* lib/cgi/session.rb (CGI::Session::FileStore::restore): use

  lockfile for exclusive locks.  a patch from <tommy AT tmtm.org>.
  [ruby-dev:32296]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@13935 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 4 deletions

diff --git a/lib/cgi/session.rb b/lib/cgi/session.rb
index 63d8cc97b2..e7e7587c65 100644
--- a/lib/cgi/session.rb
+++ b/lib/cgi/session.rb
@@ -397,8 +397,9 @@ class CGI
 	unless @hash
 	  @hash = {}
           begin
+            lockf = File.open(@path+".lock", "r")
+            lockf.flock File::LOCK_SH
 	    f = File.open(@path, 'r')
-	    f.flock File::LOCK_SH
 	    for line in f
 	      line.chomp!
 	      k, v = line.split('=',2)
@@ -406,6 +407,7 @@ class CGI
 	    end
           ensure
 	    f.close unless f.nil?
+            lockf.close if lockf
           end
 	end
 	@hash
@@ -415,13 +417,17 @@ class CGI
       def update
 	return unless @hash
         begin
-	  f = File.open(@path, File::CREAT|File::TRUNC|File::RDWR, 0600)
-	  f.flock File::LOCK_EX
+          lockf = File.open(@path+".lock", File::CREAT|File::RDWR, 0600)
+	  lockf.flock File::LOCK_EX
+          f = File.open(@path+".new", File::CREAT|File::TRUNC|File::WRONLY, 0600)
    	  for k,v in @hash
 	    f.printf "%s=%s\n", CGI::escape(k), CGI::escape(String(v))
 	  end
+          f.close
+          File.rename @path+".new", @path
         ensure
-          f.close unless f.nil?
+          f.close if f and !f.closed?
+          lockf.close if lockf
         end
       end
 
@@ -432,6 +438,8 @@ class CGI
 
       # Close and delete the session's FileStore file.
       def delete
+        File::unlink @path+".lock" rescue nil
+        File::unlink @path+".new" rescue nil
         File::unlink @path
       rescue Errno::ENOENT
       end