components

Component

Base class for components in the simulation.

Components are just an utility base class that tracks how many instances of itself are created. Its id property will be unique during the simulation.

This property is usefull to identify different components in the simulation without having to set an explicit name for them, however is not a requirement for the Simulation to run.

from pydes.process import Component, Simulator

# define the component with a main method
class Process(Component):
    def __init__(self, sim: Simulator):
        self.sim = sim

    def main(self):
        for _ in range(10):
            print(self.sim.now(),"waiting")
            self.sim.sleep(2)
            print(self.sim.now(),"waiting")

# create the simulator object
sim = Simulator()

# create an instance of the Component
process = Process(sim)

# schedule the process in the simulator
sim.schedule(process.main)

# now you can run the simulation
sim.run()

Event(sim)

Bases: Component

An event can be waited and set by components. They are very useful to model trigger conditions and model interaction between different actors across the system.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required

Methods:

Name	Description
wait	a component can call the wait method and suspend its excecution until this event is set.
set	a component can call the set method and trigger the event. This causes all the waiting components to continue its excecution.

set()

Set the event.

wait()

Wait for the event to be set.

State(sim, value)

Bases: Component

Represents a state in the simulation. It is highly recommended to use Enums to control the possible values that a State object can take.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required
value	Any	The initial value of the state.	required

Methods:

Name	Description
set	changes the state to a new provided value
wait	waits until a certain value is set in the State.

set(value)

Set the state to a new value.

Parameters:

Name	Type	Description	Default
value	Any	The new value of the state.	required

wait(value)

Wait for the state to become a specific value.

Parameters:

Name	Type	Description	Default
value	Any	The value to wait for.	required

Queue(sim, capacity=inf)

Bases: Component

Queues are used to acumulate objects in a buffer and retrieved them from it.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required
capacity	float | int	The maximun lenght of the queue.	inf

Methods:

Name	Description
put	tries to insert a new member into the queue and waits if the queue is full.
get	tries to get one member from the queue and waits if the queue is empty.

Constructor for Queue class.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required

get()

Get an item from the queue.

Waits until there is an item available in the queue.

Returns:

Name	Type	Description
Any	Any	The item retrieved from the queue.

put(member)

Put an item into the queue or waits if the queue is full.

Parameters:

Name	Type	Description	Default
member	Any	The item to be put into the queue.	required

size()

Get the size of the queue. Its equivalent to the number of member inside.

Returns:

Name	Type	Description
int	int	The number of items in the queue.

Resource(sim, capacity=1)

Bases: Component

Resources can be requested and released by components and therefore are really useful in modeling real world scenarios quere components must be shared among different processess.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required
capacity	int	The capacity of the resource, default is 1.	1

Methods:

Name	Description
request	tries to get the ownership of this Resource and waits if the resource is not avialable.
release	gives back the ownership of the Resource so that other user can make use of it.

request(by)

Request the resource.

If the resource is idle, the component can acquire it. Otherwise, it waits until the resource becomes idle.

Parameters:

Name	Type	Description	Default
by	Component	The component requesting the resource.	required

release(by)

Release the resource.

Parameters:

Name	Type	Description	Default
by	Component	The component releasing the resource.	required

Raises:

Type	Description
PydesError	If the component has not previously requested the resource.

usage()

Get the current usage of the resource.

capacity()

Get the capacity of the resource.

is_idle()

Check if the resource is idle.

Container(sim, capacity=inf)

Bases: Component

Containers have the capability to acumulate and provide continuous amounts of what contains. It is particularly useful to model non discrete accumulators like Tanks.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required
capacity	int | float	The capacity of the container, default is 1.	inf

Methods:

Name	Description
get	decrease the level of the container by some amount.
put	increase the level of the container by some amount.

get(amount=1)

Get some amount from the container.

Parameters:

Name	Type	Description	Default
amount	int | float	The amount to get from the container, default is 1.	1

put(amount=1)

Put some amount into the container.

Parameters:

Name	Type	Description	Default
amount	int | float	The amount to put into the container, default is 1.	1

level()

Get the current level of the container.

capacity()

Get the capacity of the container.

Store(sim, capacity=1)

Bases: Component

Stores are useful to save and retrieve objects. Stores can be use to insert any type of object but it requires all the objects to be of the same type.

Parameters:

Name	Type	Description	Default
sim	Simulator	The simulator instance.	required
capacity	int	The capacity of the store, default is infinity.	1

get()

Get an item from the store.

put(item)

Put an item into the store.

Parameters:

Name	Type	Description	Default
item	Any	The item to put into the store.	required

level()

Get the current level of the store.

capacity()

Get the capacity of the store.