Why is the thread status dead?

Question

That is the question. I called a function using a thread, but when I return to main control, main becomes in sleep status within a few moments.

Example (Look here is a line that calls a Win32API function GetMessage):

Start()
e = Thread.new { Look() }
for _i in 0..1000
    puts e.status
end

This code should print the e's status 1000 times, but it just prints once. I cannot find a reasonable error. Look does not return until it gets a message, so I suspect that this could be causing an error.

you'd better show us the code of `Look` – Bob Cromwell May 09 '13 at 03:11 — Bob Cromwell, May 09 '13 at 03:11

score 0 · Answer 1 · answered May 09 '13 at 03:11

0

My guess is that the status of e is nil, which puts displays as an empty string.

A nil status means the thread terminated abnormally.

Whatever is wrong, your code is printing something 1000 times, and you should put some visible text in the puts to show that.

Also, rather than use a throw-away variable _i, write

1000.times do
    puts e.status
end

answered May 09 '13 at 03:11

Borodin

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It seems to me `puts` will display `nil` in console instead of an empty string – Bob Cromwell May 09 '13 at 03:19
@BobCromwell: `puts nil.to_s.inspect` produces `""` – Borodin May 09 '13 at 04:20
you are right about your statement however `puts nil` produces `nil`. – Bob Cromwell May 09 '13 at 04:48
`puts nil` prints an empty line and returns `nil` (`puts` always returns `nil`). – Stefan May 09 '13 at 07:37
I am sorry to have used *produces*. @BobCromwell please try `puts nil` and see what you get. – Borodin May 09 '13 at 08:35
I am using Ruby 1.8.7 on Mac Mountain Lion, I do get following result: `nil ==> nil` with `puts nil` in `irb`. I am open to I am totally wrong .By the way, I raise an exception in the `Thread.new {}` block and it prints 1000 nil in console. – Bob Cromwell May 09 '13 at 12:17

Some.Proxy · Answer 2 · 2013-05-09T20:08:01.313

0

I solved thanks for all your help, the error was in that i only need to change GetMessageA for PeekMessage so thread doesn't interpret that is dead jeje

Some.Proxy

edited May 09 '13 at 20:08

answered May 09 '13 at 19:25

Some.Proxy

1
2

Why is the thread status dead?

2 Answers2