{"id":5259,"date":"2021-05-23T14:00:45","date_gmt":"2021-05-23T06:00:45","guid":{"rendered":"https:\/\/damogame.cn\/wordpress\/?p=5259"},"modified":"2021-05-23T14:00:45","modified_gmt":"2021-05-23T06:00:45","slug":"%e6%b7%b1%e5%85%a5linux-c-c-timer%e5%ae%9a%e6%97%b6%e5%99%a8%e7%9a%84%e5%ae%9e%e7%8e%b0%e6%a0%b8%e5%bf%83%e5%8e%9f%e7%90%86","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/5259","title":{"rendered":"\u6df1\u5165Linux C\/C++ Timer\u5b9a\u65f6\u5668\u7684\u5b9e\u73b0\u6838\u5fc3\u539f\u7406"},"content":{"rendered":"

\u539f\u6587\u5730\u5740<\/a><\/p>\n

 <\/p>\n

<\/div>\n
\n
\n

\u6211\u66fe\u4ee5\u4e3a\u50cf\u5b9a\u65f6\u5668\u8fd9\u6837\u57fa\u7840\u7684\u529f\u80fd\uff0c\u64cd\u4f5c\u7cfb\u7edf\u4f1a\u6709\u4e00\u4e2a\u5b8c\u5907\u7684\u5b9e\u73b0\u3002\u5f53\u9700\u8981\u5f00\u542f\u4e00\u4e2a\u5b9a\u65f6\u4efb\u52a1\u7684\u65f6\u5019\uff0c\u4f1a\u6709\u4e00\u4e2a\u4f18\u96c5\u7684\u3001\u5982\u4e0b\u5f62\u5f0f\u7684\u63a5\u53e3\uff1a<\/p>\n

typedef void (*callback)(void*);\r\nvoid setTimeout(unsigned int second,callback cb\uff0cvoid* arg);<\/pre>\n
 <\/p>\n
\u53ef\u662f\u4e8b\u4e0e\u613f\u8fdd\uff0cLinux\u4e0b\u4e0d\u5b58\u5728\u8fd9\u6837\u7684\u63a5\u53e3\u3002<\/a><\/p>\n
\n
\u5b9a\u65f6\u5668\u7684\u5b9e\u73b0\u539f\u7406<\/strong><\/h1>\n
\u5b9a\u65f6\u5668\u7684\u5b9e\u73b0\u4f9d\u8d56\u7684\u662fCPU\u65f6\u949f\u4e2d\u65ad\uff0c\u65f6\u949f\u4e2d\u65ad\u7684\u7cbe\u5ea6\u5c31\u51b3\u5b9a\u5b9a\u65f6\u5668\u7cbe\u5ea6\u7684\u6781\u9650\u3002\u4e00\u4e2a\u65f6\u949f\u4e2d\u65ad\u6e90\u5982\u4f55\u5b9e\u73b0\u591a\u4e2a\u5b9a\u65f6\u5668\u5462\uff1f\u5bf9\u4e8e\u5185\u6838\uff0c\u7b80\u5355\u6765\u8bf4\u5c31\u662f\u7528\u7279\u5b9a\u7684\u6570\u636e\u7ed3\u6784\u7ba1\u7406\u4f17\u591a\u7684\u5b9a\u65f6\u5668\uff0c\u5728\u65f6\u949f\u4e2d\u65ad\u5904\u7406\u4e2d\u5224\u65ad\u54ea\u4e9b\u5b9a\u65f6\u5668\u8d85\u65f6\uff0c\u7136\u540e\u6267\u884c\u8d85\u65f6\u5904\u7406\u52a8\u4f5c\u3002\u800c\u7528\u6237\u7a7a\u95f4\u7a0b\u5e8f\u4e0d\u76f4\u63a5\u611f\u77e5CPU\u65f6\u949f\u4e2d\u65ad\uff0c\u901a\u8fc7\u611f\u77e5\u5185\u6838\u7684\u4fe1\u53f7\u3001IO\u4e8b\u4ef6\u3001\u8c03\u5ea6\uff0c\u95f4\u63a5\u4f9d\u8d56\u65f6\u949f\u4e2d\u65ad\u3002\u7528\u8f6f\u4ef6\u6765\u5b9e\u73b0\u52a8\u6001\u5b9a\u65f6\u5668\u5e38\u7528\u6570\u636e\u7ed3\u6784\u6709\uff1a\u65f6\u95f4\u8f6e\u3001\u6700\u5c0f\u5806\u548c\u7ea2\u9ed1\u6811\u3002\u4e0b\u9762\u5c31\u662f\u4e00\u4e9b\u77e5\u540d\u7684\u5b9e\u73b0\uff1a<\/p>\n
Hierarchy \u65f6\u95f4\u8f6e\u7b97\u6cd5\uff1aLinux\u5185\u6838<\/p>\n
\u7ea2\u9ed1\u6811\u6700\u5c0f\u5806\u7b97\u6cd5\uff1aAsio C++ Library\u6216nginx<\/p>\n
 <\/p><\/blockquote>\n<\/div>\n
Linux\u4e0a\u7684\u5b9a\u65f6\u51fd\u6570<\/h1>\n
\u8981\u60f3\u4f7f\u7528\u4e0a\u9762\u90a3\u6837\u7684\u5b9a\u65f6\u5668\u529f\u80fd\uff0c\u6211\u4eec\u5fc5\u987b\u5229\u7528Linux\u4e0a\u73b0\u6709\u7684\u5b9a\u65f6\u901a\u77e5\u51fd\u6570\uff0c\u5c01\u88c5\u4e00\u4e2a\u5b9a\u65f6\u5668\u3002Linux\u4e0a\u7684\u5b9a\u65f6\u901a\u77e5\u51fd\u6570\u4e94\u82b1\u516b\u95e8\uff0c\u8981\u5c01\u88c5\u6211\u4eec\u81ea\u5df1\u7684\u5b9a\u65f6\u5668\uff0c\u9996\u5148\u9700\u8981\u9009\u7528\u4e00\u4e2a\u5b9a\u65f6\u901a\u77e5\u7684\u51fd\u6570\u3002\u67e5\u9605\u8d44\u6599\u6574\u7406\u51fa\u4e86Linux\u4e0a\u6240\u6709\u7684\u5b9a\u65f6\u51fd\u6570\uff0c\u5982\u4e0b\u8868\uff1a<\/p>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n
Function<\/th>\nType<\/th>\nPrecision<\/th>\nRemark<\/th>\n<\/tr>\n<\/thead>\n
sleep(3)<\/td>\nunsigned int<\/td>\nsecond<\/td>\n<\/td>\n<\/tr>\n
usleep(3)<\/td>\nuseconds_t<\/td>\nmicrosecond<\/td>\n<\/td>\n<\/tr>\n
nanosleep(2)<\/td>\nstruct timespec<\/td>\nnanosecond<\/td>\n<\/td>\n<\/tr>\n
clock_nanosleep(2)<\/td>\nstruct timespec<\/td>\nnanosecond<\/td>\nIt differs in allowing the caller to select the clock against which the sleep interval is to be measured, and in allowingthe sleep interval to be specified as either an absolute or a relative value.<\/td>\n<\/tr>\n
alarm(2)<\/td>\nunsigned int<\/td>\nsecond<\/td>\nSIGALRM<\/td>\n<\/tr>\n
setitimer(2)<\/td>\nstruct itimerval<\/td>\nmicrosecond<\/td>\nSIGALRM<\/td>\n<\/tr>\n
