X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlfork.pod;h=832710a80cd8d21ec4e42d1e93ef14481e8bf90e;hb=a5c75c1d181494e06a58988f267a8b3d081df483;hp=d930e9396e87565c874374ffcf1c2763f18e2acc;hpb=030866aa8d0911636ef2210b710f544fd2c85c8e;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perlfork.pod b/pod/perlfork.pod index d930e93..832710a 100644 --- a/pod/perlfork.pod +++ b/pod/perlfork.pod @@ -4,6 +4,11 @@ perlfork - Perl's fork() emulation =head1 SYNOPSIS + 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 call is available, Perl's fork() simply calls it. @@ -11,7 +16,7 @@ call is available, Perl's fork() simply calls it. On some platforms such as Windows where the fork() system call is not available, Perl can be built to emulate fork() at the interpreter level. While the emulation is designed to be as compatible as possible with the -real fork() at the the level of the Perl program, there are certain +real fork() at the level of the Perl program, there are certain important differences that stem from the fact that all the pseudo child "processes" created this way live in the same real process as far as the operating system is concerned. @@ -51,7 +56,7 @@ pseudo-processes are launched after others have been wait()-ed on. =item %ENV -Each pseudo-process maintains its own virtual enviroment. Modifications +Each pseudo-process maintains its own virtual environment. Modifications to %ENV affect the virtual environment, and are only visible within that pseudo-process, and in any processes (or pseudo-processes) launched from it. @@ -203,7 +208,6 @@ write to a forked child: else { # child while () { print; } - close STDIN; exit(0); } @@ -233,7 +237,6 @@ And this one reads from the child: else { # child print "pipe_from_fork\n"; - close STDOUT; exit(0); } @@ -282,6 +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