import SimPy.Simulation as Sim
from SimPy.Lister import *
put=9999
get=666
def putfunc(a):
    a[0][2]._put(a)
def getfunc(a):
    a[0][2]._get(a)
class Bin(Lister):
    "Bounded buffer"
    def __init__(self,capacity=0,initialAvail=0,name="a_bin"):
        self.name=name
        self.inBin=initialAvail
        self.waitQput=[]
        self.waitQget=[]
        self.capacity=capacity
    def _put(self,par):
        "Put in buffer (blocking)"
        menge=par[0][3]
        if menge+self.inBin<= self.capacity:
            self.inBin+=menge
            if self.waitQget:
                for qd in self.waitQget:
                    if qd[1]<=self.inBin:
                        Sim.reactivate(qd[0],delay=0,prior=True)
                        self.inBin-=qd[1]
                        self.waitQget.remove(qd)
                    else:
                        break
            who=par[1]
            Sim._e._post(who,at=Sim._t)
        else:
            #wait for bin space
            self.waitQput.append((par[0][1],menge))
            par[0][1]._nextTime=None

    def _get(self,par):
        "Get from buffer (blocking)"
        menge=par[0][3]
        if menge>self.inBin:
            #queue here        process   menge (==requirement)
            self.waitQget.append((par[0][1],menge))
            par[0][1]._nextTime=None
        else :
            self.inBin-=menge
            who=par[1]
            # look for processes waiting for bin space
            if self.waitQput:
                for qd in self.waitQput:
                    if qd[1]<=(self.capacity-self.inBin):
                        Sim.reactivate(qd[0],delay=0,prior=True)
                        self.inBin+=qd[1]
                        self.waitQput.remove(qd)
                    else:
                        break                       
            Sim._e._post(who,at=Sim._t)            
def simulate(until=0):
    Sim._stop=False
    if Sim._e == None:
        raise Sim.Simerror("Fatal SimPy error: Simulation not initialized")
    if Sim._e.events == {}:
        message="SimPy: No activities scheduled"
        return message
    Sim._endtime=until
    message="SimPy: Normal exit" 
    dispatch={Sim.hold:Sim.holdfunc,Sim.request:Sim.requestfunc,Sim.release:Sim.releasefunc,
              Sim.passivate:Sim.passivatefunc,put:putfunc,get:getfunc}
    commandcodes=dispatch.keys()
    commandwords={Sim.hold:"hold",Sim.request:"request",Sim.release:"release",Sim.passivate:"passivate",
        Sim.waitevent:"waitevent",Sim.queueevent:"queueevent",Sim.waituntil:"waituntil",
        put:"put",get:"get"}
    while not Sim._stop and Sim._t<=Sim._endtime:
        try:
            a=Sim._e._nextev()        
            if not a[0]==None:
                command = a[0][0]
                dispatch[command](a)     
        except Sim.Simerror, error:
            message="SimPy: "+error.value
            Sim._stop = True
    Sim._e=None
    return message