… | |
… | |
601 | $res |
601 | $res |
602 | } |
602 | } |
603 | } |
603 | } |
604 | } |
604 | } |
605 | |
605 | |
|
|
606 | =item $guard = mon $port, $rcvport # kill $rcvport when $port dies |
|
|
607 | |
|
|
608 | =item $guard = mon $port # kill $SELF when $port dies |
|
|
609 | |
606 | =item $guard = mon $port, $cb->(@reason) # call $cb when $port dies |
610 | =item $guard = mon $port, $cb->(@reason) # call $cb when $port dies |
607 | |
|
|
608 | =item $guard = mon $port, $rcvport # kill $rcvport when $port dies |
|
|
609 | |
|
|
610 | =item $guard = mon $port # kill $SELF when $port dies |
|
|
611 | |
611 | |
612 | =item $guard = mon $port, $rcvport, @msg # send a message when $port dies |
612 | =item $guard = mon $port, $rcvport, @msg # send a message when $port dies |
613 | |
613 | |
614 | Monitor the given port and do something when the port is killed or |
614 | Monitor the given port and do something when the port is killed or |
615 | messages to it were lost, and optionally return a guard that can be used |
615 | messages to it were lost, and optionally return a guard that can be used |
616 | to stop monitoring again. |
616 | to stop monitoring again. |
617 | |
617 | |
|
|
618 | The first two forms distinguish between "normal" and "abnormal" kil's: |
|
|
619 | |
|
|
620 | In the first form (another port given), if the C<$port> is C<kil>'ed with |
|
|
621 | a non-empty reason, the other port (C<$rcvport>) will be kil'ed with the |
|
|
622 | same reason. That is, on "normal" kil's nothing happens, while under all |
|
|
623 | other conditions, the other port is killed with the same reason. |
|
|
624 | |
|
|
625 | The second form (kill self) is the same as the first form, except that |
|
|
626 | C<$rvport> defaults to C<$SELF>. |
|
|
627 | |
|
|
628 | The remaining forms don't distinguish between "normal" and "abnormal" kil's |
|
|
629 | - it's up to the callback or receiver to check whether the C<@reason> is |
|
|
630 | empty and act accordingly. |
|
|
631 | |
618 | In the first form (callback), the callback is simply called with any |
632 | In the third form (callback), the callback is simply called with any |
619 | number of C<@reason> elements (no @reason means that the port was deleted |
633 | number of C<@reason> elements (empty @reason means that the port was deleted |
620 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
634 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
621 | C<eval> if unsure. |
635 | C<eval> if unsure. |
622 | |
636 | |
623 | In the second form (another port given), the other port (C<$rcvport>) |
|
|
624 | will be C<kil>'ed with C<@reason>, if a @reason was specified, i.e. on |
|
|
625 | "normal" kils nothing happens, while under all other conditions, the other |
|
|
626 | port is killed with the same reason. |
|
|
627 | |
|
|
628 | The third form (kill self) is the same as the second form, except that |
|
|
629 | C<$rvport> defaults to C<$SELF>. |
|
|
630 | |
|
|
631 | In the last form (message), a message of the form C<@msg, @reason> will be |
637 | In the last form (message), a message of the form C<$rcvport, @msg, |
632 | C<snd>. |
638 | @reason> will be C<snd>. |
633 | |
639 | |
634 | Monitoring-actions are one-shot: once messages are lost (and a monitoring |
640 | Monitoring-actions are one-shot: once messages are lost (and a monitoring |
635 | alert was raised), they are removed and will not trigger again. |
641 | alert was raised), they are removed and will not trigger again, even if it |
|
|
642 | turns out that the port is still alive. |
636 | |
643 | |
637 | As a rule of thumb, monitoring requests should always monitor a port from |
644 | As a rule of thumb, monitoring requests should always monitor a remote |
638 | a local port (or callback). The reason is that kill messages might get |
645 | port locally (using a local C<$rcvport> or a callback). The reason is that |
639 | lost, just like any other message. Another less obvious reason is that |
646 | kill messages might get lost, just like any other message. Another less |
