| … | |
… | |
| 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 "2007-11-24" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-26" "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 |
| … | |
… | |
| 458 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
458 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
| 459 | .Ve |
459 | .Ve |
| 460 | .IP "ev_default_destroy ()" 4 |
460 | .IP "ev_default_destroy ()" 4 |
| 461 | .IX Item "ev_default_destroy ()" |
461 | .IX Item "ev_default_destroy ()" |
| 462 | Destroys the default loop again (frees all memory and kernel state |
462 | Destroys the default loop again (frees all memory and kernel state |
| 463 | etc.). This stops all registered event watchers (by not touching them in |
463 | etc.). None of the active event watchers will be stopped in the normal |
| 464 | any way whatsoever, although you cannot rely on this :). |
464 | sense, so e.g. \f(CW\*(C`ev_is_active\*(C'\fR might still return true. It is your |
|
|
465 | responsibility to either stop all watchers cleanly yoursef \fIbefore\fR |
|
|
466 | calling this function, or cope with the fact afterwards (which is usually |
|
|
467 | the easiest thing, youc na just ignore the watchers and/or \f(CW\*(C`free ()\*(C'\fR them |
|
|
468 | for example). |
| 465 | .IP "ev_loop_destroy (loop)" 4 |
469 | .IP "ev_loop_destroy (loop)" 4 |
| 466 | .IX Item "ev_loop_destroy (loop)" |
470 | .IX Item "ev_loop_destroy (loop)" |
| 467 | Like \f(CW\*(C`ev_default_destroy\*(C'\fR, but destroys an event loop created by an |
471 | Like \f(CW\*(C`ev_default_destroy\*(C'\fR, but destroys an event loop created by an |
| 468 | earlier call to \f(CW\*(C`ev_loop_new\*(C'\fR. |
472 | earlier call to \f(CW\*(C`ev_loop_new\*(C'\fR. |
| 469 | .IP "ev_default_fork ()" 4 |
473 | .IP "ev_default_fork ()" 4 |
| … | |
… | |
| 713 | Libev will usually signal a few \*(L"dummy\*(R" events together with an error, |
717 | Libev will usually signal a few \*(L"dummy\*(R" events together with an error, |
| 714 | for example it might indicate that a fd is readable or writable, and if |
718 | for example it might indicate that a fd is readable or writable, and if |
| 715 | your callbacks is well-written it can just attempt the operation and cope |
719 | your callbacks is well-written it can just attempt the operation and cope |
| 716 | with the error from \fIread()\fR or \fIwrite()\fR. This will not work in multithreaded |
720 | with the error from \fIread()\fR or \fIwrite()\fR. This will not work in multithreaded |
| 717 | programs, though, so beware. |
721 | programs, though, so beware. |
| 718 | .Sh "\s-1SUMMARY\s0 \s-1OF\s0 \s-1GENERIC\s0 \s-1WATCHER\s0 \s-1FUNCTIONS\s0" |
722 | .Sh "\s-1GENERIC\s0 \s-1WATCHER\s0 \s-1FUNCTIONS\s0" |
| 719 | .IX Subsection "SUMMARY OF GENERIC WATCHER FUNCTIONS" |
723 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
| 720 | In the following description, \f(CW\*(C`TYPE\*(C'\fR stands for the watcher type, |
724 | In the following description, \f(CW\*(C`TYPE\*(C'\fR stands for the watcher type, |
| 721 | e.g. \f(CW\*(C`timer\*(C'\fR for \f(CW\*(C`ev_timer\*(C'\fR watchers and \f(CW\*(C`io\*(C'\fR for \f(CW\*(C`ev_io\*(C'\fR watchers. |
725 | e.g. \f(CW\*(C`timer\*(C'\fR for \f(CW\*(C`ev_timer\*(C'\fR watchers and \f(CW\*(C`io\*(C'\fR for \f(CW\*(C`ev_io\*(C'\fR watchers. |
| 722 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
726 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
| 723 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
727 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
| 724 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
728 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
| … | |
… | |
| 730 | which rolls both calls into one. |
734 | which rolls both calls into one. |
| 731 | .Sp |
735 | .Sp |
| 732 | You can reinitialise a watcher at any time as long as it has been stopped |
736 | You can reinitialise a watcher at any time as long as it has been stopped |
| 733 | (or never started) and there are no pending events outstanding. |
737 | (or never started) and there are no pending events outstanding. |
| 734 | .Sp |
738 | .Sp |
| 735 | The callbakc is always of type \f(CW\*(C`void (*)(ev_loop *loop, ev_TYPE *watcher, |
739 | The callback is always of type \f(CW\*(C`void (*)(ev_loop *loop, ev_TYPE *watcher, |
| 736 | int revents)\*(C'\fR. |
740 | int revents)\*(C'\fR. |
| 737 | .ie n .IP """ev_TYPE_set"" (ev_TYPE *, [args])" 4 |
741 | .ie n .IP """ev_TYPE_set"" (ev_TYPE *, [args])" 4 |
| 738 | .el .IP "\f(CWev_TYPE_set\fR (ev_TYPE *, [args])" 4 |
742 | .el .IP "\f(CWev_TYPE_set\fR (ev_TYPE *, [args])" 4 |
| 739 | .IX Item "ev_TYPE_set (ev_TYPE *, [args])" |
743 | .IX Item "ev_TYPE_set (ev_TYPE *, [args])" |
| 740 | This macro initialises the type-specific parts of a watcher. You need to |
744 | This macro initialises the type-specific parts of a watcher. You need to |
| … | |
… | |
| 818 | have been omitted.... |
822 | have been omitted.... |
| 819 | .SH "WATCHER TYPES" |
823 | .SH "WATCHER TYPES" |
| 820 | .IX Header "WATCHER TYPES" |
824 | .IX Header "WATCHER TYPES" |
| 821 | This section describes each watcher in detail, but will not repeat |
825 | This section describes each watcher in detail, but will not repeat |
| 822 | information given in the last section. |
826 | information given in the last section. |
| 823 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable" |
827 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable?" |
| 824 | .el .Sh "\f(CWev_io\fP \- is this file descriptor readable or writable" |
828 | .el .Sh "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
| 825 | .IX Subsection "ev_io - is this file descriptor readable or writable" |
829 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
| 826 | I/O watchers check whether a file descriptor is readable or writable |
830 | I/O watchers check whether a file descriptor is readable or writable |
| 827 | in each iteration of the event loop (This behaviour is called |
831 | in each iteration of the event loop, or, more precisely, when reading |
| 828 | level-triggering because you keep receiving events as long as the |
832 | would not block the process and writing would at least be able to write |
| 829 | condition persists. Remember you can stop the watcher if you don't want to |
833 | some data. This behaviour is called level-triggering because you keep |
| 830 | act on the event and neither want to receive future events). |
834 | receiving events as long as the condition persists. Remember you can stop |
|
|
