Berkeley DB Reference Guide: FreeBSD

Berkeley DB Reference Guide:
Building Berkeley DB for UNIX/POSIX systems

FreeBSD

I can't compile and run multithreaded applications.
Special compile-time flags are required when compiling threaded applications on FreeBSD. If you are compiling a threaded application, you must compile with the _THREAD_SAFE and -pthread flags:
```
cc -D_THREAD_SAFE -pthread ...
```
The Berkeley DB library will automatically build with the correct options.

I get occasional failures when running RPC-based programs under FreeBSD clients.

There is a known bug in the XDR implementation in the FreeBSD C library from version 2.2 up to version 4.0-RELEASE, that causes certain-sized messages to fail and return a zero-filled reply to the client. A bug report (#16028) has been filed with FreeBSD. The following patch is the FreeBSD fix:

*** /usr/src/lib/libc/xdr/xdr_rec.c.orig	Mon Jan 10 10:20:42 2000
--- /usr/src/lib/libc/xdr/xdr_rec.c	Wed Jan 19 10:53:45 2000
***************
*** 558,564 ****
  	 * but we don't have any way to be certain that they aren't
  	 * what the client actually intended to send us.
  	 */
! 	if ((header & (~LAST_FRAG)) == 0)
  		return(FALSE);
  	rstrm->fbtbc = header & (~LAST_FRAG);
  	return (TRUE);
--- 558,564 ----
  	 * but we don't have any way to be certain that they aren't
  	 * what the client actually intended to send us.
  	 */
! 	if (header == 0)
  		return(FALSE);
  	rstrm->fbtbc = header & (~LAST_FRAG);
  	return (TRUE);

I see fsync and close system call failures when accessing databases or log files on NFS-mounted filesystems.
Some FreeBSD releases are known to return ENOLCK from fsync and close calls on NFS-mounted filesystems, even though the call has succeeded. The Berkeley DB code should be modified to ignore ENOLCK errors, or no Berkeley DB files should be placed on NFS-mounted filesystems on these systems.