timer_settime(2)<\/td>\nstruct itimerspec<\/td>\nnanosecond<\/td>\nnotify method : struct sigevent<\/td>\n<\/tr>\n
Timerfd API<\/td>\nFile descriptor<\/td>\nnanosecond<\/td>\nFrom linux kernel 2.6.25<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u524d\u56db\u4e2a\u51fd\u6570\u6bd4\u8f83\u9e21\u808b\uff0c\u4f1a\u8ba9\u8c03\u7528\u7ebf\u7a0b\u6302\u8d77\uff0c\u539f\u5730\u7b49\u5f85\u5b9a\u65f6\u5668\u8d85\u65f6\uff0c\u5426\u5b9a\u3002<\/p>\n
alarm()\u548csetitimer()\uff0c\u5b83\u4eec\u7684\u901a\u77e5\u673a\u5236\u91c7\u7528\u4e86\u4fe1\u53f7SIGALRM\uff0c\u7531\u4e8eSIGALRM\u4fe1\u53f7\u4e0d\u53ef\u9760\uff0c\u4f1a\u9020\u6210\u8d85\u65f6\u901a\u77e5\u4e0d\u53ef\u9760\uff0c\u800c\u4e14\u591a\u7ebf\u7a0b\u4e2d\u5904\u7406\u4fe1\u53f7\u4e5f\u662f\u4e00\u4e2a\u9ebb\u70e6\u4e8b\uff0c\u4e5f\u4e0d\u8003\u8651\u3002<\/p>\n
timer_create()\/timer_settime()\u7cfb\u5217\u51fd\u6570\u662fPOSIX\u89c4\u5b9a\uff0c\u7cbe\u5ea6\u8fbe\u5230\u7eb3\u79d2\u7ea7\uff0c\u63d0\u4f9b\u4e86\u4e00\u4e2a\u6570\u636e\u7ed3\u6784struct sigevent<\/code>\u53ef\u4ee5\u6307\u5b9a\u4e00\u4e2a\u5b9e\u65f6\u4fe1\u53f7\u4f5c\u4e3a\u901a\u77e5\u4fe1\u53f7\uff0c\u540c\u65f6\u4e5f\u53ef\u4ee5\u8bbe\u7f6e\u7ebf\u7a0bID\uff0c\u5c06\u4fe1\u53f7\u4f20\u9012\u5230\u6307\u5b9a\u7684\u7ebf\u7a0b\u3002\u76f8\u6bd4\u524d\u4e24\u4e2a\u51fd\u6570\uff0c\u6709\u4e86\u4e0d\u5c0f\u7684\u6539\u8fdb\uff0c\u53ef\u4ee5\u4f5c\u4e3a\u4e00\u4e2a\u5907\u9009\u7684\u5b9e\u73b0\uff0c\u4f46\u662f\u53ef\u4ee5\u9884\u89c1\u5230\u5c01\u88c5\u8d77\u6765\u4e0d\u4f1a\u5f88\u8f7b\u677e\u3002\u6b64\u5916\u4f7f\u7528\u6b64\u7cfb\u5217\u7684\u51fd\u6570\uff0c\u9700\u8981\u94fe\u63a5librt\u5e93\u3002<\/p>\n
\u4e8b\u5b9e\u4e0a\uff0c\u6211\u4eec\u9057\u6f0f\u6389\u4e86\u51e0\u4e2a\u540c\u6837\u5177\u6709\u5b9a\u65f6\u7684\u529f\u80fd\u7684API\u2014\u2014\u591a\u8def\u590d\u7528\u3002\u5728Linux\u4e0a\u7684\u591a\u8def\u590d\u7528\u673a\u5236\u6709select\/poll\/epoll\u51e0\u79cd\uff0c\u5b83\u4eec\u8f6e\u8be2\u65f6\u90fd\u5141\u8bb8\u6307\u5b9a\u4e00\u4e2a\u8d85\u65f6\u65f6\u95f4\uff0c\u5982\u679c\u5728\u6307\u5b9a\u65f6\u95f4\u5185\uff0c\u76d1\u63a7\u7684\u4e8b\u4ef6\u6ca1\u6709\u5230\u8fbe\uff0c\u8f6e\u8be2\u51fd\u6570\u4f1a\u8d85\u65f6\u8fd4\u56de\u3002\u7cbe\u5ea6\u4e5f\u8db3\u591f\u7528\uff0cpoll\/epoll\u662f\u6beb\u79d2\u7ea7\u7684(millisecond),select\u8d85\u65f6\u53c2\u6570\u662fstruct timeval<\/code>\uff0c\u662f\u5fae\u79d2\u7ea7\u7684(microsecond)\u3002<\/p>\n
\u9009\u62e9epoll\u7684\u4f18\u52bf\u5f88\u660e\u663e\uff0c\u80fd\u5c06\u5b9a\u65f6\u529f\u80fd\u5b8c\u7f8e\u7684\u878d\u5165\u5df2\u6709\u7684event loop\u91cc\uff0c\u540c\u65f6epoll\u6709\u7740\u5929\u7136\u7684\u9ad8\u5e76\u53d1\u7684\u80fd\u529b\uff0cmillisecond\u7ea7\u7684\u7cbe\u5ea6\u4e5f\u8db3\u591f\u7528\u3002<\/p>\n
\u83b7\u53d6\u5f53\u524d\u65f6\u95f4<\/h1>\n
\u8981\u5b9e\u73b0\u4e00\u4e2a\u5b9a\u65f6\u5668\uff0c\u6709\u4e86\u5b9a\u65f6\u51fd\u6570\uff0c\u6211\u4eec\u8fd8\u9700\u8981\u9009\u7528\u4e00\u4e2a\u83b7\u53d6\u65f6\u95f4\u7684\u51fd\u6570\u3002\u540c\u6837\u5730\uff0c\u8fd9\u4e9b\u51fd\u6570\u6211\u4e5f\u6574\u7406\u4e86\u4e00\u4e0b\uff1a<\/p>\n
\n\n\n\n\n\n\n\n\n\n
Function<\/th>\nType<\/th>\nPrecision<\/th>\nRemark<\/th>\n<\/tr>\n<\/thead>\n
time(2)<\/td>\ntime_t<\/td>\nsecond<\/td>\n<\/td>\n<\/tr>\n
ftime(3)<\/td>\nstruct timeb<\/td>\nmillisecond<\/td>\nobsolete<\/td>\n<\/tr>\n
gettimeofday(2)<\/td>\nstruct timeval<\/td>\nmicrosecond<\/td>\n<\/td>\n<\/tr>\n
clock_gettime(2)<\/td>\nstruct timespec<\/td>\nnanosecond<\/td>\n<\/td>\n<\/tr>\n
Time Stamp Counter<\/td>\n64-bit register<\/td>\nCPU related<\/td>\non all x86 processors since the Pentium(TSC<\/a>)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
time()\u7cbe\u5ea6\u592a\u4f4e\uff0c\u4e0d\u5408\u9002\u3002<\/p>\n
ftime() \u6beb\u79d2\u7ea7\u7cbe\u5ea6\uff0c\u4f46\u662f\u88ab\u5e9f\u5f03\u4e86\uff0c\u4e5f\u4e0d\u5408\u9002\u3002<\/p>\n
gettimeofday() \u7cbe\u5ea6\u8fbe\u5230\u5fae\u79d2\u7ea7\uff0c\u5e76\u4e14\u5728x86-64\u5e73\u53f0\u4e0a\u8be5\u51fd\u6570\u7684\u8c03\u7528\u4e0d\u662f\u7cfb\u7edf\u8c03\u7528(vdso)\uff0c\u4f3c\u4e4e\u5f88\u5408\u9002\uff0c\u4e0d\u5e78\u7684\u662fPOSIX.1-2008\u4e2d\u4e5f\u5c06\u8fd9\u4e2a\u51fd\u6570\u5e9f\u5f03\u4e86\u3002<\/p>\n