835 | the watcher if you don't want to act on the event and neither want to |
|
|
836 | receive future events. |
| 831 | .PP |
837 | .PP |
| 832 | In general you can register as many read and/or write event watchers per |
838 | In general you can register as many read and/or write event watchers per |
| 833 | fd as you want (as long as you don't confuse yourself). Setting all file |
839 | fd as you want (as long as you don't confuse yourself). Setting all file |
| 834 | descriptors to non-blocking mode is also usually a good idea (but not |
840 | descriptors to non-blocking mode is also usually a good idea (but not |
| 835 | required if you know what you are doing). |
841 | required if you know what you are doing). |
| 836 | .PP |
842 | .PP |
| 837 | You have to be careful with dup'ed file descriptors, though. Some backends |
843 | You have to be careful with dup'ed file descriptors, though. Some backends |
| 838 | (the linux epoll backend is a notable example) cannot handle dup'ed file |
844 | (the linux epoll backend is a notable example) cannot handle dup'ed file |
| 839 | descriptors correctly if you register interest in two or more fds pointing |
845 | descriptors correctly if you register interest in two or more fds pointing |
| 840 | to the same underlying file/socket etc. description (that is, they share |
846 | to the same underlying file/socket/etc. description (that is, they share |
| 841 | the same underlying \*(L"file open\*(R"). |
847 | the same underlying \*(L"file open\*(R"). |
| 842 | .PP |
848 | .PP |
| 843 | If you must do this, then force the use of a known-to-be-good backend |
849 | If you must do this, then force the use of a known-to-be-good backend |
| 844 | (at the time of this writing, this includes only \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR and |
850 | (at the time of this writing, this includes only \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR and |
| 845 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR). |
851 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR). |
|
|
852 | .PP |
|
|
853 | Another thing you have to watch out for is that it is quite easy to |
|
|
854 | receive \*(L"spurious\*(R" readyness notifications, that is your callback might |
|
|
855 | be called with \f(CW\*(C`EV_READ\*(C'\fR but a subsequent \f(CW\*(C`read\*(C'\fR(2) will actually block |
|
|
856 | because there is no data. Not only are some backends known to create a |
|
|
857 | lot of those (for example solaris ports), it is very easy to get into |
|
|
858 | this situation even with a relatively standard program structure. Thus |
|
|
859 | it is best to always use non-blocking I/O: An extra \f(CW\*(C`read\*(C'\fR(2) returning |
|
|
860 | \&\f(CW\*(C`EAGAIN\*(C'\fR is far preferable to a program hanging until some data arrives. |
|
|
861 | .PP |
|
|
862 | If you cannot run the fd in non-blocking mode (for example you should not |
|
|
863 | play around with an Xlib connection), then you have to seperately re-test |
|
|
864 | wether a file descriptor is really ready with a known-to-be good interface |
|
|
865 | such as poll (fortunately in our Xlib example, Xlib already does this on |
|
|
866 | its own, so its quite safe to use). |
| 846 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
867 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
| 847 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
868 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
| 848 | .PD 0 |
869 | .PD 0 |
| 849 | .IP "ev_io_set (ev_io *, int fd, int events)" 4 |
870 | .IP "ev_io_set (ev_io *, int fd, int events)" 4 |
| 850 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
871 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
| 851 | .PD |
872 | .PD |
| 852 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The fd is the file descriptor to rceeive |
873 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
| 853 | events for and events is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or \f(CW\*(C`EV_READ | |
874 | rceeive events for and events is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
| 854 | EV_WRITE\*(C'\fR to receive the given events. |
875 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
| 855 | .Sp |
|
|
| 856 | Please note that most of the more scalable backend mechanisms (for example |
|
|
| 857 | epoll and solaris ports) can result in spurious readyness notifications |
|
|
| 858 | for file descriptors, so you practically need to use non-blocking I/O (and |
|
|
| 859 | treat callback invocation as hint only), or retest separately with a safe |
|
|
| 860 | interface before doing I/O (XLib can do this), or force the use of either |
|
|
| 861 | \&\f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR, which don't suffer from this |
|
|
| 862 | problem. Also note that it is quite easy to have your callback invoked |
|
|
| 863 | when the readyness condition is no longer valid even when employing |
|
|
| 864 | typical ways of handling events, so its a good idea to use non-blocking |
|
|
| 865 | I/O unconditionally. |
|
|
| 866 | .PP |
876 | .PP |
| 867 | Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
877 | Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
| 868 | readable, but only once. Since it is likely line\-buffered, you could |
878 | readable, but only once. Since it is likely line\-buffered, you could |
| 869 | attempt to read a whole line in the callback: |
879 | attempt to read a whole line in the callback: |
| 870 | .PP |
880 | .PP |
| … | |
… | |
| 883 | \& struct ev_io stdin_readable; |
893 | \& struct ev_io stdin_readable; |
| 884 | \& ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
894 | \& ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
| 885 | \& ev_io_start (loop, &stdin_readable); |
895 | \& ev_io_start (loop, &stdin_readable); |
| 886 | \& ev_loop (loop, 0); |
896 | \& ev_loop (loop, 0); |
| 887 | .Ve |
897 | .Ve |
| 888 | .ie n .Sh """ev_timer"" \- relative and optionally recurring timeouts" |
898 | .ie n .Sh """ev_timer"" \- relative and optionally repeating timeouts" |
| 889 | .el .Sh "\f(CWev_timer\fP \- relative and optionally recurring timeouts" |
899 | .el .Sh "\f(CWev_timer\fP \- relative and optionally repeating timeouts" |
| 890 | .IX Subsection "ev_timer - relative and optionally recurring timeouts" |
900 | .IX Subsection "ev_timer - relative and optionally repeating timeouts" |
| 891 | Timer watchers are simple relative timers that generate an event after a |
901 | Timer watchers are simple relative timers that generate an event after a |
