在ZThread庫中 使用互斥鎖並允許任務掛起的基類是Condition 可以在條件Condition上呼叫wait()掛起一個任務

WaxOMatic.cpp有兩個程序 一個程序給Car上蠟 另一個程序給Car拋光

拋光程序在上臘程序完成前不能進行工作 並且上臘程序在汽車客運穿上另一個臘外套之前必須等待直到拋光程序完成

//: C11:WaxOMatic.cpp {RunByHand}
// From "Thinking in C++, Volume 2", by Bruce Eckel & Chuck Allison.
// (c) 1995-2004 MindView, Inc. All Rights Reserved.
// See source code use permissions stated in the file 'License.txt',
// distributed with the code package available at www.MindView.net.
// Basic thread cooperation.
//{L} ZThread
#include <iostream>
#include <string>
#include "zthread/Thread.h"
#include "zthread/Mutex.h"
#include "zthread/Guard.h"
#include "zthread/Condition.h"
#include "zthread/ThreadedExecutor.h"
using namespace ZThread;
using namespace std;

class Car {
  Mutex lock;
  Condition condition;
  bool waxOn;
public:
  Car() : condition(lock), waxOn(false) {}
  void waxed() {
    Guard<Mutex> g(lock);
    waxOn = true; // Ready to buff
    condition.signal();
  }
  void buffed() {
    Guard<Mutex> g(lock);
    waxOn = false; // Ready for another coat of wax
    condition.signal();
  }
  void waitForWaxing() {
    Guard<Mutex> g(lock);
    while(waxOn == false)
      condition.wait();
  }
  void waitForBuffing() {
    Guard<Mutex> g(lock);
    while(waxOn == true)
      condition.wait();
  }
};

class WaxOn : public Runnable {
  CountedPtr<Car> car;
public:
  WaxOn(CountedPtr<Car>& c) : car(c) {}
  void run() {
    try {
      while(!Thread::interrupted()) {
        cout << "Wax On!" << endl;
        Thread::sleep(200);
        car->waxed();
        car->waitForBuffing();
      }
    } catch(Interrupted_Exception&) { /* Exit */ }
    cout << "Ending Wax On process" << endl;
  }
};

class WaxOff : public Runnable {
  CountedPtr<Car> car;
public:
  WaxOff(CountedPtr<Car>& c) : car(c) {}
  void run() {
    try {
      while(!Thread::interrupted()) {
        car->waitForWaxing();
        cout << "Wax Off!" << endl;
        Thread::sleep(200);
        car->buffed();
      }
    } catch(Interrupted_Exception&) { /* Exit */ }
    cout << "Ending Wax Off process" << endl;
  }
};

int main() {
  cout << "Press <Enter> to quit" << endl;
  try {
    CountedPtr<Car> car(new Car);
    ThreadedExecutor executor;
    executor.execute(new WaxOff(car));
    executor.execute(new WaxOn(car));
    cin.get();
    executor.interrupt();
  } catch(Synchronization_Exception& e) {
    cerr << e.what() << endl;
  }
  getchar();
} ///:~
 

輸出 ThreadQueue created Press <Enter> to quit User thread created. Reference thread created. 1 reference-thread added. pollPendingThreads() 1 user-thread added. Thread starting... User thread created. pollPendingThreads() 1 user-thread added. Thread starting... Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! 輸出省略

在Car的建構函式中 一個互斥鎖Mutex被封裝於Condition物件中 以便Mutex可以用於管理任務間的通訊