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Bug #13276

closed

Dir.glob returns empty array when OS has no more file handles (expected exception)

Added by floehopper (James Mead) about 5 years ago. Updated over 4 years ago.

Status:
Closed
Priority:
Normal
Target version:
-
ruby -v:
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin14]
[ruby-core:79899]

Description

The following terminal session demonstrates how Dir.glob returns an empty array when the OS has run out of file handles; whereas File.new raises a Errno::EMFILE exception.

I would expect Dir.glob to fail fast in a similar way to File.new.

$ mkdir /tmp/ruby-dir-glob-returns-empty-array-when-too-many-open-files
$ cd /tmp/ruby-dir-glob-returns-empty-array-when-too-many-open-files
$ touch foo
$ ulimit -n 16
$ ruby -e "1.upto(16).map { |i| p [i, Dir.glob('*')]; File.new('foo') }"
[1, ["foo"]]
[2, ["foo"]]
[3, ["foo"]]
[4, ["foo"]]
[5, ["foo"]]
[6, ["foo"]]
[7, ["foo"]]
[8, ["foo"]]
[9, ["foo"]]
[10, []] # Dir.glob returns empty array and does not raise exception
-e:1:in `initialize': Too many open files @ rb_sysopen - foo (Errno::EMFILE)
	from -e:1:in `new'
	from -e:1:in `block in <main>'
	from -e:1:in `upto'
	from -e:1:in `each'
	from -e:1:in `map'
	from -e:1:in `<main>'

The following is a counter example which shows how Dir.new raises an exception under the same conditions.

$ mkdir /tmp/ruby-dir-new-raises-exception-when-too-many-files-open
$ cd /tmp/ruby-dir-new-raises-exception-when-too-many-files-open
$ touch foo
$ mkdir bar
$ ulimit -n 16
$ ruby -e "1.upto(16).map { |i| p [i, Dir.new('bar')]; File.new('foo') }"
[1, #<Dir:bar>]
[2, #<Dir:bar>]
[3, #<Dir:bar>]
[4, #<Dir:bar>]
[5, #<Dir:bar>]
[6, #<Dir:bar>]
[7, #<Dir:bar>]
[8, #<Dir:bar>]
[9, #<Dir:bar>]
-e:1:in `initialize': Too many open files @ dir_initialize - bar (Errno::EMFILE)
	from -e:1:in `new'
	from -e:1:in `block in <main>'
	from -e:1:in `upto'
	from -e:1:in `each'
	from -e:1:in `map'
	from -e:1:in `<main>'

This is what I would expect for Dir.glob, i.e. I would expect an exception like this: Too many open files @ dir_s_glob (Errno::EMFILE) in the first example.

Updated by floehopper (James Mead) about 5 years ago

  • Subject changed from Ruby Dir.glob returns empty array when too many open files to Ruby Dir.glob returns empty array when too many open files (silent failure)

Updated by floehopper (James Mead) about 5 years ago

  • Subject changed from Ruby Dir.glob returns empty array when too many open files (silent failure) to Ruby Dir.glob returns empty array when OS has no more file handles (silent failure)

Updated by floehopper (James Mead) about 5 years ago

  • Subject changed from Ruby Dir.glob returns empty array when OS has no more file handles (silent failure) to Dir.glob returns empty array when OS has no more file handles (silent failure)

Updated by floehopper (James Mead) about 5 years ago

  • Subject changed from Dir.glob returns empty array when OS has no more file handles (silent failure) to Dir.glob returns empty array when OS has no more file handles (expected exception)

Updated by floehopper (James Mead) about 5 years ago

  • Description updated (diff)

Updated by nobu (Nobuyoshi Nakada) about 5 years ago

  • Assignee set to nobu (Nobuyoshi Nakada)
  • Status changed from Open to Assigned

This bug predates 1.0, so it will be fixed by 2.5 but won't be backported.

Actions #8

Updated by nobu (Nobuyoshi Nakada) about 5 years ago

  • Status changed from Assigned to Closed

Applied in changeset trunk|r58156.


dir.c: err at glob failure

  • dir.c (glob_helper): raise a SystemCallError exception when
    opendir() failed, except for ENOENT, ENOTDIR, and EACCES. this
    behavior predates 1.0; the comments in glob.c claimed that
    glob() returned -1 on error but actualy the pointer to a global
    variable, then dir_glob() did check only -1 as the comments, and
    ignored actual errors. [ruby-core:80226] [Bug #13276]

dir.c: ruby_glob_funcs_t

Actions #9

Updated by usa (Usaku NAKAMURA) about 5 years ago

  • Backport changed from 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN to 2.2: WONTFIX, 2.3: REQUIRED, 2.4: REQUIRED

Updated by nagachika (Tomoyuki Chikanaga) over 4 years ago

  • Backport changed from 2.2: WONTFIX, 2.3: REQUIRED, 2.4: REQUIRED to 2.2: WONTFIX, 2.3: REQUIRED, 2.4: DONE

ruby_2_4 r61367 merged revision(s) 58146,58150,58156.

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