對於讀寫問題，ZThread庫專門封裝了類（ReadWriteLock）來控制讀寫：

FairReadWriteLock (按FIFO的順序進行讀寫控制):

 A FairReadWriteLock maintains a balance between the order read-only access and read-write access is allowed. Threads contending for the pair of Lockable objects this ReadWriteLock provides will gain access to the locks in FIFO order.

BiasedReadWriteLock(寫優先的讀寫控制):

A BiasedReadWriteLock has a bias toward writers. It will prefer read-write access over read-only access when many threads are contending for access to either Lockable this ReadWriteLock provides.

下面是試測試程式碼（文中帶有註釋，因此後面不再分析程式）：

#include "stdafx.h" #include "zthread/Runnable.h" #include "zthread/Thread.h" #include "zthread/CountedPtr.h" #include "zthread/ReadWriteLock.h" #include "zthread/FairReadWriteLock.h" #include "zthread/BiasedReadWriteLock.h" #include "Display.h" using namespace std; using namespace ZThread; class ReadThread : public Runnable { public: ReadThread(CountedPtr<ReadWriteLock>& lock, CountedPtr<Display>& disp, int idn = -1) : Lock(lock),display(disp), id(idn){} void run() { try { while (!Thread::interrupted()) { //獲得 讀 互斥鎖 Lock->getReadLock().acquire(); //模擬 讀操作 output(" Reading..."); Thread::sleep(100); //釋放 讀 互斥鎖 Lock->getReadLock().release(); //特意留出空閒時間，使執行緒能根據BiasedReadWriteLock的行為排程執行緒 Thread::sleep(500); } } catch (Interrupted_Exception& e) { output(e.what()); } } //輸出 void output(string str) { ostringstream os; os << *this << " : " << str <<endl; display->OutPut(os); } friend ostream& operator<< (ostream& os, const ReadThread& readThread) { return os << readThread.id; } private: //共享的讀寫控制鎖，且 寫操作 優先於 讀操作 CountedPtr<ReadWriteLock> Lock; CountedPtr<Display> display; int id; }; class WriteThread : public Runnable { public: WriteThread(CountedPtr<ReadWriteLock>& lock, CountedPtr<Display>& disp, int idn = -1) : Lock(lock), display(disp), id(idn){} void run() { try { while (!Thread::interrupted()) { //獲得 寫 互斥鎖 Lock->getWriteLock().acquire(); //模擬 寫操作 output(" Wirtting..."); Thread::sleep(100); //釋放 寫 互斥鎖 Lock->getWriteLock().release(); //特意留出空閒時間，使執行緒能根據BiasedReadWriteLock的行為排程執行緒 Thread::sleep(500); } } catch (Interrupted_Exception& e) { output(e.what()); } } //同步輸出 void output(string str) { ostringstream os; os << *this << " : " << str <<endl; display->OutPut(os); } friend ostream& operator<< (ostream& os, const WriteThread& writeThread) { return os << writeThread.id; } private: CountedPtr<ReadWriteLock> Lock; CountedPtr<Display> display; int id; }; int main() { try { //FairReadWriteLock是FIFO順序的讀寫控制鎖 CountedPtr<ReadWriteLock> ReadWrite( new FairReadWriteLock); //BiasedReadWriteLock是寫優先的讀寫控制鎖 //CountedPtr<ReadWriteLock> ReadWrite( new BiasedReadWriteLock); CountedPtr<Display> disp(new Display); ThreadedExecutor executor; for (int i = 0; i < 5; i++) { executor.execute(new ReadThread(ReadWrite, disp, i)); } for (int i = 0; i < 5; i++) { executor.execute(new WriteThread(ReadWrite, disp, i)); } cin.get(); executor.interrupt(); cin.get(); } catch (Synchronization_Exception& e) { cerr << "Jarry Main Exception " << e.what() << endl; } }

使用FairReadWriteLock時的執行結果：使用BiasedReadWriteLock時的執行結果：