"build" refers to Inline creating a module in _Inline (like h2xs) and making it at use/BEGIN time (perl Makefile.PL/make install), before your program runs, ex
subsequent runs don't "build"
unless the c-source changes
The resulting directory structure
The _Inline/build directory usually gets cleaned up, but not for notdef.pl
notdef.pl also NAME's the module, so its name doesn't change, but def.pl doesn't NAME the module, so a name is derived from the filename (def.pl) and the md5 sum of the c-source code
$ cat _Inline\lib\auto\def_pl_4ff5\def_pl_4ff5.inl
md5 : 4ff5a29496365b6167324b7d80efb321
name : def_pl_4ff5
version : ""
language : C
language_id : C
installed : 0
date_compiled : Thu Nov 22 21:58:12 2012
inline_version : 0.5
ILSM : %
module : Inline::C
suffix : dll
type : compiled
Config : %
apiversion : ?
archname : MSWin32-x86-multi-thread
cc : gcc
ccflags : " -s -O2 -DWIN32 -DPERL_TEXTMODE_SCRIPTS -DPERL_IMPLICI
+T_CONTEXT -DPERL_IMPLICIT_SYS -fno-strict-aliasing
-mms-bitfields"
ld : g++
osname : MSWin32
osvers : 5.1
so : dll
version : 5.14.1
Now, can two copies of notdef.pl run simultaneously? Lets see
First cleanup $ rm -rfv _Inline
And one copy will trip over the other and die , the other will continue normally
$ perl -le " system 1, $^X, q,notdef.pl, for 1,2 "
$ validate Stage
Starting Build Preprocess Stage
get_maps Stage
Finished Build Preprocess Stage
Starting Build Parse Stage
validate Stage
Starting Build Preprocess Stage
get_maps Stage
Finished Build Preprocess Stage
Starting Build Parse Stage
Finished Build Parse Stage
Starting Build Glue 1 Stage
Finished Build Parse Stage
Starting Build Glue 1 Stage
Finished Build Glue 1 Stage
Starting Build Glue 2 Stage
Finished Build Glue 2 Stage
Starting Build Glue 3 Stage
Finished Build Glue 1 Stage
Starting Build Glue 2 Stage
Finished Build Glue 2 Stage
Starting Build Glue 3 Stage
Finished Build Glue 3 Stage
Starting Build Compile Stage
Starting "perl Makefile.PL" Stage
Finished Build Glue 3 Stage
Starting Build Compile Stage
Starting "perl Makefile.PL" Stage
Writing Makefile for modSV
Writing Makefile for modSV
Writing MYMETA.yml and MYMETA.json
Can't open Makefile for input: No such file or directory
at notdef.pl line 8.
BEGIN failed--compilation aborted at notdef.pl line 8.
Writing MYMETA.yml and MYMETA.json
Finished "perl Makefile.PL" Stage
Starting "make" Stage
...
Now I'm not sure what scenario davido is talking about in the OP, but I hope this helps
FWIW, def.pl/notdef.pl are derived from XS: returning a 64-bit unsigned int?/Re: Inline::C with multiple *.c