… | |
… | |
35 | # destroy a port again |
35 | # destroy a port again |
36 | kil $port; # "normal" kill |
36 | kil $port; # "normal" kill |
37 | kil $port, my_error => "everything is broken"; # error kill |
37 | kil $port, my_error => "everything is broken"; # error kill |
38 | |
38 | |
39 | # monitoring |
39 | # monitoring |
40 | mon $localport, $cb->(@msg) # callback is invoked on death |
40 | mon $port, $cb->(@msg) # callback is invoked on death |
41 | mon $localport, $otherport # kill otherport on abnormal death |
41 | mon $port, $localport # kill localport on abnormal death |
42 | mon $localport, $otherport, @msg # send message on death |
42 | mon $port, $localport, @msg # send message on death |
43 | |
43 | |
44 | # temporarily execute code in port context |
44 | # temporarily execute code in port context |
45 | peval $port, sub { die "kill the port!" }; |
45 | peval $port, sub { die "kill the port!" }; |
46 | |
46 | |
47 | # execute callbacks in $SELF port context |
47 | # execute callbacks in $SELF port context |
… | |
… | |
247 | |
247 | |
248 | IF true, then the values specified in the C<configure> will take |
248 | IF true, then the values specified in the C<configure> will take |
249 | precedence over any values configured via the rc file. The default is for |
249 | precedence over any values configured via the rc file. The default is for |
250 | the rc file to override any options specified in the program. |
250 | the rc file to override any options specified in the program. |
251 | |
251 | |
252 | =item secure => $pass->($nodeid) |
252 | =item secure => $pass->(@msg) |
253 | |
253 | |
254 | In addition to specifying a boolean, you can specify a code reference that |
254 | In addition to specifying a boolean, you can specify a code reference that |
255 | is called for every remote execution attempt - the execution request is |
255 | is called for every code execution attempt - the execution request is |
256 | granted iff the callback returns a true value. |
256 | granted iff the callback returns a true value. |
|
|
257 | |
|
|
258 | Most of the time the callback should look only at |
|
|
259 | C<$AnyEvent::MP::Kernel::SRCNODE> to make a decision, and not at the |
|
|
260 | actual message (which can be about anything, and is mostly provided for |
|
|
261 | diagnostic purposes). |
257 | |
262 | |
258 | See F<semp setsecure> for more info. |
263 | See F<semp setsecure> for more info. |
259 | |
264 | |
260 | =back |
265 | =back |
261 | |
266 | |
… | |
… | |
398 | |
403 | |
399 | =cut |
404 | =cut |
400 | |
405 | |
401 | sub rcv($@); |
406 | sub rcv($@); |
402 | |
407 | |
403 | sub _kilme { |
408 | my $KILME = sub { |
404 | die "received message on port without callback"; |
409 | (my $tag = substr $_[0], 0, 30) =~ s/([\x20-\x7e])/./g; |
405 | } |
410 | kil $SELF, unhandled_message => "no callback found for message '$tag'"; |
|
|
411 | }; |
406 | |
412 | |
407 | sub port(;&) { |
413 | sub port(;&) { |
408 | my $id = $UNIQ . ++$ID; |
414 | my $id = $UNIQ . ++$ID; |
409 | my $port = "$NODE#$id"; |
415 | my $port = "$NODE#$id"; |
410 | |
416 | |
411 | rcv $port, shift || \&_kilme; |
417 | rcv $port, shift || $KILME; |
412 | |
418 | |
413 | $port |
419 | $port |
414 | } |
420 | } |
415 | |
421 | |
416 | =item rcv $local_port, $callback->(@msg) |
422 | =item rcv $local_port, $callback->(@msg) |
… | |
… | |
421 | |
427 | |
422 | The global C<$SELF> (exported by this module) contains C<$port> while |
428 | The global C<$SELF> (exported by this module) contains C<$port> while |
423 | executing the callback. Runtime errors during callback execution will |
429 | executing the callback. Runtime errors during callback execution will |
424 | result in the port being C<kil>ed. |
430 | result in the port being C<kil>ed. |
425 | |
431 | |
426 | The default callback received all messages not matched by a more specific |
432 | The default callback receives all messages not matched by a more specific |
427 | C<tag> match. |
433 | C<tag> match. |
