Forum: Ruby-core [ruby-trunk - Bug #7212][Open] "stack level too deep" in Fiber much earlier in new versions of 1.9.3

Issue #7212 has been reported by fiddur (Fredrik Liljegren).

----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212

Author: fiddur (Fredrik Liljegren)
Status: Open
Priority: Normal
Assignee:
Category:
Target version:
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)

Issue #7212 has been updated by usa (Usaku NAKAMURA).

Status changed from Open to Assigned
Assignee set to ko1 (Koichi Sasada)


----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212#change-31480

Author: fiddur (Fredrik Liljegren)
Status: Assigned
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category:
Target version:
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)

Issue #7212 has been updated by fiddur (Fredrik Liljegren).


Here's a little more debug-info (not sure if it's needed, but anyhow...)

I tried the patch from #3187, increasing the stack size of fibers.  I 
confirmed that the patch is working on a normal recursing method 
(without lambda block), increasing recursability 4 times by setting 16kb 
stacksize.  That did NOT affect this bug at all, still on 11 levels of 
recursion.

Not knowing how it's implemented, I tried lambda-blocks without 
closure-behaviour; i.e. without using external variables, using just:
  def recursive
    -> do
      p "Block"
      subblock = recursive
      subblock.call
    end
  end

...but it's exactly the same.


I also tried without the lambda notation, just sending in a block to 
recursive method.  That got me up to level 250 on both 1.9.3-p194 and 
1.9.2-p320.  That's using:
  def recursive(level=0, &block)
    p "Level #{level}"
    recursive(level+1) { block.call }
  end
  Fiber.new { recursive {} }.resume


Well, hope it helps.

----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212#change-31486

Author: fiddur (Fredrik Liljegren)
Status: Assigned
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category:
Target version:
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)

Issue #7212 has been updated by ko1 (Koichi Sasada).

Target version set to 2.0.0


----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212#change-31964

Author: fiddur (Fredrik Liljegren)
Status: Assigned
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category:
Target version: 2.0.0
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)

Issue #7212 has been updated by ko1 (Koichi Sasada).

Status changed from Assigned to Feedback

Do you use same compiler and compile option on each environments?
----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212#change-34871

Author: fiddur (Fredrik Liljegren)
Status: Feedback
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category:
Target version: 2.0.0
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)

Issue #7212 has been updated by ko1 (Koichi Sasada).

Status changed from Feedback to Closed

No feedback.
----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212#change-36202

Author: fiddur (Fredrik Liljegren)
Status: Closed
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category:
Target version: 2.0.0
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)

Issue #7212 has been updated by fiddur (Fredrik Liljegren).


ko1 (Koichi Sasada) wrote:
> Do you use same compiler and compile option on each environments?

Yes, it was compiled with rvm with no options specified.



I'm sorry for the late answer, for some reason I didn't get any mail 
notification even though my settings are to get email for things "I 
watch or I'm am involved in".

----------------------------------------
Bug #7212: "stack level too deep" in Fiber much earlier in new versions 
of 1.9.3
https://bugs.ruby-lang.org/issues/7212#change-37326

Author: fiddur (Fredrik Liljegren)
Status: Closed
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category:
Target version: 2.0.0
ruby -v: ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux] (and 
others, see description)


I was getting SystemStackError in my application on some servers and not 
others; on all with 1.9.3-p286 and on some with p194, and on none with 
1.9.2-head.  I boiled it down to this:


def recursive(level = 0)
  -> do
    p "In block #{level}"
    if level < 1000
      subblock = recursive(level + 1)
      subblock.call
    end
  end
end

p "Doing recursive call in a fiber"
Fiber.new { recursive.call }.resume


On server A, 1.9.3-p194 and 1.9.3-p286 got up to 11 levels of recursion, 
while 1.9.2-head got up to 97 levels.
On server B (without 1.9.2), 1.9.3-p194 got 55 levels while p286 still 
got 11 levels.

I don't know what changes are made, but I think 11 levels are way on the 
low side for many applications.

(My original problem was with a thin-server running rack-fiber_pool with 
em-synchrony getting too deep in a regexp in Addressable::URI.)