| … | |
… | |
| 1414 | idle (this, &myclass::idle_cb) |
1414 | idle (this, &myclass::idle_cb) |
| 1415 | { |
1415 | { |
| 1416 | io.start (fd, ev::READ); |
1416 | io.start (fd, ev::READ); |
| 1417 | } |
1417 | } |
| 1418 | |
1418 | |
|
|
1419 | =head1 EMBEDDING |
|
|
1420 | |
|
|
1421 | Libev can (and often is) directly embedded into host |
|
|
1422 | applications. Examples of applications that embed it include the Deliantra |
|
|
1423 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
|
|
1424 | and rxvt-unicode. |
|
|
1425 | |
|
|
1426 | The goal is to enable you to just copy the neecssary files into your |
|
|
1427 | source directory without having to change even a single line in them, so |
|
|
1428 | you can easily upgrade by simply copying (or having a checked-out copy of |
|
|
1429 | libev somewhere in your source tree). |
|
|
1430 | |
|
|
1431 | =head2 FILESETS |
|
|
1432 | |
|
|
1433 | Depending on what features you need you need to include one or more sets of files |
|
|
1434 | in your app. |
|
|
1435 | |
|
|
1436 | =head3 CORE EVENT LOOP |
|
|
1437 | |
|
|
1438 | To include only the libev core (all the C<ev_*> functions), with manual |
|
|
1439 | configuration (no autoconf): |
|
|
1440 | |
|
|
1441 | #define EV_STANDALONE 1 |
|
|
1442 | #include "ev.c" |
|
|
1443 | |
|
|
1444 | This will automatically include F<ev.h>, too, and should be done in a |
|
|
1445 | single C source file only to provide the function implementations. To use |
|
|
1446 | it, do the same for F<ev.h> in all files wishing to use this API (best |
|
|
1447 | done by writing a wrapper around F<ev.h> that you can include instead and |
|
|
1448 | where you can put other configuration options): |
|
|
1449 | |
|
|
1450 | #define EV_STANDALONE 1 |
|
|
1451 | #include "ev.h" |
|
|
1452 | |
|
|
1453 | Both header files and implementation files can be compiled with a C++ |
|
|
1454 | compiler (at least, thats a stated goal, and breakage will be treated |
|
|
1455 | as a bug). |
|
|
1456 | |
|
|
1457 | You need the following files in your source tree, or in a directory |
|
|
1458 | in your include path (e.g. in libev/ when using -Ilibev): |
|
|
1459 | |
|
|
1460 | ev.h |
|
|
1461 | ev.c |
|
|
1462 | ev_vars.h |
|
|
1463 | ev_wrap.h |
|
|
1464 | |
|
|
1465 | ev_win32.c required on win32 platforms only |
|
|
1466 | |
|
|
1467 | ev_select.c only when select backend is enabled (which is is by default) |
|
|
1468 | ev_poll.c only when poll backend is enabled (disabled by default) |
|
|
1469 | ev_epoll.c only when the epoll backend is enabled (disabled by default) |
|
|
1470 | ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
|
|
1471 | ev_port.c only when the solaris port backend is enabled (disabled by default) |
|
|
1472 | |
|
|
1473 | F<ev.c> includes the backend files directly when enabled, so you only need |
|
|
1474 | to compile a single file. |
|
|
1475 | |
|
|
1476 | =head3 LIBEVENT COMPATIBILITY API |
|
|
1477 | |
|
|
1478 | To include the libevent compatibility API, also include: |
|
|
1479 | |
|
|
1480 | #include "event.c" |
|
|
1481 | |
|
|
1482 | in the file including F<ev.c>, and: |
|
|
1483 | |
|
|
1484 | #include "event.h" |
|
|
1485 | |
|
|
1486 | in the files that want to use the libevent API. This also includes F<ev.h>. |
|
|
1487 | |
|
|
1488 | You need the following additional files for this: |
|
|
1489 | |
|
|
1490 | event.h |
|
|
1491 | event.c |
|
|
1492 | |
|
|
1493 | =head3 AUTOCONF SUPPORT |
