Julia：如何让多个工作人员访问模块中的函数？

我有以下测试模块（MyMod.jl）来在 Julia 中存储一些测试函数。一些核心函数是串行编写的。其他函数并行调用核心函数。

module MyMod

export Dummy,distribute_data,getfrom,recombine_data,regular_test,parallel_test

function Dummy(icol,model,data,A,B) # Generate data from a model
    nz,nx,nh = size(model)  # = size(A) = size(B)
    for ih = 1:nh
        for ix = 1:nx
            for iz = 1:nz
                data[iz,icol] += A[iz,ix,ih]*B[iz,ix,ih]*model[iz,ix,ih]
            end  
        end
    end
end

function distribute_data(X, obj_name_on_worker::Symbol, dim)  # Distributes X over workers
    size_per_worker = floor(Int,size(X,1) / nworkers())
    StartIdx = 1
    EndIdx = size_per_worker
    for (idx, pid) in enumerate(workers())
        if idx == nworkers()
            EndIdx = size(X,1)
        end
        println(StartIdx:EndIdx)
        if dim == 3
            @spawnat(pid, eval(Main, Expr(:(=), obj_name_on_worker, X[StartIdx:EndIdx,:,:])))
        elseif dim == 2
            @spawnat(pid, eval(Main, Expr(:(=), obj_name_on_worker, X[StartIdx:EndIdx,:])))
        end
        StartIdx = EndIdx + 1
        EndIdx = EndIdx + size_per_worker - 1
    end
end

getfrom(p::Int, nm::Symbol; mod=Main) = fetch(@spawnat(p, getfield(mod, nm)))

function recombine_data(Data::Symbol)   # gather data from workers
    Results = cell(nworkers())
    for (idx, pid) in enumerate(workers())
        Results[idx] = getfrom(pid, Data)
    end
    return vcat(Results...)
end

function regular_test(model,data,A,B)
    ncol=size(data,2)
    map((arg)->Dummy(arg,model,data,A,B),[icol for icol = 1:ncol])
end

function parallel_test(model,data,A,B)
    distribute_data(model, :model, 3)
    distribute_data(A, :A, 3)
    distribute_data(B, :B, 3)
    distribute_data(data, :data, 2)
    @everywhere ncol=size(data,2)
    @everywhere begin
        if myid() != 1
            map((arg)->Dummy(arg,model,data,A,B),[icol for icol = 1:ncol])
        end
    end
    P_Data = recombine_data(:data)
    return P_Data
end

end

然后我打开 Julia 会话并运行：

addprocs(3)

using MyMod

nx = 250;
nz = 350;
nh = 150;
ncol = 125;

model = rand(nz,nx,nh);
data = SharedArray(Float64,nz,ncol);
A = rand(nz,nx,nh);
B = rand(nz,nx,nh);

@time P_Data = parallel_test(model,data,A,B);
@time regular_test(model,data,A,B); 

P_Data == data 

The regular_test按预期运行，但是parallel_test产生以下错误：

ERROR: On worker 2:
UndefVarError: Dummy not defined
 in anonymous at /home/username/Desktop/MyMod.jl:58
 in map at ./essentials.jl:153
 in anonymous at /home/username/Desktop/MyMod.jl:58
 in eval at ./sysimg.jl:14
 in anonymous at multi.jl:1378
 in anonymous at multi.jl:907
 in run_work_thunk at multi.jl:645
 [inlined code] from multi.jl:907
 in anonymous at task.jl:63
 in remotecall_fetch at multi.jl:731
 in remotecall_fetch at multi.jl:734
 in anonymous at multi.jl:1380

...and 2 other exceptions.

 in sync_end at ./task.jl:413
 [inlined code] from multi.jl:1389
 in parallel_test at /home/username/Desktop/MyMod.jl:51

我需要做什么调整parallel_test为了防止这个问题？

在这里，您只需要使用：

addprocs(3)  ## or, starting with julia -p 3 does the same
@everywhere using MyMod