[ruby-core:81130] [Ruby trunk Bug#11384] multi-threaded autoload sometimes fails

[normalperson@yhbt.net]

Issue #11384 has been updated by normalperson (Eric Wong).

File 0001-autoload-always-wait-on-loading-thread.patch added
Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN to 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: REQUIRED, 2.4: REQUIRED

I think the attached patch should fix it, over 12 million iterations
and still going strong.


----------------------------------------
Bug #11384: multi-threaded autoload sometimes fails
https://bugs.ruby-lang.org/issues/11384#change-64779

* Author: normalperson (Eric Wong)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: trunk r51319
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: REQUIRED, 2.4: REQUIRED
----------------------------------------
~~~
I get this failure once in a blue moon:

#8 test_autoload.rb:46:in `<top (required)>':
     open("zzz.rb", "w") {|f| f.puts "class ZZZ; def self.ok;:ok;end;end"}
     autoload :ZZZ, "./zzz.rb"
     t1 = Thread.new {ZZZ.ok}
     t2 = Thread.new {ZZZ.ok}
     [t1.value, t2.value].join
  #=> "" (expected "okok")
stderr output is not empty
   bootstraptest.tmp.rb:5:in `block in <main>': uninitialized constant ZZZ (Name
+Error)
test_autoload.rb        FAIL 1/8
FAIL 1/1010 tests failed


It is a very rare failure, I extracted it into a standalone script and
it took over 500,000 runs to hit it:

unless test(?e, "zzz.rb")
  open("zzz.rb", "w") {|f| f.puts "class ZZZ; def self.ok;:ok;end;end"}
end
autoload :ZZZ, "./zzz.rb"
t1 = Thread.new {ZZZ.ok}
t2 = Thread.new {ZZZ.ok}
[t1.value, t2.value].join
~~~

I'll work on this when I find time, but maybe somebody else can look at it
sooner.  I'm not sure if it affects older versions.


---Files--------------------------------
0001-autoload-always-wait-on-loading-thread.patch (1.96 KB)


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