Fix object writing and reading for Ruby 1.8 IO differences.

lib/process_shared/shared_memory.rb

@@ -60,6 +60,18 @@ module ProcessShared
     #
     # Raises IndexError if there is insufficient space.
     def put_object(offset, obj)
+      # FIXME: This is a workaround to an issue I'm seeing in
+      # 1.8.7-p352 (not tested in other 1.8's).  If I used the code
+      # below that works in 1.9, then inside SharedMemoryIO#write, the
+      # passed string object is 'terminated' (garbage collected?) and
+      # won't respond to any methods...  This way is less efficient
+      # since it involves the creation of an intermediate string, but
+      # it works in 1.8.7-p352.
+      if RUBY_VERSION =~ /^1.8/
+        str = Marshal.dump(obj)
+        return put_bytes(offset, str, 0, str.size)
+      end
+
       io = SharedMemoryIO.new(self)
       io.seek(offset)
       Marshal.dump(obj, io)
@@ -77,7 +89,7 @@ module ProcessShared
 
     # Equivalent to {#put_object(0, obj)}
     def write_object(obj)
-      Marshal.dump(obj, to_shm_io)
+      put_object(0, obj)
     end
 
     # Equivalent to {#read_object(0, obj)}

lib/process_shared/shared_memory_io.rb

@@ -126,8 +126,20 @@ module ProcessShared
       _getbyte
     end
 
-    def getc
+    # {#getc} in Ruby 1.9 returns String or nil.  In 1.8, it returned
-      raise NotImplementedError
+    # Fixnum of nil (identical to getbyte).
+    #
+    # FIXME: should this be encoding/character aware?
+    def getc19
+      if b = getbyte
+        '' << b
+      end
+    end
+    # FIXME: ignores versions prior to 1.8.
+    if RUBY_VERSION =~ /^1.8/
+      alias_method :getc, :getbyte
+    else
+      alias_method :getc, :getc19
     end
 
     def gets