| Filename | /usr/lib/perl5/5.20.1/constant.pm |
| Statements | Executed 80 statements in 897µs |
| Calls | P | F | Exclusive Time |
Inclusive Time |
Subroutine |
|---|---|---|---|---|---|
| 2 | 2 | 2 | 31µs | 40µs | constant::import |
| 1 | 1 | 1 | 9µs | 10µs | constant::BEGIN@24 |
| 1 | 1 | 1 | 8µs | 8µs | constant::BEGIN@2 |
| 1 | 1 | 1 | 4µs | 11µs | constant::BEGIN@39 |
| 1 | 1 | 1 | 4µs | 10µs | constant::BEGIN@126 |
| 1 | 1 | 1 | 4µs | 58µs | constant::BEGIN@4 |
| 2 | 1 | 1 | 4µs | 4µs | constant::CORE:regcomp (opcode) |
| 1 | 1 | 1 | 4µs | 20µs | constant::BEGIN@6 |
| 1 | 1 | 1 | 4µs | 9µs | constant::BEGIN@64 |
| 2 | 1 | 1 | 3µs | 3µs | constant::CORE:match (opcode) |
| 1 | 1 | 1 | 3µs | 17µs | constant::BEGIN@3 |
| 3 | 3 | 1 | 2µs | 2µs | constant::CORE:qr (opcode) |
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:159] |
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:175] |
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:177] |
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:40] |
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:41] |
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:42] |
| Line | State ments |
Time on line |
Calls | Time in subs |
Code |
|---|---|---|---|---|---|
| 1 | package constant; | ||||
| 2 | 2 | 23µs | 1 | 8µs | # spent 8µs within constant::BEGIN@2 which was called:
# once (8µs+0s) by Encode::BEGIN@8 at line 2 # spent 8µs making 1 call to constant::BEGIN@2 |
| 3 | 2 | 12µs | 2 | 32µs | # spent 17µs (3+14) within constant::BEGIN@3 which was called:
# once (3µs+14µs) by Encode::BEGIN@8 at line 3 # spent 17µs making 1 call to constant::BEGIN@3
# spent 14µs making 1 call to strict::import |
| 4 | 2 | 16µs | 2 | 112µs | # spent 58µs (4+54) within constant::BEGIN@4 which was called:
# once (4µs+54µs) by Encode::BEGIN@8 at line 4 # spent 58µs making 1 call to constant::BEGIN@4
# spent 54µs making 1 call to warnings::register::import |
| 5 | |||||
| 6 | 2 | 314µs | 2 | 37µs | # spent 20µs (4+17) within constant::BEGIN@6 which was called:
# once (4µs+17µs) by Encode::BEGIN@8 at line 6 # spent 20µs making 1 call to constant::BEGIN@6
# spent 17µs making 1 call to vars::import |
| 7 | 1 | 300ns | $VERSION = '1.31'; | ||
| 8 | |||||
| 9 | #======================================================================= | ||||
| 10 | |||||
| 11 | # Some names are evil choices. | ||||
| 12 | 1 | 3µs | my %keywords = map +($_, 1), qw{ BEGIN INIT CHECK END DESTROY AUTOLOAD }; | ||
| 13 | 1 | 800ns | $keywords{UNITCHECK}++ if $] > 5.009; | ||
| 14 | |||||
| 15 | 1 | 3µs | my %forced_into_main = map +($_, 1), | ||
| 16 | qw{ STDIN STDOUT STDERR ARGV ARGVOUT ENV INC SIG }; | ||||
| 17 | |||||
| 18 | 1 | 3µs | my %forbidden = (%keywords, %forced_into_main); | ||
| 19 | |||||
| 20 | 1 | 5µs | 1 | 2µs | my $normal_constant_name = qr/^_?[^\W_0-9]\w*\z/; # spent 2µs making 1 call to constant::CORE:qr |
| 21 | 1 | 2µs | 1 | 500ns | my $tolerable = qr/^[A-Za-z_]\w*\z/; # spent 500ns making 1 call to constant::CORE:qr |
