#coding=utf-8
from multiprocessing import Queue
#初始化一個Queue對象，最多可接收三條put消息
q = Queue(3)
q.put('消息１')
q.put('消息２')
print(q.full())#False
q.put('消息３')
print(q.full())#True
#因為消息列隊已滿下面的try都會拋出異常，第一個try會等待2秒后再拋出異常，第二個Try會立刻拋出異常
try:
  q.put('消息４', True, 2)
except:
  print('消息隊列已滿，現(xiàn)有消息數(shù)量：%s'%q.qsize())
try:
  q.put_nowait('消息４')#等同于q.put('消息４', False)
except:
  print('消息隊列已滿，現(xiàn)有消息數(shù)量：%s'%q.qsize())
#推薦的方式，先判斷消息列隊是否已滿，再寫入
if not q.full():
  q.put_nowait('消息４')
#讀取消息時，先判斷消息列隊是否為空，再讀取
if not q.empty():
  for i in range(q.qsize()):
    print(q.get_nowait())

#coding=utf-8
from multiprocessing import Queue, Process
import time, random, os
#寫數(shù)據(jù)進程執(zhí)行的代碼
def write(q):
  l1 = ['A','B','C']
  for value in l1:
    print('put %s to queue...'%value)
    q.put(value)
    time.sleep(random.random())
#讀數(shù)據(jù)執(zhí)行的代碼
def read(q):
  while True:
    if not q.empty():
      value = q.get(True)
      print('get %s from queue...' % value)
      time.sleep(random.random())
    else:
      break
if __name__ == "__main__":
  #父進程創(chuàng)建Queue,并傳給各個子進程
  q = Queue()
  qw = Process(target=write, args=(q,))
  qr = Process(target=read, args=(q,))
  #啟動子進程ｑｗ寫入
  qw.start()
  qw.join()
  # 啟動子進程ｑｒ?qū)懭?
  qr.start()
  qr.join()
  # ｑｒ進程是死循環(huán)，無法等待其結(jié)束，只能強行終止:
  print('所有數(shù)據(jù)都已經(jīng)寫入并讀取完畢')

#coding=utf-8
from multiprocessing import Manager, Pool
import time, random, os
def writer(q):
  print('writer啟動%s,父進程為%s'%(os.getpid(),os.getppid()))
  l1 = ['a','b','c','d','e']
  for value in l1:
    q.put(value)
def reader(q):
  print('reader啟動%s，父進程為%s'%(os.getpid(),os.getppid()))
  for i in range(q.qsize()):
    print('reader從Queue獲取到消息：%s'%q.get(True))
if __name__ == "__main__":
  print('父進程%s啟動．．．'%os.getpid())
  q = Manager().Queue() #使用Manager中的Queue來初始化
  po = Pool()
  # 使用阻塞模式創(chuàng)建進程，這樣就不需要在reader中使用死循環(huán)了，可以讓writer完全執(zhí)行完成后，再用reader去讀取
  po.apply(writer, (q,))
  po.apply(reader, (q,))
  po.close()
  po.join()
  print('%s結(jié)束'%os.getpid())