# This is a fork of the (for now) unmaintained Sys::Syscall 0.25,
# specifically the Debian libsys-syscall-perl 0.25-6 version to
# fix upstream regressions in 0.25.
#
# This license differs from the rest of public-inbox
#
# This module is Copyright (c) 2005 Six Apart, Ltd.
# Copyright (C) 2019 all contributors
#
# All rights reserved.
#
# You may distribute under the terms of either the GNU General Public
# License or the Artistic License, as specified in the Perl README file.
package PublicInbox::Syscall;
use strict;
use POSIX qw(ENOSYS SEEK_CUR);
use Config;
require Exporter;
use vars qw(@ISA @EXPORT_OK %EXPORT_TAGS $VERSION);
$VERSION = "0.25";
@ISA = qw(Exporter);
@EXPORT_OK = qw(epoll_ctl epoll_create epoll_wait
EPOLLIN EPOLLOUT EPOLLET
EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
EPOLLONESHOT EPOLLEXCLUSIVE);
%EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait
EPOLLIN EPOLLOUT
EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
EPOLLONESHOT EPOLLEXCLUSIVE)],
);
use constant EPOLLIN => 1;
use constant EPOLLOUT => 4;
# use constant EPOLLERR => 8;
# use constant EPOLLHUP => 16;
# use constant EPOLLRDBAND => 128;
use constant EPOLLEXCLUSIVE => (1 << 28);
use constant EPOLLONESHOT => (1 << 30);
use constant EPOLLET => (1 << 31);
use constant EPOLL_CTL_ADD => 1;
use constant EPOLL_CTL_DEL => 2;
use constant EPOLL_CTL_MOD => 3;
our $loaded_syscall = 0;
sub _load_syscall {
# props to Gaal for this!
return if $loaded_syscall++;
my $clean = sub {
delete @INC{qw};
};
$clean->(); # don't trust modules before us
my $rv = eval { require 'syscall.ph'; 1 } || eval { require 'sys/syscall.ph'; 1 };
$clean->(); # don't require modules after us trust us
return $rv;
}
our (
$SYS_epoll_create,
$SYS_epoll_ctl,
$SYS_epoll_wait,
);
our $no_deprecated = 0;
if ($^O eq "linux") {
my $machine = (POSIX::uname())[-1];
# whether the machine requires 64-bit numbers to be on 8-byte
# boundaries.
my $u64_mod_8 = 0;
# if we're running on an x86_64 kernel, but a 32-bit process,
# we need to use the i386 syscall numbers.
if ($machine eq "x86_64" && $Config{ptrsize} == 4) {
$machine = "i386";
}
# Similarly for mips64 vs mips
if ($machine eq "mips64" && $Config{ptrsize} == 4) {
$machine = "mips";
}
if ($machine =~ m/^i[3456]86$/) {
$SYS_epoll_create = 254;
$SYS_epoll_ctl = 255;
$SYS_epoll_wait = 256;
} elsif ($machine eq "x86_64") {
$SYS_epoll_create = 213;
$SYS_epoll_ctl = 233;
$SYS_epoll_wait = 232;
} elsif ($machine =~ m/^parisc/) {
$SYS_epoll_create = 224;
$SYS_epoll_ctl = 225;
$SYS_epoll_wait = 226;
$u64_mod_8 = 1;
} elsif ($machine =~ m/^ppc64/) {
$SYS_epoll_create = 236;
$SYS_epoll_ctl = 237;
$SYS_epoll_wait = 238;
$u64_mod_8 = 1;
} elsif ($machine eq "ppc") {
$SYS_epoll_create = 236;
$SYS_epoll_ctl = 237;
$SYS_epoll_wait = 238;
$u64_mod_8 = 1;
} elsif ($machine =~ m/^s390/) {
$SYS_epoll_create = 249;
$SYS_epoll_ctl = 250;
$SYS_epoll_wait = 251;
$u64_mod_8 = 1;
} elsif ($machine eq "ia64") {
$SYS_epoll_create = 1243;
$SYS_epoll_ctl = 1244;
$SYS_epoll_wait = 1245;
$u64_mod_8 = 1;
} elsif ($machine eq "alpha") {