| 892 | given time, and optionally repeating in regular intervals after that. |
902 | given time, and optionally repeating in regular intervals after that. |
| 893 | .PP |
903 | .PP |
| 894 | The timers are based on real time, that is, if you register an event that |
904 | The timers are based on real time, that is, if you register an event that |
| 895 | times out after an hour and you reset your system clock to last years |
905 | times out after an hour and you reset your system clock to last years |
| … | |
… | |
| 982 | .Vb 3 |
992 | .Vb 3 |
| 983 | \& // and in some piece of code that gets executed on any "activity": |
993 | \& // and in some piece of code that gets executed on any "activity": |
| 984 | \& // reset the timeout to start ticking again at 10 seconds |
994 | \& // reset the timeout to start ticking again at 10 seconds |
| 985 | \& ev_timer_again (&mytimer); |
995 | \& ev_timer_again (&mytimer); |
| 986 | .Ve |
996 | .Ve |
| 987 | .ie n .Sh """ev_periodic"" \- to cron or not to cron" |
997 | .ie n .Sh """ev_periodic"" \- to cron or not to cron?" |
| 988 | .el .Sh "\f(CWev_periodic\fP \- to cron or not to cron" |
998 | .el .Sh "\f(CWev_periodic\fP \- to cron or not to cron?" |
| 989 | .IX Subsection "ev_periodic - to cron or not to cron" |
999 | .IX Subsection "ev_periodic - to cron or not to cron?" |
| 990 | Periodic watchers are also timers of a kind, but they are very versatile |
1000 | Periodic watchers are also timers of a kind, but they are very versatile |
| 991 | (and unfortunately a bit complex). |
1001 | (and unfortunately a bit complex). |
| 992 | .PP |
1002 | .PP |
| 993 | Unlike \f(CW\*(C`ev_timer\*(C'\fR's, they are not based on real time (or relative time) |
1003 | Unlike \f(CW\*(C`ev_timer\*(C'\fR's, they are not based on real time (or relative time) |
| 994 | but on wallclock time (absolute time). You can tell a periodic watcher |
1004 | but on wallclock time (absolute time). You can tell a periodic watcher |
| 995 | to trigger \*(L"at\*(R" some specific point in time. For example, if you tell a |
1005 | to trigger \*(L"at\*(R" some specific point in time. For example, if you tell a |
| 996 | periodic watcher to trigger in 10 seconds (by specifiying e.g. c<ev_now () |
1006 | periodic watcher to trigger in 10 seconds (by specifiying e.g. \f(CW\*(C`ev_now () |
| 997 | + 10.>) and then reset your system clock to the last year, then it will |
1007 | + 10.\*(C'\fR) and then reset your system clock to the last year, then it will |
| 998 | take a year to trigger the event (unlike an \f(CW\*(C`ev_timer\*(C'\fR, which would trigger |
1008 | take a year to trigger the event (unlike an \f(CW\*(C`ev_timer\*(C'\fR, which would trigger |
| 999 | roughly 10 seconds later and of course not if you reset your system time |
1009 | roughly 10 seconds later and of course not if you reset your system time |
| 1000 | again). |
1010 | again). |
| 1001 | .PP |
1011 | .PP |
| 1002 | They can also be used to implement vastly more complex timers, such as |
1012 | They can also be used to implement vastly more complex timers, such as |
| … | |
… | |
| 1128 | \& struct ev_periodic hourly_tick; |
1138 | \& struct ev_periodic hourly_tick; |
| 1129 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1139 | \& ev_periodic_init (&hourly_tick, clock_cb, |
| 1130 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1140 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
| 1131 | \& ev_periodic_start (loop, &hourly_tick); |
1141 | \& ev_periodic_start (loop, &hourly_tick); |
| 1132 | .Ve |
1142 | .Ve |
| 1133 | .ie n .Sh """ev_signal"" \- signal me when a signal gets signalled" |
1143 | .ie n .Sh """ev_signal"" \- signal me when a signal gets signalled!" |
| 1134 | .el .Sh "\f(CWev_signal\fP \- signal me when a signal gets signalled" |
1144 | .el .Sh "\f(CWev_signal\fP \- signal me when a signal gets signalled!" |
| 1135 | .IX Subsection "ev_signal - signal me when a signal gets signalled" |
1145 | .IX Subsection "ev_signal - signal me when a signal gets signalled!" |
| 1136 | Signal watchers will trigger an event when the process receives a specific |
1146 | Signal watchers will trigger an event when the process receives a specific |
| 1137 | signal one or more times. Even though signals are very asynchronous, libev |
1147 | signal one or more times. Even though signals are very asynchronous, libev |
| 1138 | will try it's best to deliver signals synchronously, i.e. as part of the |
1148 | will try it's best to deliver signals synchronously, i.e. as part of the |
| 1139 | normal event processing, like any other event. |
1149 | normal event processing, like any other event. |
| 1140 | .PP |
1150 | .PP |
| … | |
… | |
| 1150 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1160 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
| 1151 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1161 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
| 1152 | .PD |
1162 | .PD |
| 1153 | Configures the watcher to trigger on the given signal number (usually one |
1163 | Configures the watcher to trigger on the given signal number (usually one |
| 1154 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
1164 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
| 1155 | .ie n .Sh """ev_child"" \- wait for pid status changes" |
1165 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
| 1156 | .el .Sh "\f(CWev_child\fP \- wait for pid status changes" |
1166 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
| 1157 | .IX Subsection "ev_child - wait for pid status changes" |
1167 | .IX Subsection "ev_child - watch out for process status changes" |
| 1158 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1168 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
| 1159 | some child status changes (most typically when a child of yours dies). |
1169 | some child status changes (most typically when a child of yours dies). |
| 1160 | .IP "ev_child_init (ev_child *, callback, int pid)" 4 |
1170 | .IP "ev_child_init (ev_child *, callback, int pid)" 4 |
| 1161 | .IX Item "ev_child_init (ev_child *, callback, int pid)" |
1171 | .IX Item "ev_child_init (ev_child *, callback, int pid)" |
| 1162 | .PD 0 |
1172 | .PD 0 |
| … | |
… | |
| 1183 | .Vb 3 |
1193 | .Vb 3 |
| 1184 | \& struct ev_signal signal_watcher; |
1194 | \& struct ev_signal signal_watcher; |
| 1185 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1195 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
| 1186 | \& ev_signal_start (loop, &sigint_cb); |
1196 | \& ev_signal_start (loop, &sigint_cb); |
| 1187 | .Ve |
1197 | .Ve |
