Apache::SIG(3) User Contributed Perl Documentation Apache::SIG(3)NAMEApache::SIG - Override apache signal handlers with Perl's
SYNOPSIS
PerlFixupHandler Apache::SIGDESCRIPTION
When a client drops a connection and apache is in the mid
dle of a write, a timeout will occur and httpd sends a
SIGPIPE. When apache's SIGPIPE handler is used, Perl may
be left in the middle of it's eval context, causing
bizarre errors during subsequent requests are handled by
that child. When Apache::SIG is used, it installs a dif
ferent SIGPIPE handler which rewinds the context to make
sure Perl is back to normal state, preventing these
bizarre errors.
If you would like to log when a request was cancelled by a
SIGPIPE in your Apache access_log, you can declare
Apache::SIG as a handler (any Perl*Handler will do, as
long as it is run before PerlHandler, e.g. PerlFixupHan
dler), and you must also define a custom LogFormat in your
httpd.conf, like so:
PerlFixupHandler Apache::SIG LogFormat "%h %l %u %t \"%r\"
%s %b %{SIGPIPE}e"
If the server has noticed that the request was cancelled
via a SIGPIPE, then the log line will end with "1", other
wise it will just be a dash.
CAVEATS
The signal handler in this package uses the subprocess_env
table of the main request object to supply the 'SIGPIPE'
"environment variable" to the log handler. If you already
use the key 'SIGPIPE' in your subprocess_env table, then
you can redefine the key like this:
$Apache::SIG::PipeKey = 'my_SIGPIPE';
and log it like this:
LogFormat "%h %l %u %t \"%r\" %s %b %{my_SIGPIPE}e"
AUTHORS
Doug MacEachern and Doug Bagley
SEE ALSOperlvar(1)2000-03-03 mod_perl-1.27 Apache::SIG(3)
