| 1 | Perl 5 DynaLoader |
| 2 | |
| 3 | See DynaLoader.pm for detailed specification. |
| 4 | |
| 5 | This module is very similar to the other Perl 5 modules except that |
| 6 | Configure selects which dl_*.xs file to use. |
| 7 | |
| 8 | After Configure has been run the Makefile.PL will generate a Makefile |
| 9 | which will run xsubpp on a specific dl_*.xs file and write the output |
| 10 | to DynaLoader.c |
| 11 | |
| 12 | After that the processing is the same as any other module. |
| 13 | |
| 14 | Note that, to be effective, the DynaLoader module must be _statically_ |
| 15 | linked into perl! Configure should arrange this. |
| 16 | |
| 17 | This interface is based on the work and comments of (in no particular |
| 18 | order): Larry Wall, Robert Sanders, Dean Roehrich, Jeff Okamoto, Anno |
| 19 | Siegel, Thomas Neumann, Paul Marquess, Charles Bailey and others. |
| 20 | |
| 21 | The dl_*.xs files should either be named after the dynamic linking |
| 22 | operating system interface used if that interface is available on more |
| 23 | than one type of system, e.g.: |
| 24 | dlopen for dlopen()/dlsym() type functions (SunOS, BSD) |
| 25 | dld for the GNU dld library functions (linux, ?) |
| 26 | or else the osname, e.g., hpux, next, vms etc. |
| 27 | |
| 28 | Both are determined by Configure and so only those specific names that |
| 29 | Configure knows/uses will work. |
| 30 | |
| 31 | If porting the DynaLoader to a platform that has a core dynamic linking |
| 32 | interface similar to an existing generic type, e.g., dlopen or dld, |
| 33 | please try to port the corresponding dl_*.xs file (using #ifdef's if |
| 34 | required). |
| 35 | |
| 36 | Otherwise, or if that proves too messy, create a new dl_*.xs file named |
| 37 | after your osname. Configure will give preference to a dl_$osname.xs |
| 38 | file if one exists. |
| 39 | |
| 40 | The file dl_dlopen.xs is a reference implementation by Paul Marquess |
| 41 | which is a good place to start if porting from scratch. For more complex |
| 42 | platforms take a look at dl_dld.xs. The dlutils.c file holds some |
| 43 | common definitions that are #included into the dl_*.xs files. |
| 44 | |
| 45 | After the initial implementation of a new DynaLoader dl_*.xs file you |
| 46 | may need to edit or create ext/MODULE/MODULE.bs files (library bootstrap |
| 47 | files) to reflect the needs of your platform and linking software. |
| 48 | |
| 49 | Refer to DynaLoader.pm, lib/ExtUtils/MakeMaker.pm and any existing |
| 50 | ext/MODULE/MODULE.bs files for more information. |
| 51 | |
| 52 | Tim Bunce. |
| 53 | August 1994 |