# natural alignment, ints are 32-bits
$SYS_epoll_create = 407;
$SYS_epoll_ctl = 408;
$SYS_epoll_wait = 409;
$u64_mod_8 = 1;
} elsif ($machine eq "aarch64") {
$SYS_epoll_create = 20; # (sys_epoll_create1)
$SYS_epoll_ctl = 21;
$SYS_epoll_wait = 22; # (sys_epoll_pwait)
$u64_mod_8 = 1;
$no_deprecated = 1;
} elsif ($machine =~ m/arm(v\d+)?.*l/) {
# ARM OABI
$SYS_epoll_create = 250;
$SYS_epoll_ctl = 251;
$SYS_epoll_wait = 252;
$u64_mod_8 = 1;
} elsif ($machine =~ m/^mips64/) {
$SYS_epoll_create = 5207;
$SYS_epoll_ctl = 5208;
$SYS_epoll_wait = 5209;
$u64_mod_8 = 1;
} elsif ($machine =~ m/^mips/) {
$SYS_epoll_create = 4248;
$SYS_epoll_ctl = 4249;
$SYS_epoll_wait = 4250;
$u64_mod_8 = 1;
} else {
# as a last resort, try using the *.ph files which may not
# exist or may be wrong
_load_syscall();
$SYS_epoll_create = eval { &SYS_epoll_create; } || 0;
$SYS_epoll_ctl = eval { &SYS_epoll_ctl; } || 0;
$SYS_epoll_wait = eval { &SYS_epoll_wait; } || 0;
}
if ($u64_mod_8) {
*epoll_wait = \&epoll_wait_mod8;
*epoll_ctl = \&epoll_ctl_mod8;
} else {
*epoll_wait = \&epoll_wait_mod4;
*epoll_ctl = \&epoll_ctl_mod4;
}
}
elsif ($^O eq "freebsd") {
if ($ENV{FREEBSD_SENDFILE}) {
# this is still buggy and in development
}
}
############################################################################
# epoll functions
############################################################################
sub epoll_defined { return $SYS_epoll_create ? 1 : 0; }
sub epoll_create {
syscall($SYS_epoll_create, $no_deprecated ? 0 : ($_[0]||100)+0);
}
# epoll_ctl wrapper
# ARGS: (epfd, op, fd, events_mask)
sub epoll_ctl_mod4 {
syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLL", $_[3], $_[2], 0));
}
sub epoll_ctl_mod8 {
syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLLL", $_[3], 0, $_[2], 0));
}
# epoll_wait wrapper
# ARGS: (epfd, maxevents, timeout (milliseconds), arrayref)
# arrayref: values modified to be [$fd, $event]
our $epoll_wait_events;
our $epoll_wait_size = 0;
sub epoll_wait_mod4 {
# resize our static buffer if requested size is bigger than we've ever done
if ($_[1] > $epoll_wait_size) {
$epoll_wait_size = $_[1];
$epoll_wait_events = "\0" x 12 x $epoll_wait_size;
}
my $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0);
for (0..$ct-1) {
@{$_[3]->[$_]}[1,0] = unpack("LL", substr($epoll_wait_events, 12*$_, 8));
}
return $ct;
}
sub epoll_wait_mod8 {
# resize our static buffer if requested size is bigger than we've ever done
if ($_[1] > $epoll_wait_size) {
$epoll_wait_size = $_[1];
$epoll_wait_events = "\0" x 16 x $epoll_wait_size;
}
my $ct;
if ($no_deprecated) {
$ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0, undef);
} else {
$ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0);
}
for (0..$ct-1) {
# 16 byte epoll_event structs, with format:
# 4 byte mask [idx 1]
# 4 byte padding (we put it into idx 2, useless)
# 8 byte data (first 4 bytes are fd, into idx 0)
@{$_[3]->[$_]}[1,2,0] = unpack("LLL", substr($epoll_wait_events, 16*$_, 12));
}
return $ct;
}
1;
=head1 WARRANTY
This is free software. IT COMES WITHOUT WARRANTY OF ANY KIND.
=head1 AUTHORS
Brad Fitzpatrick