Process Name Change?

[howard4086]

Is there any way to change the name of a Julia process? I am using Julia to run a few different optimization processes, and it would be nice if they didn't all have the same "julia.exe" name in the task manager so I can more easily monitor them.

Thanks.

[StefanKarpinski]

You can call whatever C API Windows has to change process names. It might be nice to provide a consistent cross-platform API for this that works similarly on both UNIX and Windows.

[vtjnash]

Doesn't libuv have a function for doing this?

[ihnorton]

055dcdd works on Windows (gui window title changes); is a no-op on linux; should work on BSD.

[vtjnash]

on linux, it'll call prctl:

       PR_SET_NAME (since Linux 2.6.9)
              Set  the  name of the calling thread, using the value in the location pointed to by (char *) arg2.  The name can be up to 16 bytes long, and should be null-terminated
              if it contains fewer bytes.  This is the same attribute that can be set via pthread_setname_np(3) and retrieved using pthread_getname_np(3).  The attribute  is  like‐
              wise accessible via /proc/self/task/[tid]/comm, where tid is the name of the calling thread.

[ihnorton]

Doesn't seem to do anything user-visible on my system. No change in top, ps, etc.

[vtjnash]

how about cat /proc/self/task/*/comm?

[ihnorton]

That doesn't help because the thread there is called cat.

julia> Base.set_process_title("foo")

julia> let d = "/proc/self/task/"
           for dd in readdir(d)
               readall(open(joinpath(d,dd,"comm"))) |> show
           end
       end
"julia\n""julia\n""julia\n""julia\n"

[vtjnash]

you're right, that doesn't seem to work

shell> cat /proc/$(getpid())/task/*/comm
julia
julia
julia
julia
julia
julia
julia
julia

julia> Base.set_process_title("foo")

shell> cat /proc/$(getpid())/task/*/comm
julia
julia
julia
julia
julia
julia
julia
julia

[vtjnash]

apparently we're missing a call to uv_setup_args that should be happening, probably in _julia_init:

julia> ccall(:uv_setup_args, Ptr{Ptr{Uint8}}, (Cint, Ptr{Ptr{Uint8}}), 1, ["foo"])
Ptr{Ptr{UInt8}} @0x0000000003291ff0

julia> Base.get_process_title()
"foo"

julia> Base.set_process_title("bar")

julia> Base.get_process_title()
"bar"

shell> cat /proc/$(getpid())/task/*/comm
bar
julia
julia
julia
julia
julia
julia
julia

[ihnorton]

This works on windows, but fixing on linux is blocked on #9482 right now. Assigning to myself so I remember to change it eventually.