From: Jarkko Hietaniemi Date: Sat, 23 Aug 2003 07:13:29 +0000 (+0000) Subject: Doc tweaks on perlhack. X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=a958818a694caec0b76e9ef74fd37212931fdce7;p=p5sagit%2Fp5-mst-13.2.git Doc tweaks on perlhack. p4raw-id: //depot/perl@20851 --- diff --git a/pod/perlhack.pod b/pod/perlhack.pod index 08a9906..b2fb021 100644 --- a/pod/perlhack.pod +++ b/pod/perlhack.pod @@ -1904,9 +1904,32 @@ some common testing and debugging tools with Perl. This is meant as a guide to interfacing these tools with Perl, not as any kind of guide to the use of the tools themselves. -Note that running under memory debuggers such as Purify, valgrind, -or Third Degree greatly slows down the execution: seconds become minutes, -minutes become hours. +B: Running under memory debuggers such as Purify, valgrind, or +Third Degree greatly slows down the execution: seconds become minutes, +minutes become hours. For example as of Perl 5.8.1, the +ext/Encode/t/Unicode.t takes extraordinarily long to complete under +e.g. Purify, Third Degree, and valgrind. Under valgrind it takes more +than six hours, even on a snappy computer-- the said test must be +doing something that is quite unfriendly for memory debuggers. If you +don't feel like waiting, that you can simply kill away the perl +process. + +B: To minimize the number of memory leak false alarms (see +L for more information), you have to have +environment variable PERL_DESTRUCT_LEVEL set to 2. The F +and harness scripts do that automatically. But if you are running +some of the tests manually-- for csh-like shells: + + setenv PERL_DESTRUCT_LEVEL 2 + +and for Bourne-type shells: + + PERL_DESTRUCT_LEVEL=2 + export PERL_DESTRUCT_LEVEL + +or in UNIXy environments you can also use the C command: + + env PERL_DESTRUCT_LEVEL=2 valgrind ./perl -Ilib ... =head2 Rational Software's Purify @@ -1969,17 +1992,6 @@ which creates a binary named 'pureperl' that has been Purify'ed. This binary is used in place of the standard 'perl' binary when you want to debug Perl memory problems. -To minimize the number of memory leak false alarms -(see L), set environment variable -PERL_DESTRUCT_LEVEL to 2. - - setenv PERL_DESTRUCT_LEVEL 2 - -In Bourne-type shells: - - PERL_DESTRUCT_LEVEL=2 - export PERL_DESTRUCT_LEVEL - As an example, to show any memory leaks produced during the standard Perl testset you would create and run the Purify'ed perl as: @@ -2062,14 +2074,6 @@ standard Perl testset you would create and run Purify as: which would instrument Perl in memory, run Perl on test.pl, then finally report any memory problems. -B: as of Perl 5.8.0, the ext/Encode/t/Unicode.t takes -extraordinarily long (hours?) to complete under Purify. It has been -theorized that it would eventually finish, but nobody has so far been -patient enough :-) (This same extreme slowdown has been seen also with -the Third Degree tool, so the said test must be doing something that -is quite unfriendly for memory debuggers.) It is suggested that you -simply kill away that testing process. - =head2 valgrind The excellent valgrind tool can be used to find out both memory leaks @@ -2118,12 +2122,12 @@ aren't. See L for more information. =head2 PERL_DESTRUCT_LEVEL -If you want to run any of the tests yourself manually using the -pureperl or perl.third executables, please note that by default -perl B explicitly cleanup all the memory it has allocated -(such as global memory arenas) but instead lets the exit() of -the whole program "take care" of such allocations, also known -as "global destruction of objects". +If you want to run any of the tests yourself manually using e.g. +valgrind, or the pureperl or perl.third executables, please note that +by default perl B explicitly cleanup all the memory it has +allocated (such as global memory arenas) but instead lets the exit() +of the whole program "take care" of such allocations, also known as +"global destruction of objects". There is a way to tell perl to do complete cleanup: set the environment variable PERL_DESTRUCT_LEVEL to a non-zero value.