| 22 | 1 | 1µs | 1 | 200ns | my $boolean = qr/^[01]?\z/; # spent 200ns making 1 call to constant::CORE:qr |
| 23 | |||||
| 24 | # spent 10µs (9+600ns) within constant::BEGIN@24 which was called:
# once (9µs+600ns) by Encode::BEGIN@8 at line 44 | ||||
| 25 | # We'd like to do use constant _CAN_PCS => $] > 5.009002 | ||||
| 26 | # but that's a bit tricky before we load the constant module :-) | ||||
| 27 | # By doing this, we save 1 run time check for *every* call to import. | ||||
| 28 | 1 | 700ns | my $const = $] > 5.009002; | ||
| 29 | 1 | 300ns | my $downgrade = $] < 5.015004; # && $] >= 5.008 | ||
| 30 | 1 | 300ns | my $constarray = exists &_make_const; | ||
| 31 | 1 | 2µs | if ($const) { | ||
| 32 | 1 | 4µs | 1 | 500ns | Internals::SvREADONLY($const, 1); # spent 500ns making 1 call to Internals::SvREADONLY |
| 33 | 1 | 1µs | 1 | 100ns | Internals::SvREADONLY($downgrade, 1); # spent 100ns making 1 call to Internals::SvREADONLY |
| 34 | 1 | 800ns | $constant::{_CAN_PCS} = \$const; | ||
| 35 | 1 | 100ns | $constant::{_DOWNGRADE} = \$downgrade; | ||
| 36 | 1 | 400ns | $constant::{_CAN_PCS_FOR_ARRAY} = \$constarray; | ||
| 37 | } | ||||
| 38 | else { | ||||
| 39 | 2 | 47µs | 2 | 18µs | # spent 11µs (4+6) within constant::BEGIN@39 which was called:
# once (4µs+6µs) by Encode::BEGIN@8 at line 39 # spent 11µs making 1 call to constant::BEGIN@39
# spent 6µs making 1 call to strict::unimport |
| 40 | *{"_CAN_PCS"} = sub () {$const}; | ||||
| 41 | *{"_DOWNGRADE"} = sub () { $downgrade }; | ||||
| 42 | *{"_CAN_PCS_FOR_ARRAY"} = sub () { $constarray }; | ||||
| 43 | } | ||||
| 44 | 1 | 42µs | 1 | 10µs | } # spent 10µs making 1 call to constant::BEGIN@24 |
| 45 | |||||
| 46 | #======================================================================= | ||||
| 47 | # import() - import symbols into user's namespace | ||||
| 48 | # | ||||
| 49 | # What we actually do is define a function in the caller's namespace | ||||
| 50 | # which returns the value. The function we create will normally | ||||
| 51 | # be inlined as a constant, thereby avoiding further sub calling | ||||
| 52 | # overhead. | ||||
| 53 | #======================================================================= | ||||
| 54 | # spent 40µs (31+9) within constant::import which was called 2 times, avg 20µs/call:
# once (18µs+6µs) by Encode::BEGIN@8 at line 8 of Encode.pm
# once (14µs+4µs) by Encode::Alias::BEGIN@6 at line 6 of Encode/Alias.pm | ||||
| 55 | 2 | 500ns | my $class = shift; | ||
| 56 | 2 | 300ns | return unless @_; # Ignore 'use constant;' | ||
| 57 | 2 | 200ns | my $constants; | ||
| 58 | 2 | 700ns | my $multiple = ref $_[0]; | ||
| 59 | 2 | 700ns | my $pkg = caller; | ||
| 60 | 2 | 200ns | my $flush_mro; | ||
| 61 | my $symtab; | ||||
| 62 | |||||
| 63 | 2 | 600ns | if (_CAN_PCS) { | ||
| 64 | 2 | 143µs | 2 | 14µs | # spent 9µs (4+5) within constant::BEGIN@64 which was called:
