diff options
| -rw-r--r-- | include/linux/sem.h | 5 | ||||
| -rw-r--r-- | ipc/sem.c | 37 |
2 files changed, 36 insertions, 6 deletions
diff --git a/include/linux/sem.h b/include/linux/sem.h index 1b191c1..8a4adbef 100644 --- a/include/linux/sem.h +++ b/include/linux/sem.h @@ -86,6 +86,7 @@ struct task_struct; struct sem { int semval; /* current value */ int sempid; /* pid of last operation */ + struct list_head sem_pending; /* pending single-sop operations */ }; /* One sem_array data structure for each set of semaphores in the system. */ @@ -96,11 +97,13 @@ struct sem_array { struct sem *sem_base; /* ptr to first semaphore in array */ struct list_head sem_pending; /* pending operations to be processed */ struct list_head list_id; /* undo requests on this array */ - unsigned long sem_nsems; /* no. of semaphores in array */ + int sem_nsems; /* no. of semaphores in array */ + int complex_count; /* pending complex operations */ }; /* One queue for each sleeping process in the system. */ struct sem_queue { + struct list_head simple_list; /* queue of pending operations */ struct list_head list; /* queue of pending operations */ struct task_struct *sleeper; /* this process */ struct sem_undo *undo; /* undo structure */ @@ -241,6 +241,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) key_t key = params->key; int nsems = params->u.nsems; int semflg = params->flg; + int i; if (!nsems) return -EINVAL; @@ -273,6 +274,11 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) ns->used_sems += nsems; sma->sem_base = (struct sem *) &sma[1]; + + for (i = 0; i < nsems; i++) + INIT_LIST_HEAD(&sma->sem_base[i].sem_pending); + + sma->complex_count = 0; INIT_LIST_HEAD(&sma->sem_pending); INIT_LIST_HEAD(&sma->list_id); sma->sem_nsems = nsems; @@ -419,6 +425,15 @@ static void wake_up_sem_queue(struct sem_queue *q, int error) preempt_enable(); } +static void unlink_queue(struct sem_array *sma, struct sem_queue *q) +{ + list_del(&q->list); + if (q->nsops == 1) + list_del(&q->simple_list); + else + sma->complex_count--; +} + /* Go through the pending queue for the indicated semaphore * looking for tasks that can be completed. */ @@ -438,7 +453,7 @@ again: if (error > 0) continue; - list_del(&q->list); + unlink_queue(sma, q); /* * The next operation that must be checked depends on the type @@ -532,8 +547,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) /* Wake up all pending processes and let them fail with EIDRM. */ list_for_each_entry_safe(q, tq, &sma->sem_pending, list) { - list_del(&q->list); - + unlink_queue(sma, q); wake_up_sem_queue(q, -EIDRM); } @@ -1191,6 +1205,19 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, else list_add(&queue.list, &sma->sem_pending); + if (nsops == 1) { + struct sem *curr; + curr = &sma->sem_base[sops->sem_num]; + + if (alter) + list_add_tail(&queue.simple_list, &curr->sem_pending); + else + list_add(&queue.simple_list, &curr->sem_pending); + } else { + INIT_LIST_HEAD(&queue.simple_list); + sma->complex_count++; + } + queue.status = -EINTR; queue.sleeper = current; current->state = TASK_INTERRUPTIBLE; @@ -1232,7 +1259,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, */ if (timeout && jiffies_left == 0) error = -EAGAIN; - list_del(&queue.list); + unlink_queue(sma, &queue); out_unlock_free: sem_unlock(sma); @@ -1375,7 +1402,7 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it) struct sem_array *sma = it; return seq_printf(s, - "%10d %10d %4o %10lu %5u %5u %5u %5u %10lu %10lu\n", + "%10d %10d %4o %10u %5u %5u %5u %5u %10lu %10lu\n", sma->sem_perm.key, sma->sem_perm.id, sma->sem_perm.mode, |
