Capture SIGINT with @async, in a script or in the REPL

[chunjiw]

Define this function in REPL:

julia> function try_interrupt()
           while true
               try
                   sleep(1)
                   println("trying...")
                   @async 1+1
               catch e
                   if typeof(e) <: InterruptException
                       println("caught Interrupt")
                       return
                   end
               end
           end
           return
       end
try_interrupt (generic function with 1 method)

In Julia 1.7.2, everything works:

julia> try_interrupt()
trying...
trying...
^Ccaught Interrupt

julia> versioninfo()
Julia Version 1.7.2
Commit bf53498635 (2022-02-06 15:21 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-6850K CPU @ 3.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, broadwell)

But in 1.9.0 it does not work:

julia> versioninfo()
Julia Version 1.9.0-DEV.426
Commit 4dfef57535 (2022-04-21 19:14 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 12 × Intel(R) Core(TM) i7-6850K CPU @ 3.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, broadwell)
  Threads: 1 on 12 virtual cores

julia> try_interrupt()
trying...
trying...
^Cfatal: error thrown and no exception handler available.
InterruptException()
jl_mutex_unlock at /home/chunjiw/projects/playground/buildjulia/julia/src/julia_locks.h:129 [inlined]
ijl_task_get_next at /home/chunjiw/projects/playground/buildjulia/julia/src/partr.c:382
poptask at ./task.jl:931
wait at ./task.jl:940
task_done_hook at ./task.jl:640
jfptr_task_done_hook_61719 at /home/chunjiw/projects/playground/buildjulia/julia/usr/lib/julia/sys.so (unknown line)
jl_apply at /home/chunjiw/projects/playground/buildjulia/julia/src/julia.h:1838 [inlined]
jl_finish_task at /home/chunjiw/projects/playground/buildjulia/julia/src/task.c:254
start_task at /home/chunjiw/projects/playground/buildjulia/julia/src/task.c:942

In another word, issue #19467 comes back.

If I put the code in a script file.jl, then run it with

• julia -i file.jl or
• julia -e 'include(popfirst!(ARGS))' file.jl,
  then both 1.7.2 and 1.9.0 returns fatal error when attempt to interrupt with Ctrl-C: fatal: error thrown and no exception handler available.

Note: using Base.exit_on_sigint(false) does not solve this issue

[chunjiw]

I'm not sure how this is related to #40416 or #35524

[arnaudh]

Just coming to say I'm bumping into the same issue. I'm running multiple AWS.jl calls in an asyncmap, and Ctrl-C kills the REPL with the same C stack trace as in this issue. The example in this issue seems to also be the MWE for my case. Note I'm on 1.8.3.

julia> versioninfo()
Julia Version 1.8.3
Commit 0434deb161e (2022-11-14 20:14 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, skylake-avx512)
  Threads: 1 on 8 virtual cores

[chunjiw]

With just released 1.10.0, this issue is gone in the REPL, but persists in scripting.

[nsajko]

Reproducible on the master branch. Changing the @async to Threads.@spawn and adding synchronization still results in the same issue:

/tmp/file.jl:

function try_interrupt()
    @sync while true
        br = try
            sleep(1)
            println("trying...")
            Threads.@spawn 1+1
            false
        catch e
            if typeof(e) <: InterruptException
                println("caught Interrupt")
                true
            else
                false
            end
        end::Bool
        br && break
    end
end

try_interrupt()

Results in:

$ ./build_master/julia -g2 /tmp/file.jl 
trying...
trying...
^C
[103873] signal 2: Interrupt
in expression starting at /tmp/file.jl:20
epoll_wait at /usr/lib/libc.so.6 (unknown line)
uv__io_poll at /workspace/srcdir/libuv/src/unix/epoll.c:236
uv_run at /workspace/srcdir/libuv/src/unix/core.c:400
ijl_task_get_next at /home/nsajko/tmp/jl/jl/julia-git/src/scheduler.c:514
poptask at ./task.jl:998
wait at ./task.jl:1007
task_done_hook at ./task.jl:687
jfptr_task_done_hook_59818 at /home/nsajko/tmp/jl/jl/julia-git/build_master/usr/lib/julia/sys.so (unknown line)
jl_apply at /home/nsajko/tmp/jl/jl/julia-git/src/julia.h:2152 [inlined]
jl_finish_task at /home/nsajko/tmp/jl/jl/julia-git/src/task.c:327
start_task at /home/nsajko/tmp/jl/jl/julia-git/src/task.c:1317
unknown function (ip: (nil))
Allocations: 1 (Pool: 1; Big: 0); GC: 0

[Thuener]

This is still an issue?
For me it works on version 1.10.2:

julia> function try_interrupt()
                  while true
                      try
                          sleep(1)
                          println("trying...")
                          @async 1+1
                      catch e
                          if typeof(e) <: InterruptException
                              println("caught Interrupt")
                              return
                          end
                      end
                  end
                  return
              end
try_interrupt (generic function with 1 method)

julia> try_interrupt()
trying...
trying...
caught Interrupt

julia>

[IoachimusRoderici]

This is still an issue?

@Thuener yes it is. It was fixed in the repl, but running the same function in a script produces this:

function (@main)(args)
    Base.exit_on_sigint(false)
    while true
        try
            sleep(1)
            println("trying...")
            @async 1+1
        catch e
            if typeof(e) <: InterruptException
                println("caught Interrupt")
                return
            end
        end
    end
    return
end

trying...
trying...
^Cfatal: error thrown and no exception handler available.
InterruptException()
_jl_mutex_unlock at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/threading.c:959
jl_mutex_unlock at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/julia_locks.h:80 [inlined]
ijl_task_get_next at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/scheduler.c:526
poptask at ./task.jl:1012
wait at ./task.jl:1021
task_done_hook at ./task.jl:694
...