… | |
… | |
127 | .\} |
127 | .\} |
128 | .rm #[ #] #H #V #F C |
128 | .rm #[ #] #H #V #F C |
129 | .\" ======================================================================== |
129 | .\" ======================================================================== |
130 | .\" |
130 | .\" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-29" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-12-07" "perl v5.8.8" "User Contributed Perl Documentation" |
133 | .SH "NAME" |
133 | .SH "NAME" |
134 | libev \- a high performance full\-featured event loop written in C |
134 | libev \- a high performance full\-featured event loop written in C |
135 | .SH "SYNOPSIS" |
135 | .SH "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
137 | .Vb 1 |
137 | .Vb 1 |
… | |
… | |
420 | a fork, you can also make libev check for a fork in each iteration by |
420 | a fork, you can also make libev check for a fork in each iteration by |
421 | enabling this flag. |
421 | enabling this flag. |
422 | .Sp |
422 | .Sp |
423 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
423 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
424 | and thus this might slow down your event loop if you do a lot of loop |
424 | and thus this might slow down your event loop if you do a lot of loop |
425 | iterations and little real work, but is usually not noticable (on my |
425 | iterations and little real work, but is usually not noticeable (on my |
426 | Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence |
426 | Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence |
427 | without a syscall and thus \fIvery\fR fast, but my Linux system also has |
427 | without a syscall and thus \fIvery\fR fast, but my Linux system also has |
428 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
428 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
429 | .Sp |
429 | .Sp |
430 | The big advantage of this flag is that you can forget about fork (and |
430 | The big advantage of this flag is that you can forget about fork (and |
… | |
… | |
581 | .IP "ev_loop_fork (loop)" 4 |
581 | .IP "ev_loop_fork (loop)" 4 |
582 | .IX Item "ev_loop_fork (loop)" |
582 | .IX Item "ev_loop_fork (loop)" |
583 | Like \f(CW\*(C`ev_default_fork\*(C'\fR, but acts on an event loop created by |
583 | Like \f(CW\*(C`ev_default_fork\*(C'\fR, but acts on an event loop created by |
584 | \&\f(CW\*(C`ev_loop_new\*(C'\fR. Yes, you have to call this on every allocated event loop |
584 | \&\f(CW\*(C`ev_loop_new\*(C'\fR. Yes, you have to call this on every allocated event loop |
585 | after fork, and how you do this is entirely your own problem. |
585 | after fork, and how you do this is entirely your own problem. |
|
|
586 | .IP "unsigned int ev_loop_count (loop)" 4 |
|
|
587 | .IX Item "unsigned int ev_loop_count (loop)" |
|
|
588 | Returns the count of loop iterations for the loop, which is identical to |
|
|
589 | the number of times libev did poll for new events. It starts at \f(CW0\fR and |
|
|
590 | happily wraps around with enough iterations. |
|
|
591 | .Sp |
|
|
592 | This value can sometimes be useful as a generation counter of sorts (it |
|
|
593 | \&\*(L"ticks\*(R" the number of loop iterations), as it roughly corresponds with |
|
|
594 | \&\f(CW\*(C`ev_prepare\*(C'\fR and \f(CW\*(C`ev_check\*(C'\fR calls. |
586 | .IP "unsigned int ev_backend (loop)" 4 |
595 | .IP "unsigned int ev_backend (loop)" 4 |
587 | .IX Item "unsigned int ev_backend (loop)" |
596 | .IX Item "unsigned int ev_backend (loop)" |
588 | Returns one of the \f(CW\*(C`EVBACKEND_*\*(C'\fR flags indicating the event backend in |
597 | Returns one of the \f(CW\*(C`EVBACKEND_*\*(C'\fR flags indicating the event backend in |
589 | use. |
598 | use. |
590 | .IP "ev_tstamp ev_now (loop)" 4 |
599 | .IP "ev_tstamp ev_now (loop)" 4 |
… | |
… | |
885 | Returns the callback currently set on the watcher. |
894 | Returns the callback currently set on the watcher. |
886 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
895 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
887 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
896 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
888 | Change the callback. You can change the callback at virtually any time |
897 | Change the callback. You can change the callback at virtually any time |
