pthread_join_spawn_2.cpp

/**
 * @author github.com/luncliff (luncliff@gmail.com)
 */
#include <cstring>

#include <coroutine/pthread.h>
#include <coroutine/return.h>

using namespace std;
using namespace coro;

auto spawn_and_join(pthread_t& tid, const pthread_attr_t* attr)
    -> pthread_joiner {
    co_await attr;
    tid = pthread_self();
    co_return;
}

int main(int, char*[]) {
    printf("before spawn: %llx \n", (uint64_t)pthread_self());

    pthread_t tid{};
    {
        // joiner's destructor will wait for the new thread to return
        auto joiner = spawn_and_join(tid, nullptr);
    }
    // the new thread's id must be visible at this moment
    printf("after join: %llx \n", (uint64_t)tid);

    if (tid == pthread_t{})
        return __LINE__;
    if (tid == pthread_self())
        return __LINE__;

    // it's already joined.
    // so if we trying to join it again, the operation must fail
    if (const auto ec = pthread_join(tid, nullptr); ec != ESRCH) {
        puts(strerror(ec));
        return __LINE__;
    }

    return EXIT_SUCCESS;
}