34 lines
665 B
C++
34 lines
665 B
C++
#include <atomic>
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#include <thread>
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#include <assert.h>
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std::atomic<bool> x,y;
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std::atomic<int> z;
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void write_x_then_y()
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{
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x.store(true,std::memory_order_relaxed);
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std::atomic_thread_fence(std::memory_order_release);
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y.store(true,std::memory_order_relaxed);
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}
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void read_y_then_x()
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{
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while(!y.load(std::memory_order_relaxed));
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std::atomic_thread_fence(std::memory_order_acquire);
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if(x.load(std::memory_order_relaxed))
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++z;
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}
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int main()
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{
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x=false;
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y=false;
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z=0;
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std::thread a(write_x_then_y);
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std::thread b(read_y_then_x);
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a.join();
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b.join();
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assert(z.load()!=0);
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}
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