1 files changed, 25 insertions, 7 deletions
diff --git a/lib/uri/common.rb b/lib/uri/common.rb
index 915c0e9519..ab3234cb37 100644
--- a/lib/uri/common.rb
+++ b/lib/uri/common.rb
@@ -16,6 +16,7 @@ module URI
   REGEXP = RFC2396_REGEXP
   Parser = RFC2396_Parser
   RFC3986_PARSER = RFC3986_Parser.new
+  Ractor.make_shareable(RFC3986_PARSER) if defined?(Ractor)
 
   # URI::Parser.new
   DEFAULT_PARSER = Parser.new
@@ -27,6 +28,7 @@ module URI
   DEFAULT_PARSER.regexp.each_pair do |sym, str|
     const_set(sym, str)
   end
+  Ractor.make_shareable(DEFAULT_PARSER) if defined?(Ractor)
 
   module Util # :nodoc:
     def make_components_hash(klass, array_hash)
@@ -62,10 +64,30 @@ module URI
 
   include REGEXP
 
-  @@schemes = {}
+  SCHEME_LIST_MUTEX = Mutex.new
+  private_constant :SCHEME_LIST_MUTEX
+
   # Returns a Hash of the defined schemes.
+  # The list is lazily calculated.
   def self.scheme_list
-    @@schemes
+    return const_get(:SCHEMES) if defined?(SCHEMES)
+
+    SCHEME_LIST_MUTEX.synchronize do
+      const_set(:SCHEMES, ObjectSpace.
+        each_object(Class).
+        select { |klass| klass < URI::Generic }.
+        each_with_object({}) { |klass, acc| acc[klass.name.split('::').last.upcase] = klass }.
+        freeze)
+    end
+  end
+
+  # Re-calculate scheme list
+  def self.refresh_scheme_list
+    SCHEME_LIST_MUTEX.synchronize do
+      remove_const(:SCHEMES) if defined?(SCHEMES)
+    end
+
+    scheme_list
   end
 
   #
@@ -73,11 +95,7 @@ module URI
   # from +URI.scheme_list+.
   #
   def self.for(scheme, *arguments, default: Generic)
-    if scheme
-      uri_class = @@schemes[scheme.upcase] || default
-    else
-      uri_class = default
-    end
+    uri_class = scheme_list[scheme.to_s.upcase] || default
 
     return uri_class.new(scheme, *arguments)
   end