4 files changed, 46 insertions, 1 deletions
diff --git a/lib/ffi/autopointer.rb b/lib/ffi/autopointer.rb
index 6c6333c..bd4c911 100644
--- a/lib/ffi/autopointer.rb
+++ b/lib/ffi/autopointer.rb
@@ -107,6 +107,7 @@ module FFI
     # @return [Boolean] +autorelease+
     # Set +autorelease+ property. See {Pointer Autorelease section at Pointer}.
     def autorelease=(autorelease)
+      raise FrozenError.new("can't modify frozen #{self.class}") if frozen?
       @releaser.autorelease=(autorelease)
     end
 
diff --git a/lib/ffi/compat.rb b/lib/ffi/compat.rb
new file mode 100644
index 0000000..7569013
--- /dev/null
+++ b/lib/ffi/compat.rb
@@ -0,0 +1,43 @@
+#
+# Copyright (C) 2023-2023 Lars Kanis
+#
+# This file is part of ruby-ffi.
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above copyright notice
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+# * Neither the name of the Ruby FFI project nor the names of its contributors
+#   may be used to endorse or promote products derived from this software
+#   without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+module FFI
+  if defined?(Ractor.make_shareable)
+    # This is for FFI internal use only.
+    def self.make_shareable(obj)
+      Ractor.make_shareable(obj)
+    end
+  else
+    def self.make_shareable(obj)
+      obj.freeze
+    end
+  end
+end
diff --git a/lib/ffi/ffi.rb b/lib/ffi/ffi.rb
index dfffa8c..31f25d1 100644
--- a/lib/ffi/ffi.rb
+++ b/lib/ffi/ffi.rb
@@ -28,6 +28,7 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+require 'ffi/compat'
 require 'ffi/platform'
 require 'ffi/data_converter'
 require 'ffi/types'
diff --git a/lib/ffi/struct.rb b/lib/ffi/struct.rb
index 725b9cb..1283d63 100644
--- a/lib/ffi/struct.rb
+++ b/lib/ffi/struct.rb
@@ -219,7 +219,7 @@ module FFI
         end
         builder.size = @size if defined?(@size) && @size > builder.size
         cspec = builder.build
-        @layout = cspec unless self == Struct
+        @layout = FFI.make_shareable(cspec) unless self == Struct
         @size = cspec.size
         return cspec
       end