Processes

Process functions

A process target is a normal Python callable. Positional and keyword arguments passed to cimba.Process are forwarded to the target.

def customer(model):
    model.server.acquire()
    cimba.hold(model.service_time())
    model.server.release()

cimba.Process("Customer", customer, model).start()

Bound methods are often the cleanest way to keep model state close to model behavior:

cimba.Process("Customer", model.customer).start()

Use pass_process=True only when the target needs the cimba.Process object itself:

def sleeper(me, log):
    me.timer_set(5.0)
    log.append(cimba.yield_process())

cimba.Process("Sleeper", sleeper, log, pass_process=True).start()

The process can return a value. Another process can retrieve it with exit_value() after waiting for the process.

Scheduling and lifecycle

Process(...).start() schedules the process at the current simulation time and returns the process object.

The lifecycle constants are:

PROCESS_CREATED
PROCESS_RUNNING
PROCESS_FINISHED

Process priorities

Priorities are integer values used by waiting and resource queues. A higher priority process is considered before a lower priority process where the native object supports priority ordering.

urgent = cimba.Process("Urgent", job, model, priority=10).start()
urgent.priority = 20

Timers and yielding

hold(duration) is the most common way to yield. yield_process() yields without scheduling a time wakeup; another process, event, or timer must resume the yielded process.

timer_add() schedules an independent wakeup. timer_set() clears existing timers before adding one.