889 | (modulo threads). |
898 | (modulo threads). |
|
|
899 | .IP "ev_set_priority (ev_TYPE *watcher, priority)" 4 |
|
|
900 | .IX Item "ev_set_priority (ev_TYPE *watcher, priority)" |
|
|
901 | .PD 0 |
|
|
902 | .IP "int ev_priority (ev_TYPE *watcher)" 4 |
|
|
903 | .IX Item "int ev_priority (ev_TYPE *watcher)" |
|
|
904 | .PD |
|
|
905 | Set and query the priority of the watcher. The priority is a small |
|
|
906 | integer between \f(CW\*(C`EV_MAXPRI\*(C'\fR (default: \f(CW2\fR) and \f(CW\*(C`EV_MINPRI\*(C'\fR |
|
|
907 | (default: \f(CW\*(C`\-2\*(C'\fR). Pending watchers with higher priority will be invoked |
|
|
908 | before watchers with lower priority, but priority will not keep watchers |
|
|
909 | from being executed (except for \f(CW\*(C`ev_idle\*(C'\fR watchers). |
|
|
910 | .Sp |
|
|
911 | This means that priorities are \fIonly\fR used for ordering callback |
|
|
912 | invocation after new events have been received. This is useful, for |
|
|
913 | example, to reduce latency after idling, or more often, to bind two |
|
|
914 | watchers on the same event and make sure one is called first. |
|
|
915 | .Sp |
|
|
916 | If you need to suppress invocation when higher priority events are pending |
|
|
917 | you need to look at \f(CW\*(C`ev_idle\*(C'\fR watchers, which provide this functionality. |
|
|
918 | .Sp |
|
|
919 | The default priority used by watchers when no priority has been set is |
|
|
920 | always \f(CW0\fR, which is supposed to not be too high and not be too low :). |
|
|
921 | .Sp |
|
|
922 | Setting a priority outside the range of \f(CW\*(C`EV_MINPRI\*(C'\fR to \f(CW\*(C`EV_MAXPRI\*(C'\fR is |
|
|
923 | fine, as long as you do not mind that the priority value you query might |
|
|
924 | or might not have been adjusted to be within valid range. |
890 | .Sh "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0" |
925 | .Sh "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0" |
891 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
926 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
892 | Each watcher has, by default, a member \f(CW\*(C`void *data\*(C'\fR that you can change |
927 | Each watcher has, by default, a member \f(CW\*(C`void *data\*(C'\fR that you can change |
893 | and read at any time, libev will completely ignore it. This can be used |
928 | and read at any time, libev will completely ignore it. This can be used |
894 | to associate arbitrary data with your watcher. If you need more data and |
929 | to associate arbitrary data with your watcher. If you need more data and |
… | |
… | |
1005 | it is best to always use non-blocking I/O: An extra \f(CW\*(C`read\*(C'\fR(2) returning |
1040 | it is best to always use non-blocking I/O: An extra \f(CW\*(C`read\*(C'\fR(2) returning |
1006 | \&\f(CW\*(C`EAGAIN\*(C'\fR is far preferable to a program hanging until some data arrives. |
1041 | \&\f(CW\*(C`EAGAIN\*(C'\fR is far preferable to a program hanging until some data arrives. |
1007 | .PP |
1042 | .PP |
1008 | If you cannot run the fd in non-blocking mode (for example you should not |
1043 | If you cannot run the fd in non-blocking mode (for example you should not |
1009 | play around with an Xlib connection), then you have to seperately re-test |
1044 | play around with an Xlib connection), then you have to seperately re-test |
1010 | wether a file descriptor is really ready with a known-to-be good interface |
1045 | whether a file descriptor is really ready with a known-to-be good interface |
1011 | such as poll (fortunately in our Xlib example, Xlib already does this on |
1046 | such as poll (fortunately in our Xlib example, Xlib already does this on |
1012 | its own, so its quite safe to use). |
1047 | its own, so its quite safe to use). |
1013 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
1048 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
1014 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
1049 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
1015 | .PD 0 |
1050 | .PD 0 |
… | |
… | |
1499 | \& ev_stat_start (loop, &passwd); |
1534 | \& ev_stat_start (loop, &passwd); |
1500 | .Ve |
1535 | .Ve |
1501 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1536 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1502 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
