semaphores.py 文件源码

def getOverallDeferredSemaphore():
    global OVERALL_SEMAPHORE

    if OVERALL_SEMAPHORE is None:
        preferences = zope.component.queryUtility(
            ICollectorPreferences, 'zenpython')

        if preferences:
            OVERALL_SEMAPHORE = defer.DeferredSemaphore(preferences.options.twistedconcurrenthttp)
        else:
            # When we are running in a daemon other than zenpython, the preferences
            # value will not be available
            OVERALL_SEMAPHORE = defer.DeferredSemaphore(DEFAULT_TWISTEDCONCURRENTHTTP)

    return OVERALL_SEMAPHORE