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// mutex::try_lock example
#include <iostream> // std::cout
#include <thread> // std::thread
#include <mutex> // std::mutex
volatile int counter (0); // non-atomic counter
std::mutex mtx; // locks access to counter
void attempt_10k_increases () {
for (int i=0; i<10000; ++i) {
if (mtx.try_lock()) { // only increase if currently not locked:
++counter;
mtx.unlock();
}
}
}
int main ()
{
std::thread threads[10];
// spawn 10 threads:
for (int i=0; i<10; ++i)
threads[i] = std::thread(attempt_10k_increases);
for (auto& th : threads) th.join();
std::cout << counter << " successful increases of the counter.\n";
return 0;
}
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