//: C11:ToastOMatic.cpp {RunByHand} // Problems with thread cooperation. //{L} ZThread #include <iostream> #include <cstdlib> #include <ctime> #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; // Apply jam to buttered toast: class Jammer : public Runnable { Mutex lock; Condition butteredToastReady; bool gotButteredToast; int jammed; public: Jammer() : butteredToastReady(lock) { gotButteredToast = false; jammed = 0; } void moreButteredToastReady() { Guard<Mutex> g(lock); gotButteredToast = true; butteredToastReady.signal(); } void run() { try { while(!Thread::interrupted()) { { Guard<Mutex> g(lock); while(!gotButteredToast) butteredToastReady.wait(); ++jammed; } cout << "Putting jam on toast " << jammed << endl; { Guard<Mutex> g(lock); gotButteredToast = false; } } } catch(Interrupted_Exception&) { /* Exit */ } cout << "Jammer off" << endl; } }; // Apply butter to toast: class Butterer : public Runnable { Mutex lock; Condition toastReady; CountedPtr<Jammer> jammer; bool gotToast; int buttered; public: Butterer(CountedPtr<Jammer>& j) : toastReady(lock), jammer(j) { gotToast = false; buttered = 0; } void moreToastReady() { Guard<Mutex> g(lock); gotToast = true; toastReady.signal(); } void run() { try { while(!Thread::interrupted()) { { Guard<Mutex> g(lock); while(!gotToast) toastReady.wait(); ++buttered; } cout << "Buttering toast " << buttered << endl; jammer->moreButteredToastReady(); { Guard<Mutex> g(lock); gotToast = false; } } } catch(Interrupted_Exception&) { /* Exit */ } cout << "Butterer off" << endl; } }; class Toaster : public Runnable { CountedPtr<Butterer> butterer; int toasted; public: Toaster(CountedPtr<Butterer>& b) : butterer(b) { toasted = 0; } void run() { try { while(!Thread::interrupted()) { Thread::sleep(rand()/(RAND_MAX/5)*100); // ... // Create new toast // ... cout << "New toast " << ++toasted << endl; butterer->moreToastReady(); } } catch(Interrupted_Exception&) { /* Exit */ } cout << "Toaster off" << endl; } }; int main() { srand(time(0)); // Seed the random number generator try { cout << "Press <Return> to quit" << endl; CountedPtr<Jammer> jammer(new Jammer); CountedPtr<Butterer> butterer(new Butterer(jammer)); ThreadedExecutor executor; executor.execute(new Toaster(butterer)); executor.execute(butterer); executor.execute(jammer); cin.get(); executor.interrupt(); } catch(Synchronization_Exception& e) { cerr << e.what() << endl; } } ///:~
Listado 10.30. C11/ToastOMatic.cpp