| 1188 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do" |
1198 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
| 1189 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do" |
1199 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
| 1190 | .IX Subsection "ev_idle - when you've got nothing better to do" |
1200 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
| 1191 | Idle watchers trigger events when there are no other events are pending |
1201 | Idle watchers trigger events when there are no other events are pending |
| 1192 | (prepare, check and other idle watchers do not count). That is, as long |
1202 | (prepare, check and other idle watchers do not count). That is, as long |
| 1193 | as your process is busy handling sockets or timeouts (or even signals, |
1203 | as your process is busy handling sockets or timeouts (or even signals, |
| 1194 | imagine) it will not be triggered. But when your process is idle all idle |
1204 | imagine) it will not be triggered. But when your process is idle all idle |
| 1195 | watchers are being called again and again, once per event loop iteration \- |
1205 | watchers are being called again and again, once per event loop iteration \- |
| … | |
… | |
| 1225 | .Vb 3 |
1235 | .Vb 3 |
| 1226 | \& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1236 | \& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
| 1227 | \& ev_idle_init (idle_watcher, idle_cb); |
1237 | \& ev_idle_init (idle_watcher, idle_cb); |
| 1228 | \& ev_idle_start (loop, idle_cb); |
1238 | \& ev_idle_start (loop, idle_cb); |
| 1229 | .Ve |
1239 | .Ve |
| 1230 | .ie n .Sh """ev_prepare""\fP and \f(CW""ev_check"" \- customise your event loop" |
1240 | .ie n .Sh """ev_prepare""\fP and \f(CW""ev_check"" \- customise your event loop!" |
| 1231 | .el .Sh "\f(CWev_prepare\fP and \f(CWev_check\fP \- customise your event loop" |
1241 | .el .Sh "\f(CWev_prepare\fP and \f(CWev_check\fP \- customise your event loop!" |
| 1232 | .IX Subsection "ev_prepare and ev_check - customise your event loop" |
1242 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
| 1233 | Prepare and check watchers are usually (but not always) used in tandem: |
1243 | Prepare and check watchers are usually (but not always) used in tandem: |
| 1234 | prepare watchers get invoked before the process blocks and check watchers |
1244 | prepare watchers get invoked before the process blocks and check watchers |
| 1235 | afterwards. |
1245 | afterwards. |
| 1236 | .PP |
1246 | .PP |
|
|
1247 | You \fImust not\fR call \f(CW\*(C`ev_loop\*(C'\fR or similar functions that enter |
|
|
1248 | the current event loop from either \f(CW\*(C`ev_prepare\*(C'\fR or \f(CW\*(C`ev_check\*(C'\fR |
|
|
1249 | watchers. Other loops than the current one are fine, however. The |
|
|
1250 | rationale behind this is that you do not need to check for recursion in |
|
|
1251 | those watchers, i.e. the sequence will always be \f(CW\*(C`ev_prepare\*(C'\fR, blocking, |
|
|
1252 | \&\f(CW\*(C`ev_check\*(C'\fR so if you have one watcher of each kind they will always be |
|
|
1253 | called in pairs bracketing the blocking call. |
|
|
1254 | .PP |
| 1237 | Their main purpose is to integrate other event mechanisms into libev and |
1255 | Their main purpose is to integrate other event mechanisms into libev and |
| 1238 | their use is somewhat advanced. This could be used, for example, to track |
1256 | their use is somewhat advanced. This could be used, for example, to track |
| 1239 | variable changes, implement your own watchers, integrate net-snmp or a |
1257 | variable changes, implement your own watchers, integrate net-snmp or a |
| 1240 | coroutine library and lots more. |
1258 | coroutine library and lots more. They are also occasionally useful if |
|
|
1259 | you cache some data and want to flush it before blocking (for example, |
|
|
1260 | in X programs you might want to do an \f(CW\*(C`XFlush ()\*(C'\fR in an \f(CW\*(C`ev_prepare\*(C'\fR |
|
|
1261 | watcher). |
| 1241 | .PP |
1262 | .PP |
| 1242 | This is done by examining in each prepare call which file descriptors need |
1263 | This is done by examining in each prepare call which file descriptors need |
| 1243 | to be watched by the other library, registering \f(CW\*(C`ev_io\*(C'\fR watchers for |
1264 | to be watched by the other library, registering \f(CW\*(C`ev_io\*(C'\fR watchers for |
| 1244 | them and starting an \f(CW\*(C`ev_timer\*(C'\fR watcher for any timeouts (many libraries |
1265 | them and starting an \f(CW\*(C`ev_timer\*(C'\fR watcher for any timeouts (many libraries |
| 1245 | provide just this functionality). Then, in the check watcher you check for |
1266 | provide just this functionality). Then, in the check watcher you check for |
| … | |
… | |
| 1264 | .PD |
1285 | .PD |
| 1265 | Initialises and configures the prepare or check watcher \- they have no |
1286 | Initialises and configures the prepare or check watcher \- they have no |
| 1266 | parameters of any kind. There are \f(CW\*(C`ev_prepare_set\*(C'\fR and \f(CW\*(C`ev_check_set\*(C'\fR |
1287 | parameters of any kind. There are \f(CW\*(C`ev_prepare_set\*(C'\fR and \f(CW\*(C`ev_check_set\*(C'\fR |
| 1267 | macros, but using them is utterly, utterly and completely pointless. |
1288 | macros, but using them is utterly, utterly and completely pointless. |
| 1268 | .PP |
1289 | .PP |
| 1269 | Example: *TODO*. |
1290 | Example: To include a library such as adns, you would add \s-1IO\s0 watchers |
|
|
1291 | and a timeout watcher in a prepare handler, as required by libadns, and |
|
|
1292 | in a check watcher, destroy them and call into libadns. What follows is |
|
|
1293 | pseudo-code only of course: |
|
|
1294 | .PP |
|
|
1295 | .Vb 2 |
|
|
1296 | \& static ev_io iow [nfd]; |
|
|
1297 | \& static ev_timer tw; |
|
|
1298 | .Ve |
|
|
1299 | .PP |
|
|
1300 | .Vb 9 |
|
|
1301 | \& static void |
|
|
1302 | \& io_cb (ev_loop *loop, ev_io *w, int revents) |
|
|
1303 | \& { |
|
|
1304 | \& // set the relevant poll flags |
|
|
1305 | \& // could also call adns_processreadable etc. here |
|
|
1306 | \& struct pollfd *fd = (struct pollfd *)w->data; |
|
|
1307 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
|
|
1308 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
|
|
1309 | \& } |
|
|
1310 | .Ve |
|
|
1311 | .PP |
|
|
1312 | .Vb 7 |
|
|
1313 | \& // create io watchers for each fd and a timer before blocking |
|
|
1314 | \& static void |
|
|
1315 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
|
|
1316 | \& { |
|
|
1317 | \& int timeout = 3600000;truct pollfd fds [nfd]; |