1537 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
1503 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
1538 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
1504 | Idle watchers trigger events when there are no other events are pending |
1539 | Idle watchers trigger events when no other events of the same or higher |
1505 | (prepare, check and other idle watchers do not count). That is, as long |
1540 | priority are pending (prepare, check and other idle watchers do not |
1506 | as your process is busy handling sockets or timeouts (or even signals, |
1541 | count). |
1507 | imagine) it will not be triggered. But when your process is idle all idle |
1542 | .PP |
1508 | watchers are being called again and again, once per event loop iteration \- |
1543 | That is, as long as your process is busy handling sockets or timeouts |
|
|
1544 | (or even signals, imagine) of the same or higher priority it will not be |
|
|
1545 | triggered. But when your process is idle (or only lower-priority watchers |
|
|
1546 | are pending), the idle watchers are being called once per event loop |
1509 | until stopped, that is, or your process receives more events and becomes |
1547 | iteration \- until stopped, that is, or your process receives more events |
1510 | busy. |
1548 | and becomes busy again with higher priority stuff. |
1511 | .PP |
1549 | .PP |
1512 | The most noteworthy effect is that as long as any idle watchers are |
1550 | The most noteworthy effect is that as long as any idle watchers are |
1513 | active, the process will not block when waiting for new events. |
1551 | active, the process will not block when waiting for new events. |
1514 | .PP |
1552 | .PP |
1515 | Apart from keeping your process non-blocking (which is a useful |
1553 | Apart from keeping your process non-blocking (which is a useful |
… | |
… | |
1610 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1648 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1611 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1649 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1612 | \& } |
1650 | \& } |
1613 | .Ve |
1651 | .Ve |
1614 | .PP |
1652 | .PP |
1615 | .Vb 7 |
1653 | .Vb 8 |
1616 | \& // create io watchers for each fd and a timer before blocking |
1654 | \& // create io watchers for each fd and a timer before blocking |
1617 | \& static void |
1655 | \& static void |
1618 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1656 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1619 | \& { |
1657 | \& { |
1620 | \& int timeout = 3600000;truct pollfd fds [nfd]; |
1658 | \& int timeout = 3600000; |
|
|
1659 | \& struct pollfd fds [nfd]; |
1621 | \& // actual code will need to loop here and realloc etc. |
1660 | \& // actual code will need to loop here and realloc etc. |
1622 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1661 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1623 | .Ve |
1662 | .Ve |
1624 | .PP |
1663 | .PP |
1625 | .Vb 3 |
1664 | .Vb 3 |
… | |
… | |
1952 | \& } |
1991 | \& } |
1953 | .Ve |
1992 | .Ve |
1954 | .SH "MACRO MAGIC" |
1993 | .SH "MACRO MAGIC" |
1955 | .IX Header "MACRO MAGIC" |
1994 | .IX Header "MACRO MAGIC" |
1956 | Libev can be compiled with a variety of options, the most fundemantal is |
1995 | Libev can be compiled with a variety of options, the most fundemantal is |
1957 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines wether (most) functions and |
1996 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most) functions and |
1958 | callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument. |
1997 | callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument. |
1959 | .PP |
1998 | .PP |
1960 | To make it easier to write programs that cope with either variant, the |
1999 | To make it easier to write programs that cope with either variant, the |
1961 | following macros are defined: |
2000 | following macros are defined: |
1962 | .ie n .IP """EV_A""\fR, \f(CW""EV_A_""" 4 |
2001 | .ie n .IP """EV_A""\fR, \f(CW""EV_A_""" 4 |
… | |
… | |
1997 | .el .IP "\f(CWEV_DEFAULT\fR, \f(CWEV_DEFAULT_\fR" 4 |
2036 | .el .IP "\f(CWEV_DEFAULT\fR, \f(CWEV_DEFAULT_\fR" 4 |
1998 | .IX Item "EV_DEFAULT, EV_DEFAULT_" |
2037 | .IX Item "EV_DEFAULT, EV_DEFAULT_" |
1999 | Similar to the other two macros, this gives you the value of the default |