640 | even monitoring requests can get lost (for example, when the connection |
647 | obvious reason is that even monitoring requests can get lost (for example, |
641 | to the other node goes down permanently). When monitoring a port locally |
648 | when the connection to the other node goes down permanently). When |
642 | these problems do not exist. |
649 | monitoring a port locally these problems do not exist. |
643 | |
650 | |
644 | C<mon> effectively guarantees that, in the absence of hardware failures, |
651 | C<mon> effectively guarantees that, in the absence of hardware failures, |
645 | after starting the monitor, either all messages sent to the port will |
652 | after starting the monitor, either all messages sent to the port will |
646 | arrive, or the monitoring action will be invoked after possible message |
653 | arrive, or the monitoring action will be invoked after possible message |
647 | loss has been detected. No messages will be lost "in between" (after |
654 | loss has been detected. No messages will be lost "in between" (after |
… | |
… | |
1254 | |
1261 | |
1255 | =back |
1262 | =back |
1256 | |
1263 | |
1257 | =head1 PORTING FROM AnyEvent::MP VERSION 1.X |
1264 | =head1 PORTING FROM AnyEvent::MP VERSION 1.X |
1258 | |
1265 | |
1259 | AEMP version 2 has three major incompatible changes compared to version 1: |
1266 | AEMP version 2 has a few major incompatible changes compared to version 1: |
1260 | |
1267 | |
1261 | =over 4 |
1268 | =over 4 |
1262 | |
1269 | |
1263 | =item AnyEvent::MP::Global no longer has group management functions. |
1270 | =item AnyEvent::MP::Global no longer has group management functions. |
1264 | |
1271 | |
1265 | AnyEvent::MP now comes with a distributed database that is more |
1272 | AnyEvent::MP now comes with a distributed database that is more |
1266 | powerful. It's database families map closely to ports, but the API has |
1273 | powerful. Its database families map closely to port groups, but the API |
1267 | minor differences: |
1274 | has changed (the functions are also now exported by AnyEvent::MP). Here is |
|
|
1275 | a rough porting guide: |
1268 | |
1276 | |
1269 | grp_reg $group, $port # old |
1277 | grp_reg $group, $port # old |
1270 | db_reg $group, $port # new |
1278 | db_reg $group, $port # new |
1271 | |
1279 | |
1272 | $list = grp_get $group # old |
1280 | $list = grp_get $group # old |
1273 | db_keys $group, sub { my $list = shift } # new |
1281 | db_keys $group, sub { my $list = shift } # new |
1274 | |
1282 | |
1275 | grp_mon $group, $cb->(\@ports, $add, $del) # old |
1283 | grp_mon $group, $cb->(\@ports, $add, $del) # old |
1276 | db_mon $group, $cb->(\%ports, $add, $change, $del) # new |
1284 | db_mon $group, $cb->(\%ports, $add, $change, $del) # new |
1277 | |
1285 | |
1278 | C<grp_reg> is a no-brainer (just replace by C<db_reg>), but C<grp_get> |
1286 | C<grp_reg> is a no-brainer (just replace by C<db_reg>), but C<grp_get> is |
1279 | is no longer instant, because the local node might not have a copy of |
1287 | no longer instant, because the local node might not have a copy of the |
1280 | the group. This can be partially remedied by using C<db_mon> to keep an |
1288 | group. You can either modify your code to allow for a callback, or use |
1281 | updated copy of the group: |
1289 | C<db_mon> to keep an updated copy of the group: |
1282 | |
1290 | |
1283 | my $local_group_copy; |
1291 | my $local_group_copy; |
1284 | db_mon $group => sub { $local_group_copy = shift }; |
1292 | db_mon $group => sub { $local_group_copy = $_[0] }; |
1285 | |
1293 | |
1286 | # no keys %$local_group_copy always returns the most up-to-date |
1294 | # now "keys %$local_group_copy" always returns the most up-to-date |
1287 | # list of ports in the group. |
1295 | # list of ports in the group. |
1288 | |
1296 | |
1289 | C<grp_mon> can almost be replaced by C<db_mon>: |
1297 | C<grp_mon> can be replaced by C<db_mon> with minor changes - C<db_mon> |
|
|
1298 | passes a hash as first argument, and an extra C<$chg> argument that can be |
|
|
1299 | ignored: |
1290 | |
1300 | |
1291 | db_mon $group => sub { |
