Queues And Servers Blocks
FIFOwServers
File: QueuesAndServers/FIFOwServers.sim
Description
FIFOwServers models a FIFO queue and its servers. For each data
structure that enters
the queue on the inDS input port, a service time
for that data structure must be placed
on the ServiceTimeIn input port. Then, the queue
orders the data structures on a first
come first served basis. The maximum length of the queue
is specified by the MaxQsize
parameter. Data structures that are received after the
queue has reached its maximum size
are discarded.
Ports
Input Ports
- inDS
Data Type: DATA STRUCTURE
- ServiceTimeIn Data Type: REAL
Output Ports
- out
Data Type: DATA STRUCTURE
Parameters
- MaxQsize = 10 Data
Type: INTEGER
- Nservers = 10 Data
Type: INTEGER
MultipleServers
File: QueuesAndServers/MultipleServers.sim
Description
MultipleServers models multiple servers of a queue. Input
data structures arrive on the
inDS input. These data structures are placed on the out
port after experiencing
an absolute delay. The amount of the delay, which is the
amount of time the data
structure spends in the server, is specified by the value
on the ServiceTimeIn input.
The Ready trigger is used to indicate that an empty
server is available and the queue
can send in the next data structure.
Ports
Input Ports
- inDS
Data Type: DATA STRUCTURE
- ServiceTimeIn Data Type: REAL
Output Ports
- out
Data Type: DATA STRUCTURE
- Ready
Data Type: TRIGGER
Parameters
- Nservers = 10
Data Type: INTEGER
ParallelQueues
File: QueuesAndServers/ParallelQueues.sim
Description
The model is used to form two parallel queues for an input
data structure, placed
on inDS, and its service time in the queue which
is placed on the ServiceTimeIn port.
Each time the ClrToSnd input is triggered, the
data structure at the head of the queue
is placed on the ToServer port. The service time
of this data structure is placed on the
ServTimeOut port. The maximum length of the
queue is specified by the MaxQsize
parameter. Data structures that are received after the
queue has reached its maximum size
are placed on the Rejected port.
Ports
Input Ports
- inDS
Data Type: DATA STRUCTURE
- ServiceTimeIn Data Type:
REAL
- ClrToSnd
Data Type: TRIGGER
Output Ports
- ToServer
Data Type: DATA STRUCTURE
- Rejected
Data Type: DATA STRUCTURE
- ServTimeOut Data
Type: REAL
Parameters
- MaxQsize = 10 Data Type: INTEGER
PQwServers
File: QueuesAndServers/PQwServers.sim
Description
Prioritized Queue With Servers.
This model contains a prioritized FIFO queue with servers who
reference a specified resource.
Data arriving while the resource is busy, is placed on the
queue in priority order. Each time the resource becomes
available, the next item is removed from the queue and allocated
to the resource for the specified service time delay.
At the end of the service time delay, the data item is passed
out the OutDS port, and the resource is deallocated.
The resource may then be allocated by another item in the queue,
or another irequestern the system.
If a data structure arrives when the queue is empty and the
resource is available, then the resource is allocated
the specified service time delay. At the end of the service
time delay, as above, the data item is passed out the OutDS
port, and the resource is deallocated.
Ports
Input Ports
- inDS
Data Type: DATA STRUCTURE
- ServiceTimeIn Data
Type: REAL
- Priority
Data Type: INTEGER
Output Ports
- outDS
Data Type: DATA STRUCTURE
- reject
Data Type: DATA STRUCTURE
Parameters
- MaxQsize = 10 Data Type: INTEGER
- Nservers = 1
Data Type: INTEGER