|
|
1318 | \& // actual code will need to loop here and realloc etc. |
|
|
1319 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
|
|
1320 | .Ve |
|
|
1321 | .PP |
|
|
1322 | .Vb 3 |
|
|
1323 | \& /* the callback is illegal, but won't be called as we stop during check */ |
|
|
1324 | \& ev_timer_init (&tw, 0, timeout * 1e-3); |
|
|
1325 | \& ev_timer_start (loop, &tw); |
|
|
1326 | .Ve |
|
|
1327 | .PP |
|
|
1328 | .Vb 6 |
|
|
1329 | \& // create on ev_io per pollfd |
|
|
1330 | \& for (int i = 0; i < nfd; ++i) |
|
|
1331 | \& { |
|
|
1332 | \& ev_io_init (iow + i, io_cb, fds [i].fd, |
|
|
1333 | \& ((fds [i].events & POLLIN ? EV_READ : 0) |
|
|
1334 | \& | (fds [i].events & POLLOUT ? EV_WRITE : 0))); |
|
|
1335 | .Ve |
|
|
1336 | .PP |
|
|
1337 | .Vb 5 |
|
|
1338 | \& fds [i].revents = 0; |
|
|
1339 | \& iow [i].data = fds + i; |
|
|
1340 | \& ev_io_start (loop, iow + i); |
|
|
1341 | \& } |
|
|
1342 | \& } |
|
|
1343 | .Ve |
|
|
1344 | .PP |
|
|
1345 | .Vb 5 |
|
|
1346 | \& // stop all watchers after blocking |
|
|
1347 | \& static void |
|
|
1348 | \& adns_check_cb (ev_loop *loop, ev_check *w, int revents) |
|
|
1349 | \& { |
|
|
1350 | \& ev_timer_stop (loop, &tw); |
|
|
1351 | .Ve |
|
|
1352 | .PP |
|
|
1353 | .Vb 2 |
|
|
1354 | \& for (int i = 0; i < nfd; ++i) |
|
|
1355 | \& ev_io_stop (loop, iow + i); |
|
|
1356 | .Ve |
|
|
1357 | .PP |
|
|
1358 | .Vb 2 |
|
|
1359 | \& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop)); |
|
|
1360 | \& } |
|
|
1361 | .Ve |
| 1270 | .ie n .Sh """ev_embed"" \- when one backend isn't enough" |
1362 | .ie n .Sh """ev_embed"" \- when one backend isn't enough..." |
| 1271 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough" |
1363 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..." |
| 1272 | .IX Subsection "ev_embed - when one backend isn't enough" |
1364 | .IX Subsection "ev_embed - when one backend isn't enough..." |
| 1273 | This is a rather advanced watcher type that lets you embed one event loop |
1365 | This is a rather advanced watcher type that lets you embed one event loop |
| 1274 | into another (currently only \f(CW\*(C`ev_io\*(C'\fR events are supported in the embedded |
1366 | into another (currently only \f(CW\*(C`ev_io\*(C'\fR events are supported in the embedded |
| 1275 | loop, other types of watchers might be handled in a delayed or incorrect |
1367 | loop, other types of watchers might be handled in a delayed or incorrect |
| 1276 | fashion and must not be used). |
1368 | fashion and must not be used). |
| 1277 | .PP |
1369 | .PP |
| … | |
… | |
| 1428 | .IP "* The libev emulation is \fInot\fR \s-1ABI\s0 compatible to libevent, you need to use the libev header file and library." 4 |
1520 | .IP "* The libev emulation is \fInot\fR \s-1ABI\s0 compatible to libevent, you need to use the libev header file and library." 4 |
| 1429 | .IX Item "The libev emulation is not ABI compatible to libevent, you need to use the libev header file and library." |
1521 | .IX Item "The libev emulation is not ABI compatible to libevent, you need to use the libev header file and library." |
| 1430 | .PD |
1522 | .PD |
| 1431 | .SH "\*(C+ SUPPORT" |
1523 | .SH "\*(C+ SUPPORT" |
| 1432 | .IX Header " SUPPORT" |
1524 | .IX Header " SUPPORT" |
| 1433 | \&\s-1TBD\s0. |
1525 | Libev comes with some simplistic wrapper classes for \*(C+ that mainly allow |
|
|
1526 | you to use some convinience methods to start/stop watchers and also change |
|
|
1527 | the callback model to a model using method callbacks on objects. |
|
|
1528 | .PP |
|
|
1529 | To use it, |
|
|
1530 | .PP |
|
|
1531 | .Vb 1 |
|
|
1532 | \& #include <ev++.h> |
|
|
1533 | .Ve |
|
|
1534 | .PP |
|
|
1535 | (it is not installed by default). This automatically includes \fIev.h\fR |
|
|
1536 | and puts all of its definitions (many of them macros) into the global |
|
|
1537 | namespace. All \*(C+ specific things are put into the \f(CW\*(C`ev\*(C'\fR namespace. |
|
|
1538 | .PP |
|
|
1539 | It should support all the same embedding options as \fIev.h\fR, most notably |
|
|
1540 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. |
|
|
1541 | .PP |
|
|
1542 | Here is a list of things available in the \f(CW\*(C`ev\*(C'\fR namespace: |
|
|
1543 | .ie n .IP """ev::READ""\fR, \f(CW""ev::WRITE"" etc." 4 |
|
|
1544 | .el .IP "\f(CWev::READ\fR, \f(CWev::WRITE\fR etc." 4 |
|
|
1545 | .IX Item "ev::READ, ev::WRITE etc." |
|
|
1546 | These are just enum values with the same values as the \f(CW\*(C`EV_READ\*(C'\fR etc. |
|
|
1547 | macros from \fIev.h\fR. |
|
|
1548 | .ie n .IP """ev::tstamp""\fR, \f(CW""ev::now""" 4 |
|
|
1549 | .el .IP "\f(CWev::tstamp\fR, \f(CWev::now\fR" 4 |
|
|
1550 | .IX Item "ev::tstamp, ev::now" |
|
|
1551 | Aliases to the same types/functions as with the \f(CW\*(C`ev_\*(C'\fR prefix. |
|
|
1552 | .ie n .IP """ev::io""\fR, \f(CW""ev::timer""\fR, \f(CW""ev::periodic""\fR, \f(CW""ev::idle""\fR, \f(CW""ev::sig"" etc." 4 |
|
|
1553 | .el .IP "\f(CWev::io\fR, \f(CWev::timer\fR, \f(CWev::periodic\fR, \f(CWev::idle\fR, \f(CWev::sig\fR etc." 4 |
|
|
1554 | .IX Item "ev::io, ev::timer, ev::periodic, ev::idle, ev::sig etc." |
|
|
1555 | For each \f(CW\*(C`ev_TYPE\*(C'\fR watcher in \fIev.h\fR there is a corresponding class of |
|
|
1556 | the same name in the \f(CW\*(C`ev\*(C'\fR namespace, with the exception of \f(CW\*(C`ev_signal\*(C'\fR |
|
|
1557 | which is called \f(CW\*(C`ev::sig\*(C'\fR to avoid clashes with the \f(CW\*(C`signal\*(C'\fR macro |
|
|
1558 | defines by many implementations. |
|
|
1559 | .Sp |
|
|
1560 | All of those classes have these methods: |
|
|
1561 | .RS 4 |
|
|
1562 | .IP "ev::TYPE::TYPE (object *, object::method *)" 4 |
|
|
1563 | .IX Item "ev::TYPE::TYPE (object *, object::method *)" |
|
|
1564 | .PD 0 |
|
|
1565 | .IP "ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)" 4 |
|
|
1566 | .IX Item "ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)" |
|
|
1567 | .IP "ev::TYPE::~TYPE" 4 |
|
|
1568 | .IX Item "ev::TYPE::~TYPE" |
|
|
1569 | .PD |
|
|
1570 | The constructor takes a pointer to an object and a method pointer to |
|
|
1571 | the event handler callback to call in this class. The constructor calls |
|
|
1572 | \&\f(CW\*(C`ev_init\*(C'\fR for you, which means you have to call the \f(CW\*(C`set\*(C'\fR method |
|
|
1573 | before starting it. If you do not specify a loop then the constructor |
|
|
1574 | automatically associates the default loop with this watcher. |
|
|
1575 | .Sp |
|
|
1576 | The destructor automatically stops the watcher if it is active. |
|
|
1577 | .IP "w\->set (struct ev_loop *)" 4 |
|
