nobu	2008-07-11 06:45:17 +0900 (Fri, 11 Jul 2008)

  New Revision: 18021

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=18021

  Log:
    * vm_core.h (rb_thread_t): per-thread cwd support.  [EXPERIMENTAL]
    
    * io.c (rb_sysopen), dir.c (dir_s_chdir),
      file.c (ruby_readlink, ruby_absolute_path_p),
      thread.c (thread_create_core, ruby_thread_getcwd, ruby_getcwd),
      vm.c (Init_VM): ditto.
    
    * string.c (rb_str_wrap): wrap a heap pointer with string.
    
    * thread.c (ruby_system_alone): returns if only current VM is running.

  Modified files:
    branches/mvm/ChangeLog
    branches/mvm/common.mk
    branches/mvm/dir.c
    branches/mvm/file.c
    branches/mvm/include/ruby/intern.h
    branches/mvm/include/ruby/mvm.h
    branches/mvm/io.c
    branches/mvm/string.c
    branches/mvm/thread.c
    branches/mvm/util.c
    branches/mvm/vm.c
    branches/mvm/vm_core.h