… | |
… | |
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 |
… | |
… | |
197 | NODE $NODE *SELF node_of after |
197 | NODE $NODE *SELF node_of after |
198 | configure |
198 | configure |
199 | snd rcv mon mon_guard kil psub peval spawn cal |
199 | snd rcv mon mon_guard kil psub peval spawn cal |
200 | port |
200 | port |
201 | db_set db_del db_reg |
201 | db_set db_del db_reg |
|
|
202 | db_mon db_family db_keys db_values |
202 | ); |
203 | ); |
203 | |
204 | |
204 | our $SELF; |
205 | our $SELF; |
205 | |
206 | |
206 | sub _self_die() { |
207 | sub _self_die() { |
… | |
… | |
230 | |
231 | |
231 | This function configures a node - it must be called exactly once (or |
232 | This function configures a node - it must be called exactly once (or |
232 | never) before calling other AnyEvent::MP functions. |
233 | never) before calling other AnyEvent::MP functions. |
233 | |
234 | |
234 | The key/value pairs are basically the same ones as documented for the |
235 | The key/value pairs are basically the same ones as documented for the |
235 | F<aemp> command line utility (sans the set/del prefix), with two additions: |
236 | F<aemp> command line utility (sans the set/del prefix), with these additions: |
236 | |
237 | |
237 | =over 4 |
238 | =over 4 |
238 | |
239 | |
239 | =item norc => $boolean (default false) |
240 | =item norc => $boolean (default false) |
240 | |
241 | |
… | |
… | |
245 | =item force => $boolean (default false) |
246 | =item force => $boolean (default false) |
246 | |
247 | |
247 | 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 |
248 | 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 |
249 | the rc file to override any options specified in the program. |
250 | the rc file to override any options specified in the program. |
|
|
251 | |
|
|
252 | =item secure => $pass->($nodeid) |
|
|
253 | |
|
|
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 |
|
|
256 | granted iff the callback returns a true value. |
|
|
257 | |
|
|
258 | See F<semp setsecure> for more info. |
250 | |
259 | |
251 | =back |
260 | =back |
252 | |
261 | |
253 | =over 4 |
262 | =over 4 |
254 | |
263 | |
… | |
… | |
389 | |
398 | |
390 | =cut |
399 | =cut |
391 | |
400 | |
392 | sub rcv($@); |
401 | sub rcv($@); |
393 | |
402 | |
394 | sub _kilme { |
403 | my $KILME = sub { |
395 | die "received message on port without callback"; |
404 | die "received message on port without callback"; |
396 | } |
405 | }; |
397 | |
406 | |
398 | sub port(;&) { |
407 | sub port(;&) { |
399 | my $id = $UNIQ . ++$ID; |
408 | my $id = $UNIQ . ++$ID; |
400 | my $port = "$NODE#$id"; |
409 | my $port = "$NODE#$id"; |
401 | |
410 | |
402 | rcv $port, shift || \&_kilme; |
411 | rcv $port, shift || $KILME; |
403 | |
412 | |
404 | $port |
413 | $port |
405 | } |
414 | } |
406 | |
415 | |
407 | =item rcv $local_port, $callback->(@msg) |
416 | =item rcv $local_port, $callback->(@msg) |
… | |
… | |
825 | ref $action[0] |
834 | ref $action[0] |
826 | ? $action[0]() |
835 | ? $action[0]() |
827 | : snd @action; |
836 | : snd @action; |
828 | }; |
837 | }; |
829 | } |
838 | } |
|
|
839 | |
|
|
840 | #=item $cb2 = timeout $seconds, $cb[, @args] |
830 | |
841 | |
831 | =item cal $port, @msg, $callback[, $timeout] |
842 | =item cal $port, @msg, $callback[, $timeout] |
832 | |
843 | |
833 | A simple form of RPC - sends a message to the given C<$port> with the |
844 | A simple form of RPC - sends a message to the given C<$port> with the |
834 | given contents (C<@msg>), but adds a reply port to the message. |
845 | given contents (C<@msg>), but adds a reply port to the message. |
… | |
… | |
883 | =back |
894 | =back |
884 | |
895 | |
885 | =head1 DISTRIBUTED DATABASE |
896 | =head1 DISTRIBUTED DATABASE |
886 | |
897 | |
887 | AnyEvent::MP comes with a simple distributed database. The database will |
898 | AnyEvent::MP comes with a simple distributed database. The database will |
