相关疑难解决方法(0)

我用原子而不是锁写了一些东西,并且在我的情况下,我写了下面这个迷你测试的速度慢得多:

#include <pthread.h>
#include <vector>

struct test
{
    test(size_t size) : index_(0), size_(size), vec2_(size)
        {
            vec_.reserve(size_);
            pthread_mutexattr_init(&attrs_);
            pthread_mutexattr_setpshared(&attrs_, PTHREAD_PROCESS_PRIVATE);
            pthread_mutexattr_settype(&attrs_, PTHREAD_MUTEX_ADAPTIVE_NP);

            pthread_mutex_init(&lock_, &attrs_);
        }

    void lockedPush(int i);
    void atomicPush(int* i);

    size_t              index_;
    size_t              size_;
    std::vector<int>    vec_;
    std::vector<int>    vec2_;
    pthread_mutexattr_t attrs_;
    pthread_mutex_t     lock_;
};

void test::lockedPush(int i)
{
    pthread_mutex_lock(&lock_);
    vec_.push_back(i);
    pthread_mutex_unlock(&lock_);
}

void test::atomicPush(int* i)
{
    int ii       = (int) (i - &vec2_.front());
    size_t index = __sync_fetch_and_add(&index_, 1);
    vec2_[index & (size_ - 1)] = ii;
}

int main(int argc, char** argv) …