… | |
… | |
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 |
… | |
… | |
717 | 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, |
718 | 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 |
719 | 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 |
720 | 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 |
721 | programs, though, so beware. |
721 | programs, though, so beware. |
722 | .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" |
723 | .IX Subsection "SUMMARY OF GENERIC WATCHER FUNCTIONS" |
723 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
724 | 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, |
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. |
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. |
726 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
726 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
727 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
727 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
728 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
728 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
… | |
… | |
734 | which rolls both calls into one. |
734 | which rolls both calls into one. |
735 | .Sp |
735 | .Sp |
736 | 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 |
737 | (or never started) and there are no pending events outstanding. |
737 | (or never started) and there are no pending events outstanding. |
738 | .Sp |
738 | .Sp |
739 | 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, |
740 | int revents)\*(C'\fR. |
740 | int revents)\*(C'\fR. |
741 | .ie n .IP """ev_TYPE_set"" (ev_TYPE *, [args])" 4 |
741 | .ie n .IP """ev_TYPE_set"" (ev_TYPE *, [args])" 4 |
742 | .el .IP "\f(CWev_TYPE_set\fR (ev_TYPE *, [args])" 4 |
742 | .el .IP "\f(CWev_TYPE_set\fR (ev_TYPE *, [args])" 4 |
743 | .IX Item "ev_TYPE_set (ev_TYPE *, [args])" |
743 | .IX Item "ev_TYPE_set (ev_TYPE *, [args])" |
744 | 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 |
… | |
… | |
822 | have been omitted.... |
822 | have been omitted.... |
823 | .SH "WATCHER TYPES" |
823 | .SH "WATCHER TYPES" |
824 | .IX Header "WATCHER TYPES" |
824 | .IX Header "WATCHER TYPES" |
825 | This section describes each watcher in detail, but will not repeat |
825 | This section describes each watcher in detail, but will not repeat |
826 | information given in the last section. |
826 | information given in the last section. |
827 | .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?" |
828 | .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?" |
829 | .IX Subsection "ev_io - is this file descriptor readable or writable" |
829 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
830 | 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 |
831 | in each iteration of the event loop (This behaviour is called |
831 | in each iteration of the event loop, or, more precisely, when reading |
832 | 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 |
833 | 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 |
834 | 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. |
835 | .PP |
837 | .PP |
836 | 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 |
837 | 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 |
838 | 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 |
839 | required if you know what you are doing). |
841 | required if you know what you are doing). |
840 | .PP |
842 | .PP |
841 | 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 |
842 | (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 |
843 | 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 |
844 | 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 |
845 | the same underlying \*(L"file open\*(R"). |
847 | the same underlying \*(L"file open\*(R"). |
846 | .PP |
848 | .PP |
847 | 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 |
848 | (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 |
849 | \&\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). |
850 | .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 |
851 | .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)" |
852 | .PD 0 |
869 | .PD 0 |
853 | .IP "ev_io_set (ev_io *, int fd, int events)" 4 |
870 | .IP "ev_io_set (ev_io *, int fd, int events)" 4 |
854 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
871 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
855 | .PD |
872 | .PD |
856 | 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 |
857 | 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 |
