X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlfork.pod;h=48d65ed4c589659180468c99b3a1bd6c98f4f33a;hb=c1effa61278e47c916466883d74905b04fedc388;hp=82ac6891dbdeeae472ad773df5f7585327505254;hpb=106325ad18a7d364436c509de7040f7817bf07da;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/pod/perlfork.pod b/pod/perlfork.pod
index 82ac689..48d65ed 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.
@@ -90,12 +95,15 @@ manipulation functions applied to the ID returned by fork() will affect the
 waiting pseudo-process that called exec(), not the real process it is
 waiting for after the exec().
 
+When exec() is called inside a pseudo-process then DESTROY methods and
+END blocks will still be called after the external process returns.
+
 =item exit()
 
 exit() always exits just the executing pseudo-process, after automatically
 wait()-ing for any outstanding child pseudo-processes.  Note that this means
 that the process as a whole will not exit unless all running pseudo-processes
-have exited.
+have exited.  See below for some limitations with open filehandles.
 
 =item Open handles to files, directories and network sockets
 
@@ -172,6 +180,13 @@ the seek position in the parent will change it in the child and vice-versa.
 One can avoid this by opening files that need distinct seek pointers
 separately in the child.
 
+On some operating systems, notably Solaris and Unixware, calling C<exit()>
+from a child process will flush and close open filehandles in the parent,
+thereby corrupting the filehandles.  On these systems, calling C<_exit()>
+is suggested instead.  C<_exit()> is available in Perl through the 
+C<POSIX> module.  Please consult your systems manpages for more information
+on this.
+
 =item Forking pipe open() not yet implemented
 
 The C<open(FOO, "|-")> and C<open(BAR, "-|")> constructs are not yet
@@ -203,7 +218,6 @@ write to a forked child:
     else {
 	# child
 	while (<STDIN>) { print; }
-	close STDIN;
 	exit(0);
     }
 
@@ -233,7 +247,6 @@ And this one reads from the child:
     else {
 	# child
 	print "pipe_from_fork\n";
-	close STDOUT;
 	exit(0);
     }
 
@@ -282,6 +295,15 @@ 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