c/c++原子操作 接口函数　自查文档

type __sync_fetch_and_add (type *ptr, type value);
type __sync_fetch_and_sub (type *ptr, type value);
type __sync_fetch_and_or (type *ptr, type value);
type __sync_fetch_and_and (type *ptr, type value);
type __sync_fetch_and_xor (type *ptr, type value);
type __sync_fetch_and_nand (type *ptr, type value);
type __sync_add_and_fetch (type *ptr, type value);
type __sync_sub_and_fetch (type *ptr, type value);
type __sync_or_and_fetch (type *ptr, type value);
type __sync_and_and_fetch (type *ptr, type value);
type __sync_xor_and_fetch (type *ptr, type value);
type __sync_nand_and_fetch (type *ptr, type value);

bool __sync_bool_compare_and_swap (type *ptr, type oldval type newval, ...)
type __sync_val_compare_and_swap (type *ptr, type oldval type newval, ...)
type __sync_lock_test_and_set (type *ptr, type value, ...)
将*ptr设为value并返回*ptr操作之前的值。

void __sync_lock_release (type *ptr, ...)
将*ptr置0

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>

static int count = 0;

void *test_func(void *arg)
{
int i=0;
for(i=0;i<20000;++i){
__sync_fetch_and_add(&count,1);
}
returnNULL;
}

int main(int argc, const char *argv[])
{
pthread_tid[20];
int i =0;

for(i=0;i<20;++i){
pthread_create(&id[i],NULL,test_func,NULL);
}

for(i=0;i<20;++i){
pthread_join(id[i],NULL);
}

printf("%d\n",count);
return0;
}

std::atomic_char    std::atomic<char>
std::atomic_schar   std::atomic<signed char>
std::atomic_uchar   std::atomic<unsigned char>
std::atomic_short   std::atomic<short>
std::atomic_ushort  std::atomic<unsigned short>
std::atomic_int std::atomic<int>
std::atomic_uint    std::atomic<unsigned int>
std::atomic_long    std::atomic<long>
std::atomic_ulong   std::atomic<unsigned long>
std::atomic_llong   std::atomic<long long>
std::atomic_ullong  std::atomic<unsigned long long>

#include <iostream>
#include <thread>
#include <atomic>                 // modified

std::atomic_long sum = {0L};  　　//  modified

void fun()
{
for(int i=0;i<100;++i)
sum += i;
}

int main()
{
std::cout << "Before joining,sun = " << sum << std::endl;
std::thread t1(fun);
std::thread t2(fun);
t1.join();
t2.join();
std::cout << "After joining,sun = " << sum << std::endl;
}