Time Stamp Counter \u4f7f\u7528\u6c47\u7f16\u6307\u5b9a\u83b7\u53d6\u65f6\u95f4\u6233\u7684\u8ba1\u6570\u5668\uff0c\u7cbe\u5ea6\u5e94\u8be5\u662f\u6700\u9ad8\u7684\uff0c\u6548\u7387\u53ef\u80fd<\/em>\u4e5f\u5e94\u8be5\u662f\u6700\u9ad8\u7684\uff0c\u4e00\u6761\u6c47\u7f16\u6307\u4ee4rdtscp<\/code>(\u76f8\u6bd4rdtsc<\/code>\uff0crdtscp\u53ef\u4ee5\u907f\u514d\uff0c\u56e0\u4e3acpu\u4e71\u5e8f\u6267\u884c\u5e26\u6765\u7684\u8bef\u5dee\u95ee\u9898)\u5373\u53ef\u3002\u662f\u53ef\u4ee5\u4f5c\u4e3a\u4e00\u4e2a\u9009\u62e9\u7684\uff0c\u817e\u8baf\u7684libco<\/code>\u5c31\u662f\u4f18\u5148\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5\u83b7\u53d6\u65f6\u95f4\u7684\u3002<\/p>\n
clock_gettime() \u3002\u9ed8\u8ba4\u662fnanosecond \u7ea7\u7cbe\u5ea6\uff0c\u662f\u7cfb\u7edf\u8c03\u7528(_sys_clock_gettime())\uff0c\u4f1a\u6709\u5f00\u9500\u3002\u8c03\u7528\u9891\u7e41\u7684\u8bdd\uff0c\u53ef\u80fd\u9020\u6210\u635f\u5931\u6027\u80fd\u3002\u4f46\u662fLinux 2.6.32\u540e\u53ef\u4ee5\u6307\u5b9a\u53c2\u6570CLOCK_REALTIME_COARSE<\/code>\u548cCLOCK_MONOTONIC_COARSE<\/code>\uff0c\u7c97\u7c92\u5ea6\u5730\u83b7\u53d6\u65f6\u95f4\uff0c\u800c\u4e0d\u9700\u8981\u53d1\u751f\u4e0a\u4e0b\u6587\u5207\u6362(\u548cgettimeofday()\u4e00\u6837\u4e5f\u662fvdso\u6280\u672f\uff0chttps:\/\/access.redhat.com\/documentation\/en-us\/red_hat_enterprise_linux_for_real_time\/7\/html\/reference_guide\/sect-posix_clocks#CLOCK_MONOTONIC_COARSE_and_CLOCK_REALTIME_COARSE<\/a>)\u3002\u4f7f\u7528_COARSE<\/code>\u540e\u7f00\u83b7\u53d6\u7684\u65f6\u95f4\uff0c\u7cbe\u5ea6\u662fmillisecond\u7ea7\u3002\u5bf9\u6211\u4eec\u6765\u8bf4\u4e5f\u591f\u7528\u4e86\u3002<\/p>\n
\u8981\u5bf9clock_gettime\u7cfb\u7edf\u8c03\u7528\u7684\u5f00\u9500\u6709\u4e00\u4e2a\u76f4\u89c2\u7684\u611f\u53d7\u7684\u8bdd\u53ef\u4ee5\uff0c\u501f\u52a9\u4e8estrace<\/code>\u5de5\u5177\uff0c\u5229\u7528-T<\/code>\u53c2\u6570\u53ef\u4ee5\u8ffd\u8e2a\u6bcf\u4e2a\u7cfb\u7edf\u8c03\u7528\u7684\u65f6\u95f4\u5f00\u9500\uff0c\u6bd4\u6211\u6211\u7684\u73af\u5883\u4e0aCLOCK_MONOTONIC<\/code>\u83b7\u53d6\u65f6\u95f4\u7684\u5f00\u9500\u5927\u6982\u662f50\u5fae\u79d2<\/p>\n
\"clock\"<\/a><\/p>\n
\u6362\u6210CLOCK_MONOTONIC_COARSE<\/code>\u65b9\u5f0f\u518d\u53bb\u83b7\u53d6\u65f6\u95f4\uff0c\u7528strace\u5c31\u8ffd\u8e2a\u4e0d\u5230\u4e86\u3002<\/p>\n
\u5b9a\u65f6\u5668\u7684\u8bbe\u8ba1<\/h1>\n
\u6709\u4e86\u83b7\u53d6\u65f6\u95f4\u51fd\u6570clock_gettime\u548c\u5b9a\u65f6\u51fd\u6570epoll\u4e4b\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5f00\u59cb\u8bbe\u8ba1\u5b9a\u65f6\u5668\u4e86\u3002\u9996\u5148\u660e\u786e\u4e00\u70b9\uff0cepoll\u548c\u5176\u4ed6\u7684\u5b9a\u65f6\u901a\u77e5\u51fd\u6570\u4e00\u6837\uff0c\u4e00\u6b21\u4e5f\u53ea\u80fd\u8bbe\u7f6e\u4e00\u4e2a\u8d85\u65f6\u65f6\u95f4\uff0c\u4f9d\u7136\u4e0d\u80fd\u6ee1\u8db3\u6211\u5f00\u7bc7\u63d0\u51fa\u7684\u9700\u6c42\u3002<\/p>\n
\u4e3b\u6d41\u7684\u505a\u6cd5\u662f\u5229\u7528\u4e00\u4e2a\u5bb9\u5668\u4fdd\u5b58\u6240\u6709\u8bbe\u7f6e\u7684\u8d85\u65f6\u65f6\u95f4\uff0c\u5c06\u5bb9\u5668\u91cc\u6700\u5feb\u7684\u8d85\u65f6\u7684\u65f6\u95f4\u8bbe\u7f6e\u4e3aepoll_wait\u7684\u8d85\u65f6\u65f6\u95f4\u3002\u6bd4\u5982\uff0c\u6211\u5148\u540e\u8bbe\u7f6e\u4e861400ms,800ms,300ms,2900ms\uff0c\u90a3\u4e48\u4e0b\u4e00\u6b21\u4e8b\u4ef6\u5faa\u73af\u5c31\u5c06epoll_wait\u7684\u7b2c\u56db\u4e2a\u53c2\u6570\u8bbe\u7f6e\u4e3a300ms\u3002<\/p>\n
\u5982\u679c\u7528\u94fe\u8868\u4fdd\u5b58\u7684\u8bdd\uff0c\u6bcf\u6b21\u8bbe\u7f6e\u5b9a\u65f6\u5668\u90fd\u8981\u904d\u5386\u4e00\u904d\u94fe\u8868\u624d\u80fd\u9009\u5230\u6700\u5feb\u8d85\u65f6\u7684\u90a3\u4e2a\u65f6\u95f4\uff0c\u590d\u6742\u5ea6\u592a\u9ad8\uff0c\u5982\u679c\u8bbe\u7f6e\u4e86\u5b9a\u65f6\u5668\u7279\u522b\u591a\u7684\u8bdd\uff0c\u8fd9\u6837\u7684\u5f00\u9500\u4e0d\u80fd\u63a5\u53d7\u3002<\/p>\n
\u8981\u50cfO(1)\u7684\u65f6\u95f4\u83b7\u53d6\u5230\u6700\u5c0f\u7684\u54ea\u4e2a\u503c\uff0c\u7528\u6700\u5c0f\u5806\u4fdd\u5b58\u8d85\u65f6\u65f6\u95f4\u6b63\u5408\u9002\uff0c\u6548\u7387\u5927\u5927\u63d0\u9ad8\u3002\u4e8b\u5b9e\u4e0alibevent\u5c31\u662f\u8fd9\u4e48\u5b9e\u73b0\u7684(C\u8bed\u8a00\u5b9e\u73b0\u7684min_heap_t)\u3002<\/p>\n