|
|
1494 | |
|
|
1495 | Instead of using C<EV_STANDALONE=1> and providing your config in |
|
|
1496 | whatever way you want, you can also C<m4_include([libev.m4])> in your |
|
|
1497 | F<configure.ac> and leave C<EV_STANDALONE> off. F<ev.c> will then include |
|
|
1498 | F<config.h> and configure itself accordingly. |
|
|
1499 | |
|
|
1500 | For this of course you need the m4 file: |
|
|
1501 | |
|
|
1502 | libev.m4 |
|
|
1503 | |
|
|
1504 | =head2 PREPROCESSOR SYMBOLS/MACROS |
|
|
1505 | |
|
|
1506 | Libev can be configured via a variety of preprocessor symbols you have to define |
|
|
1507 | before including any of its files. The default is not to build for multiplicity |
|
|
1508 | and only include the select backend. |
|
|
1509 | |
|
|
1510 | =over 4 |
|
|
1511 | |
|
|
1512 | =item EV_STANDALONE |
|
|
1513 | |
|
|
1514 | Must always be C<1> if you do not use autoconf configuration, which |
|
|
1515 | keeps libev from including F<config.h>, and it also defines dummy |
|
|
1516 | implementations for some libevent functions (such as logging, which is not |
|
|
1517 | supported). It will also not define any of the structs usually found in |
|
|
1518 | F<event.h> that are not directly supported by the libev core alone. |
|
|
1519 | |
|
|
1520 | =item EV_USE_MONOTONIC |
|
|
1521 | |
|
|
1522 | If defined to be C<1>, libev will try to detect the availability of the |
|
|
1523 | monotonic clock option at both compiletime and runtime. Otherwise no use |
|
|
1524 | of the monotonic clock option will be attempted. If you enable this, you |
|
|
1525 | usually have to link against librt or something similar. Enabling it when |
|
|
1526 | the functionality isn't available is safe, though, althoguh you have |
|
|
1527 | to make sure you link against any libraries where the C<clock_gettime> |
|
|
1528 | function is hiding in (often F<-lrt>). |
|
|
1529 | |
|
|
1530 | =item EV_USE_REALTIME |
|
|
1531 | |
|
|
1532 | If defined to be C<1>, libev will try to detect the availability of the |
|
|
1533 | realtime clock option at compiletime (and assume its availability at |
|
|
1534 | runtime if successful). Otherwise no use of the realtime clock option will |
|
|
1535 | be attempted. This effectively replaces C<gettimeofday> by C<clock_get |
|
|
1536 | (CLOCK_REALTIME, ...)> and will not normally affect correctness. See tzhe note about libraries |
|
|
1537 | in the description of C<EV_USE_MONOTONIC>, though. |
|
|
1538 | |
|
|
1539 | =item EV_USE_SELECT |
|
|
1540 | |
|
|
1541 | If undefined or defined to be C<1>, libev will compile in support for the |
|
|
1542 | C<select>(2) backend. No attempt at autodetection will be done: if no |
|
|
1543 | other method takes over, select will be it. Otherwise the select backend |
|
|
1544 | will not be compiled in. |
|
|
1545 | |
|
|
1546 | =item EV_SELECT_USE_FD_SET |
|
|
1547 | |
|
|
1548 | If defined to C<1>, then the select backend will use the system C<fd_set> |
|
|
1549 | structure. This is useful if libev doesn't compile due to a missing |
|
|
1550 | C<NFDBITS> or C<fd_mask> definition or it misguesses the bitset layout on |
|
|
1551 | exotic systems. This usually limits the range of file descriptors to some |
|
|
1552 | low limit such as 1024 or might have other limitations (winsocket only |
|
|
1553 | allows 64 sockets). The C<FD_SETSIZE> macro, set before compilation, might |
|
|
1554 | influence the size of the C<fd_set> used. |
|
|
