jruby · headius · Jul 26, 2021 · Jul 26, 2021 · Jul 26, 2021 · Jul 26, 2021
diff --git a/core/src/main/ruby/jruby/kernel/file.rb b/core/src/main/ruby/jruby/kernel/file.rb
@@ -4,19 +4,19 @@
 
   class File
     def self.symlink(target, link)
-      # lazy load FFI-based file logic
-      require_relative 'jruby/file_ffi'
+      # lazy load FFI-based File.symlink logic
+      require_relative 'jruby/windows_ffi_file'
 
       symlink(target, link)
     end
+  end
 
-    class String
-      # Convenience method for converting strings to UTF-16LE for wide character
-      # functions that require it.
-      #
-      def wincode
-        (self.tr(File::SEPARATOR, File::ALT_SEPARATOR) + 0.chr).encode('UTF-16LE')
-      end
+  class String
+    # Convenience method for converting strings to UTF-16LE for wide character
+    # functions that require it.
+    #
+    def wincode
+      (self.tr(File::SEPARATOR, File::ALT_SEPARATOR) + 0.chr).encode('UTF-16LE')
     end
   end
 
@@ -27,8 +27,8 @@ def wincode
 
   class File
     def flock(operation)
-      # lazy load FFI-based file logic
-      require_relative 'jruby/file_ffi'
+      # lazy load FFI-based File#flock logic
+      require_relative 'jruby/solaris_ffi_file'
 
       flock(operation)
     end

diff --git a/core/src/main/ruby/jruby/kernel/jruby/file_ffi.rb b/core/src/main/ruby/jruby/kernel/jruby/file_ffi.rb
diff --git a/core/src/main/ruby/jruby/kernel/jruby/solaris_ffi_file.rb b/core/src/main/ruby/jruby/kernel/jruby/solaris_ffi_file.rb
@@ -0,0 +1,77 @@
+# flock support for Solaris
+
+begin
+  require 'ffi'
+
+  module JRuby::Fcntl
+    F_RDLCK = 1
+    F_SETLK = 6
+    F_SETLKW = 7
+    F_UNLCK = 3
+    F_WRLCK = 2
+
+    extend FFI::Library
+    ffi_lib 'c'
+    attach_function :fcntl, [:short, :short, :varargs], :int
+
+    class Flock < FFI::Struct
+      self.size = 44
+      layout :l_type, :short, 0,
+             :l_whence, :short, 2,
+             :l_start, :off_t, 4,
+             :l_len, :off_t, 12,
+             :l_sysid, :int, 20,
+             :l_pid, :int, 24,
+             :l_pad, :int, 28
+    end
+  end
+
+  class File
+    # Adapted from MRI's missing/flock.c
+    def flock(operation)
+      type = case (operation & ~LOCK_NB)
+             when LOCK_SH
+               JRuby::Fcntl::F_RDLCK
+             when LOCK_EX
+               JRuby::Fcntl::F_WRLCK
+             when LOCK_UN
+               JRuby::Fcntl::F_UNLCK
+             else
+               raise Errno::EINVAL
+             end
+
+      flock = JRuby::Fcntl::Flock.new
+      flock[:l_type] = type
+      flock[:l_whence] = File::SEEK_SET
+      flock[:l_start] = flock[:l_len] = 0
+
+      while JRuby::Fcntl.fcntl(fileno, (operation & LOCK_NB) != 0 ? JRuby::Fcntl::F_SETLK : JRuby::Fcntl::F_SETLKW, :pointer, flock) != 0
+        errno = FFI.errno
+        case errno
+        when Errno::EAGAIN::Errno, Errno::EWOULDBLOCK::Errno, Errno::EACCES::Errno
+          return false if operation & LOCK_NB != 0
+
+          sleep 0.1
+          next
+        when Errno::EINTR::Errno
+          # try again
+          next
+        else
+          raise SystemCallError.new('fcntl', FFI.errno)
+        end
+      end
+
+      return 0
+    end
+  end
+
+rescue LoadError
+
+  # Could not load FFI or fcntl not available, define File#flock to raise NotImplementedError
+  class ::File
+    def flock(*)
+      raise NotImplementedError.new("fcntl-based flock not available on this platform")
+    end
+  end
+
+end