Vous avez cherché: semaphore (Anglais - Chinois (simplifié))

semaphore, shared memory and ipc functions
semaphore, shared memory and ipc functions

after removing the semaphore, it is no more accessible.
after removing the semaphore, it is no more accessible.

a positive semaphore identifier on success, or false on error.
description

and there's almost this sort of semaphore around us all the time.
很多人有着类似的想法。

sem_acquire() blocks (if necessary) until the semaphore can be acquired.
returns: true on success, false on error.

after releasing the semaphore, sem_acquire() may be called to re-acquire it.
after releasing the semaphore, sem_acquire() may be called to re-acquire it.

sem_get() returns an id that can be used to access the system v semaphore with the given key.
returns: a positive semaphore identifier on success, or false on error.

the number of processes that can acquire the semaphore simultaneously is set to max_acquire (defaults to 1).
sem_get() returns an id that can be used to access the system v semaphore with the given key. the semaphore is created if necessary using the permission bits specified in perm (defaults to 0666). the number of processes that can acquire the semaphore simultaneously is set to max_acquire (defaults to 1). actually this value is set only if the process finds it is the only process currently attached to the semaphore.

sem_release() releases the semaphore if it is currently acquired by the calling process, otherwise a warning is generated.
sem_release() releases the semaphore if it is currently acquired by the calling process, otherwise a warning is generated.

a process attempting to acquire a semaphore which it has already acquired will block forever if acquiring the semaphore would cause its max_acquire value to be exceeded.
sem_acquire() blocks (if necessary) until the semaphore can be acquired. a process attempting to acquire a semaphore which it has already acquired will block forever if acquiring the semaphore would cause its max_acquire value to be exceeded.

a second call to sem_get() for the same key will return a different semaphore identifier, but both identifiers access the same underlying semaphore.
a second call to sem_get() for the same key will return a different semaphore identifier, but both identifiers access the same underlying semaphore.

sem_remove() removes the semaphore sem_identifier if it has been created by sem_get(), otherwise generates a warning.
sem_remove() removes the semaphore sem_identifier if it has been created by sem_get(), otherwise generates a warning.

(1) installation of two new semaphores by 2008, with the cooperation of the french government.
1. 2008年以前，利用法国合作安装两台新的信号机。