1301 | db_mon $group => sub { |
1292 | my ($ports, $add, $chg, $lde) = @_; |
1302 | my ($ports, $add, $chg, $lde) = @_; |
1293 | $ports = [keys %$ports]; |
1303 | $ports = [keys %$ports]; |
1294 | |
1304 | |
… | |
… | |
1311 | of its seed nodes. If that seed node isn't a global node yet, it will |
1321 | of its seed nodes. If that seed node isn't a global node yet, it will |
1312 | automatically be upgraded to a global node. |
1322 | automatically be upgraded to a global node. |
1313 | |
1323 | |
1314 | So in many cases, nothing needs to be changed - one just has to make sure |
1324 | So in many cases, nothing needs to be changed - one just has to make sure |
1315 | that all seed nodes are meshed together with the other seed nodes (as with |
1325 | that all seed nodes are meshed together with the other seed nodes (as with |
1316 | AEMP 1.x), and other nodes specify them as seed nodes. |
1326 | AEMP 1.x), and other nodes specify them as seed nodes. This is most easily |
|
|
1327 | achieved by specifying the same set of seed nodes for all nodes in the |
|
|
1328 | network. |
1317 | |
1329 | |
1318 | Not opening a connection to every other node is usually an advantage, |
1330 | Not opening a connection to every other node is usually an advantage, |
1319 | except when you need the lower latency of an already established |
1331 | except when you need the lower latency of an already established |
1320 | connection. To ensure a node establishes a connection to another node, |
1332 | connection. To ensure a node establishes a connection to another node, |
1321 | you can monitor the node port (C<mon $node, ...>), which will attempt to |
1333 | you can monitor the node port (C<mon $node, ...>), which will attempt to |
1322 | create the connection (and notify you when the connection fails). |
1334 | create the connection (and notify you when the connection fails). |
1323 | |
1335 | |
1324 | =item Listener-less nodes (nodes without binds) are gone. |
1336 | =item Listener-less nodes (nodes without binds) are gone. |
1325 | |
1337 | |
1326 | And are not coming back, at least not in their old form. If no C<binds> |
1338 | And are not coming back, at least not in their old form. If no C<binds> |
1327 | are specified for a node, AnyEvent::MP now assumes a default of C<*:*>. |
1339 | are specified for a node, AnyEvent::MP assumes a default of C<*:*>. |
1328 | |
1340 | |
1329 | There are vague plans to implement some form of routing domains, which |
1341 | There are vague plans to implement some form of routing domains, which |
1330 | might or might not bring back listener-less nodes, but don't count on it. |
1342 | might or might not bring back listener-less nodes, but don't count on it. |
1331 | |
1343 | |
1332 | The fact that most connections are now optional somewhat mitigates this, |
1344 | The fact that most connections are now optional somewhat mitigates this, |
… | |
… | |
1341 | |
1353 | |
1342 | Every module now documents what kinds of messages it generates, with |
1354 | Every module now documents what kinds of messages it generates, with |
1343 | AnyEvent::MP acting as a catch all. |
1355 | AnyEvent::MP acting as a catch all. |
1344 | |
1356 | |
1345 | On the positive side, this means that instead of setting |
1357 | On the positive side, this means that instead of setting |
1346 | C<PERL_ANYEVENT_MP_WARNLEVEL>, you can get away by setting C<AE_VERBOSE>, |
1358 | C<PERL_ANYEVENT_MP_WARNLEVEL>, you can get away by setting C<AE_VERBOSE> - |
1347 | much less to type. |
1359 | much less to type. |
1348 | |
1360 | |
1349 | =back |
1361 | =back |
|
|
1362 | |
|
|
1363 | =head1 LOGGING |
|
|
1364 | |
|
|
1365 | AnyEvent::MP does not normally log anything by itself, but sinc eit is the |
|
|
1366 | root of the contetx hierarchy for AnyEvent::MP modules, it will receive |
|
|
1367 | all log messages by submodules. |
1350 | |
1368 | |
1351 | =head1 SEE ALSO |
1369 | =head1 SEE ALSO |
1352 | |
1370 | |
1353 | L<AnyEvent::MP::Intro> - a gentle introduction. |
1371 | L<AnyEvent::MP::Intro> - a gentle introduction. |
1354 | |
1372 | |