Design Questions for MingW libjava 3.4 Refactoring

Fri Jun 27 00:09:00 GMT 2003

Hi Michael + Everyone,
I have a design question related to the
cleanup / refactoring / enhancements I'm
making to MingW libjava 3.4, particularly after
the Posix <-> Win32 networking code fork.
Currently, in platform.h (win32.h or posix.h),
there are a number of _Jv methods pertaining
to socket functions. I have eliminated these
in both win32.h as well as nat*Socket*ImplWin32.h
because I believe that the rationale was that
networking code should be split and not
conditionalized. Things seem to work except
for _Jv_select(), used by gnu/java/nio/natSelectorImpl.cc:
---------------------------8<----------------------------
jint
gnu::java::nio::SelectorImpl::java_do_select (jintArray read, jintArray write,
 jintArray except, jlong timeout)
{
 jint result;
 int max_fd = 0;
 fd_set read_fds;
 fd_set write_fds;
 fd_set except_fds;
 struct timeval real_time_data;
 struct timeval *time_data = NULL;
 real_time_data.tv_sec = 0;
 real_time_data.tv_usec = timeout;
 // If not legal timeout value is given, use NULL.
 // This means an infinite timeout.
 if (timeout >= 0)
 {
 time_data = &real_time_data;
 }
 // Reset all fd_set structures
 FD_ZERO (&read_fds);
 FD_ZERO (&write_fds);
 FD_ZERO (&except_fds);
 // Fill the fd_set data structures for the _Jv_select() call.
 helper_put_filedescriptors (read, read_fds, max_fd);
 helper_put_filedescriptors (write, write_fds, max_fd);
 helper_put_filedescriptors (except, except_fds, max_fd);
 // Actually do the select
 result = _Jv_select (max_fd + 1, &read_fds, &write_fds, &except_fds, time_data);
 if (result < 0)
 {
 char* strerr = strerror (errno);
 throw new ::java::io::IOException (JvNewStringUTF (strerr));
 }
 // Set the file descriptors according to the values returned from select().
 helper_get_filedescriptors (read, read_fds);
 helper_get_filedescriptors (write, write_fds);
 helper_get_filedescriptors (except, except_fds);
 return result;
}
---------------------------8<----------------------------
Two questions:
- Does my reasoning behind removing the socket-related _Jv methods
 in platform.h seem well-founded?
 
- Assuming the answer to the previous question is "yes", do we
 fork the above code too, which could easily be reused if
 we provided _Jv_select()? Wait a minute, if (result < 0),
 then we use errno / strerror() instead of the Win32 equivalents
 of WSAGetLastError() / FormatMessage(), so I think I just answered
 my own question.
 
Your thoughts?
-- Mohan
http://www.thisiscool.com/
http://www.animalsong.org/