__thread:在多线程变成中，使用于global变量，使每个线程都私有一份。
static __thread int count;
void *function1(void *argc)
{
printf("porgran pid:%u, the function1 pthread id is %lu, count:%d\n",getpid(), pthread_self(), count);
count = 10;
printf("porgran pid:%u, last the function1 pthread id is %lu, count:%d\n",getpid(), pthread_self(), count);
return 0;
}
void *function2(void *argc)
{
printf("porgran pid:%u, the function2 pthread id is %lu, count:%d\n", getpid(), pthread_self(), count);
sleep(2);
count = 100;
printf("porgran pid:%u, last the function2 pthread id is %lu, count:%d\n", getpid(), pthread_self(), count);
return 0;
}
int main()
{
pthread_t thread_id[2];
int ret;
pthread_t mian_thread_id;
mian_thread_id = pthread_self();
count = 2;
printf("porgran pid:%u, mian_thread_id:%lu, count:%d\n", getpid(), mian_thread_id, count);
ret = pthread_create(thread_id, NULL, function1, NULL);
assert(ret == 0);
ret = pthread_create(thread_id + 1, NULL, function2, NULL);
assert(ret == 0);
ret = pthread_join(thread_id[0], NULL);
assert(ret == 0);
ret = pthread_join(thread_id[1], NULL);
assert(ret == 0);
count = 1000;
printf("porgran pid:%u, last mian_thread_id:%lu, count:%d\n", getpid(), mian_thread_id, count);
return 0;
}
__typeof__(var) 是gcc对C语言的一个扩展保留字，用于声明变量类型,var可以是数据类型（int， char*..),也可以是变量表达式。
define DEFINE_MY_TYPE(type, name) __thread __typeof__(type) my_var_##name
DEFINE_MY_TYPE(int, one); //It is equivalent to '__thread int my_var_'; which is a thread variable.
int main()
{
__typeof__(int *) x; //It is equivalent to 'int *x';
__typeof__(int) a;//It is equivalent to 'int a';
__typeof__(*x) y;//It is equivalent to 'int y';
__typeof__(&a) b;//It is equivalent to 'int b';
__typeof__(__typeof__(int *)[4]) z; //It is equivalent to 'int *z[4]';
y = *x;
b = &a;
z[0] = x;
z[1] = &a;
return 0;
}
