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Edit File: counter.hpp
#ifndef _COUNTER_HPP_ #define _COUNTER_HPP_ #include <boost/shared_ptr.hpp> #include <boost/thread.hpp> #include <boost/thread/thread_time.hpp> struct Counter; typedef boost::shared_ptr<Counter> CounterPtr; /** * A synchronization mechanism with counter-like properties. * * To avoid memory corruption when unit tests fail, one should * never store Counter objects on the stack. Instead, one should * create them on the heap and use CounterPtr smart pointers. */ struct Counter { struct timeout_expired { }; unsigned int value; boost::mutex mutex; boost::condition_variable cond; static CounterPtr create_ptr() { return CounterPtr(new Counter()); } Counter() { value = 0; } /** * Wait until other threads have increment this counter to at least wanted_value. * If this doesn't happen within <tt>timeout</tt> miliseconds, then a timeout_expired * exception will be thrown. */ void wait_until(unsigned int wanted_value, unsigned int timeout = 1000) { boost::unique_lock<boost::mutex> l(mutex); while (value < wanted_value) { if (!cond.timed_wait(l, boost::get_system_time() + boost::posix_time::milliseconds(timeout))) { throw timeout_expired(); } } } /** Increment the counter by one. */ void increment() { boost::unique_lock<boost::mutex> l(mutex); value++; cond.notify_all(); } }; #endif /* _COUNTER_HPP_ */