858 | EV_WRITE\*(C'\fR to receive the given events. |
875 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
859 | .Sp |
|
|
860 | Please note that most of the more scalable backend mechanisms (for example |
|
|
861 | epoll and solaris ports) can result in spurious readyness notifications |
|
|
862 | for file descriptors, so you practically need to use non-blocking I/O (and |
|
|
863 | treat callback invocation as hint only), or retest separately with a safe |
|
|
864 | interface before doing I/O (XLib can do this), or force the use of either |
|
|
865 | \&\f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR, which don't suffer from this |
|
|
866 | problem. Also note that it is quite easy to have your callback invoked |
|
|
867 | when the readyness condition is no longer valid even when employing |
|
|
868 | typical ways of handling events, so its a good idea to use non-blocking |
|
|
869 | I/O unconditionally. |
|
|
870 | .PP |
876 | .PP |
871 | 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 |
872 | 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 |
873 | attempt to read a whole line in the callback: |
879 | attempt to read a whole line in the callback: |
874 | .PP |
880 | .PP |
… | |
… | |
887 | \& struct ev_io stdin_readable; |
893 | \& struct ev_io stdin_readable; |
888 | \& 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); |
889 | \& ev_io_start (loop, &stdin_readable); |
895 | \& ev_io_start (loop, &stdin_readable); |
890 | \& ev_loop (loop, 0); |
896 | \& ev_loop (loop, 0); |
891 | .Ve |
897 | .Ve |
892 | .ie n .Sh """ev_timer"" \- relative and optionally recurring timeouts" |
898 | .ie n .Sh """ev_timer"" \- relative and optionally repeating timeouts" |
893 | .el .Sh "\f(CWev_timer\fP \- relative and optionally recurring timeouts" |
899 | .el .Sh "\f(CWev_timer\fP \- relative and optionally repeating timeouts" |
894 | .IX Subsection "ev_timer - relative and optionally recurring timeouts" |
900 | .IX Subsection "ev_timer - relative and optionally repeating timeouts" |
895 | 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 |
896 | given time, and optionally repeating in regular intervals after that. |
902 | given time, and optionally repeating in regular intervals after that. |
897 | .PP |
903 | .PP |
898 | 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 |
899 | 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 |
… | |
… | |
986 | .Vb 3 |
992 | .Vb 3 |
987 | \& // 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": |
988 | \& // reset the timeout to start ticking again at 10 seconds |
994 | \& // reset the timeout to start ticking again at 10 seconds |
989 | \& ev_timer_again (&mytimer); |
995 | \& ev_timer_again (&mytimer); |
990 | .Ve |
996 | .Ve |
991 | .ie n .Sh """ev_periodic"" \- to cron or not to cron" |
997 | .ie n .Sh """ev_periodic"" \- to cron or not to cron?" |
992 | .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?" |
993 | .IX Subsection "ev_periodic - to cron or not to cron" |
999 | .IX Subsection "ev_periodic - to cron or not to cron?" |
994 | 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 |
995 | (and unfortunately a bit complex). |
1001 | (and unfortunately a bit complex). |
996 | .PP |
1002 | .PP |
997 | 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) |
998 | 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 |
… | |
… | |
1132 | \& struct ev_periodic hourly_tick; |
1138 | \& struct ev_periodic hourly_tick; |
1133 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1139 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1134 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1140 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1135 | \& ev_periodic_start (loop, &hourly_tick); |
1141 | \& ev_periodic_start (loop, &hourly_tick); |
1136 | .Ve |
1142 | .Ve |
1137 | .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!" |
1138 | .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!" |
1139 | .IX Subsection "ev_signal - signal me when a signal gets signalled" |
1145 | .IX Subsection "ev_signal - signal me when a signal gets signalled!" |
1140 | 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 |
1141 | 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 |
1142 | 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 |
1143 | normal event processing, like any other event. |
1149 | normal event processing, like any other event. |
1144 | .PP |
1150 | .PP |
… | |
… | |
