47 lines
788 B
C++
47 lines
788 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()
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{
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x.store(true,std::memory_order_seq_cst);
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}
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void write_y()
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{
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y.store(true,std::memory_order_seq_cst);
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}
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void read_x_then_y()
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{
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while(!x.load(std::memory_order_seq_cst));
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if(y.load(std::memory_order_seq_cst))
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++z;
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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_seq_cst));
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if(x.load(std::memory_order_seq_cst))
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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);
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std::thread b(write_y);
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std::thread c(read_x_then_y);
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std::thread d(read_y_then_x);
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a.join();
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b.join();
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c.join();
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d.join();
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assert(z.load()!=0);
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}
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