Program not exiting after using POSIX timers

Consider the following program:

#define _POSIX_C_SOURCE 200809L
#include <time.h>
#include <pthread.h>
#include <signal.h>

void timerfunc(union sigval val) { }

int main()
{
        struct sigevent sev = { .sigev_notify = SIGEV_THREAD,
                .sigev_notify_function = timerfunc };
        timer_t t;
        timer_create(CLOCK_REALTIME, &sev, &t);
        timer_delete(t);
        pthread_exit(0);
}

Linked with glibc, it not only fails to terminate, but it is unkillable except by 开发者_Go百科kill -9/SIGKILL. Is this behavior permitted by the standard? Are there good workarounds aside from either always explicitly exiting the process (as opposed to just exiting all threads)?

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Well, POSIX specifically says it is

...impossible to determine the lifetime of the created thread...

which implies that any lifetime is allowed.

SIGEV_THREAD is simply bad mojo, and should be avoided.

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Does pthread_exit work with the main process thread? I've always wondered if pthread functions work on threads not created by pthread_create.