pthread-like windows manual-reset event

Question

is there any easier solution in porting a windows manual-reset event to pthread, than a pthread conditional-variable + pthread mutex + a flag if event is set or unset?

Answer 1

Pthreads are low level constructs. No, there isn't a simpler mechanism; pthread_cond__* is conceptually similar to an auto-reset event. Be careful, pthread_cond_wait may have spurious wakeups, so it should never be used without some sort of external flag regardless of the situation.

Building your own wouldn't be too hard, though.

#include <pthread.h>
#include <stdbool.h>
struct mrevent {
    pthread_mutex_t mutex;
    pthread_cond_t cond;
    bool triggered;
};
void mrevent_init(struct mrevent *ev) {
    pthread_mutex_init(&ev->mutex, 0);
    pthread_cond_init(&ev->cond, 0);
    ev->triggered = false;
}
void mrevent_trigger(struct mrevent *ev) {
    pthread_mutex_lock(&ev->mutex);
    ev->triggered = true;
    pthread_cond_signal(&ev->cond);
    pthread_mutex_unlock(&ev->mutex);
}
void mrevent_reset(struct mrevent *ev) {
    pthread_mutex_lock(&ev->mutex);
    ev->triggered = false;
    pthread_mutex_unlock(&ev->mutex);
}
void mrevent_wait(struct mrevent *ev) {
     pthread_mutex_lock(&ev->mutex);
     while (!ev->triggered)
         pthread_cond_wait(&ev->cond, &ev->mutex);
     pthread_mutex_unlock(&ev->mutex);
}

This may not fit your usage, as you will often have a different lock that you'd want to use in place of ev->mutex, but this is the gist of how it's typically used.

Answer 2

I think Windows Events are more akin to a semaphore. I.e. for auto-reset, you'd use a binary semaphore and the sem_timedwait() function.