main.lua

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--- @file main.lua
--- @brief Main ...
--- @todo TODO docu
---------------------------------

-- globally available utility functions
require "utils"
-- all available headers, packets, ... and their utility functions
require "proto.proto"

local dpdk      = require "dpdk"
local dpdkc     = require "dpdkc"
local dev       = require "device"
local stp       = require "StackTracePlus"
local ffi       = require "ffi"
local memory    = require "memory"
local serpent   = require "Serpent"

-- TODO: add command line switches for this and other luajit-debugging features
--require("jit.v").on()

local function getStackTrace(err)
    printf("[ERROR] Lua error in task %s", MOONGEN_TASK_NAME)
    print(stp.stacktrace(err, 2))
end

local function run(file, ...)
    local script, err = loadfile(file)
    if not script then
        error(err)
    end
    xpcall(script, getStackTrace, ...)
end

local function parseCommandLineArgs(...)
    local args = { ... }
    for i, v in ipairs(args) do
        -- is it just a simple number?
        if tonumber(v) then
            v = tonumber(v)
        end
        -- currently not supported as we can't pass structs to slaves
        -- ip?
        -- local ip = parseIPAddress(v)
        -- if ip then
        --  v = ip
        -- end
        args[i] = v
    end
    return args
end

local function master(_, file, ...)
    MOONGEN_TASK_NAME = "master"
    if not dpdk.init() then
        print("Could not initialize DPDK")
        return
    end
    local devices = dev.getDevices()
    printf("Found %d usable devices:", #devices)
    for _, device in ipairs(devices) do
        printf("   Device %d: %s (%s)", device.id, device.mac, device.name)
    end
    dpdk.userScript = file -- needs to be passed to slave cores
    local args = parseCommandLineArgs(...)
    arg = args -- for cliargs in busted
    run(file) -- should define a global called "master"
    xpcall(_G["master"], getStackTrace, unpack(args))
    -- exit program once the master task finishes
    -- it is up to the user program to wait for slaves to finish, e.g. by calling dpdk.waitForSlaves()
end

local function slave(taskId, userscript, args)
    -- must be done before parsing the args as they might rely on deserializers defined in the script
    run(userscript)
    args = loadstring(args)()
    func = args[1]
    if func == "master" then
        print("[WARNING] Calling master as slave. This is probably a bug.")
    end
    if not _G[func] then
        errorf("slave function %s not found", func)
    end
    --require("jit.p").start("l")
    --require("jit.dump").on()
    MOONGEN_TASK_NAME = func
    MOONGEN_TASK_ID = taskId
    -- decode args
    local results = { select(2, xpcall(_G[func], getStackTrace, select(2, unpackAll(args)))) }
    local vals = serpent.dump(results)
    local buf = ffi.new("char[?]", #vals + 1)
    ffi.copy(buf, vals)
    dpdkc.store_result(taskId, buf)
    local ok, err = pcall(dev.reclaimTxBuffers)
    if ok then
        memory.freeMemPools()
    else
        printf("Could not reclaim tx memory: %s", err)
    end
    --require("jit.p").stop()
end

function main(task, ...)
    (task == "master" and master or slave)(...)
end