428 | |
434 | |
429 | =item rcv $local_port, tag => $callback->(@msg_without_tag), ... |
435 | =item rcv $local_port, tag => $callback->(@msg_without_tag), ... |
430 | |
436 | |
431 | Register (or replace) callbacks to be called on messages starting with the |
437 | Register (or replace) callbacks to be called on messages starting with the |
… | |
… | |
732 | will be reported as reason C<< die => $@ >>. |
738 | will be reported as reason C<< die => $@ >>. |
733 | |
739 | |
734 | Transport/communication errors are reported as C<< transport_error => |
740 | Transport/communication errors are reported as C<< transport_error => |
735 | $message >>. |
741 | $message >>. |
736 | |
742 | |
737 | =cut |
743 | Common idioms: |
|
|
744 | |
|
|
745 | # silently remove yourself, do not kill linked ports |
|
|
746 | kil $SELF; |
|
|
747 | |
|
|
748 | # report a failure in some detail |
|
|
749 | kil $SELF, failure_mode_1 => "it failed with too high temperature"; |
|
|
750 | |
|
|
751 | # do not waste much time with killing, just die when something goes wrong |
|
|
752 | open my $fh, "<file" |
|
|
753 | or die "file: $!"; |
738 | |
754 | |
739 | =item $port = spawn $node, $initfunc[, @initdata] |
755 | =item $port = spawn $node, $initfunc[, @initdata] |
740 | |
756 | |
741 | Creates a port on the node C<$node> (which can also be a port ID, in which |
757 | Creates a port on the node C<$node> (which can also be a port ID, in which |
742 | case it's the node where that port resides). |
758 | case it's the node where that port resides). |
… | |
… | |
834 | ref $action[0] |
850 | ref $action[0] |
835 | ? $action[0]() |
851 | ? $action[0]() |
836 | : snd @action; |
852 | : snd @action; |
837 | }; |
853 | }; |
838 | } |
854 | } |
|
|
855 | |
|
|
856 | #=item $cb2 = timeout $seconds, $cb[, @args] |
839 | |
857 | |
840 | =item cal $port, @msg, $callback[, $timeout] |
858 | =item cal $port, @msg, $callback[, $timeout] |
841 | |
859 | |
842 | A simple form of RPC - sends a message to the given C<$port> with the |
860 | A simple form of RPC - sends a message to the given C<$port> with the |
843 | given contents (C<@msg>), but adds a reply port to the message. |
861 | given contents (C<@msg>), but adds a reply port to the message. |
… | |
… | |
892 | =back |
910 | =back |
893 | |
911 | |
894 | =head1 DISTRIBUTED DATABASE |
912 | =head1 DISTRIBUTED DATABASE |
895 | |
913 | |
896 | AnyEvent::MP comes with a simple distributed database. The database will |
914 | AnyEvent::MP comes with a simple distributed database. The database will |
897 | be mirrored asynchronously at all global nodes. Other nodes bind to one of |
915 | be mirrored asynchronously on all global nodes. Other nodes bind to one |
898 | the global nodes for their needs. |
916 | of the global nodes for their needs. Every node has a "local database" |
|
|
917 | which contains all the values that are set locally. All local databases |
|
|
918 | are merged together to form the global database, which can be queried. |
899 | |
919 | |
900 | The database consists of a two-level hash - a hash contains a hash which |
920 | The database structure is that of a two-level hash - the database hash |
901 | contains values. |
921 | contains hashes which contain values, similarly to a perl hash of hashes, |
|
|
922 | i.e.: |
|
|
923 | |
|
|
924 | $DATABASE{$family}{$subkey} = $value |
902 | |
925 | |
903 | The top level hash key is called "family", and the second-level hash key |
926 | The top level hash key is called "family", and the second-level hash key |
904 | is called "subkey" or simply "key". |
927 | is called "subkey" or simply "key". |
905 | |
928 | |
906 | The family must be alphanumeric, i.e. start with a letter and consist |
929 | The family must be alphanumeric, i.e. start with a letter and consist |
… | |
… | |
911 | with the name of the application or module using it. |
934 | with the name of the application or module using it. |
912 | |
935 | |
913 | The subkeys must be non-empty strings, with no further restrictions. |