1154 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1160 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1155 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1161 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1156 | .PD |
1162 | .PD |
1157 | 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 |
1158 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
1164 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
1159 | .ie n .Sh """ev_child"" \- wait for pid status changes" |
1165 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1160 | .el .Sh "\f(CWev_child\fP \- wait for pid status changes" |
1166 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1161 | .IX Subsection "ev_child - wait for pid status changes" |
1167 | .IX Subsection "ev_child - watch out for process status changes" |
1162 | 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 |
1163 | 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). |
1164 | .IP "ev_child_init (ev_child *, callback, int pid)" 4 |
1170 | .IP "ev_child_init (ev_child *, callback, int pid)" 4 |
1165 | .IX Item "ev_child_init (ev_child *, callback, int pid)" |
1171 | .IX Item "ev_child_init (ev_child *, callback, int pid)" |
1166 | .PD 0 |
1172 | .PD 0 |
… | |
… | |
1187 | .Vb 3 |
1193 | .Vb 3 |
1188 | \& struct ev_signal signal_watcher; |
1194 | \& struct ev_signal signal_watcher; |
1189 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1195 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1190 | \& ev_signal_start (loop, &sigint_cb); |
1196 | \& ev_signal_start (loop, &sigint_cb); |
1191 | .Ve |
1197 | .Ve |
1192 | .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..." |
1193 | .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..." |
1194 | .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..." |
1195 | 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 |
1196 | (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 |
1197 | 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, |
1198 | 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 |
1199 | 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 \- |
… | |
… | |
1229 | .Vb 3 |
1235 | .Vb 3 |
1230 | \& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1236 | \& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1231 | \& ev_idle_init (idle_watcher, idle_cb); |
1237 | \& ev_idle_init (idle_watcher, idle_cb); |
1232 | \& ev_idle_start (loop, idle_cb); |
1238 | \& ev_idle_start (loop, idle_cb); |
1233 | .Ve |
1239 | .Ve |
1234 | .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!" |
1235 | .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!" |
1236 | .IX Subsection "ev_prepare and ev_check - customise your event loop" |
1242 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
1237 | 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: |
1238 | prepare watchers get invoked before the process blocks and check watchers |
1244 | prepare watchers get invoked before the process blocks and check watchers |
1239 | afterwards. |
1245 | afterwards. |
1240 | .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 |
1241 | 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 |
1242 | 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 |
1243 | variable changes, implement your own watchers, integrate net-snmp or a |
1257 | variable changes, implement your own watchers, integrate net-snmp or a |
1244 | 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). |
1245 | .PP |
1262 | .PP |
1246 | 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 |
1247 | 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 |
1248 | 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 |
1249 | 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 |
… | |
… | |
1268 | .PD |
1285 | .PD |
1269 | Initialises and configures the prepare or check watcher \- they have no |
1286 | Initialises and configures the prepare or check watcher \- they have no |
1270 | 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 |
1271 | macros, but using them is utterly, utterly and completely pointless. |
1288 | macros, but using them is utterly, utterly and completely pointless. |
1272 | .PP |
1289 | .PP |
1273 | 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 8 |
|
|
1301 | \& static void |
|
|
1302 | \& io_cb (ev_loop *loop, ev_io *w, int revents) |
|
|
1303 | \& { |
|
|
1304 | \& // set the relevant poll flags |
|
|
1305 | \& struct pollfd *fd = (struct pollfd *)w->data; |
|
|
1306 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
|
|
1307 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
|
|
1308 | \& } |
|
|
