With respect to the issue OpenBSD has, it is very operating system specific. We still have a userland library that simulates threading using various tricks like making all file descriptors non-blocking and emulating blocking behavior. The workaround for OpenBSD in closeDescriptors is only applicable to OpenBSD since the rest of the supported OS's have kernel supported threads. What it does is prevent the child process from resetting the file descriptors back to blocking directly before execv's another program. If the child resets them to blocking, the next time the parent does a read on them it will block and wedge the userland thread library (think deadlock). I would not suggest this work-around be generally applicable based on the presence of _thread_sys_closefrom since it only applies to OpenBSD's particular issues. Work continues on kernel based thread for OpenBSD and I'm looking forward to when any OS specific work-arounds can be removed. Regards, -Kurt Martin Buchholz wrote:
Looks good to me, .... but I am tempted to try very hard to avoid constructs of the form #ifdef OS_FLAVOR
At startup time (in a static init method), you can determine whether /proc/self/fd is a directory and contains only entries that look like smallish integers. Similarly for /dev/fd. If we can assume dlopen/dlsym, we could dynamically check for the presence of _thread_sys_closefrom And if all else fails, we can simply loop up to some maximum.
One way to only use readdir64 if available is to use readdir64 only if _LFS64_LARGEFILE is defined to 1, else fall back to readdir.
Martin
On Tue, Nov 11, 2008 at 19:08, <glewis@eyesbeyond.com> wrote:
Changeset: c20eddeb23e3 Author: glewis@misty.eyesbeyond.com Date: 2008-11-11 19:07 -0800 URL: http://hg.openjdk.java.net/bsd-port/bsd-port/jdk/rev/c20eddeb23e3
. Merge all of the special *BSD version of closeDescriptors() with the Linux and Solaris, save for OpenBSD. OpenBSD had its own version of closeDescriptors() and based on the comments in the code the issues that lead to it being separate still apply.
This fixes exec'ing external programmes on FreeBSD and Mac OS X at least and reduces the number of variants of this function from 3 to 2.
This is different from submitted version in that it keeps the OpenBSD version. It would be good to remove that, but we need someone to test on OpenBSD before doing so.
Submitted by: Michael Franz <mvfranz@gmail.com>
! src/solaris/native/java/lang/UNIXProcess_md.c