读者写者问题

精品文档 1欢迎下载 精品文档 2欢迎下载 include include include include include include define MAX PERSON 100 define READER 0 读者 define WRITER 1 写者 define END 1 define R READER define W WRITER typedef struct Person HANDLE m hThread 定义处理线程的句柄 int m nType 进程类型 读写 精品文档 3欢迎下载 int m nStartTime 开始时间 int m nWorkTime 运行时间 int m nID 进程号 Person Person g Persons MAX PERSON int g NumPerson 0 long g CurrentTime 0 基本时间片数 int g PersonLists 进程队列 1 W 3 5 2 W 16 5 3 R 5 2 4 W 6 5 5 R 4 3 6 R 17 7 END int g NumOfReading 0 int g NumOfWriteRequest 0 申请写进程的个数 HANDLE g hReadSemaphore 读者信号 HANDLE g hWriteSemaphore 写者信号 bool finished false 所有的读完成 bool wfinished false 所有的写完成 void CreatePersonList int pPersonList bool CreateReader int StartTime int WorkTime int ID bool CreateWriter int StartTime int WorkTime int ID DWORD WINAPI ReaderProc LPVOID lpParam DWORD WINAPI WriterProc LPVOID lpParam int main 精品文档 4欢迎下载 g hReadSemaphore CreateSemaphore NULL 1 100 NULL 创建信号灯 当前可用的资 源数为 1 最大为 100 g hWriteSemaphore CreateSemaphore NULL 1 100 NULL 创建信号灯 当前可用的 资源数为 1 最大为 100 CreatePersonList g PersonLists Create All the reader and writers printf 创建所有读者写者 n g CurrentTime 0 while true g CurrentTime Sleep 300 300 ms printf 当前时间 d n g CurrentTime if finished return 0 return 0 void CreatePersonList int pPersonLists int i 0 int pList pPersonLists bool Ret while pList 0 END switch pList 1 case R Ret CreateReader pList 2 pList 3 pList 0 351 w452 523 654 精品文档 5欢迎下载 break case W Ret CreateWriter pList 2 pList 3 pList 0 break if Ret printf 创建 d 错误 n pList 0 pList 4 move to next person list DWORD WINAPI ReaderProc LPVOID lpParam 读过程 Person pPerson Person lpParam wait for the start time while g CurrentTime pPerson m nStartTime printf 读者 d 正在请求 n pPerson m nID printf n n n wait for the write request WaitForSingleObject g hReadSemaphore INFINITE if g NumOfReading 0 WaitForSingleObject g hWriteSemaphore INFINITE g NumOfReading ReleaseSemaphore g hReadSemaphore 1 NULL pPerson m nStartTime g CurrentTime printf 读者 d 正在读取共享缓冲区 n pPerson m nID 精品文档 6欢迎下载 printf n n n while g CurrentTime m nStartTime pPerson m nWorkTime printf 读者 d 正在退出 n pPerson m nID printf n n n WaitForSingleObject g hReadSemaphore INFINITE g NumOfReading if g NumOfReading 0 ReleaseSemaphore g hWriteSemaphore 1 NULL 此时没有读者 可以写 ReleaseSemaphore g hReadSemaphore 1 NULL if pPerson m nID 4 finished true 所有的读写完成 ExitThread 0 return 0 DWORD WINAPI WriterProc LPVOID lpParam Person pPerson Person lpParam wait for the start time while g CurrentTime pPerson m nStartTime printf 写者 d 正在请求进行写操作 n pPerson m nID printf n n n WaitForSingleObject g hWriteSemaphore INFINITE modify the writer s real start time 精品文档 7欢迎下载 pPerson m nStartTime g CurrentTime printf 写者 d 正在向共享缓冲区写内容 n pPerson m nID while g CurrentTime m nStartTime pPerson m nWorkTime printf 写者 d 正在退出 n pPerson m nID printf n n n g NumOfWriteRequest ReleaseSemaphore g hWriteSemaphore 1 NULL if pPerson m nID 4 finished true 所有的读写完成 ExitThread 0 return 0 bool CreateReader int StartTime int WorkTime int ID DWORD dwThreadID if g NumPerson MAX PERSON return false Person pPerson pPerson m nID ID pPerson m nStartTime StartTime pPerson m nWorkTime WorkTime pPerson m nType READER g NumPerson Create an New Thread pPerson m hThread 精品文档 8欢迎下载 CreateThread NULL 0 ReaderProc LPVOID pPerson 0 if pPerson m hThread NULL return false return true bool CreateWriter int StartTime int WorkTime int ID DWORD dwThreadID if g NumPerson MAX PERSON return false Person pPerson pPerson m nID ID pPerson m nStartTime StartTime pPerson m nWorkTime WorkTime pPerson m nType WRITER g NumPerson Create an New Thread pPerson