|
1578 | .IX Item "w->set (struct ev_loop *)" |
|
|
1579 | Associates a different \f(CW\*(C`struct ev_loop\*(C'\fR with this watcher. You can only |
|
|
1580 | do this when the watcher is inactive (and not pending either). |
|
|
1581 | .IP "w\->set ([args])" 4 |
|
|
1582 | .IX Item "w->set ([args])" |
|
|
1583 | Basically the same as \f(CW\*(C`ev_TYPE_set\*(C'\fR, with the same args. Must be |
|
|
1584 | called at least once. Unlike the C counterpart, an active watcher gets |
|
|
1585 | automatically stopped and restarted. |
|
|
1586 | .IP "w\->start ()" 4 |
|
|
1587 | .IX Item "w->start ()" |
|
|
1588 | Starts the watcher. Note that there is no \f(CW\*(C`loop\*(C'\fR argument as the |
|
|
1589 | constructor already takes the loop. |
|
|
1590 | .IP "w\->stop ()" 4 |
|
|
1591 | .IX Item "w->stop ()" |
|
|
1592 | Stops the watcher if it is active. Again, no \f(CW\*(C`loop\*(C'\fR argument. |
|
|
1593 | .ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4 |
|
|
1594 | .el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4 |
|
|
1595 | .IX Item "w->again () ev::timer, ev::periodic only" |
|
|
1596 | For \f(CW\*(C`ev::timer\*(C'\fR and \f(CW\*(C`ev::periodic\*(C'\fR, this invokes the corresponding |
|
|
1597 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
|
|
1598 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
|
|
1599 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
|
|
1600 | .IX Item "w->sweep () ev::embed only" |
|
|
1601 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
|
|
1602 | .RE |
|
|
1603 | .RS 4 |
|
|
1604 | .RE |
|
|
1605 | .PP |
|
|
1606 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
|
|
1607 | the constructor. |
|
|
1608 | .PP |
|
|
1609 | .Vb 4 |
|
|
1610 | \& class myclass |
|
|
1611 | \& { |
|
|
1612 | \& ev_io io; void io_cb (ev::io &w, int revents); |
|
|
1613 | \& ev_idle idle void idle_cb (ev::idle &w, int revents); |
|
|
1614 | .Ve |
|
|
1615 | .PP |
|
|
1616 | .Vb 2 |
|
|
1617 | \& myclass (); |
|
|
1618 | \& } |
|
|
1619 | .Ve |
|
|
1620 | .PP |
|
|
1621 | .Vb 6 |
|
|
1622 | \& myclass::myclass (int fd) |
|
|
1623 | \& : io (this, &myclass::io_cb), |
|
|
1624 | \& idle (this, &myclass::idle_cb) |
|
|
1625 | \& { |
|
|
1626 | \& io.start (fd, ev::READ); |
|
|
1627 | \& } |
|
|
1628 | .Ve |
|
|
1629 | .SH "EMBEDDING" |
|
|
1630 | .IX Header "EMBEDDING" |
|
|
1631 | Libev can (and often is) directly embedded into host |
|
|
1632 | applications. Examples of applications that embed it include the Deliantra |
|
|
1633 | Game Server, the \s-1EV\s0 perl module, the \s-1GNU\s0 Virtual Private Ethernet (gvpe) |
|
|
1634 | and rxvt\-unicode. |
|
|
1635 | .PP |
|
|
1636 | The goal is to enable you to just copy the neecssary files into your |
|
|
1637 | source directory without having to change even a single line in them, so |
|
|
1638 | you can easily upgrade by simply copying (or having a checked-out copy of |
|
|
1639 | libev somewhere in your source tree). |
|
|
1640 | .Sh "\s-1FILESETS\s0" |
|
|
1641 | .IX Subsection "FILESETS" |
|
|
1642 | Depending on what features you need you need to include one or more sets of files |
|
|
1643 | in your app. |
|
|
1644 | .PP |
|
|
1645 | \fI\s-1CORE\s0 \s-1EVENT\s0 \s-1LOOP\s0\fR |
|
|
1646 | .IX Subsection "CORE EVENT LOOP" |
|
|
1647 | .PP |
|
|
1648 | To include only the libev core (all the \f(CW\*(C`ev_*\*(C'\fR functions), with manual |
|
|
1649 | configuration (no autoconf): |
|
|
1650 | .PP |
|
|
1651 | .Vb 2 |
|
|
1652 | \& #define EV_STANDALONE 1 |
|
|
1653 | \& #include "ev.c" |
|
|
1654 | .Ve |
|
|
1655 | .PP |
|
|
1656 | This will automatically include \fIev.h\fR, too, and should be done in a |
|
|
1657 | single C source file only to provide the function implementations. To use |
|
|
1658 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API\s0 (best |
|
|
1659 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
|
|
1660 | where you can put other configuration options): |
|
|
1661 | .PP |
|
|
1662 | .Vb 2 |
|
|
1663 | \& #define EV_STANDALONE 1 |
|
|
1664 | \& #include "ev.h" |
|
|
1665 | .Ve |
|
|
1666 | .PP |
|
|
1667 | Both header files and implementation files can be compiled with a \*(C+ |
|
|
1668 | compiler (at least, thats a stated goal, and breakage will be treated |
|
|
1669 | as a bug). |
|
|
1670 | .PP |
|
|
1671 | You need the following files in your source tree, or in a directory |
|
|
1672 | in your include path (e.g. in libev/ when using \-Ilibev): |
|
|
1673 | .PP |
|
|
1674 | .Vb 4 |
|
|
1675 | \& ev.h |
|
|
1676 | \& ev.c |
|
|
1677 | \& ev_vars.h |
|
|
1678 | \& ev_wrap.h |
|
|
1679 | .Ve |
|
|
1680 | .PP |
|
|
1681 | .Vb 1 |
|
|
1682 | \& ev_win32.c required on win32 platforms only |
|
|
1683 | .Ve |
|
|
1684 | .PP |
|
|
1685 | .Vb 5 |
|
|
1686 | \& ev_select.c only when select backend is enabled (which is by default) |
|
|
1687 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
|
|
1688 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
|
|
1689 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
|
|
1690 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
|
|
1691 | .Ve |
|
|
1692 | .PP |
|
|
1693 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
|
|
1694 | to compile this single file. |
|
|
1695 | .PP |
|
|
1696 | \fI\s-1LIBEVENT\s0 \s-1COMPATIBILITY\s0 \s-1API\s0\fR |
|
|
1697 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
|
|
1698 | .PP |
|
|
1699 | To include the libevent compatibility \s-1API\s0, also include: |
|
|
1700 | .PP |
|
|
1701 | .Vb 1 |
|
|
1702 | \& #include "event.c" |
|
|
1703 | .Ve |
|
|
1704 | .PP |
|
|
1705 | in the file including \fIev.c\fR, and: |
|
|
1706 | .PP |
|
|
1707 | .Vb 1 |
|
|
1708 | \& #include "event.h" |
|
|
1709 | .Ve |
|
|
1710 | .PP |
|
|
1711 | in the files that want to use the libevent \s-1API\s0. This also includes \fIev.h\fR. |
|
|
1712 | .PP |
|
|
1713 | You need the following additional files for this: |
|
|
1714 | .PP |
|
|
1715 | .Vb 2 |
|
|
1716 | \& event.h |
|
|
1717 | \& event.c |
|
|
1718 | .Ve |
|
|
1719 | .PP |
|
|
1720 | \fI\s-1AUTOCONF\s0 \s-1SUPPORT\s0\fR |
|
|
1721 | .IX Subsection "AUTOCONF SUPPORT" |
|
|
1722 | .PP |
|
|
1723 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your config in |
|
|
1724 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
|
|
1725 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR undefined. \fIev.c\fR will then |
|
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1726 | include \fIconfig.h\fR and configure itself accordingly. |
|
|
1727 | .PP |
|
|
1728 | For this of course you need the m4 file: |
|
|
1729 | .PP |