\u6700\u5c0f\u5806\u5b9e\u73b0<\/h2>\n
\u5148\u5b9e\u73b0\u4e00\u4e2a\u7c7bTimer<\/code>\u8868\u793a\u6bcf\u4e00\u4e2a\u88ab\u6dfb\u52a0\u7684\u5b9a\u65f6\uff0c\u6784\u9020\u65f6\u9700\u8981\u4e00\u4e2amillisecond\u4e3a\u5355\u4f4d\u7684\u8d85\u65f6\u65f6\u95f4\uff0c\u4e00\u4e2a\u56de\u8c03\u51fd\u6570\uff0c\u4e00\u4e2a\u56de\u8c03\u51fd\u6570\u7684\u53c2\u6570\u3002\u4e3a\u4e86\u7b80\u5316\u5b9e\u73b0\uff0c\u6211\u6d4b\u8bd5\u7528\u7684\u8d85\u65f6\u7684\u56de\u8c03\u51fd\u6570\uff0c\u5e76\u672a\u4f7f\u7528\u56de\u8c03\u51fd\u6570\u7684\u53c2\u6570\uff0c\u4f46\u4e5f\u6ca1\u6709\u53bb\u6389\uff0c\u4ec5\u4ec5\u662f\u5360\u4e2a\u5751\u7684\u4f5c\u7528\u3002\u672c\u6765\u662f\u60f3\u6253\u7b97\u628aargs\u62bd\u8c61\uff0c\u5c06Timer\u5199\u6210\u6a21\u677f\u7c7b\uff0c\u9632\u6b62\u672c\u672b\u5012\u7f6e\uff0c\u672c\u6587\u4ec5\u4e3a\u6f14\u793a\u5b9a\u65f6\u5668\u7684\u5b9e\u73b0\uff0c\u8d8a\u7b80\u5355\u8d8a\u597d\u3002<\/p>\n
expire<\/code>\u65f6\u95f4\u7528\u7684\u662f\u76f8\u5bf9\u7cfb\u7edf\u542f\u52a8\u7684\u65f6\u95f4,\u662f\u4e00\u4e2a\u4e0d\u53ef\u4ee5\u8bbe\u7f6e\u7684\u6052\u5b9a\u7684\u65f6\u95f4(nonsettable monotonic clock)\uff0c\u800c\u4e0d\u662f\u7528\u7684\u771f\u5b9e\u7684\u65f6\u95f4(Wall time \uff0c\u5899\u4e0a\u65f6\u95f4)\uff0c\u56e0\u4e3a\u8fd9\u4e2a\u65f6\u95f4\u53ef\u80fd\u4f1a\u968f\u7740\u8bbe\u7f6e\u7cfb\u7edf\u7684\u65e5\u671f\u65f6\u95f4\u800c\u53d1\u751f\u8df3\u8dc3\u6027\u7684\u6539\u53d8\u3002<\/p>\n
<\/div>\n
TimerManager<\/code>\u662f\u7528\u6237\u64cd\u4f5c\u7684\u63a5\u53e3\uff0c\u63d0\u4f9b\u589e\u52a0\uff0c\u5220\u9664\u5b9a\u65f6\u5668\u7684\u529f\u80fd\u3002STL\u4e2d\u63d0\u4f9b\u80fd\u4f18\u5148\u961f\u5217<\/a>\uff0c\u76f4\u63a5\u53ef\u4ee5\u62ff\u6765\u7528\u3002<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n15\r\n16\r\n17\r\n18\r\n<\/span><\/pre>\n<\/td>\n
\n
class TimerManager\r\n{\r\npublic:\r\n    TimerManager() {}\r\n\r\n    Timer *addTimer(int timeout, std::function<void(void)> fun, void *args = NULL);\r\n    void delTimer(Timer* timer);\r\n    unsigned long long getRecentTimeout();\r\n    void takeAllTimeout();\r\n    unsigned long long getCurrentMillisecs();\r\n\r\nprivate:\r\n    struct cmp\r\n    {\r\n        bool operator()(Timer*& lhs, Timer*& rhs) const { return lhs->getExpire() > rhs->getExpire(); }\r\n    };\r\n    std::priority_queue<Timer*,std::vector<Timer*>,cmp> queue_;\r\n};\r\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
addTimer()\u53c2\u6570\u548cTimer\u6784\u9020\u51fd\u6570\u4e00\u76f4\uff0c\u5b9e\u73b0\u5c31\u662f\u6784\u9020\u4e00\u4e2aTimer\u7136\u540e\u52a0\u5165\u5230std::priority_queue\u540e\uff0c\u8fd4\u56deTimer\u6307\u9488\u3002<\/p>\n
delTimer() \u5220\u9664\u4e00\u4e2a\u6307\u5b9a\u7684Timer\uff0c\u7531\u4e8epriority_queue\u6ca1\u6709\u63d0\u4f9berease()\u63a5\u53e3\uff0c\u56e0\u6b64\u5220\u9664Timer\u7684\u64cd\u4f5c\uff0c\u6211\u8fd9\u91cc\u91c7\u7528\u4e86\u65b0\u5efa\u4e00\u4e2apriority_queue\u7684\u505a\u6cd5\uff0c\u590d\u6742\u5ea6O(n)\u3002<\/p>\n
getRecentTimeout()\u83b7\u53d6\u4e00\u4e2a\u6700\u8fd1\u7684\u8d85\u65f6\u65f6\u95f4(\u8d85\u65f6\u65f6\u95f4 = \u4f18\u5148\u961f\u5217\u91cc\u7684\u65f6\u95f4 – \u5f53\u524d\u83b7\u53d6\u7684\u7cfb\u7edf\u542f\u52a8\u65f6\u95f4)\u3002\u5982\u679c\u8fd9\u4e2a\u503c\u5c0f\u4e8e0\uff0c\u90a3\u4e48\u8bf4\u660e\u8fd9\u4e2a\u5b9a\u65f6\u5668\u5df2\u7ecf\u8d85\u65f6\u4e86\uff0c\u5c06\u5176\u7f6e\u4e3a0\uff0c\u7a0d\u540e\u7684epoll_wait\u5c06\u4f1a\u7acb\u9a6c\u8fd4\u56de\u3002<\/p>\n
takeAllTimeout() \u51fd\u6570\uff0c\u5904\u7406\u8d85\u65f6\u7684\u5b9a\u65f6\uff0c\u5e76\u56de\u8c03\u5176\u7ed1\u5b9a\u7684\u56de\u8c03\u51fd\u6570\u3002\u7531\u4e8e\u8d85\u65f6\u7684\u53ef\u80fd\u4e0d\u6b62\u4e00\u4e2a\u5b9a\u65f6\uff0c\u9700\u8981\u7528\u4e00\u4e2a\u5faa\u73af\u904d\u5386\u6240\u6709\u8d85\u65f6\u7684Timer\uff0c\u4e00\u4e00\u5904\u7406\u3002<\/p>\n
getCurrentMillisecs()\u5bf9clock_gettime()\u7684\u5c01\u88c5\uff0c\u83b7\u53d6\u5230\u7684struct timespec<\/code>\u8f6c\u6362\u4e3amillisecond\u3002<\/p>\n
