### Berkeley DB Reference Guide: Building Berkeley DB for UNIX systems |

# HP-UX

1. I can't specify the DB_SYSTEM_MEM flag to DBENV->open.

   The shmget(2) interfaces are not always used on HP-UX, even though they exist, as anonymous memory allocated using shmget(2) cannot be used to store the standard HP-UX msemaphore semaphores. For this reason, it may not be possible to specify the DB_SYSTEM_MEM flag on some versions of HP-UX. (We have only seen this problem on HP-UX 10.XX, so the simplest workaround may be to upgrade your HP-UX release.)

2. I can't specify both the DB_PRIVATE and DB_THREAD flags to DBENV->open.

   It is not possible to store the standard HP-UX msemaphore semaphores in memory returned by malloc(3) in some versions of HP-UX. For this reason, it may not be possible to specify both the DB_PRIVATE and DB_THREAD flags on some versions of HP-UX. (We have only seen this problem on HP-UX 10.XX, so the simplest workaround may be to upgrade your HP-UX release.)

3. During configuration I see a message that large file support has been turned off.

   Some HP-UX system include files redefine "open" when big-file support (the HAVE_FILE_OFFSET_BITS and _FILE_OFFSET_BITS #defines) is enabled. This causes problems when compiling for C++, where "open" is a legal identifier, used in the Berkeley DB C++ API. For this reason, we automatically turn off big-file support when Berkeley DB is configured with a C++ API. This should not be a problem for applications unless there is a need to create databases larger than 2GB.

4. I can't compile and run multi-threaded applications.

   Special compile-time flags are required when compiling threaded applications on HP-UX. If you are compiling a threaded application, you must compile with the _REENTRANT flag:

   >     cc -D_REENTRANT ...

   The Berkeley DB library will automatically build with the correct options.

5. An ENOMEM error is returned from DBENV->open or DBENV->remove.

   Due to the constraints of the PA-RISC memory architecture, HP-UX does not allow a process to map a file into its address space multiple times. For this reason, each Berkeley DB environment may be opened only once by a process on HP-UX, i.e., calls to DBENV->open will fail if the specified Berkeley DB environment has been opened and not subsequently closed.

6. When compiling with gcc, I see the following error:

   >     #error "Large Files (ILP32) not supported in strict ANSI mode."

   We believe this is an error in the HP-UX include files, but we don't really understand it. The only workaround we have found is to add -D__STDC_EXT__ to the C preprocessor defines as part of compilation.

7. When using the Tcl API (including running the test suite) I see the error "Can't shl_load() a library containing Thread Local Storage".

   This problem happens when HP-UX has been configured to use pthread mutex locking and an attempt is made to call Berkeley DB using the Tcl API. We have never found any way to fix this problem as part of the Berkeley DB build process. To work around the problem, rebuild tclsh and modify its build process to explicitly link it against the HP-UX pthread library (currently /usr/lib/libpthread.a).

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