xbt_os_mutex_t mutex; /* pool's mutex */
xbt_os_cond_t job_posted; /* job is posted */
xbt_os_cond_t job_taken; /* job is taken */
xbt_os_mutex_t mutex; /* pool's mutex */
xbt_os_cond_t job_posted; /* job is posted */
xbt_os_cond_t job_taken; /* job is taken */