\u8fd9\u4e24\u4e2a\u7c7b\u7684\u5b8c\u6574\u5b9e\u73b0\uff0c\u6211\u653e\u5230\u4e86Github\u4e0a\u4e86:https:\/\/gist.github.com\/baixiangcpp\/b2199f1f1c7108f22f47d2ca617f6960<\/a>\u3002\u4f7f\u7528\u7684\u65f6\u5019\uff0c\u53ea\u9700\u8981\u5728\u4f60\u7684\u4e3b\u5faa\u73af\u91cc\uff0c\u628aepoll_wait\u7684\u8d85\u65f6\u53c2\u6570\u8bbe\u7f6e\u4e3aTimerManager::getRecentTimeout()\uff0c\u6bcf\u6b21epoll_wait()\u8fd4\u56de\u540e\uff0c\u5904\u7406\u4e00\u4e0b\u8d85\u65f6\u4e8b\u4ef6TimerManager::takeAllTimeout()\u3002<\/p>\n
\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n<\/span><\/pre>\n<\/td>\n
\n
int dispatch()\r\n{\r\n    ...\r\n    TimerManager tm;\r\n    tm.addTimer(1000, []() { std::cout << \"hello world\" << std::endl; }, NULL);\r\n    tm.addTimer(5000, []() { std::cout << \"hello baixiancpp\" << std::endl; }, NULL);\r\n    for(;;)\r\n    {\r\n        int ret = epoll_wait(epollfd,events,events_num,tm.getRecentTimeout());\r\n        tm.takeAllTimeout();\r\n    }\r\n    ...\r\n}\r\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u65f6\u95f4\u8f6e\u5b9e\u73b0<\/h2>\n
\u53e6\u5916\u4e00\u79cd\u5e38\u89c1\u7684\u5b9a\u65f6\u5668\u8bbe\u8ba1\u4f7f\u7528\u7684\u5b58\u653e\u8d85\u65f6\u65f6\u95f4\u7684\u5bb9\u5668\u53eb\u505a\u201d\u65f6\u95f4\u8f6e\u201d\u3002\u5fae\u4fe1\u7684\u5f00\u6e90\u9879\u76eelibco\u4e2d\u4f7f\u7528\u7684\u5c31\u662f\u8fd9\u79cd\u6570\u636e\u7ed3\u6784\u3002<\/p>\n
\n
Hierarchy \u65f6\u95f4\u8f6e\u7684\u539f\u7406\u5927\u81f4\u5982\u4e0b\uff0c\u4e0b\u9762\u662f\u4e00\u4e2a\u65f6\u5206\u79d2\u7684Hierarchy\u65f6\u95f4\u8f6e\uff0c\u4e0d\u540c\u4e8eLinux\u5185\u6838\u7684\u5b9e\u73b0\uff0c\u4f46\u539f\u7406\u7c7b\u4f3c\u3002\u5bf9\u4e8e\u65f6\u5206\u79d2\u4e09\u7ea7\u65f6\u95f4\u8f6e\uff0c\u6bcf\u4e2a\u65f6\u95f4\u8f6e\u90fd\u7ef4\u62a4\u4e00\u4e2acursor\uff0c\u65b0\u5efa\u4e00\u4e2atimer\u65f6\uff0c\u8981\u6302\u5728\u5408\u9002\u7684\u683c\u5b50\uff0c\u5269\u4f59\u8f6e\u6570\u4ee5\u53ca\u65f6\u95f4\u90fd\u8981\u8bb0\u5f55\uff0c\u5230\u671f\u5224\u65ad\u8d85\u65f6\u5e76\u8c03\u6574\u4f4d\u7f6e\u3002\u539f\u7406\u56fe\u5927\u81f4\u5982\u4e0b:<\/div>\n<\/div>\n
\"timer<\/a><\/p>\n
\"\"<\/p>\n
\u5bf9\u4e8e\u65f6\u95f4\u8f6e\u7684\u5b9e\u73b0\uff0cTimer\u4f9d\u7136\u662f\u5b58\u653e\u5728\u94fe\u8868\u4e0a\uff0c\u4f46\u662f\u501f\u52a9\u4e86hash\u7684\u601d\u60f3\uff0c\u5c06\u76f8\u540c\u95f4\u9694(\u6216\u8005\u76f8\u540c\u5468\u671f\u7684\u6574\u6570\u500d)\u7684\u8d85\u65f6Timer\u653e\u5728\u540c\u4e00\u4e2a\u65f6\u95f4\u8f6e\u5b50\u4e0a\u7684\u69fd(slot)\u4e0a\u3002\u65f6\u95f4\u8f6e\u4e0a\u6709\u4e00\u4e2a\u6307\u9488\uff0c\u6309\u7167\u4e00\u4e2a\u57fa\u51c6\u7684\u9891\u7387(\u6bd4\u59821ms,5ms,10ms\u7b49\uff0clibco\u4e2d\u8bbe\u7f6e\u7684\u662f1ms)\u5411\u524d\u79fb\u52a8\u3002\u8fd9\u4e2a\u57fa\u51c6\u7684\u9891\u7387\u5c31\u662f\u4f20\u9012\u7ed9epoll_wait()\u8d85\u65f6\u7684\u503c\uff0c\u4e5f\u662f\u5b9a\u65f6\u5668\u7cbe\u5ea6\u7684\u57fa\u672c\u5355\u4f4d<\/code>\u3002<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n15\r\n<\/span><\/pre>\n<\/td>\n
\n
class Timer\r\n{\r\npublic:\r\n    Timer(int rotations,int slot,std::function<void(void)> fun,void* args)\r\n        : rotations_(rotations),slot_(slot),fun(fun) { }\r\n    inline int getRotations() { return rotations_; }\r\n    inline void decreaseRotations() { --rotations_; }\r\n    inline void active() { fun(); }\r\n    inline int getSlot() { return slot_; }\r\nprivate:\r\n    int rotations_;\r\n    int slot_;\r\n    std::function<void(void)> fun;\r\n    void* args;\r\n};\r\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u65f6\u95f4\u8f6e\u4e2d\u7684Timer<\/code>\u7c7b\u548c\u6700\u5c0f\u5806\u4e2d\u7684\u5b9e\u73b0\uff0c\u591a\u4e86\u4e24\u4e2a\u53c2\u6570\uff0crotations\u8868\u793a\u65f6\u95f4\u8f6e\u8f6c\u591a\u5c11\u5708\u540e\u5f53\u524d\u7684Timer\u4f1a\u89e6\u53d1\uff0cslot\u8868\u793a\u5f53\u524d\u7684Timer\u5e94\u8be5\u6302\u5728\u5bf9\u5e94\u7684\u69fd\u6307\u5411\u7684\u94fe\u8868\u4e0a\u3002\u6210\u5458\u51fd\u6570\u6bd4\u8f83\u7b80\u5355\uff0c\u4e0d\u591a\u8d58\u8ff0\u3002<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n15\r\n16\r\n17\r\n18\r\n19\r\n<\/span><\/pre>\n<\/td>\n
\n