# once (4µs+5µs) by Encode::BEGIN@8 at line 64 # spent 9µs making 1 call to constant::BEGIN@64
# spent 5µs making 1 call to strict::unimport |
| 65 | 2 | 2µs | $symtab = \%{$pkg . '::'}; | ||
| 66 | }; | ||||
| 67 | |||||
| 68 | 2 | 500ns | if ( $multiple ) { | ||
| 69 | if (ref $_[0] ne 'HASH') { | ||||
| 70 | require Carp; | ||||
| 71 | Carp::croak("Invalid reference type '".ref(shift)."' not 'HASH'"); | ||||
| 72 | } | ||||
| 73 | $constants = shift; | ||||
| 74 | } else { | ||||
| 75 | 2 | 300ns | unless (defined $_[0]) { | ||
| 76 | require Carp; | ||||
| 77 | Carp::croak("Can't use undef as constant name"); | ||||
| 78 | } | ||||
| 79 | 2 | 1µs | $constants->{+shift} = undef; | ||
| 80 | } | ||||
| 81 | |||||
| 82 | 2 | 2µs | foreach my $name ( keys %$constants ) { | ||
| 83 | # Normal constant name | ||||
| 84 | 2 | 14µs | 4 | 7µs | if ($name =~ $normal_constant_name and !$forbidden{$name}) { # spent 4µs making 2 calls to constant::CORE:regcomp, avg 2µs/call
# spent 3µs making 2 calls to constant::CORE:match, avg 2µs/call |
| 85 | # Everything is okay | ||||
| 86 | |||||
| 87 | # Name forced into main, but we're not in main. Fatal. | ||||
| 88 | } elsif ($forced_into_main{$name} and $pkg ne 'main') { | ||||
| 89 | require Carp; | ||||
| 90 | Carp::croak("Constant name '$name' is forced into main::"); | ||||
| 91 | |||||
| 92 | # Starts with double underscore. Fatal. | ||||
| 93 | } elsif ($name =~ /^__/) { | ||||
| 94 | require Carp; | ||||
| 95 | Carp::croak("Constant name '$name' begins with '__'"); | ||||
| 96 | |||||
| 97 | # Maybe the name is tolerable | ||||
| 98 | } elsif ($name =~ $tolerable) { | ||||
| 99 | # Then we'll warn only if you've asked for warnings | ||||
| 100 | if (warnings::enabled()) { | ||||
| 101 | if ($keywords{$name}) { | ||||
| 102 | warnings::warn("Constant name '$name' is a Perl keyword"); | ||||
| 103 | } elsif ($forced_into_main{$name}) { | ||||
| 104 | warnings::warn("Constant name '$name' is " . | ||||
| 105 | "forced into package main::"); | ||||
| 106 | } | ||||
| 107 | } | ||||
| 108 | |||||
| 109 | # Looks like a boolean | ||||
| 110 | # use constant FRED == fred; | ||||
| 111 | } elsif ($name =~ $boolean) { | ||||
| 112 | require Carp; | ||||
| 113 | if (@_) { | ||||
| 114 | Carp::croak("Constant name '$name' is invalid"); | ||||
| 115 | } else { | ||||
| 116 | Carp::croak("Constant name looks like boolean value"); | ||||
| 117 | } | ||||
| 118 | |||||
| 119 | } else { | ||||
| 120 | # Must have bad characters | ||||
| 121 | require Carp; | ||||
| 122 | Carp::croak("Constant name '$name' has invalid characters"); | ||||
| 123 | } | ||||
| 124 | |||||
| 125 | { | ||||
| 126 | 4 | 230µs | 2 | 16µs | # spent 10µs (4+6) within constant::BEGIN@126 which was called:
# once (4µs+6µs) by Encode::BEGIN@8 at line 126 # spent 10µs making 1 call to constant::BEGIN@126
# spent 6µs making 1 call to strict::unimport |
| 127 | 2 | 900ns | my $full_name = "${pkg}::$name"; | ||
| 128 | 2 | 800ns | $declared{$full_name}++; | ||