936 | The subkeys must be non-empty strings, with no further restrictions. |
914 | |
937 | |
915 | The values should preferably be strings, but other perl scalars should |
938 | The values should preferably be strings, but other perl scalars should |
916 | work as well (such as undef, arrays and hashes). |
939 | work as well (such as C<undef>, arrays and hashes). |
917 | |
940 | |
918 | Every database entry is owned by one node - adding the same family/subkey |
941 | Every database entry is owned by one node - adding the same family/subkey |
919 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
942 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
920 | but the result might be nondeterministic, i.e. the key might have |
943 | but the result might be nondeterministic, i.e. the key might have |
921 | different values on different nodes. |
944 | different values on different nodes. |
… | |
… | |
925 | pools. For example, a worker port for image scaling might do this: |
948 | pools. For example, a worker port for image scaling might do this: |
926 | |
949 | |
927 | db_set my_image_scalers => $port; |
950 | db_set my_image_scalers => $port; |
928 | |
951 | |
929 | And clients looking for an image scaler will want to get the |
952 | And clients looking for an image scaler will want to get the |
930 | C<my_image_scalers> keys: |
953 | C<my_image_scalers> keys from time to time: |
931 | |
954 | |
932 | db_keys "my_image_scalers" => 60 => sub { |
955 | db_keys my_image_scalers => sub { |
933 | #d##TODO# |
956 | @ports = @{ $_[0] }; |
|
|
957 | }; |
|
|
958 | |
|
|
959 | Or better yet, they want to monitor the database family, so they always |
|
|
960 | have a reasonable up-to-date copy: |
|
|
961 | |
|
|
962 | db_mon my_image_scalers => sub { |
|
|
963 | @ports = keys %{ $_[0] }; |
|
|
964 | }; |
|
|
965 | |
|
|
966 | In general, you can set or delete single subkeys, but query and monitor |
|
|
967 | whole families only. |
|
|
968 | |
|
|
969 | If you feel the need to monitor or query a single subkey, try giving it |
|
|
970 | it's own family. |
934 | |
971 | |
935 | =over |
972 | =over |
936 | |
973 | |
937 | =item db_set $family => $subkey [=> $value] |
974 | =item db_set $family => $subkey [=> $value] |
938 | |
975 | |
939 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
976 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
940 | C<undef> is used instead. |
977 | C<undef> is used instead. |
941 | |
978 | |
942 | =item db_del $family => $subkey |
979 | =item db_del $family => $subkey... |
943 | |
980 | |
944 | Deletes a key from the database. |
981 | Deletes one or more subkeys from the database family. |
945 | |
982 | |
946 | =item $guard = db_reg $family => $subkey [=> $value] |
983 | =item $guard = db_reg $family => $subkey [=> $value] |
947 | |
984 | |
948 | Sets the key on the database and returns a guard. When the guard is |
985 | Sets the key on the database and returns a guard. When the guard is |
949 | destroyed, the key is deleted from the database. If C<$value> is missing, |
986 | destroyed, the key is deleted from the database. If C<$value> is missing, |
950 | then C<undef> is used. |
987 | then C<undef> is used. |
951 | |
988 | |
|
|
989 | =item db_family $family => $cb->(\%familyhash) |
|
|
990 | |
|
|
991 | Queries the named database C<$family> and call the callback with the |
|
|
992 | family represented as a hash. You can keep and freely modify the hash. |
|
|
993 | |
|
|
994 | =item db_keys $family => $cb->(\@keys) |
|
|
995 | |
|
|
996 | Same as C<db_family>, except it only queries the family I<subkeys> and passes |
|
|
997 | them as array reference to the callback. |
|
|
998 | |
|
|
999 | =item db_values $family => $cb->(\@values) |
|
|
1000 | |
|
|
1001 | Same as C<db_family>, except it only queries the family I<values> and passes them |
|
|
1002 | as array reference to the callback. |
|
|
1003 | |
952 | =item $guard = db_mon $family => $cb->($familyhash, \@subkeys...) |