class TimeWheel\r\n{\r\n  public:\r\n    TimeWheel(int nslots)\r\n        : nslosts_(nslots),curslot_(0),\r\n            slots_(nslosts_,std::vector<Timer*>()),starttime_(getCurrentMillisecs()) { }\r\n    ~TimeWheel();\r\n    unsigned long long getCurrentMillisecs();\r\n    Timer *addTimer(int timeout,std::function<void(void)> fun,void* args);\r\n    void delTimer(Timer *timer);\r\n    void tick();\r\n    void takeAllTimeout();\r\n\r\nprivate:\r\n    int nslosts_;\r\n    int curslot_;\r\n    unsigned long long starttime_;\r\n    std::vector<std::vector<Timer*>> slots_;\r\n};\r\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
curslot_\u8868\u793a\u65f6\u95f4\u8f6e\u5f53\u524d\u6307\u5411\u7684\u90a3\u4e2aslot\u3002nslosts_\u8868\u793a\u8fd9\u4e2a\u65f6\u95f4\u8f6e\u62e5\u6709\u591a\u5c11\u4e2aslot\uff0c\u4e0d\u8981\u4e0a\u56fe\u8ff7\u60d1\u4e86\uff0c\u5b9e\u9645\u4e0aslot\u4f1a\u8fdc\u8fdc\u8d85\u8fc7\u8fd98\u4e2a\u3002\u8981\u60f3\u6548\u7387\u8db3\u591f\u9ad8\uff0cslot\u5c31\u8981\u8d8a\u5927\uff0c\u5f53\u7136\u5360\u7528\u7684\u5185\u5b58\u4e5f\u4f1a\u8d8a\u5927(\u73b0\u4ee3\u8ba1\u7b97\u673a\uff0c\u8fd9\u70b9\u5185\u5b58\u53ef\u4ee5\u5ffd\u7565\u4e0d\u8ba1)\uff0clibco\u9ed8\u8ba4\u4f7f\u7528\u4e86 60 * 1000 \u4e2aslot \u3002<\/p>\n
addTimer()\u662f\u6dfb\u52a0\u4e00\u4e2aTimer\u5230TimeWheel\u4e0a\uff0c\u9700\u8981\u6839\u636e\u4f20\u9012\u7684timeout\u53c2\u6570\uff0c\u8ba1\u7b97\u51fa\u8be5Timer\u6240\u5bf9\u5e94\u7684slot (slot = (curslot_ + (timeout % nslosts_)) % nslosts_;<\/code>) ,\u8fd8\u6709\u5230\u8fd9\u4e2aTimer\u8d85\u65f6\u65f6\u95f4\u8f6e\u7684\u6307\u9488\u9700\u8981\u8f6c\u8fc7\u7684\u5708\u6570(timeout \/ nslosts_<\/code>)\u3002<\/p>\n
delTimer() \u6839\u636eTimer*\u53c2\u6570\uff0c\u5220\u9664\u65f6\u95f4\u8f6e\u4e0a\u5bf9\u5e94\u7684Timer\u3002<\/p>\n
tick() \u65f6\u95f4\u8f6e\u7684\u6307\u9488\u8d70\u52a8\u4e00\u4e0b\u3002\u540c\u65f6\u904d\u5386\u5f53\u524dslot\u4e0a\u94fe\u8868\u91cc\u7684\u6bcf\u4e00\u4e2aTimer\uff0c\u5982\u679cTimer\u7684\u5708\u6570\u5927\u4e8e0\uff0c\u5c06Timer\u91cc\u7684\u5708\u6570-1\uff0c\u5426\u5219\u6fc0\u6d3b\u8fd9\u4e2aTimer\u3002<\/p>\n
takeAllTimeout() \u662f\u5fc5\u8981\u7684\uff0c\u7531\u4e8e\u8bef\u5dee\u7684\u5b58\u5728\uff0c\u6bcf\u6b21epoll_wait\u8d85\u65f6\u540e(\u4e00\u4e2a\u57fa\u51c6\u9891\u7387)\uff0c\u65f6\u95f4\u8f6e\u53ef\u80fd\u9700\u8981\u8d70\u52a8\u597d\u51e0\u6b65\u3002\u5982\u679c\u6bcf\u6b21epoll_wait\u540e\u76f4\u63a5tick()\u800c\u4e0d\u662ftakeAllTimeout()\uff0c\u4f1a\u5bfc\u81f4\u8bef\u5dee\u4e00\u76f4\u88ab\u7d2f\u79ef\uff0c\u65f6\u95f4\u8f6e\u4e0a\u5269\u4f59\u7684\u5b9a\u65f6\u5668\u88ab\u6ede\u540e\u89e6\u53d1\u3002<\/p>\n
\u65f6\u95f4\u8f6e\u7684\u5b9e\u73b0\u6211\u4e5f\u653e\u5230\u4e86Github\u4e0a:https:\/\/gist.github.com\/baixiangcpp\/63278c0087201a655f940ab8de543abd<\/a>\u3002\u4f7f\u7528\u65b9\u5f0f\u548c\u4e4b\u524d\u7684\u6700\u5c0f\u5806\u5b9e\u73b0\u7684\u57fa\u672c\u662f\u4e00\u6837\u7684\u3002<\/p>\n
\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n<\/span><\/pre>\n<\/td>\n
\n
int dispatch()\r\n{\r\n    ...\r\n    TimeWheel tw(60 * 1000);\r\n    tw.addTimer(1000, []() { std::cout << \"hello world\" << std::endl; }, NULL);\r\n    tw.addTimer(5000, []() { std::cout << \"hello baixiancpp\" << std::endl; }, NULL);\r\n    for(;;)\r\n    {\r\n        int ret = epoll_wait(epollfd,events,events_num,1); \/\/ \u57fa\u51c6\u9891\u7387 1ms\r\n        \/\/ tw.tick(); \u4e0d\u8981\u8fd9\u4e48\u505a\uff0c\u4f1a\u5bfc\u81f4\u8bef\u5dee\u7d2f\u79ef\r\n        tw.takeAllTimeout();\r\n    }\r\n    ...\r\n}\r\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u6700\u5c0f\u5806\u548c\u65f6\u95f4\u8f6e\u7684\u65f6\u95f4\u590d\u6742\u5ea6\uff0c\u5982\u4e0b\uff1a<\/p>\n
\n\n\n\n\n\n\n\n
Type<\/th>\nadd<\/th>\nexec<\/th>\n<\/tr>\n<\/thead>\n
list<\/td>\nO(1)<\/td>\nO(n)<\/td>\n<\/tr>\n
min-heap<\/td>\nO(lgn)<\/td>\nO(1)<\/td>\n<\/tr>\n
time wheel<\/td>\nO(1)<\/td>\nO(n)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u8fd9\u91cc\u6211\u53ea\u5217\u51fa\u6dfb\u52a0\u5b9a\u65f6\u5668\u548c\u89e6\u53d1\u5b9a\u65f6\u5668\u7684\u65f6\u95f4\u590d\u6742\u5ea6\uff0c\u56e0\u4e3a\u8fd9\u51e0\u79cd\u5b9e\u73b0\u4e2d\uff0c\u5220\u9664\u4e00\u4e2a\u5b9a\u65f6\u5668\u53ef\u4ee5\u4f18\u5316\u5230O(1)\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u2014\u2014\u2014\u2014\u628a\u5176\u5bf9\u5e94\u7684\u56de\u8c03\u51fd\u6570\u7f6e\u7a7a\u3002\u524d\u9762\u7684\u4f8b\u5b50\u6211\u6ca1\u6709\u8fd9\u4e48\u505a\uff0c\u4ec5\u4e3a\u5c55\u793a\uff0c\u6709\u5174\u8da3\u7684\u8bdd\u53ef\u4ee5\u81ea\u884c\u4fee\u6539\u3002<\/p>\n
