linux系统课程-课件09day09线程同步2其他

读写锁的特点：读共享，写独占，写优先级高读写锁仍然是一把锁，有不同的状态：读写读写锁场景练习线程A加写锁成功 线程B请求读线程B线程A持有读锁 线程B请求写线程B线程A拥有读锁 线程B请求读B加锁 BCA释放后，BB释放后，C线程A持有写锁 然后线程B请求读锁 然后程C请求BC阻A释放，C加C释放，B加constpthread_rwlockattr_t*restrictattr);pthread_rwlock_trwlock=销毁读intintintint条件变 条件变量不是所，要和互斥量-pthread_mutex_t*restrictmutex,structtimespec}

time_t longtv_nsec;/*nanosecondes*tv_sec绝对时间，填写的时候time(NULL)+600==>设置超时条件变量阻塞pthread_mutex_t*restrict先释放锁阻塞在cond条件变量上intpthread_cond_destroy(pthread_cond_t初始化一个条constpthread_condattr_t*restrictattr);intpthread_cond_broadcast(pthread_cond_t条件变量的作用：避免无必要内容 创建线程回收线程线程退出pthread_exit杀死线程pthread_cancel线程分离pthread_detach,也可以通过属性设置pthread_attr_setdetachstate设置属性分离，之前需要查看线程IDpthread_self在进程内唯一 信号量是进化版的互斥量，允许多个线程共享资intsem_init(sem_t*sem,intpshared,unsignedintsem定义的信号量0代表线程信非0代表进程信value定义信号量的sem_destroy摧毁信号intsem_destroy(sem_t*sem);申请信号量，申请成功value--intsem_wait(sem_t*sem);释放信号量value++intsem_post(sem_t分区linux-day09-线程同步的第9 实现常见两个现象的死锁，锁了又锁以及交叉实现哲学家分区linux-day09-线程同步的第10errno #defineEPERM 1/*Operationnotpermitted*/#defineENOENT 2/*Nosuchfileordirectory*/#defineESRCH 3/*Nosuchprocess*/#defineEINTR /*Interruptedsystemcall*/#defineEIO /*I/Oerror*/#defineENXIO /*Nosuchdeviceoraddress*/#defineE2BIG /*Argumentlisttoolong*/#defineENOEXEC /*Execformaterror*/#defineEBADF /*Badfilenumber*/#defineECHILD /*Nochildprocesses*/#defineEAGAIN /*Tryagain*/#defineENOMEM12/*Outofmemory*/#defineEACCES13/*Permissiondenied*/#defineEFAULT14/*Badaddress*/#defineENOTBLK15/*Blockdevicerequired*/#defineEBUSY 16/*Deviceorresourcebusy*/#defineEEXIST17/*Fileexists*/#defineEXDEV /*Cross-devicelink*/#defineENODEV /*Nosuchdevice*/#defineENOTDIR /*Notadirectory*/#defineEISDIR /*Isadirectory*/#defineEINVAL 22 /*Invalidargument*/#defineENFILE /*Filetableoverflow*/#defineEMFILE 24 /*Toomanyopenfiles*/#defineENOTTY /*Notatypewriter*/#defineETXTBSY /*Textfilebusy*/#defineEFBIG /*Filetoolarge*/#defineENOSPC /*Nospaceleftondevice*/#defineESPIPE /*Illegalseek*/#defineEROFS /*Read-onlyfilesystem*/#defineEMLINK /*Toomanylinks*/ /*Brokenpipe /*Mathargumentoutofof /*Mathresultnotrepresentable#defineEDEADLK /*Resourcedeadlockwouldoccur*/#defineENALONG /*Filenametoolong*/#defineENOLCK /*Norecordlocksavailable*/#defineENOSYS /*Invalidsystemcallnumber*/#defineENOTEMPTY /*Directorynotempty*/ /*Toomanysymboliclinks#defineEWOULDBLOCK EAGAIN/*Operationwouldblock*/#defineENOMSG /*Nomessageofdesiredtype*/#defineEIDRM /*Identifierremoved*/#defineECHRNG /*Channelnumberoutofrange*/#defineEL2NSYNC /*Level2notsynchronized*/#defineEL3HLT /*Level3halted*/ /*Level3reset#defineELNRNG /*Linknumberoutofrange*/#defineEUNATCH /*Protocoldrivernotattached*/#defineENOCSI /*NoCSIstructureavailable*/#defineEL2HLT /*Level2halted*/ /*Invalidexchange#defineEBADR 53 /*Invalidrequestdescriptor*/#defineEXFULL /*Exchangefull*/ /*Noanode#defineEBADRQC /*Invalidrequestcode*/#defineEBADSLT /*Invalidslot*/ #defineEBFONT /*Badfontfileformat*/#defineENOSTR /*Devicenotastream*/#defineENODATA /*Nodataavailable*/#defineETIME /*Timerexpired*/ /*Outofstreamsresources#defineENONET /*Machineisnotonthenetwork*/#defineENOPKG 65 /*Packagenotinstalled*/#defineEREMOTE /*Objectisremote*/#defineENOLINK /*Linkhasbeensevered*/#defineEADV /*Advertiseerror*/ /*Srmounterror#defineECOMM /*Communicationerroronsend*/#defineEPROTO /*Protocolerror*/#defineEMULTIHOP /*Multihopattempted*/#defineEDOTDOT /*RFSspecificerror*/#defineEBADMSG /*Notadatamessage*/#defineEOVERFLOW /*Valuetoolargefordefineddatatype*/#defineENOTUNIQ /*Namenotuniqueonnetwork*/#defineEBADFD /*Filedescriptorinbadstate*/#defineEREMCHG /*Remoteaddresschanged*/ /*Cannotaccessaneededshared#defineELIBBAD 80 /*Accessingacorruptedsharedlibrary*/ /*.libsectionina.outcorrupted*/#defineELIBMAX /*Attemptingtolinkintoomanysharedlibraries*/ /*Cannotexecasharedlibrary /*Illegalbytesequence#defineERESTART /*Interruptedsystemcallshouldberestarted*/#defineESTRPIPE /*Streamspipeerror*/#defineEUSERS /*Toomanyusers*/#defineENOTSOCK88/*Socketoperationonnon-socket*/#defineEDESTADDRREQ89/*Destinationaddressrequired*/#defineEMSGSIZE90/*Messagetoolong*/#defineEPROTOTYPE /*Protocolwrongtypeforsocket*/#defineENOPROTOOPT /*Protocolnotavailable*/#defineEPROTONOSUPPORT93 /*Protocolnotsupported*/#defineESOCKTNOSUPPORT94 /*Sockettypenotsupported*/#defineEOPNOTSUPP /*Operationnotsupportedontransportendpoint*/ /*Protocolfamilynotsupported#defineEAFNOSUPPORT /*Addressfamilynotsupportedbyprotocol*/ /*Addressalreadyinuse /*Cannotassignrequested /*Networkisdown#defineENETUNREACH101/*Networkisunreachable*/#defineENETRESET102/*Networkdroppedconnectionbecauseofreset*/#defineECONNABORTED103/*Softwarecausedconnectionabort*/#defineECONNRESET104/*Connectionresetbypeer#define/*Nobufferspaceavailable#define/*Transportendpointisconnected#defineENOTCONN /*Transportendpointisnotconnected*/#defineESHUTDOWN /*Cannotsendaftertransportendpointshutdown*/#defineETOOMANYREFS /*Toomanyreferences:cannotsplice*/#defineETIMEDOUT /*Connectiontimedout*/#defineECONNREFUSED /*Connectionrefused*/#defineEHOSTDOWN /*Hostisdown*/#defineEHOSTUNREACH /*Noroutetohost*