Question

在simpy中触发进程的默认顺序似乎依赖于它们的创建顺序？我想明确地对流程进行排名，以便按照精确的顺序触发，无论它们何时被创建。如果你需要一个例子，这里有3个过程的模拟：吃食物，补充板，移除板。 eat()进程会触发plateEmpty事件，期望重新填充该事件。但是如果removePlate()进程发生在refillPlate()之前，那么重新填充就不会发生。我想要先重新装满。我可以执行的唯一方法是订购44和45号线。还有另外一种方法吗？

[PS：我知道优先资源，但这不是我想要的。]

import simpy

env = simpy.Environment()
plateEmpty = env.event()
plateGone = env.event()
scoop = 5

def eat(env):
  global plateEmpty
  global food
  while True:
    e = yield env.timeout(5) | plateGone
    if plateGone in e:
      print "Ack! my plate is gone."   #bad
      break
    if food > 0:
      food -= 1  # one bite
      print env.now,"took a bite"
    if food == 0:
      plateEmpty.succeed("I want more food")

def refillPlate(env):
  global food
  global plateEmpty
  while True:
    e = yield plateEmpty | plateGone
    if plateGone in e:
      print env.now, "cannot refill."
      break
    food += scoop
    print env.now,"refilled plate"
    plateEmpty = env.event()   # reset trigger

def removePlate(env):
  while True:
    e = yield plateEmpty | plateGone
    if plateEmpty not in e: continue  # trigger was reset
    print env.now,"removed plate"
    plateGone.succeed()
    break

food = scoop
env.process(eat(env))
env.process(removePlate(env))  # line 44: want this triggered last
env.process(refillPlate(env))  # line 45: want this triggered first
env.run(until=100)

Answer 1

我找到了两个解决方案。

引入一个小延迟。（根据进程之间的优先级缩放延迟。）
检查队列中是否有特定条件，并先让它处理。

解决方案1：

def removePlate(env):
  while True:
    e = yield plateEmpty | plateGone
    yield env.timeout(0.00001)
    if plateEmpty not in e: continue  # trigger was reset
    print(env.now,"removed plate")
    plateGone.succeed()
    break

解决方案2：

import simpy

env = simpy.Environment()
plateEmpty = env.event()
plateGone = env.event()
scoop = 5

condition = None

def eat(env):
  global plateEmpty
  global food
  while True:
    e = yield env.timeout(5) | plateGone
    if plateGone in e:
      print("Ack! my plate is gone.")   #bad
      break
    if food > 0:
      food -= 1  # one bite
      print(env.now,"took a bite")
    if food == 0:
      plateEmpty.succeed("I want more food")

def refillPlate(env):
  global food
  global plateEmpty
  global condition
  while True:
    condition = plateEmpty | plateGone
    e = yield condition
    if plateGone in e:
      print(env.now, "cannot refill.")
      break
    food += scoop
    print(env.now,"refilled plate")
    plateEmpty = env.event()   # reset trigger

def removePlate(env):
  global spec_proc
  while True:
    e = yield plateEmpty | plateGone
    # Check if the other process is scheduled to run at the same time
    if (env.now, condition) in [(time, condition) for time, _, _, condition in env._queue]:
        yield env.timeout(0.00001)
    if plateEmpty not in e: continue  # trigger was reset
    print(env.now,"removed plate")
    plateGone.succeed()
    break

food = scoop
env.process(eat(env))
spec_proc = env.process(removePlate(env))  # line 44: want this triggered last
env.process(refillPlate(env))  # line 45: want this triggered first
env.run(until=100)

如何设置简单的进程回调优先级？

1 个答案: