AE.handle_exception(e = Fixnum: 8)

[ibc]

Running this code and pressing Ctrl+C:

loop do
  t = Thread.new {  AE.run { AE.add_periodic_timer(0.05){printf "."} }  }

  sleep 0.05
  t.kill
  sleep 0.01
end

causes:

WARN: AE.handle_exception(e = Fixnum: 8)
./bugs.rb:69:in `sleep': Interrupt

Fixnum????

Also, test_basic.rb contains something like this (simplified):

AE.set_exception_handler {|e| puts "AE.exception_handler rescues #{e.class}: #{e}" }

assert_nothing_raised do
  AE.run { qweqwe }
  AE.run { AE.next_tick { uhhhh } }
  AE.run { AE.add_timer(0) { uhhhh } }
end

All those assert pass the test. The first and second ones perfectly, but the third one makes Ruby TestUnit to fail (rake test --trace):

AE.exception_handler rescues NameError: undefined local variable or method `uhhhh' for #
...............
Finished in 0.192000 seconds.

16 tests, 73 assertions, 0 failures, 0 errors, 0 skips

Test run options: --seed 12359
rake aborted!
Command failed with status (1): [/usr/bin/ruby1.9.1 -I"lib:test" -I"/var/li...]
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils.rb:53:in `block in create_shell_runner'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils.rb:45:in `call'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils.rb:45:in `sh'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils_ext.rb:39:in `sh'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils.rb:82:in `ruby'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils_ext.rb:39:in `ruby'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/testtask.rb:99:in `block (2 levels) in define'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/file_utils_ext.rb:60:in `verbose'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/testtask.rb:98:in `block in define'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/usr/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/var/lib/gems/1.9.1/gems/rake-0.9.2.2/bin/rake:33:in `'
/usr/local/bin/rake:19:in `load'
/usr/local/bin/rake:19:in `
'

[ibc]

Without Ruby assert stuff it does not occur:

AE.set_exception_handler {|e| puts "AE.exception_handler rescues #{e.class}: #{e}" }

AE.run { AE.next_tick { uhhhh } }

causes:

AE.exception_handler rescues NameError: undefined local variable or method `uhhhh' for main:Object

[ibc]

And within test_basic.rb, it seems that the captured exception is OK (NameError)...

[ibc]

Fixed.

[ibc]

Unfortunatelly it occurs again after baf1fa3ed8b2ab85c53d47a3e11d1ddf0fc00dfc, but just in the first usecase above.

[ibc]

Humm, this could occur when using Thread#kill since it seems that it's not "rescue-able": http://www.ruby-forum.com/topic/4402523

Yes, it is!:

irb(main):028:0> t = Thread.new { AE.run { AE.add_periodic_timer(1) { printf "." } } }
#
irb(main):029:0> t.kill
AE_TRACE2: asyncengine_ruby.c:128:ae_ubf
#
*** ae_ubf_uv_async_callback(): AE_status: 2, AE_uv_loop: 140126363202112
AE_WARN: ae_handle_common.c:217:execute_function_with_glv_and_rb_protect::  ************ exception_tag == 8
/home/ibc/Proyectos/AsyncEngine/lib/asyncengine.rb:79:in `raise': exception class/object expected (TypeError)
        from /home/ibc/Proyectos/AsyncEngine/lib/asyncengine.rb:79:in `block in run'
        from :10:in `synchronize'
        from /home/ibc/Proyectos/AsyncEngine/lib/asyncengine.rb:64:in `run'
        from (irb):28:in `block in irb_binding'

[ibc]

The "issue" is reported in http://bugs.ruby-lang.org/issues/6575. Probably it's not a bug so in case rb_errinfo() returns != Exception object, I should not attempt to raise it.

[ibc]

I must assume that rb_errinfo() returns a Fixnum (instead of an Exception object) when the thread has been killed with Thread#kill. If I get another explanation I will reopen the issue.

[ibc]

I've found something in ruby sources:

thread.c:

static void
rb_threadptr_execute_interrupts_common(rb_thread_t *th)
{
  [...]

  /* exception from another thread */
  if (th->thrown_errinfo) {
    VALUE err = th->thrown_errinfo;
    th->thrown_errinfo = 0;
    thread_debug("rb_thread_execute_interrupts: %"PRIdVALUE"\n", err);

    if (err == eKillSignal || err == eTerminateSignal) {
      th->errinfo = INT2FIX(TAG_FATAL);
      TH_JUMP_TAG(th, TAG_FATAL);

and in eval_intern.h:

  RUBY_TAG_FATAL        = 0x8,
  #define TAG_FATAL RUBY_TAG_FATAL

So, there is my Fixnum 8 :)

[ibc]

So it seems a bug in Ruby, fixed in trunk: http://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/35622

[ibc]

It's not a Ruby bug (regardless it makes no lot of sense...). It seems this explains it: http://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/35625

So the way in which AE handles this issue is by replacing the Fixnum by an Interrupt exception.