APR::Status - Perl Interface to the APR_STATUS_IS_* macros
use APR::Status ();
eval { $obj->mp_method() };
if ($@ && $ref $@ eq 'APR::Error' && APR::Status::is_EAGAIN($@)) {
# APR_STATUS_IS_EAGAIN(s) of apr_errno.h is satisfied
}
An interface to apr_errno.h composite error codes.
As discussed in the APR::Error
manpage, it is possible to handle APR/Apache/mod_perl exceptions in
the following way:
eval { $obj->mp_method() };
if ($@ && $ref $@ eq 'APR::Error' && $@ == $some_code)
warn "handled exception: $@";
}
However, in cases where $some_code is an APR::Const
constant, there may be more than one
condition satisfying the intent of this exception. For this purpose
the APR C library provides in apr_errno.h a series of macros,
APR_STATUS_IS_*, which are the recommended way to check for such
conditions. For example, the APR_STATUS_IS_EAGAIN macro is defined
as
#define APR_STATUS_IS_EAGAIN(s) ((s) == APR_EAGAIN \
|| (s) == APR_OS_START_SYSERR + ERROR_NO_DATA \
|| (s) == APR_OS_START_SYSERR + SOCEWOULDBLOCK \
|| (s) == APR_OS_START_SYSERR + ERROR_LOCK_VIOLATION)
The purpose of APR::Status is to provide functions corresponding
to these macros.
is_EACCES
Check if the error is matching EACCES and its variants (corresponds
to the APR_STATUS_IS_EACCES macro).
$status = APR::Status::is_EACCES($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
An example of using is_EACCES is when reading the contents of a
file where access may be forbidden:
eval { $obj->slurp_filename(0) };
if ($@) {
return Apache2::Const::FORBIDDEN
if ref $@ eq 'APR::Error' && APR::Status::is_EACCES($@);
die $@;
}
Due to possible variants in conditions matching EACCES,
the use of this function is recommended for checking error codes
against this value, rather than just using
APR::Const::EACCES
directly.
is_EAGAIN
Check if the error is matching EAGAIN and its variants (corresponds
to the APR_STATUS_IS_EAGAIN macro).
$status = APR::Status::is_EAGAIN($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
For example, here is how you may want to handle socket read exceptions and do retries:
use APR::Status ();
# ....
my $tries = 0;
my $buffer;
RETRY: my $rlen = eval { $socket->recv($buffer, SIZE) };
if ($@ && ref($@) && APR::Status::is_EAGAIN($@)) {
if ($tries++ < 3) {
goto RETRY;
}
else {
# do something else
}
}
else {
die "eval block has failed: $@";
}
Notice that just checking against
APR::Const::EAGAIN
may work on some Unices, but then it will certainly break on
win32. Thefore make sure to use this macro and not
APR::Const::EAGAIN unless you know what you are doing.
is_ENOENT
Check if the error is matching ENOENT and its variants (corresponds
to the APR_STATUS_IS_ENOENT macro).
$status = APR::Status::is_ENOENT($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
An example of using is_ENOENT is when reading the contents of a
file which may not exist:
eval { $obj->slurp_filename(0) };
if ($@) {
return Apache2::Const::NOT_FOUND
if ref $@ eq 'APR::Error' && APR::Status::is_ENOENT($@);
die $@;
}
Due to possible variants in conditions matching ENOENT,
the use of this function is recommended for checking error codes
against this value, rather than just using
APR::Const::ENOENT
directly.
is_EOF
Check if the error is matching EOF and its variants (corresponds
to the APR_STATUS_IS_EOF macro).
$status = APR::Status::is_EOF($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
Due to possible variants in conditions matching EOF,
the use of this function is recommended for checking error codes
against this value, rather than just using
APR::Const::EOF
directly.
is_ECONNABORTED
Check if the error is matching ECONNABORTED and its variants (corresponds
to the APR_STATUS_IS_ECONNABORTED macro).
$status = APR::Status::is_ECONNABORTED($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
Due to possible variants in conditions matching ECONNABORTED,
the use of this function is recommended for checking error codes
against this value, rather than just using
APR::Const::ECONNABORTED directly.
is_ECONNRESET
Check if the error is matching ECONNRESET and its variants
(corresponds to the APR_STATUS_IS_ECONNRESET macro).
$status = APR::Status::is_ECONNRESET($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
Due to possible variants in conditions matching ECONNRESET, the use
of this function is recommended for checking error codes against this
value, rather than just using
APR::Const::ECONNRESET
directly.
is_TIMEUP
Check if the error is matching TIMEUP and its variants (corresponds
to the APR_STATUS_IS_TIMEUP macro).
$status = APR::Status::is_TIMEUP($error_code);
$error_code (integer or APR::Error
object )
$@ blessed into APR::Error
object.
$status ( boolean )
Due to possible variants in conditions matching TIMEUP,
the use of this function is recommended for checking error codes
against this value, rather than just using
APR::Const::TIMEUP
directly.
mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.