1555 | |
|
|
1556 | =item EV_SELECT_IS_WINSOCKET |
|
|
1557 | |
|
|
1558 | When defined to C<1>, the select backend will assume that |
|
|
1559 | select/socket/connect etc. don't understand file descriptors but |
|
|
1560 | wants osf handles on win32 (this is the case when the select to |
|
|
1561 | be used is the winsock select). This means that it will call |
|
|
1562 | C<_get_osfhandle> on the fd to convert it to an OS handle. Otherwise, |
|
|
1563 | it is assumed that all these functions actually work on fds, even |
|
|
1564 | on win32. Should not be defined on non-win32 platforms. |
|
|
1565 | |
|
|
1566 | =item EV_USE_POLL |
|
|
1567 | |
|
|
1568 | If defined to be C<1>, libev will compile in support for the C<poll>(2) |
|
|
1569 | backend. Otherwise it will be enabled on non-win32 platforms. It |
|
|
1570 | takes precedence over select. |
|
|
1571 | |
|
|
1572 | =item EV_USE_EPOLL |
|
|
1573 | |
|
|
1574 | If defined to be C<1>, libev will compile in support for the Linux |
|
|
1575 | C<epoll>(7) backend. Its availability will be detected at runtime, |
|
|
1576 | otherwise another method will be used as fallback. This is the |
|
|
1577 | preferred backend for GNU/Linux systems. |
|
|
1578 | |
|
|
1579 | =item EV_USE_KQUEUE |
|
|
1580 | |
|
|
1581 | If defined to be C<1>, libev will compile in support for the BSD style |
|
|
1582 | C<kqueue>(2) backend. Its actual availability will be detected at runtime, |
|
|
1583 | otherwise another method will be used as fallback. This is the preferred |
|
|
1584 | backend for BSD and BSD-like systems, although on most BSDs kqueue only |
|
|
1585 | supports some types of fds correctly (the only platform we found that |
|
|
1586 | supports ptys for example was NetBSD), so kqueue might be compiled in, but |
|
|
1587 | not be used unless explicitly requested. The best way to use it is to find |
|
|
1588 | out wether kqueue supports your type of fd properly and use an embedded |
|
|
1589 | kqueue loop. |
|
|
1590 | |
|
|
1591 | =item EV_USE_PORT |
|
|
1592 | |
|
|
1593 | If defined to be C<1>, libev will compile in support for the Solaris |
|
|
1594 | 10 port style backend. Its availability will be detected at runtime, |
|
|
1595 | otherwise another method will be used as fallback. This is the preferred |
|
|
1596 | backend for Solaris 10 systems. |
|
|
1597 | |
|
|
1598 | =item EV_USE_DEVPOLL |
|
|
1599 | |
|
|
1600 | reserved for future expansion, works like the USE symbols above. |
|
|
1601 | |
|
|
1602 | =item EV_H |
|
|
1603 | |
|
|
1604 | The name of the F<ev.h> header file used to include it. The default if |
|
|
1605 | undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This |
|
|
1606 | can be used to virtually rename the F<ev.h> header file in case of conflicts. |
|
|
1607 | |
|
|
1608 | =item EV_CONFIG_H |
|
|
1609 | |
|
|
1610 | If C<EV_STANDALONE> isn't C<1>, this variable can be used to override |
|
|
1611 | F<ev.c>'s idea of where to find the F<config.h> file, similarly to |
|
|
1612 | C<EV_H>, above. |
|
|
1613 | |
|
|
1614 | =item EV_EVENT_H |
|
|
1615 | |
|
|
1616 | Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea |
|
|
1617 | of how the F<event.h> header can be found. |
|
|
1618 | |
|
|
1619 | =item EV_PROTOTYPES |
|
|
1620 | |
|
|
1621 | If defined to be C<0>, then F<ev.h> will not define any function |
|
|
1622 | prototypes, but still define all the structs and other symbols. This is |
|
|