| 129 | 2 | 900ns | if ($multiple || @_ == 1) { | ||
| 130 | 2 | 500ns | my $scalar = $multiple ? $constants->{$name} : $_[0]; | ||
| 131 | |||||
| 132 | if (_DOWNGRADE) { # for 5.8 to 5.14 | ||||
| 133 | # Work around perl bug #31991: Sub names (actually glob | ||||
| 134 | # names in general) ignore the UTF8 flag. So we have to | ||||
| 135 | # turn it off to get the "right" symbol table entry. | ||||
| 136 | utf8::is_utf8 $name and utf8::encode $name; | ||||
| 137 | } | ||||
| 138 | |||||
| 139 | # The constant serves to optimise this entire block out on | ||||
| 140 | # 5.8 and earlier. | ||||
| 141 | 2 | 400ns | if (_CAN_PCS) { | ||
| 142 | # Use a reference as a proxy for a constant subroutine. | ||||
| 143 | # If this is not a glob yet, it saves space. If it is | ||||
| 144 | # a glob, we must still create it this way to get the | ||||
| 145 | # right internal flags set, as constants are distinct | ||||
| 146 | # from subroutines created with sub(){...}. | ||||
| 147 | # The check in Perl_ck_rvconst knows that inlinable | ||||
| 148 | # constants from cv_const_sv are read only. So we have to: | ||||
| 149 | 2 | 4µs | 2 | 800ns | Internals::SvREADONLY($scalar, 1); # spent 800ns making 2 calls to Internals::SvREADONLY, avg 400ns/call |
| 150 | 2 | 900ns | if ($symtab && !exists $symtab->{$name}) { | ||
| 151 | 2 | 700ns | $symtab->{$name} = \$scalar; | ||
| 152 | 2 | 300ns | ++$flush_mro; | ||
| 153 | } | ||||
| 154 | else { | ||||
| 155 | local $constant::{_dummy} = \$scalar; | ||||
| 156 | *$full_name = \&{"_dummy"}; | ||||
| 157 | } | ||||
| 158 | } else { | ||||
| 159 | *$full_name = sub () { $scalar }; | ||||
| 160 | } | ||||
| 161 | } elsif (@_) { | ||||
| 162 | my @list = @_; | ||||
| 163 | if (_CAN_PCS_FOR_ARRAY) { | ||||
| 164 | _make_const($list[$_]) for 0..$#list; | ||||
| 165 | _make_const(@list); | ||||
| 166 | if ($symtab && !exists $symtab->{$name}) { | ||||
| 167 | $symtab->{$name} = \@list; | ||||
| 168 | $flush_mro++; | ||||
| 169 | } | ||||
| 170 | else { | ||||
| 171 | local $constant::{_dummy} = \@list; | ||||
| 172 | *$full_name = \&{"_dummy"}; | ||||
| 173 | } | ||||
| 174 | } | ||||
| 175 | else { *$full_name = sub () { @list }; } | ||||
| 176 | } else { | ||||
| 177 | *$full_name = sub () { }; | ||||
| 178 | } | ||||
| 179 | } | ||||
| 180 | } | ||||
| 181 | # Flush the cache exactly once if we make any direct symbol table changes. | ||||
| 182 | 2 | 9µs | 2 | 1µs | mro::method_changed_in($pkg) if _CAN_PCS && $flush_mro; # spent 1µs making 2 calls to mro::method_changed_in, avg 700ns/call |
| 183 | } | ||||
| 184 | |||||
| 185 | 1 | 4µs | 1; | ||
| 186 | |||||
| 187 | __END__ | ||||
# spent 3µs within constant::CORE:match which was called 2 times, avg 2µs/call:
# 2 times (3µs+0s) by constant::import at line 84, avg 2µs/call | |||||
sub constant::CORE:qr; # opcode | |||||
# spent 4µs within constant::CORE:regcomp which was called 2 times, avg 2µs/call:
# 2 times (4µs+0s) by constant::import at line 84, avg 2µs/call |