u8bb0\u8fd9\u79cd\u6a21\u5f0f\u7684\u5f31\u70b9\uff1a\u5982\u679c\u8d85\u8d8a\u4e86\u8be5\u6a21\u5f0f\u7684\u6700\u57fa\u672c\u5e94\u7528\uff0c\u7ed3\u5408\u8fd9\u4e24\u4e2a\u7ade\u4e89\u7684\u540c\u6b65\u673a\u5236\u5c06\u53d8\u5f97\u975e\u5e38\u56f0\u96be\u3002<\/div>\n
        \u7ed3\u675f\u8bed<\/b><\/div>\n
        \u4e0e\u9501\u76f8\u6bd4\uff0cVolatile\u53d8\u91cf\u662f\u4e00\u79cd\u975e\u5e38\u7b80\u5355\u4f46\u540c\u65f6\u53c8\u975e\u5e38\u8106\u5f31\u7684\u540c\u6b65\u673a\u5236\uff0c\u5b83\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u5c06\u63d0\u4f9b\u4f18\u4e8e\u9501\u7684\u6027\u80fd\u548c\u4f38\u7f29\u6027\u3002\u5982\u679c\u4e25\u683c\u9075\u5faa volatile \u7684\u4f7f\u7528\u6761\u4ef6 \u2014\u2014 \u5373\u53d8\u91cf\u771f\u6b63\u72ec\u7acb\u4e8e\u5176\u4ed6\u53d8\u91cf\u548c\u81ea\u5df1\u4ee5\u524d\u7684\u503c \u2014\u2014 \u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u53ef\u4ee5\u4f7f\u7528 volatile \u4ee3\u66ff synchronized \u6765\u7b80\u5316\u4ee3\u7801\u3002\u7136\u800c\uff0c\u4f7f\u7528 volatile \u7684\u4ee3\u7801\u5f80\u5f80\u6bd4\u4f7f\u7528\u9501\u7684\u4ee3\u7801\u66f4\u52a0\u5bb9\u6613\u51fa\u9519\u3002\u672c\u6587\u4ecb\u7ecd\u7684\u6a21\u5f0f\u6db5\u76d6\u4e86\u53ef\u4ee5\u4f7f\u7528 volatile \u4ee3\u66ff synchronized \u7684\u6700\u5e38\u89c1\u7684\u4e00\u4e9b\u7528\u4f8b\u3002\u9075\u5faa\u8fd9\u4e9b\u6a21\u5f0f\uff08\u6ce8\u610f\u4f7f\u7528\u65f6\u4e0d\u8981\u8d85\u8fc7\u5404\u81ea\u7684\u9650\u5236\uff09\u53ef\u4ee5\u5e2e\u52a9\u60a8\u5b89\u5168\u5730\u5b9e\u73b0\u5927\u591a\u6570\u7528\u4f8b\uff0c\u4f7f\u7528 volatile\u53d8\u91cf\u83b7\u5f97\u66f4\u4f73\u6027\u80fd\u3002<\/div>\n
        <\/a><\/a><\/a><\/div>\n
        \n

        \u8bcd\u5178\u89e3\u91ca<\/h2>\n

        \u7f16\u8f91<\/a><\/p>\n<\/div>\n

        \u5f62\u5bb9\u8bcd a.<\/b><\/div>\n
        1. \uff08\u6db2\u4f53\u7b49\uff09\u6613\u6325\u53d1\u7684<\/div>\n
        Gasoline is volatile.<\/div>\n
        \u6c7d\u6cb9\u662f\u6613\u6325\u53d1\u7684\u3002<\/div>\n
        \u2489 \u6613\u53d1\u4f5c\u7684\uff1b\u7206\u70b8\u6027\u7684<\/div>\n
        The situation in that area was tense,dangerous and volatile.<\/div>\n
        \u8be5\u5730\u533a\u7684\u5c40\u52bf\u7d27\u5f20\u3001\u5371\u9669\uff0c\u4e14\u6709\u4e00\u89e6\u5373\u53d1\u4e4b\u52bf\u3002<\/div>\n
        \u248a \u6613\u53d8\u7684\uff1b\u53cd\u590d\u65e0\u5e38\u7684\uff1b\u8f7b\u6d6e\u7684<\/div>\n
        \u248b \u6d3b\u6cfc\u7684\uff1b\u8f7b\u5feb\u7684<\/div>\n
        \u248c \u98de\u901d\u7684\uff1b\u77ed\u6682\u7684<\/div>\n","protected":false},"excerpt":{"rendered":"

        \u7f16\u8f91 volatile\u662f\u4e00\u4e2a\u7c7b\u578b\u4fee\u9970\u7b26\uff08<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[118],"class_list":["post-826","post","type-post","status-publish","format-standard","hentry","tag-02-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/826","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=826"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/826\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=826"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=826"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}