[GR-18264] Use 1 concurrent download in RubyGems to avoid races in Gem::Specification._all.

PullRequest: truffleruby/1279

Author: eregon

CHANGELOG.md

@@ -75,6 +75,7 @@ Bug fixes:
 * Fixed `Kernel#Integer` conversion.
 * Fixed `IO.try_convert` parameter conversion.
 * Fixed linking of always-inline C API functions with `-std=gnu90` (#1837, #1879).
+* Avoid race conditions during `gem install` by using a single download thread.
 
 Compatibility:
 

lib/mri/rubygems/config_file.rb

@@ -44,7 +44,12 @@ class Gem::ConfigFile
   DEFAULT_BULK_THRESHOLD = 1000
   DEFAULT_VERBOSITY = true
   DEFAULT_UPDATE_SOURCES = true
-  DEFAULT_CONCURRENT_DOWNLOADS = 8
+  if defined?(::TruffleRuby)
+    # GR-18264: Gem::Specification._all does not seem thread safe and raises "nil spec! included in"
+    DEFAULT_CONCURRENT_DOWNLOADS = 1
+  else
+    DEFAULT_CONCURRENT_DOWNLOADS = 8
+  end
   DEFAULT_CERT_EXPIRATION_LENGTH_DAYS = 365
 
   ##

spec/truffle/rubygems/install_spec.rb

@@ -0,0 +1,17 @@
+# Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+#
+# Eclipse Public License version 2.0, or
+# GNU General Public License version 2, or
+# GNU Lesser General Public License version 2.1.
+# OTHER DEALINGS IN THE SOFTWARE.
+
+require_relative '../../ruby/spec_helper'
+require 'rubygems'
+
+describe "Downloading gems with RubyGems" do
+  it "is thread-safe by using a single thread to fetch (GR-18264)" do
+    Gem.configuration.concurrent_downloads.should == 1
+  end
+end

src/main/java/org/truffleruby/core/bool/NilClassNodes.java

@@ -21,7 +21,7 @@ public abstract class NilClassNodes {
 
     /** Needs to be in Java for {@link InlinedIsNilNode} */
     @CoreMethod(names = "nil?", needsSelf = false)
-    public abstract static class AndNode extends CoreMethodNode {
+    public abstract static class IsNilNode extends CoreMethodNode {
 
         @Specialization
         protected boolean isNil() {

src/main/java/org/truffleruby/core/kernel/KernelNodes.java

@@ -1270,7 +1270,7 @@ protected DynamicObject methodsSingleton(VirtualFrame frame, Object self, boolea
     }
 
     @CoreMethod(names = "nil?", needsSelf = false)
-    public abstract static class NilNode extends CoreMethodArrayArgumentsNode {
+    public abstract static class IsNilNode extends CoreMethodArrayArgumentsNode {
 
         @Specialization
         protected boolean isNil() {