Worker Pools in VHDL

Our example demonstrates how to implement a worker pool using processes and signals in VHDL.

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;

entity WorkerPool is
end WorkerPool;

architecture Behavioral of WorkerPool is
    constant NUM_WORKERS : integer := 3;
    constant NUM_JOBS : integer := 5;
    
    type job_array is array (0 to NUM_JOBS-1) of integer;
    signal jobs : job_array := (1, 2, 3, 4, 5);
    
    type result_array is array (0 to NUM_JOBS-1) of integer;
    signal results : result_array := (others => 0);
    
    signal job_index : integer := 0;
    signal result_index : integer := 0;
    
    procedure worker(
        signal job_index : inout integer;
        signal result_index : inout integer;
        signal jobs : in job_array;
        signal results : out result_array;
        constant id : in integer) is
    begin
        while job_index < NUM_JOBS loop
            report "worker " & integer'image(id) & " started job " & integer'image(jobs(job_index));
            wait for 1 sec;
            report "worker " & integer'image(id) & " finished job " & integer'image(jobs(job_index));
            results(result_index) <= jobs(job_index) * 2;
            job_index <= job_index + 1;
            result_index <= result_index + 1;
        end loop;
    end procedure;

begin
    -- Start worker processes
    worker_gen: for i in 1 to NUM_WORKERS generate
        worker_proc: process
        begin
            worker(job_index, result_index, jobs, results, i);
            wait;
        end process;
    end generate;
    
    -- Main process to collect results
    main_proc: process
    begin
        wait for 5 sec;
        for i in 0 to NUM_JOBS-1 loop
            report "Result " & integer'image(i+1) & ": " & integer'image(results(i));
        end loop;
        wait;
    end process;

end Behavioral;

In this VHDL implementation, we create a worker pool using concurrent processes. Here’s a breakdown of the code:

We define constants for the number of workers (3) and the number of jobs (5).
We use arrays to represent the jobs and results.
The worker procedure simulates the work of each worker. It processes jobs from the jobs array and stores results in the results array.
We generate NUM_WORKERS processes using a generate statement. Each process calls the worker procedure with a unique ID.
The main process waits for 5 seconds (simulating the time for all jobs to complete) and then reports the results.

To run this VHDL code, you would typically use a VHDL simulator like ModelSim or GHDL. The simulation would show the workers processing jobs concurrently and the final results being reported.

This VHDL implementation doesn’t have direct equivalents for channels or goroutines as in the original example. Instead, it uses VHDL’s concurrent processes and shared signals to achieve similar functionality. The wait for 1 sec statement simulates the delay of each job.

Remember that VHDL is typically used for hardware description, so this example is more of a simulation of concurrent behavior rather than a practical implementation of a worker pool in hardware.

Tickers in VHDL

Waitgroups in VHDL

Learn X By Example

Title here

Worker Pools in VHDL