c - 如何将 POSIX sem_t 信号量增加 1 以上？

Question

我可以让 sem_t(信号量)对象的 a 值大于 1 吗？由于sem_post只增加1。有sem_set吗？

Answer 1

是的，sem_t 的值可以大于 1。您可以使用 sem_init 将信号量初始化为任意值。引用自this link :

To initialize a semaphore, use sem_init():

  int sem_init(sem_t *sem, int pshared, unsigned int value); 

• sem points to a semaphore object to initialize
• pshared is a flag indicating whether or not the semaphore should be shared with fork()ed processes. LinuxThreads does not currently support shared semaphores
• value is an initial value to set the semaphore to

Example of use:

  sem_init(&sem_name, 0, 10);

我不知道有任何函数可以将 sem_t 增加任意值。