semaphores.py 文件源码

def getKeyedDeferredSemaphore(key, limit):
    global KEYED_SEMAPHORES

    if key not in KEYED_SEMAPHORES:
        KEYED_SEMAPHORES[key] = defer.DeferredSemaphore(limit)
    semaphore = KEYED_SEMAPHORES[key]

    if semaphore.limit != limit:
        if limit >= semaphore.tokens:
            semaphore.limit = limit
            log.info("Unable to lower maximum parallel query limit for %s to %d ", key, limit)
        else:
            log.warning("Unable to lower maximum parallel query limit for %s to %d at this time (%d connections currently active)", key, limit, semaphore.tokens)

    return semaphore