|
|
1730 | .Vb 1 |
|
|
1731 | \& libev.m4 |
|
|
1732 | .Ve |
|
|
1733 | .Sh "\s-1PREPROCESSOR\s0 \s-1SYMBOLS/MACROS\s0" |
|
|
1734 | .IX Subsection "PREPROCESSOR SYMBOLS/MACROS" |
|
|
1735 | Libev can be configured via a variety of preprocessor symbols you have to define |
|
|
1736 | before including any of its files. The default is not to build for multiplicity |
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|
1737 | and only include the select backend. |
|
|
1738 | .IP "\s-1EV_STANDALONE\s0" 4 |
|
|
1739 | .IX Item "EV_STANDALONE" |
|
|
1740 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
|
|
1741 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
|
|
1742 | implementations for some libevent functions (such as logging, which is not |
|
|
1743 | supported). It will also not define any of the structs usually found in |
|
|
1744 | \&\fIevent.h\fR that are not directly supported by the libev core alone. |
|
|
1745 | .IP "\s-1EV_USE_MONOTONIC\s0" 4 |
|
|
1746 | .IX Item "EV_USE_MONOTONIC" |
|
|
1747 | If defined to be \f(CW1\fR, libev will try to detect the availability of the |
|
|
1748 | monotonic clock option at both compiletime and runtime. Otherwise no use |
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|
1749 | of the monotonic clock option will be attempted. If you enable this, you |
|
|
1750 | usually have to link against librt or something similar. Enabling it when |
|
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1751 | the functionality isn't available is safe, though, althoguh you have |
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1752 | to make sure you link against any libraries where the \f(CW\*(C`clock_gettime\*(C'\fR |
|
|
1753 | function is hiding in (often \fI\-lrt\fR). |
|
|
1754 | .IP "\s-1EV_USE_REALTIME\s0" 4 |
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|
1755 | .IX Item "EV_USE_REALTIME" |
|
|
1756 | If defined to be \f(CW1\fR, libev will try to detect the availability of the |
|
|
1757 | realtime clock option at compiletime (and assume its availability at |
|
|
1758 | runtime if successful). Otherwise no use of the realtime clock option will |
|
|
1759 | be attempted. This effectively replaces \f(CW\*(C`gettimeofday\*(C'\fR by \f(CW\*(C`clock_get |
|
|
1760 | (CLOCK_REALTIME, ...)\*(C'\fR and will not normally affect correctness. See tzhe note about libraries |
|
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1761 | in the description of \f(CW\*(C`EV_USE_MONOTONIC\*(C'\fR, though. |
|
|
1762 | .IP "\s-1EV_USE_SELECT\s0" 4 |
|
|
1763 | .IX Item "EV_USE_SELECT" |
|
|
1764 | If undefined or defined to be \f(CW1\fR, libev will compile in support for the |
|
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1765 | \&\f(CW\*(C`select\*(C'\fR(2) backend. No attempt at autodetection will be done: if no |
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|
1766 | other method takes over, select will be it. Otherwise the select backend |
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|
1767 | will not be compiled in. |
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|
1768 | .IP "\s-1EV_SELECT_USE_FD_SET\s0" 4 |
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|
1769 | .IX Item "EV_SELECT_USE_FD_SET" |
|
|
1770 | If defined to \f(CW1\fR, then the select backend will use the system \f(CW\*(C`fd_set\*(C'\fR |
|
|
1771 | structure. This is useful if libev doesn't compile due to a missing |
|
|
1772 | \&\f(CW\*(C`NFDBITS\*(C'\fR or \f(CW\*(C`fd_mask\*(C'\fR definition or it misguesses the bitset layout on |
|
|
1773 | exotic systems. This usually limits the range of file descriptors to some |
|
|
1774 | low limit such as 1024 or might have other limitations (winsocket only |
|
|
1775 | allows 64 sockets). The \f(CW\*(C`FD_SETSIZE\*(C'\fR macro, set before compilation, might |
|
|
1776 | influence the size of the \f(CW\*(C`fd_set\*(C'\fR used. |
|
|
1777 | .IP "\s-1EV_SELECT_IS_WINSOCKET\s0" 4 |
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|
1778 | .IX Item "EV_SELECT_IS_WINSOCKET" |
|
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1779 | When defined to \f(CW1\fR, the select backend will assume that |
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|
1780 | select/socket/connect etc. don't understand file descriptors but |
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|
1781 | wants osf handles on win32 (this is the case when the select to |
|
|
1782 | be used is the winsock select). This means that it will call |
|
|
1783 | \&\f(CW\*(C`_get_osfhandle\*(C'\fR on the fd to convert it to an \s-1OS\s0 handle. Otherwise, |
|
|
1784 | it is assumed that all these functions actually work on fds, even |
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1785 | on win32. Should not be defined on non\-win32 platforms. |
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|
1786 | .IP "\s-1EV_USE_POLL\s0" 4 |
|
|
1787 | .IX Item "EV_USE_POLL" |
|
|
1788 | If defined to be \f(CW1\fR, libev will compile in support for the \f(CW\*(C`poll\*(C'\fR(2) |
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|
1789 | backend. Otherwise it will be enabled on non\-win32 platforms. It |
|
|
1790 | takes precedence over select. |
|
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1791 | .IP "\s-1EV_USE_EPOLL\s0" 4 |
|
|
1792 | .IX Item "EV_USE_EPOLL" |
|
|
1793 | If defined to be \f(CW1\fR, libev will compile in support for the Linux |
|
|
1794 | \&\f(CW\*(C`epoll\*(C'\fR(7) backend. Its availability will be detected at runtime, |
|
|
1795 | otherwise another method will be used as fallback. This is the |
|
|
1796 | preferred backend for GNU/Linux systems. |
|
|
1797 | .IP "\s-1EV_USE_KQUEUE\s0" 4 |
|
|
1798 | .IX Item "EV_USE_KQUEUE" |
|
|
1799 | If defined to be \f(CW1\fR, libev will compile in support for the \s-1BSD\s0 style |
|
|
1800 | \&\f(CW\*(C`kqueue\*(C'\fR(2) backend. Its actual availability will be detected at runtime, |
|
|
1801 | otherwise another method will be used as fallback. This is the preferred |
|
|
1802 | backend for \s-1BSD\s0 and BSD-like systems, although on most BSDs kqueue only |
|
|
1803 | supports some types of fds correctly (the only platform we found that |
|
|
1804 | supports ptys for example was NetBSD), so kqueue might be compiled in, but |
|
|
1805 | not be used unless explicitly requested. The best way to use it is to find |
|
|
1806 | out whether kqueue supports your type of fd properly and use an embedded |
|
|
1807 | kqueue loop. |
|
|
1808 | .IP "\s-1EV_USE_PORT\s0" 4 |
|
|
1809 | .IX Item "EV_USE_PORT" |
|
|