888 | be mirrored asynchronously at all global nodes. Other nodes bind to one of |
899 | be mirrored asynchronously on all global nodes. Other nodes bind to one |
889 | the global nodes for their needs. |
900 | of the global nodes for their needs. Every node has a "local database" |
|
|
901 | which contains all the values that are set locally. All local databases |
|
|
902 | are merged together to form the global database, which can be queried. |
890 | |
903 | |
891 | The database consists of a two-level hash - a hash contains a hash which |
904 | The database structure is that of a two-level hash - the database hash |
892 | contains values. |
905 | contains hashes which contain values, similarly to a perl hash of hashes, |
|
|
906 | i.e.: |
|
|
907 | |
|
|
908 | $DATABASE{$family}{$subkey} = $value |
893 | |
909 | |
894 | The top level hash key is called "family", and the second-level hash key |
910 | The top level hash key is called "family", and the second-level hash key |
895 | is called "subkey" or simply "key". |
911 | is called "subkey" or simply "key". |
896 | |
912 | |
897 | The family must be alphanumeric, i.e. start with a letter and consist |
913 | The family must be alphanumeric, i.e. start with a letter and consist |
… | |
… | |
902 | with the name of the application or module using it. |
918 | with the name of the application or module using it. |
903 | |
919 | |
904 | The subkeys must be non-empty strings, with no further restrictions. |
920 | The subkeys must be non-empty strings, with no further restrictions. |
905 | |
921 | |
906 | The values should preferably be strings, but other perl scalars should |
922 | The values should preferably be strings, but other perl scalars should |
907 | work as well (such as undef, arrays and hashes). |
923 | work as well (such as C<undef>, arrays and hashes). |
908 | |
924 | |
909 | Every database entry is owned by one node - adding the same family/subkey |
925 | Every database entry is owned by one node - adding the same family/subkey |
910 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
926 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
911 | but the result might be nondeterministic, i.e. the key might have |
927 | but the result might be nondeterministic, i.e. the key might have |
912 | different values on different nodes. |
928 | different values on different nodes. |
… | |
… | |
916 | pools. For example, a worker port for image scaling might do this: |
932 | pools. For example, a worker port for image scaling might do this: |
917 | |
933 | |
918 | db_set my_image_scalers => $port; |
934 | db_set my_image_scalers => $port; |
919 | |
935 | |
920 | And clients looking for an image scaler will want to get the |
936 | And clients looking for an image scaler will want to get the |
921 | C<my_image_scalers> keys: |
937 | C<my_image_scalers> keys from time to time: |
922 | |
938 | |
923 | db_keys "my_image_scalers" => 60 => sub { |
939 | db_keys my_image_scalers => sub { |
924 | #d##TODO# |
940 | @ports = @{ $_[0] }; |
|
|
941 | }; |
|
|
942 | |
|
|
943 | Or better yet, they want to monitor the database family, so they always |
|
|
944 | have a reasonable up-to-date copy: |
|
|
945 | |
|
|
946 | db_mon my_image_scalers => sub { |
|
|
947 | @ports = keys %{ $_[0] }; |
|
|
948 | }; |
|
|
949 | |
|
|
950 | In general, you can set or delete single subkeys, but query and monitor |
|
|
951 | whole families only. |
|
|
952 | |
|
|
953 | If you feel the need to monitor or query a single subkey, try giving it |
|
|
954 | it's own family. |
925 | |
955 | |
926 | =over |
956 | =over |
927 | |
957 | |
928 | =item db_set $family => $subkey [=> $value] |
958 | =item db_set $family => $subkey [=> $value] |
929 | |
959 | |
930 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
960 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
931 | C<undef> is used instead. |
961 | C<undef> is used instead. |
932 | |
