C++环境下，pthread_cancel终止一个线程时，被终止线程内部的栈变量会自动销毁吗？

Question

下面这段代码中，主线程创建了2个子线程，线程1和线程2，在线程2中使用pthread_cancel去终止线程1，线程1终止时其内部的栈变量（如my_class）会自动销毁吗？

实测结果：LINUX环境下会自动销毁，QNX环境下不会自动销毁（根本不会调用MyClass和MyClass2的析构函数），这是为什么？LINUX和QNX的pthread都说是遵循POSIX API规范，难道是和系统实现有关系？

#include <iostream>
#include <pthread.h>
#include <thread>
using namespace std;
pthread_t thread_id_1;
pthread_t thread_id_2;
class MyClass2
{
public:
    MyClass2() {
        cout << "Build MyClass2" << endl;
    }
    ~MyClass2() {
        cout << "Destory MyClass2" << endl;
    }
};
class MyClass
{
public:
    MyClass() {
        cout << "Build MyClass" << endl;
        p = new char[1024 * 1024 *100];
    }
    ~MyClass() {
        cout << "Destory MyClass" << endl;
        free(p);
    }
    char *p;
};
void func(int i)
{
    MyClass2 c2;
    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
    cout << "thread 1 func:" << i << endl;
}
static void *otx_thread_1(void *arg)
{
    MyClass my_class;
    int type_value = pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
    cout << "thread_1 set cancle type+++++:" << type_value << endl;
    for (int i = 0; i < 10; i++) {
        func(i);
        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
    }
    return nullptr;
}
static void *otx_thread_2(void *arg)
{
    for (int i = 0; i < 10; i++) {
        cout << "thread_2:" << i << endl;
        std::this_thread::sleep_for(std::chrono::milliseconds(10));
    }
    int ret = pthread_cancel(thread_id_1);
    cout << "otx_thread_2 cancel thread 1 ret:" << ret << endl;
    return nullptr;
}
int main(int argc, char *argv[])
{
    cout << "Main start" << endl;

    pthread_attr_t attr;
    pthread_attr_init( &attr );
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
    cout << "Main set detch" << endl;
    if (pthread_create(&thread_id_1, &attr, otx_thread_1, nullptr) != 0) {
        cout << "pthread_create() 1 error" << endl;
        return -1;
    }
    if (pthread_create(&thread_id_2, nullptr, otx_thread_2, nullptr) != 0) {
        cout << "pthread_create() 2 error" << endl;
        return -1;
    }
    if (pthread_join(thread_id_2, NULL) != 0) {
        cout << "pthread_join() 1 error";
        return -1;
    }
    while (1) {
        cout << "Main Loop" << endl;
        std::this_thread::sleep_for(std::chrono::milliseconds(1000));
    }
    return 0;
}