\u4e4d\u770b\u4e0b\u6765\uff0c\u65f6\u95f4\u8f6e\u7684\u590d\u6742\u5ea6\u548c\u94fe\u8868\u662f\u4e00\u6837\u7684\u3002\u5176\u5b9e\u4e0d\u7136\uff0c\u65f6\u95f4\u8f6e\u4e0a\u89e6\u53d1\u4e00\u4e2a\u5b9a\u65f6\u5668\uff0c\u4ec5\u4ec5\u662f\u7406\u8bba\u4e0a\u7684O(n),\u53ea\u8981slot\u7684\u6570\u91cf\u8bbe\u7f6e\u5408\u7406\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u4f1a\u4e0b\u964d\u81f3\u63a5\u8fd1O(1)\u3002<\/p>\n
\u53ef\u4ee5\u6839\u636e\u5b9e\u9645\u9700\u8981\uff0c\u9009\u62e9\u5408\u9002\u7684\u5b9a\u65f6\u5668\u5bb9\u5668\u3002<\/p>\n
\u8981\u4e0d\u8981\u7528Timerfd\uff1f<\/h1>\n
\u5f00\u7bc7\u7684\u8868\u683c\u91cc\u6709\u63d0\u5230\uff0c\u4eceLinux2.6.25\u5f00\u59cb\uff0ctimerfd\u7cfb\u5217API\uff0c\u5e26\u6765\u4e86\u4e00\u79cd\u5168\u65b0\u7684\u5b9a\u65f6\u673a\u5236\u3002\u628a\u8d85\u65f6\u4e8b\u4ef6\u8f6c\u6362\u4e3a\u4e86\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u5f53\u8d85\u65f6\u53d1\u751f\u540e\u8be5\u6587\u4ef6\u63cf\u8ff0\u7b26\u4f1a\u53d8\u6210\u53ef\u8bfb\u3002\u4e8e\u662f\u8d85\u65f6\u4e8b\u4ef6\u5c31\u53d8\u6210\u4e86\u666e\u901a\u7684IO\u4e8b\u4ef6\u3002\u5982\u679c\u672a\u5bf9timerfd\u8bbe\u7f6e\u963b\u585e\uff0c\u5bf9\u5176read\u64cd\u4f5c\u4f1a\u4e00\u76f4\u963b\u585e\u5230\u8d85\u65f6\u53d1\u751f\u3002\u6b64\u5916timerfd\u7684\u7cbe\u5ea6\u8fbe\u5230\u4e86\u7eb3\u79d2\u7ea7\u3002\u4e0d\u8003\u8651\u8de8\u5e73\u53f0\u7b49\u56e0\u7d20\uff0c\u8fd9\u662f\u4e00\u4e2a\u975e\u5e38\u4e0d\u9519\u7684\u9009\u62e9\u3002<\/p>\n
libevent2.1\u7684\u6e90\u7801\u91cc\u4e5f\u652f\u6301timerfd\u4e86\uff0c\u5728\u7248\u672c\u8bf4\u660e<\/a>\u91cc\u4e5f\u5f88\u660e\u786e\u4e86\u8bf4\u660e\u4e86\u4f7f\u7528\u591a\u8def\u590d\u7528\u7684\u8d85\u65f6\u53c2\u6570\u548c\u4f7f\u7528timerfd\u4e4b\u95f4\u7684\u5dee\u5f02 \uff0c\u5b83\u4f7f\u7528\u4e86\u4e24\u4e2a\u8bcd\u201defficient\u201d\u548c\u201dprecise\u201d\uff0c\u5206\u522b\u8868\u793a\u8fd9\u79cd\u5b9e\u73b0\u4e4b\u95f4\u7684\u5dee\u5f02\uff0c\u6211\u60f3\u7740\u8fd9\u8fd8\u662f\u975e\u5e38\u6709\u8bf4\u670d\u529b\u7684\u3002<\/p>\n
\u6bcf\u4e2a\u8d85\u65f6\u4e8b\u4ef6\u72ec\u4eab\u4e00\u4e2atimerfd<\/h2>\n
\u5982\u679c\u5bf9\u4e8e\u6bcf\u4e00\u4e2a\u8d85\u65f6\u4e8b\u4ef6\u90fd\u7528timerfd_create()\u521b\u5efa\u4e00\u4e2a\u5bf9\u5e94\u7684fd\uff0c\u653e\u5230epoll\u4e2d\u7edf\u4e00\u7ba1\u7406\u3002\u8fd9\u6837\u7684\u505a\u6cd5\u662f\u4e0d\u5408\u9002\u7684\u3002\u6bcf\u589e\u52a0\u4e00\u4e2a\u5b9a\u65f6\u4e8b\u4ef6\uff0c\u90fd\u9700\u8981\u989d\u5916\u76843\u4e2a\u7cfb\u7edf\u8c03\u7528:<\/p>\n
\"timerfd\"<\/a><\/p>\n
\u6b64\u5916\uff0c\u6587\u4ef6\u63cf\u8ff0\u7b26\u8fd8\u662f\u7a00\u7f3a\u7684\u8d44\u6e90\uff0c\u6bcf\u4e2a\u8fdb\u7a0b\u80fd\u591f\u4f7f\u7528\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u662f\u53d7\u7cfb\u7edf\u9650\u5236\u7684\uff0c\u5982\u679c\u5b9a\u65f6\u5668\u8fc7\u591a\uff0c\u4f1a\u9020\u6210\u4e25\u91cd\u7684\u6d6a\u8d39\u3002<\/p>\n
\u8fd9\u79cd\u65b9\u5f0f\u7684\u5b9a\u65f6\u5668\uff0c\u6bd4\u8f83\u5bb9\u6613\u5b9e\u73b0\uff0c\u8fd9\u91cc\u6211\u5c31\u4e0d\u518d\u6d6a\u8d39\u7bc7\u5e45\u4e86\u3002<\/p>\n
\u6240\u6709\u8d85\u65f6\u4e8b\u4ef6\u5171\u4eab\u4e00\u4e2atimerfd<\/h2>\n
libevent\u5c31\u662f\u4f7f\u7528\u7684\u8fd9\u79cd\u65b9\u5f0f\u3002\u5b9a\u65f6\u65f6\u95f4\u4ecd\u7136\u4f7f\u7528\u6700\u5c0f\u5806\u6765\u4fdd\u5b58\uff0c\u6bcf\u4e2aevent loop\u5171\u4eab\u540c\u4e00\u4e2atimerfd\u3002\u6bcf\u6b21\u4e8b\u4ef6\u5faa\u73af\u4e4b\u524d\uff0c\u53d6\u51fa\u6700\u8fd1\u7684\u4e00\u4e2a\u8d85\u65f6\u7684\u65f6\u95f4\uff0c\u5c06\u8fd9\u4e2atimerfd\u8bbe\u7f6e\u4e3a\u8fd9\u4e2a\u8d85\u65f6\u65f6\u95f4\u3002<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n4\r\n5\r\n6\r\n7\r\n8\r\n9\r\n10\r\n11\r\n12\r\n13\r\n14\r\n15\r\n16\r\n17\r\n18\r\n19\r\n<\/span><\/pre>\n<\/td>\n
\n
