Sergey Bugaev, le sam. 22 août 2026 12:01:25 +0300, a ecrit:
> pthread_cond_timedwait and pthread_cond_clockwait both take absolute time.
>
> But they are allowed to return spuriously,
Well, generally yes, but most often no, and people really do assume that
quite a lot...
I have tested this on Linux:
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
#include <pthread.h>
void handle(int sig) {
printf("handle\n");
}
int main(void) {
pthread_cond_t cond;
pthread_condattr_t condattr;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
struct timespec abstime;
signal(SIGALRM, handle);
alarm(2);
pthread_condattr_init(&condattr);
pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC);
pthread_cond_init(&cond, &condattr);
pthread_mutex_lock(&mutex);
clock_gettime(CLOCK_MONOTONIC, &abstime);
abstime.tv_sec += 5;
printf("waiting\n");
pthread_cond_timedwait(&cond, &mutex, &abstime);
printf("waited\n");
pthread_mutex_unlock(&mutex);
return 0;
}
pthread_cond_timedwait does *not* return spuriously, it keeps waiting
until the 5s are elapsed.
So I'd really rather *not* introduce such spurious wake-up, because they
will really be a surprise to various programs.
Again, what is actually supposed to wake the condition in the issue at
stake?
Samuel