1810 | If defined to be \f(CW1\fR, libev will compile in support for the Solaris |
|
|
1811 | 10 port style backend. Its availability will be detected at runtime, |
|
|
1812 | otherwise another method will be used as fallback. This is the preferred |
|
|
1813 | backend for Solaris 10 systems. |
|
|
1814 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
|
|
1815 | .IX Item "EV_USE_DEVPOLL" |
|
|
1816 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
|
|
1817 | .IP "\s-1EV_H\s0" 4 |
|
|
1818 | .IX Item "EV_H" |
|
|
1819 | The name of the \fIev.h\fR header file used to include it. The default if |
|
|
1820 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
|
|
1821 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
|
|
1822 | .IP "\s-1EV_CONFIG_H\s0" 4 |
|
|
1823 | .IX Item "EV_CONFIG_H" |
|
|
1824 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
|
|
1825 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
|
|
1826 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
|
|
1827 | .IP "\s-1EV_EVENT_H\s0" 4 |
|
|
1828 | .IX Item "EV_EVENT_H" |
|
|
1829 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
|
|
1830 | of how the \fIevent.h\fR header can be found. |
|
|
1831 | .IP "\s-1EV_PROTOTYPES\s0" 4 |
|
|
1832 | .IX Item "EV_PROTOTYPES" |
|
|
1833 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
|
|
1834 | prototypes, but still define all the structs and other symbols. This is |
|
|
1835 | occasionally useful if you want to provide your own wrapper functions |
|
|
1836 | around libev functions. |
|
|
1837 | .IP "\s-1EV_MULTIPLICITY\s0" 4 |
|
|
1838 | .IX Item "EV_MULTIPLICITY" |
|
|
1839 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
|
|
1840 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
|
|
1841 | additional independent event loops. Otherwise there will be no support |
|
|
1842 | for multiple event loops and there is no first event loop pointer |
|
|
1843 | argument. Instead, all functions act on the single default loop. |
|
|
1844 | .IP "\s-1EV_PERIODICS\s0" 4 |
|
|
1845 | .IX Item "EV_PERIODICS" |
|
|
1846 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported, |
|
|
1847 | otherwise not. This saves a few kb of code. |
|
|
1848 | .IP "\s-1EV_COMMON\s0" 4 |
|
|
1849 | .IX Item "EV_COMMON" |
|
|
1850 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
|
|
1851 | this macro to a something else you can include more and other types of |
|
|
1852 | members. You have to define it each time you include one of the files, |
|
|
1853 | though, and it must be identical each time. |
|
|
1854 | .Sp |
|
|
1855 | For example, the perl \s-1EV\s0 module uses something like this: |
|
|
1856 | .Sp |
|
|
1857 | .Vb 3 |
|
|
1858 | \& #define EV_COMMON \e |
|
|
1859 | \& SV *self; /* contains this struct */ \e |
|
|
1860 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
|
|
1861 | .Ve |
|
|
1862 | .IP "\s-1EV_CB_DECLARE\s0 (type)" 4 |
|
|
1863 | .IX Item "EV_CB_DECLARE (type)" |
|
|
1864 | .PD 0 |
|
|
1865 | .IP "\s-1EV_CB_INVOKE\s0 (watcher, revents)" 4 |
|
|
1866 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
|
|
1867 | .IP "ev_set_cb (ev, cb)" 4 |
|
|
1868 | .IX Item "ev_set_cb (ev, cb)" |
|
|
1869 | .PD |
|
|
1870 | Can be used to change the callback member declaration in each watcher, |
|
|
1871 | and the way callbacks are invoked and set. Must expand to a struct member |
|
|
1872 | definition and a statement, respectively. See the \fIev.v\fR header file for |
|
|
1873 | their default definitions. One possible use for overriding these is to |
|
|
1874 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
|
|
1875 | method calls instead of plain function calls in \*(C+. |
|
|
1876 | .Sh "\s-1EXAMPLES\s0" |
|
|
1877 | .IX Subsection "EXAMPLES" |
|
|
1878 | For a real-world example of a program the includes libev |
|
|
1879 | verbatim, you can have a look at the \s-1EV\s0 perl module |
|
|
1880 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
|
|
1881 | the \fIlibev/\fR subdirectory and includes them in the \fI\s-1EV/EVAPI\s0.h\fR (public |
|
|
1882 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
|
|
1883 | will be compiled. It is pretty complex because it provides its own header |
|
|
1884 | file. |
|
|
1885 | .Sp |
|
|
1886 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
|
|
1887 | that everybody includes and which overrides some autoconf choices: |
|
|
1888 | .Sp |
|
|
1889 | .Vb 4 |
|
|
1890 | \& #define EV_USE_POLL 0 |
|
|
1891 | \& #define EV_MULTIPLICITY 0 |
|
|
1892 | \& #define EV_PERIODICS 0 |
|
|
1893 | \& #define EV_CONFIG_H <config.h> |
|
|
1894 | .Ve |
|
|
1895 | .Sp |
|
|
1896 | .Vb 1 |
|
|
1897 | \& #include "ev++.h" |
|
|
1898 | .Ve |
|
|
1899 | .Sp |
|
|
1900 | And a \fIev_cpp.C\fR implementation file that contains libev proper and is compiled: |
|
|
1901 | .Sp |
|
|
1902 | .Vb 2 |
|
|
1903 | \& #include "ev_cpp.h" |
|
|
1904 | \& #include "ev.c" |
|
|
1905 | .Ve |
|
|
1906 | .SH "COMPLEXITIES" |
|
|
1907 | .IX Header "COMPLEXITIES" |
|
|
1908 | In this section the complexities of (many of) the algorithms used inside |
|
|
1909 | libev will be explained. For complexity discussions about backends see the |
|
|
1910 | documentation for \f(CW\*(C`ev_default_init\*(C'\fR. |
|
|
1911 | .RS 4 |
|
|
1912 | .IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4 |
|
|
1913 | .IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" |
|
|
1914 | .PD 0 |
|
|
1915 | .IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4 |
|
|
1916 | .IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" |
|
|
1917 | .IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4 |
|
|
1918 | .IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)" |
|
|
1919 | .IP "Stopping check/prepare/idle watchers: O(1)" 4 |
|
|
1920 | .IX Item "Stopping check/prepare/idle watchers: O(1)" |
|
|
1921 | .IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" 4 |
|
|
1922 | .IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" |
|
|
1923 | .IP "Finding the next timer per loop iteration: O(1)" 4 |
|
|
1924 | .IX Item "Finding the next timer per loop iteration: O(1)" |
|
|
1925 | .IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4 |
|
|
1926 | .IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" |
|
|
1927 | .IP "Activating one watcher: O(1)" 4 |
|
|
1928 | .IX Item "Activating one watcher: O(1)" |
|
|
1929 | .RE |
|
|
1930 | .RS 4 |
|
|
1931 | .PD |
| 1434 | .SH "AUTHOR" |
1932 | .SH "AUTHOR" |
| 1435 | .IX Header "AUTHOR" |
1933 | .IX Header "AUTHOR" |
| 1436 | Marc Lehmann <libev@schmorp.de>. |
1934 | Marc Lehmann <libev@schmorp.de>. |