962 | |
933 | =item db_del $family => $subkey |
963 | =item db_del $family => $subkey... |
934 | |
964 | |
935 | Deletes a key from the database. |
965 | Deletes one or more subkeys from the database family. |
936 | |
966 | |
937 | =item $guard = db_reg $family => $subkey [=> $value] |
967 | =item $guard = db_reg $family => $subkey [=> $value] |
938 | |
968 | |
939 | Sets the key on the database and returns a guard. When the guard is |
969 | Sets the key on the database and returns a guard. When the guard is |
940 | destroyed, the key is deleted from the database. If C<$value> is missing, |
970 | destroyed, the key is deleted from the database. If C<$value> is missing, |
941 | then C<undef> is used. |
971 | then C<undef> is used. |
|
|
972 | |
|
|
973 | =item db_family $family => $cb->(\%familyhash) |
|
|
974 | |
|
|
975 | Queries the named database C<$family> and call the callback with the |
|
|
976 | family represented as a hash. You can keep and freely modify the hash. |
|
|
977 | |
|
|
978 | =item db_keys $family => $cb->(\@keys) |
|
|
979 | |
|
|
980 | Same as C<db_family>, except it only queries the family I<subkeys> and passes |
|
|
981 | them as array reference to the callback. |
|
|
982 | |
|
|
983 | =item db_values $family => $cb->(\@values) |
|
|
984 | |
|
|
985 | Same as C<db_family>, except it only queries the family I<values> and passes them |
|
|
986 | as array reference to the callback. |
|
|
987 | |
|
|
988 | =item $guard = db_mon $family => $cb->($familyhash, \@added, \@changed, \@deleted) |
|
|
989 | |
|
|
990 | Creates a monitor on the given database family. Each time a key is set |
|
|
991 | or or is deleted the callback is called with a hash containing the |
|
|
992 | database family and three lists of added, changed and deleted subkeys, |
|
|
993 | respectively. If no keys have changed then the array reference might be |
|
|
994 | C<undef> or even missing. |
|
|
995 | |
|
|
996 | If not called in void context, a guard object is returned that, when |
|
|
997 | destroyed, stops the monitor. |
|
|
998 | |
|
|
999 | The family hash reference and the key arrays belong to AnyEvent::MP and |
|
|
1000 | B<must not be modified or stored> by the callback. When in doubt, make a |
|
|
1001 | copy. |
|
|
1002 | |
|
|
1003 | As soon as possible after the monitoring starts, the callback will be |
|
|
1004 | called with the intiial contents of the family, even if it is empty, |
|
|
1005 | i.e. there will always be a timely call to the callback with the current |
|
|
1006 | contents. |
|
|
1007 | |
|
|
1008 | It is possible that the callback is called with a change event even though |
|
|
1009 | the subkey is already present and the value has not changed. |
|
|
1010 | |
|
|
1011 | The monitoring stops when the guard object is destroyed. |
|
|
1012 | |
|
|
1013 | Example: on every change to the family "mygroup", print out all keys. |
|
|
1014 | |
|
|
1015 | my $guard = db_mon mygroup => sub { |
|
|
1016 | my ($family, $a, $c, $d) = @_; |
|
|
1017 | print "mygroup members: ", (join " ", keys %$family), "\n"; |
|
|
1018 | }; |
|
|
1019 | |
|
|
1020 | Exmaple: wait until the family "My::Module::workers" is non-empty. |
|
|
1021 | |
|
|
1022 | my $guard; $guard = db_mon My::Module::workers => sub { |
|
|
1023 | my ($family, $a, $c, $d) = @_; |
|
|
1024 | return unless %$family; |
|
|
1025 | undef $guard; |
|
|
1026 | print "My::Module::workers now nonempty\n"; |
|
|
1027 | }; |
|
|
1028 | |
|
|
1029 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
|
|
1030 | |
|
|
1031 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
|
|
1032 | my ($family, $a, $c, $d) = @_; |
|
|
1033 | |
|
|
1034 | print "+$_=$family->{$_}\n" for @$a; |
|
|
1035 | print "*$_=$family->{$_}\n" for @$c; |
|
|
1036 | print "-$_=$family->{$_}\n" for @$d; |
|
|
1037 | }; |
942 | |
1038 | |
943 | =cut |
1039 | =cut |
944 | |
1040 | |
945 | =back |
1041 | =back |
946 | |
1042 | |