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// condition_variable_any::notify_all
#include <iostream> // std::cout
#include <thread> // std::thread
#include <mutex> // std::mutex
#include <condition_variable> // std::condition_variable_any
std::mutex mtx;
std::condition_variable_any cv;
bool ready = false;
void print_id (int id) {
mtx.lock();
while (!ready) cv.wait(mtx);
// ...
std::cout << "thread " << id << '\n';
mtx.unlock();
}
void go() {
mtx.lock();
ready = true;
cv.notify_all();
mtx.unlock();
}
int main ()
{
std::thread threads[10];
// spawn 10 threads:
for (int i=0; i<10; ++i)
threads[i] = std::thread(print_id,i);
std::cout << "10 threads ready to race...\n";
go(); // go!
for (auto& th : threads) th.join();
return 0;
}
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