1623 | occasionally useful if you want to provide your own wrapper functions |
|
|
1624 | around libev functions. |
|
|
1625 | |
|
|
1626 | =item EV_MULTIPLICITY |
|
|
1627 | |
|
|
1628 | If undefined or defined to C<1>, then all event-loop-specific functions |
|
|
1629 | will have the C<struct ev_loop *> as first argument, and you can create |
|
|
1630 | additional independent event loops. Otherwise there will be no support |
|
|
1631 | for multiple event loops and there is no first event loop pointer |
|
|
1632 | argument. Instead, all functions act on the single default loop. |
|
|
1633 | |
|
|
1634 | =item EV_PERIODICS |
|
|
1635 | |
|
|
1636 | If undefined or defined to be C<1>, then periodic timers are supported, |
|
|
1637 | otherwise not. This saves a few kb of code. |
|
|
1638 | |
|
|
1639 | =item EV_COMMON |
|
|
1640 | |
|
|
1641 | By default, all watchers have a C<void *data> member. By redefining |
|
|
1642 | this macro to a something else you can include more and other types of |
|
|
1643 | members. You have to define it each time you include one of the files, |
|
|
1644 | though, and it must be identical each time. |
|
|
1645 | |
|
|
1646 | For example, the perl EV module uses something like this: |
|
|
1647 | |
|
|
1648 | #define EV_COMMON \ |
|
|
1649 | SV *self; /* contains this struct */ \ |
|
|
1650 | SV *cb_sv, *fh /* note no trailing ";" */ |
|
|
1651 | |
|
|
1652 | =item EV_CB_DECLARE(type) |
|
|
1653 | |
|
|
1654 | =item EV_CB_INVOKE(watcher,revents) |
|
|
1655 | |
|
|
1656 | =item ev_set_cb(ev,cb) |
|
|
1657 | |
|
|
1658 | Can be used to change the callback member declaration in each watcher, |
|
|
1659 | and the way callbacks are invoked and set. Must expand to a struct member |
|
|
1660 | definition and a statement, respectively. See the F<ev.v> header file for |
|
|
1661 | their default definitions. One possible use for overriding these is to |
|
|
1662 | avoid the ev_loop pointer as first argument in all cases, or to use method |
|
|
1663 | calls instead of plain function calls in C++. |
|
|
1664 | |
|
|
1665 | =head2 EXAMPLES |
|
|
1666 | |
|
|
1667 | For a real-world example of a program the includes libev |
|
|
1668 | verbatim, you can have a look at the EV perl module |
|
|
1669 | (L<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
|
|
1670 | the F<libev/> subdirectory and includes them in the F<EV/EVAPI.h> (public |
|
|
1671 | interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file |
|
|
1672 | will be compiled. It is pretty complex because it provides its own header |
|
|
1673 | file. |
|
|
1674 | |
|
|
1675 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
|
|
1676 | that everybody includes and which overrides some autoconf choices: |
|
|
1677 | |
|
|
1678 | #define EV_USE_POLL 0 |
|
|
1679 | #define EV_MULTIPLICITY 0 |
|
|
1680 | #define EV_PERIODICS 0 |
|
|
1681 | #define EV_CONFIG_H <config.h> |
|
|
1682 | |
|
|
1683 | #include "ev++.h" |
|
|
1684 | |
|
|
1685 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
|
|
1686 | |
|
|
1687 | #include "rxvttoolkit.h" |
|
|
1688 | |
|
|
1689 | /* darwin has problems with its header files in C++, requiring this namespace juggling */ |
|
|
1690 | using namespace ev; |
|
|
1691 | |
|
|
1692 | #include "ev.c" |
|
|
1693 | |
|
|
1694 | |
| 1419 | =head1 AUTHOR |
1695 | =head1 AUTHOR |
| 1420 | |
1696 | |
| 1421 | Marc Lehmann <libev@schmorp.de>. |
1697 | Marc Lehmann <libev@schmorp.de>. |
| 1422 | |
1698 | |
