int x = a.fetch_add(1,std::memory_order_relaxed);编译出来就是两条指令：movl $1, %edxlock xaddl%edx, (%rax)其中 lock xaddl 是原子的，%rax 是 a 的地址，执行完之后 %edx 是 (%rax) 的旧值，也就是 x 。https://en.wikipedia.org/wiki/Fetch-an
问std::memory_order_relaxed与fetch_addEN学习如下代码： 线程竞争和乱序执行 #include <thread> #inclu...
fetch_sub方法执行read-modify-write操作自动减去Value从*this中的存储值, 在Order指定的内存约束内。 #include<iostream>#include<thread>#include<atomic>std::atomic<longlong>data; int main() { long orginal = data.fetch_add(1, std::memory_order_relaxed); std::cout << "orginal:" << orginal <<...
fetch_add(1, std::memory_order_relaxed); } int main() { std::thread th1(do_work); std::thread th2(do_work); std::thread th3(do_work); std::thread th4(do_work); std::thread th5(do_work); th1.join(); th2.join(); th3.join(); th4.join(); th5.join(); std::cout...
counter.fetch_add(1, std::memory_order_relaxed); } } int main() { std::thread t1(increment); std::thread t2(increment); t1.join(); t2.join(); std::cout << "Final counter value: " << counter << std::endl; return 0; } ``` 在这个示例中,我们定义了一个全局的`std::atomic...
atomic_fetch_add_explicit(&counter, 1, memory_order_relaxed); Run Code Online (Sandbox Code Playgroud) atomic_fetch_add如果您不知道什么是内存顺序,那么使用具有“最安全”顺序顺序的普通格式可能会更好。 atomic_fetch_add(&counter, 1); Run Code Online (Sandbox Code Playgroud) 话虽这么说,如果...
fetch_add(1, std::memory_order_relaxed); } int main() { std::thread th1(do_work); std::thread th2(do_work); std::thread th3(do_work); std::thread th4(do_work); std::thread th5(do_work); th1.join(); th2.join(); th3.join(); th4.join(); th5.join(); std::cout...
order - memory order constraints to enforce 返回值 中此函数的效果之前的值。修改顺序成*this... 例外 noexcept规格: noexcept 例 二次 代码语言:javascript 复制 #include<iostream>#include<thread>#include<atomic>std::atomic<long long>data;voiddo_work(){data.fetch_add(1,std::memory_order_relaxed)...
#include <iostream> #include <thread> #include <atomic> std::atomic<long long> data; void do_work() { data.fetch_add(1, std::memory_order_relaxed); } int main() { std::thread th1(do_work); std::thread th2(do_work); std::thread th3(do_work); std::thread th4(do_work); ...
#include <array>#include <atomic>#include <iostream>#include <thread>std::atomic<longlong>data{10};std::array<longlong,5>return_values{};voiddo_work(intthread_num){longlongval=data.fetch_add(1,std::memory_order_relaxed);return_values[thread_num]=val;}intmain(){{std::jthreadth0{do_...