1004 | =item $guard = db_mon $family => $cb->($familyhash, \@added, \@changed, \@deleted) |
953 | |
1005 | |
954 | Creates a monitor on the given database family. Each time a key is set or |
1006 | Creates a monitor on the given database family. Each time a key is set |
955 | or is deleted the callback is called with a hash containing the database |
1007 | or or is deleted the callback is called with a hash containing the |
956 | family and an arrayref with subkeys that have changed. |
1008 | database family and three lists of added, changed and deleted subkeys, |
|
|
1009 | respectively. If no keys have changed then the array reference might be |
|
|
1010 | C<undef> or even missing. |
957 | |
1011 | |
958 | Specifically, if one of the passed subkeys exists in the $familyhash, then |
1012 | If not called in void context, a guard object is returned that, when |
959 | it is currently set to the value in the $familyhash. Otherwise, it has |
1013 | destroyed, stops the monitor. |
960 | been deleted. |
|
|
961 | |
1014 | |
962 | The first call will be with the current contents of the family and all |
1015 | The family hash reference and the key arrays belong to AnyEvent::MP and |
963 | keys, as if they were just added. |
1016 | B<must not be modified or stored> by the callback. When in doubt, make a |
|
|
1017 | copy. |
|
|
1018 | |
|
|
1019 | As soon as possible after the monitoring starts, the callback will be |
|
|
1020 | called with the intiial contents of the family, even if it is empty, |
|
|
1021 | i.e. there will always be a timely call to the callback with the current |
|
|
1022 | contents. |
964 | |
1023 | |
965 | It is possible that the callback is called with a change event even though |
1024 | It is possible that the callback is called with a change event even though |
966 | the subkey is already present and the value has not changed. |
1025 | the subkey is already present and the value has not changed. |
967 | |
1026 | |
968 | The monitoring stops when the guard object is destroyed. |
1027 | The monitoring stops when the guard object is destroyed. |
969 | |
1028 | |
970 | Example: on every change to the family "mygroup", print out all keys. |
1029 | Example: on every change to the family "mygroup", print out all keys. |
971 | |
1030 | |
972 | my $guard = db_mon mygroup => sub { |
1031 | my $guard = db_mon mygroup => sub { |
973 | my ($family, $keys) = @_; |
1032 | my ($family, $a, $c, $d) = @_; |
974 | print "mygroup members: ", (join " ", keys %$family), "\n"; |
1033 | print "mygroup members: ", (join " ", keys %$family), "\n"; |
975 | }; |
1034 | }; |
976 | |
1035 | |
977 | Exmaple: wait until the family "My::Module::workers" is non-empty. |
1036 | Exmaple: wait until the family "My::Module::workers" is non-empty. |
978 | |
1037 | |
979 | my $guard; $guard = db_mon My::Module::workers => sub { |
1038 | my $guard; $guard = db_mon My::Module::workers => sub { |
980 | my ($family, $keys) = @_; |
1039 | my ($family, $a, $c, $d) = @_; |
981 | return unless %$family; |
1040 | return unless %$family; |
982 | undef $guard; |
1041 | undef $guard; |
983 | print "My::Module::workers now nonempty\n"; |
1042 | print "My::Module::workers now nonempty\n"; |
984 | }; |
1043 | }; |
985 | |
1044 | |
986 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
1045 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
987 | |
1046 | |
988 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
1047 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
989 | my ($family, $keys) = @_; |
1048 | my ($family, $a, $c, $d) = @_; |
990 | |
1049 | |
991 | for (@$keys) { |
1050 | print "+$_=$family->{$_}\n" for @$a; |
992 | print "$_: ", |
1051 | print "*$_=$family->{$_}\n" for @$c; |
993 | (exists $family->{$_} |
1052 | print "-$_=$family->{$_}\n" for @$d; |
994 | ? $family->{$_} |
|
|
995 | : "(deleted)"), |
|
|
996 | "\n"; |
|
|
997 | } |
|
|
998 | }; |
1053 | }; |
999 | |
1054 | |
1000 | =cut |
1055 | =cut |
1001 | |
1056 | |
1002 | =back |
1057 | =back |