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concurrent_bitset 并发bitset
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#include <atomic> | |
#include <array> | |
#include <cstddef> | |
class cbs_8 | |
{ | |
private: | |
std::atomic<uint8_t> data_; | |
bool load(size_t idx) const | |
{ | |
return 0 != (data_.load(std::memory_order_acquire) & (1 << idx)); | |
} | |
void store(size_t idx, bool v) | |
{ | |
for (;;) { | |
uint8_t data_before = data_.load(std::memory_order_acquire); | |
uint8_t data_after; | |
if (v) { | |
data_after = data_before | (1 << idx); | |
} else { | |
data_after = data_before & ~(1 << idx); | |
} | |
if (data_.compare_exchange_weak( | |
data_before, data_after, | |
std::memory_order_release, | |
std::memory_order_relaxed)) | |
return; | |
} | |
} | |
public: | |
class reference | |
{ | |
private: | |
cbs_8& container_; | |
size_t idx_; | |
public: | |
reference(cbs_8& container, size_t idx) | |
: container_(container), idx_(idx) | |
{} | |
operator bool() const { | |
return container_.load(idx_); | |
} | |
reference& operator=(bool v) { | |
container_.store(idx_, v); | |
return *this; | |
} | |
}; | |
bool operator[](size_t idx) const | |
{ | |
return load(idx); | |
} | |
reference operator[](size_t idx) | |
{ | |
return reference{*this, idx}; | |
} | |
}; | |
template <size_t Size> | |
class concurrent_bitset | |
{ | |
private: | |
static const size_t unit_size = 8; | |
std::array<cbs_8, (Size + (unit_size - 1)) / unit_size> units_; | |
public: | |
using reference = cbs_8::reference; | |
bool operator[](size_t idx) const | |
{ | |
return units_[idx / unit_size][idx % unit_size]; | |
} | |
reference operator[](size_t idx) | |
{ | |
return units_[idx / unit_size][idx % unit_size]; | |
} | |
}; |
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#include "concurrent_bitset.hpp" | |
#include <iostream> | |
int main(void) { | |
concurrent_bitset<20> u; | |
u[0] = true; | |
u[7] = false; | |
u[14] = true; | |
u[15] = false; | |
u[19] = true; | |
std::cout << "u[0] = " << u[0] << std::endl; | |
std::cout << "u[7] = " << u[7] << std::endl; | |
std::cout << "u[14] = " << u[14] << std::endl; | |
std::cout << "u[15] = " << u[15] << std::endl; | |
std::cout << "u[19] = " << u[19] << std::endl; | |
return 0; | |
} | |
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