X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlfork.pod;h=832710a80cd8d21ec4e42d1e93ef14481e8bf90e;hb=a537debe17982e491ffa12d12441cf74a452acb2;hp=d797dae2f5de21f461720ecda74b6054ebdd3e37;hpb=c73eb41b014273bd1c38add390d63cd8b903af3e;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perlfork.pod b/pod/perlfork.pod index d797dae..832710a 100644 --- a/pod/perlfork.pod +++ b/pod/perlfork.pod @@ -1,13 +1,13 @@ =head1 NAME -perlfork - Perl's fork() emulation (EXPERIMENTAL, subject to change) +perlfork - Perl's fork() emulation =head1 SYNOPSIS - WARNING: As of the 5.8.0 release, the fork() emulation continues - to be an experimental feature. Use in production applications is - not recommended. See the "BUGS" and "CAVEATS AND LIMITATIONS" - sections below. + NOTE: As of the 5.8.0 release, fork() emulation has considerably + matured. However, there are still a few known bugs and differences + from real fork() that might affect you. See the "BUGS" and + "CAVEATS AND LIMITATIONS" sections below. Perl provides a fork() keyword that corresponds to the Unix system call of the same name. On most Unix-like platforms where the fork() system @@ -208,7 +208,6 @@ write to a forked child: else { # child while () { print; } - close STDIN; exit(0); } @@ -238,7 +237,6 @@ And this one reads from the child: else { # child print "pipe_from_fork\n"; - close STDOUT; exit(0); } @@ -279,17 +277,6 @@ are expected to be fixed for thread-safety. =item * -Perl's regular expression engine currently does not play very nicely -with the fork() emulation. There are known race conditions arising -from the regular expression engine modifying state carried in the opcode -tree at run time (the fork() emulation relies on the opcode tree being -immutable). This typically happens when the regex contains paren groups -or variables interpolated within it that force a run time recompilation -of the regex. Due to this major bug, the fork() emulation is not -recommended for use in production applications at this time. - -=item * - Having pseudo-process IDs be negative integers breaks down for the integer C<-1> because the wait() and waitpid() functions treat this number as being special. The tacit assumption in the current implementation is that @@ -298,6 +285,15 @@ representation for pseudo-process IDs will be implemented in future. =item * +In certain cases, the OS-level handles created by the pipe(), socket(), +and accept() operators are apparently not duplicated accurately in +pseudo-processes. This only happens in some situations, but where it +does happen, it may result in deadlocks between the read and write ends +of pipe handles, or inability to send or receive data across socket +handles. + +=item * + This document may be incomplete in some respects. =back