m4_comment([$Id: aix.so,v 11.27 2005/04/06 01:45:22 mjc Exp $])

m4_ref_title(Building m4_db for UNIX/POSIX systems,
    AIX, @AIX, build_unix/notes, build_unix/freebsd)

m4_nlistbegin

m4_nlist([dnl
m4_bold([I can't compile and run multithreaded applications.])

m4_p([dnl
Special compile-time flags are required when compiling threaded
applications on AIX.  If you are compiling a threaded application, you
must compile with the _THREAD_SAFE flag and load with specific
libraries; for example, "-lc_r".  Specifying the compiler name with a
trailing "_r" usually performs the right actions for the system.])

m4_indent([dnl
xlc_r ...
cc -D_THREAD_SAFE -lc_r ...])

m4_p([dnl
The m4_db library will automatically build with the correct options.])])

m4_hl
m4_nlist([dnl
m4_bold([I can't run using the m4_ref(DB_SYSTEM_MEM) option to
m4_ref(dbenv_open).])

m4_p([dnl
AIX 4.1 allows applications to map only 10 system shared memory
segments.  In AIX 4.3, this has been raised to 256K segments, but only
if you set the environment variable "export EXTSHM=ON".])])

m4_hl
m4_nlist([m4_bold([dnl
On AIX 4.3.2 (or before) I see duplicate symbol warnings when
building the C++ shared library and when linking applications.])

m4_p([dnl
We are aware of some duplicate symbol warnings with this platform,
but they do not appear to affect the correct operation of applications.])])

m4_hl
m4_nlist([m4_bold([dnl
On AIX 4.3.3 I see undefined symbols for DbEnv::set_error_stream,
Db::set_error_stream or DbEnv::verify when linking C++ applications.
(These undefined symbols also appear when building the m4_db C++ example
applications).])

m4_p([dnl
By default, m4_db is built with _LARGE_FILES set to 1 to support the
creation of "large" database files.  However, this also affects how
standard classes, like iostream, are named internally.  When building
your application, use a "-D_LARGE_FILES=1" compilation option, or insert
"[#define _LARGE_FILES 1]" before any [#include] statements.])])

m4_hl
m4_nlist([dnl
m4_bold([I can't create database files larger than 1GB on AIX.])

m4_p([dnl
If you're running on AIX 4.1 or earlier, try changing the source code
for m4_path(os/os_open.c) to always specify the m4_bold(O_LARGEFILE)
flag to the m4_manref(open, 2) system call, and recompile m4_db from
scratch.])

m4_p([dnl
Also, the documentation for the IBM Visual Age compiler states that it
does not not support the 64-bit filesystem APIs necessary for creating
large files; the ibmcxx product must be used instead.  We have not heard
whether the GNU gcc compiler supports the 64-bit APIs or not.])

m4_p([dnl
Finally, to create large files under AIX, the filesystem has to be
configured to support large files and the system wide user hard-limit
for file sizes has to be greater than 1GB.])])

m4_hl
m4_nlist([dnl
m4_bold([I see errors about "open64" when building m4_db applications.])

m4_p([dnl
System include files (most commonly fcntl.h) in some releases of AIX,
HP-UX and Solaris redefine "open" when large-file support is enabled for
applications.  This causes problems when compiling applications because
"open" is a method in the m4_db APIs.  To work around this problem:
m4_nlistbegin
m4_nlist([dnl
Avoid including the problematical system include files in source code
files which also include m4_db include files and call into the m4_db
API.])
m4_nlistns([dnl
Before building m4_db, modify the generated include file db.h to itself
include the problematical system include files.])
m4_nlistns([dnl
Turn off m4_db large-file support by specifying the
m4_linkpage(M4RELDIR/ref/build_unix/conf, --disable-largefile,
--disable-largefile) configuration option and rebuilding.])
m4_nlistend])])

m4_nlistend

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