英文字典中文字典51ZiDian.com
|
|
semaphore n. 臂式号志,信号,手旗信号
vt. 以信号机联络 vi. 打信号 臂式号志,信号,手旗信号以信号机联络打信号 semaphore 信号; 信号标志; 信号灯 semaphore 旗号 semaphore n 1: an apparatus for visual signaling with lights or mechanically moving arms v 1: send signals by or as if by semaphore 2: convey by semaphore, of information Semaphore \Sem"a*phore\, n. [Gr. sh^ma a sign fe`rein to bear: cf. F. s['e]maphore.] A signal telegraph; an apparatus for giving signals by the disposition of lanterns, flags, oscillating arms, etc. [1913 Webster] Semaphoric 72 Moby Thesaurus words for "semaphore": Roman candle, aid to navigation, alarm, amber light, balefire, beacon, beacon fire, bell, bell buoy, blinker, blue peter, buoy, caution light, flare, fog bell, fog signal, fog whistle, foghorn, glance, go light, gong buoy, green light, heliograph, high sign, international alphabet flag, international numeral pennant, kick, leer, marker beacon, nod, nudge, parachute flare, pilot flag, poke, police whistle, quarantine flag, radio beacon, red flag, red light, rocket, sailing aid, semaphore flag, semaphore telegraph, sign, signal, signal beacon, signal bell, signal fire, signal flag, signal gong, signal gun, signal lamp, signal light, signal mast, signal post, signal rocket, signal shot, signal siren, signal tower, spar buoy, stop light, the nod, the wink, touch, traffic light, traffic signal, watch fire, white flag, wigwag, wigwag flag, wink, yellow flag restricting access to shared resources (e.g. storage) in a {multi-processing} environment. They were invented by {Dijkstra} and first used in {T.H.E} {operating system}. A semaphore is a {protected variable} (or {abstract data type}) which can only be accessed using the following operations: P(s) Semaphore s; { while (s == 0) ; /* wait until s>0 */ s = s-1; } V(s) Semaphore s; { s = s1; } Init(s, v) Semaphore s; Int v; { s = v; } P and V stand for Dutch "Proberen", to test, and "Verhogen", to increment. The value of a semaphore is the number of units of the resource which are free (if there is only one resource a "binary semaphore" with values 0 or 1 is used). The P operation {busy-waits} (or maybe {sleeps}) until a resource is available whereupon it immediately claims one. V is the inverse, it simply makes a resource available again after the process has finished using it. Init is only used to initialise the semaphore before any requests are made. The P and V operations must be {indivisible}, i.e. no other process can access the semaphore during the their execution. To avoid {busy-wait}ing, a semaphore may have an associated {queue} of processes (usually a {FIFO}). If a process does a P on a semaphore which is zero the process is added to the semaphore's queue. When another process increments the semaphore by doing a V and there are tasks on the queue, one is taken off and resumed. (1995-02-01)
请选择你想看的字典辞典：
|
安装中文字典英文字典查询工具!
英文字典中文字典相关资料:
|
中文字典-英文字典 2005-2009