int epoll_dispatch( ...)\r\n{\r\n    ...\r\n    if (epollop->timerfd >= 0)\r\n    {\r\n        struct itimerspec is;\r\n        is.it_value.tv_sec = tv->tv_sec;\r\n        is.it_value.tv_nsec = tv->tv_usec * 1000;\r\n        timerfd_settime(epollop->timerfd, 0, &is, NULL);\r\n    }\r\n\r\n    res = epoll_wait(epollop->epfd, events, epollop->nevents, -1);\r\n\r\n    for (i = 0; i < res; i++) \r\n    {\r\n        if (events[i].data.fd == epollop->timerfd)\r\n            ;\/\/\r\n    }\r\n}\r\n<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u8fd9\u6837\u7684\u6539\u8fdb\u89c4\u907f\u4e86\u524d\u4e00\u79cd\u65b9\u5f0f\u63d0\u5230\u7684\u9020\u6210\u6587\u4ef6\u63cf\u8ff0\u7b26\u8d44\u6e90\u6d6a\u8d39\u7684\u95ee\u9898\uff0c\u4ec5\u4ec5\u9700\u89811\u4e2a\u989d\u5916\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u3002<\/p>\n
\u989d\u5916\u7684\u7cfb\u7edf\u8c03\u7528\u4ece\u989d\u5916\u76843\u4e2a\uff0c\u964d\u5230\u4e861\u4e2a\u3002\u800c\u4e14\u8fd8\u6709\u6539\u8fdb\u7684\u7a7a\u95f4\uff0c\u53ea\u6709\u5f53\u6808\u9876\u7684timeout\u53d8\u5316\u65f6\uff0c\u624d\u8c03\u7528timerfd_settime()\u6539\u53d8\u3002<\/p>\n
\u8fd9\u79cd\u65b9\u5f0f\u5b9e\u73b0\u7684\u5b9a\u65f6\u5668\uff0c\u7cbe\u5ea6\u63d0\u9ad8\u4e86\u4f46\u662f\u591a\u4e861\u4e2a\u989d\u5916\u7684\u7cfb\u7edf\u8c03\u7528\u3002libevent\u628a\u9009\u62e9\u6743\u7ed9\u4e86\u7528\u6237\uff0c\u7528\u6237\u53ef\u4ee5\u6839\u636e\u5b9e\u9645\u60c5\u51b5\u5728\u521b\u5efaevent base\u7684\u65f6\u5019\u662f\u5426\u914d\u7f6eEVENT_BASE_FLAG_PRECISE_TIMER<\/code>\u5b8f\u800c\u9009\u62e9\u4f7f\u7528\u54ea\u4e2a\u5b9a\u65f6\u5668\u5b9e\u73b0\u3002<\/p>\n
\u603b\u7ed3<\/h1>\n
std::priority_queue\u662f\u4e00\u4e2a\u5bb9\u5668\u9002\u914d\u5668\uff0c\u5e95\u5c42\u7684\u5bb9\u5668\u9ed8\u8ba4\u4f7f\u7528\u7684std::vector(make_heap()<\/a>)\u3002\u4f46\u662f\u8fd9\u4e0d\u610f\u5473\u7740\u5f80std::priority_queue\u63d2\u5165\u4e00\u4e2a\u5143\u7d20\u7684\u5f00\u9500\u662fO(n)\uff0cC++\u6807\u51c6\u5bf9\u6b64\u5b9e\u73b0\u6709\u8981\u6c42\uff0c\u53ef\u4ee5\u653e\u5fc3\u5927\u80c6\u7684\u53bb\u7528\u3002\u4f46\u662fstd::priority_queue\u6ca1\u6709\u63d0\u4f9b\u9ad8\u6548\u5220\u9664\u5143\u7d20\u7684\u63a5\u53e3\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5c06\u56de\u8c03\u51fd\u6570\u7f6e\u7a7a\u7684\u65b9\u5f0f\uff0c\u4ee5O(1)\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u5b9e\u73b0\u5220\u9664\u3002<\/p>\n
\u4ee5C++\u5b9e\u73b0\u7684muduo\u7f51\u7edc\u5e93\u4f7f\u7528\u7684\u662fstd::set\u96c6\u5408\u5b58\u653eTimer\uff1a<\/p>\n
\n\n\n\n
\n
1\r\n2\r\n3\r\n<\/span><\/pre>\n<\/td>\n
\n
typedef std::pair<Timestamp, Timer*> Entry;\r\ntypedef std::set<Entry> TimerList;\r\nTimerList timers_;\r\n<\/span><\/span><\/span><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u5b9e\u9645\u4e0astd::set\u5b9e\u73b0\u5e94\u8be5\u662f\u4e8c\u53c9\u641c\u7d22\u6811\uff0c\u56e0\u6b64\u6548\u7387\u53ef\u80fd\u4f1a\u6bd4\u7528std::priority_queue\u7565\u5dee\u4e00\u70b9\uff08\u300alinux\u591a\u7ebf\u7a0b\u7f51\u7edc\u7f16\u7a0b\u300b 8.2 \uff09\u3002<\/p>\n
\u6b64\u5916\uff0clibev<\/a>\u00a0\u5141\u8bb8\u4f7f\u7528\u4e00\u4e2a\u5b8fEV_USE_4HEAP<\/code>\u6307\u5b9a\u4ee5\u4e00\u4e2a4-heap\u7684\u6570\u636e\u7ed3\u6784\u4fdd\u5b58\u5b9a\u65f6\u5668\uff0c\u636e\u8bf4<\/em>\u6548\u7387\u66f4\u9ad8\uff0c\u6211\u4e5f\u6ca1\u6709\u6d4b\u8bd5\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u76ee\u524d\u4e00\u4e9bc\/c++\u8bed\u8a00\u5b9e\u73b0\u7684\u7f51\u7edc\u5e93\u91cc\u8fb9\u5b9a\u65f6\u5668\u5e38\u7528\u7684\u8bbe\u8ba1\u624b\u6cd5\u3002<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
\u539f\u6587\u5730\u5740   \u6211\u66fe\u4ee5\u4e3a\u50cf\u5b9a\u65f6\u5668<\/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":[119],"class_list":["post-5259","post","type-post","status-publish","format-standard","hentry","tag-03-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/5259","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=5259"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/5259\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=5259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=5259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=5259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}