fix: avoid race condition in singleton instance method

open-telemetry · Dec 16, 2024 · f3e7e34 · f3e7e34
1 parent 8def74b
commit f3e7e34
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/instrumentation/base/lib/opentelemetry/instrumentation/base.rb b/instrumentation/base/lib/opentelemetry/instrumentation/base.rb
@@ -69,8 +69,9 @@ class << self
           integer: ->(v) { v.is_a?(Integer) },
           string: ->(v) { v.is_a?(String) }
         }.freeze
+        SINGLETON_MUTEX = Thread::Mutex.new
 
-        private_constant :NAME_REGEX, :VALIDATORS
+        private_constant :NAME_REGEX, :VALIDATORS, :SINGLETON_MUTEX
 
         private :new
 
@@ -163,8 +164,10 @@ def option(name, default:, validate:)
         end
 
         def instance
-          @instance ||= new(instrumentation_name, instrumentation_version, install_blk,
-                            present_blk, compatible_blk, options)
+          @instance || SINGLETON_MUTEX.synchronize do
+            @instance ||= new(instrumentation_name, instrumentation_version, install_blk,
+                              present_blk, compatible_blk, options)
+          end
         end
 
         private