2038 | Similar to the other two macros, this gives you the value of the default |
2000 | loop, if multiple loops are supported (\*(L"ev loop default\*(R"). |
2039 | loop, if multiple loops are supported (\*(L"ev loop default\*(R"). |
2001 | .PP |
2040 | .PP |
2002 | Example: Declare and initialise a check watcher, working regardless of |
2041 | Example: Declare and initialise a check watcher, utilising the above |
2003 | wether multiple loops are supported or not. |
2042 | macros so it will work regardless of whether multiple loops are supported |
|
|
2043 | or not. |
2004 | .PP |
2044 | .PP |
2005 | .Vb 5 |
2045 | .Vb 5 |
2006 | \& static void |
2046 | \& static void |
2007 | \& check_cb (EV_P_ ev_timer *w, int revents) |
2047 | \& check_cb (EV_P_ ev_timer *w, int revents) |
2008 | \& { |
2048 | \& { |
… | |
… | |
2071 | .Vb 1 |
2111 | .Vb 1 |
2072 | \& ev_win32.c required on win32 platforms only |
2112 | \& ev_win32.c required on win32 platforms only |
2073 | .Ve |
2113 | .Ve |
2074 | .PP |
2114 | .PP |
2075 | .Vb 5 |
2115 | .Vb 5 |
2076 | \& ev_select.c only when select backend is enabled (which is by default) |
2116 | \& ev_select.c only when select backend is enabled (which is enabled by default) |
2077 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
2117 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
2078 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
2118 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
2079 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
2119 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
2080 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
2120 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
2081 | .Ve |
2121 | .Ve |
… | |
… | |
2239 | .IP "\s-1EV_PERIODIC_ENABLE\s0" 4 |
2279 | .IP "\s-1EV_PERIODIC_ENABLE\s0" 4 |
2240 | .IX Item "EV_PERIODIC_ENABLE" |
2280 | .IX Item "EV_PERIODIC_ENABLE" |
2241 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If |
2281 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If |
2242 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
2282 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
2243 | code. |
2283 | code. |
|
|
2284 | .IP "\s-1EV_IDLE_ENABLE\s0" 4 |
|
|
2285 | .IX Item "EV_IDLE_ENABLE" |
|
|
2286 | If undefined or defined to be \f(CW1\fR, then idle watchers are supported. If |
|
|
2287 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
|
|
2288 | code. |
2244 | .IP "\s-1EV_EMBED_ENABLE\s0" 4 |
2289 | .IP "\s-1EV_EMBED_ENABLE\s0" 4 |
2245 | .IX Item "EV_EMBED_ENABLE" |
2290 | .IX Item "EV_EMBED_ENABLE" |
2246 | If undefined or defined to be \f(CW1\fR, then embed watchers are supported. If |
2291 | If undefined or defined to be \f(CW1\fR, then embed watchers are supported. If |
2247 | defined to be \f(CW0\fR, then they are not. |
2292 | defined to be \f(CW0\fR, then they are not. |
2248 | .IP "\s-1EV_STAT_ENABLE\s0" 4 |
2293 | .IP "\s-1EV_STAT_ENABLE\s0" 4 |
… | |
… | |
2308 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
2353 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
2309 | will be compiled. It is pretty complex because it provides its own header |
2354 | will be compiled. It is pretty complex because it provides its own header |
2310 | file. |
2355 | file. |
2311 | .Sp |
2356 | .Sp |
2312 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
2357 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
2313 | that everybody includes and which overrides some autoconf choices: |
2358 | that everybody includes and which overrides some configure choices: |
2314 | .Sp |
2359 | .Sp |
2315 | .Vb 4 |
2360 | .Vb 9 |
|
|
2361 | \& #define EV_MINIMAL 1 |
2316 | \& #define EV_USE_POLL 0 |
2362 | \& #define EV_USE_POLL 0 |
2317 | \& #define EV_MULTIPLICITY 0 |
2363 | \& #define EV_MULTIPLICITY 0 |
2318 | \& #define EV_PERIODICS 0 |
2364 | \& #define EV_PERIODIC_ENABLE 0 |
|
|
2365 | \& #define EV_STAT_ENABLE 0 |
|
|
2366 | \& #define EV_FORK_ENABLE 0 |
2319 | \& #define EV_CONFIG_H <config.h> |
2367 | \& #define EV_CONFIG_H <config.h> |
|
|
2368 | \& #define EV_MINPRI 0 |
|
|
2369 | \& #define EV_MAXPRI 0 |
2320 | .Ve |
2370 | .Ve |
2321 | .Sp |
2371 | .Sp |
2322 | .Vb 1 |
2372 | .Vb 1 |
2323 | \& #include "ev++.h" |
2373 | \& #include "ev++.h" |
2324 | .Ve |
2374 | .Ve |