1309 | .Ve |
|
|
1310 | .PP |
|
|
1311 | .Vb 7 |
|
|
1312 | \& // create io watchers for each fd and a timer before blocking |
|
|
1313 | \& static void |
|
|
1314 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
|
|
1315 | \& { |
|
|
1316 | \& int timeout = 3600000;truct pollfd fds [nfd]; |
|
|
1317 | \& // actual code will need to loop here and realloc etc. |
|
|
1318 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
|
|
1319 | .Ve |
|
|
1320 | .PP |
|
|
1321 | .Vb 3 |
|
|
1322 | \& /* the callback is illegal, but won't be called as we stop during check */ |
|
|
1323 | \& ev_timer_init (&tw, 0, timeout * 1e-3); |
|
|
1324 | \& ev_timer_start (loop, &tw); |
|
|
1325 | .Ve |
|
|
1326 | .PP |
|
|
1327 | .Vb 6 |
|
|
1328 | \& // create on ev_io per pollfd |
|
|
1329 | \& for (int i = 0; i < nfd; ++i) |
|
|
1330 | \& { |
|
|
1331 | \& ev_io_init (iow + i, io_cb, fds [i].fd, |
|
|
1332 | \& ((fds [i].events & POLLIN ? EV_READ : 0) |
|
|
1333 | \& | (fds [i].events & POLLOUT ? EV_WRITE : 0))); |
|
|
1334 | .Ve |
|
|
1335 | .PP |
|
|
1336 | .Vb 5 |
|
|
1337 | \& fds [i].revents = 0; |
|
|
1338 | \& iow [i].data = fds + i; |
|
|
1339 | \& ev_io_start (loop, iow + i); |
|
|
1340 | \& } |
|
|
1341 | \& } |
|
|
1342 | .Ve |
|
|
1343 | .PP |
|
|
1344 | .Vb 5 |
|
|
1345 | \& // stop all watchers after blocking |
|
|
1346 | \& static void |
|
|
1347 | \& adns_check_cb (ev_loop *loop, ev_check *w, int revents) |
|
|
1348 | \& { |
|
|
1349 | \& ev_timer_stop (loop, &tw); |
|
|
1350 | .Ve |
|
|
1351 | .PP |
|
|
1352 | .Vb 2 |
|
|
1353 | \& for (int i = 0; i < nfd; ++i) |
|
|
1354 | \& ev_io_stop (loop, iow + i); |
|
|
1355 | .Ve |
|
|
1356 | .PP |
|
|
1357 | .Vb 2 |
|
|
1358 | \& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop)); |
|
|
1359 | \& } |
|
|
1360 | .Ve |
1274 | .ie n .Sh """ev_embed"" \- when one backend isn't enough" |
1361 | .ie n .Sh """ev_embed"" \- when one backend isn't enough..." |
1275 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough" |
1362 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..." |
1276 | .IX Subsection "ev_embed - when one backend isn't enough" |
1363 | .IX Subsection "ev_embed - when one backend isn't enough..." |
1277 | This is a rather advanced watcher type that lets you embed one event loop |
1364 | This is a rather advanced watcher type that lets you embed one event loop |
1278 | into another (currently only \f(CW\*(C`ev_io\*(C'\fR events are supported in the embedded |
1365 | into another (currently only \f(CW\*(C`ev_io\*(C'\fR events are supported in the embedded |
1279 | loop, other types of watchers might be handled in a delayed or incorrect |
1366 | loop, other types of watchers might be handled in a delayed or incorrect |
1280 | fashion and must not be used). |
1367 | fashion and must not be used). |
1281 | .PP |
1368 | .PP |
… | |
… | |
1593 | .Vb 1 |
1680 | .Vb 1 |
1594 | \& ev_win32.c required on win32 platforms only |
1681 | \& ev_win32.c required on win32 platforms only |
1595 | .Ve |
1682 | .Ve |
1596 | .PP |
1683 | .PP |
1597 | .Vb 5 |
1684 | .Vb 5 |
1598 | \& ev_select.c only when select backend is enabled (which is is by default) |
1685 | \& ev_select.c only when select backend is enabled (which is by default) |
1599 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
1686 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
1600 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1687 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1601 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1688 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1602 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
1689 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
1603 | .Ve |
1690 | .Ve |
1604 | .PP |
1691 | .PP |
1605 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
1692 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
1606 | to compile a single file. |
1693 | to compile this single file. |
1607 | .PP |
1694 | .PP |
1608 | \fI\s-1LIBEVENT\s0 \s-1COMPATIBILITY\s0 \s-1API\s0\fR |
1695 | \fI\s-1LIBEVENT\s0 \s-1COMPATIBILITY\s0 \s-1API\s0\fR |
1609 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
1696 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
1610 | .PP |
1697 | .PP |
1611 | To include the libevent compatibility \s-1API\s0, also include: |
1698 | To include the libevent compatibility \s-1API\s0, also include: |
… | |
… | |
1632 | \fI\s-1AUTOCONF\s0 \s-1SUPPORT\s0\fR |
1719 | \fI\s-1AUTOCONF\s0 \s-1SUPPORT\s0\fR |
1633 | .IX Subsection "AUTOCONF SUPPORT" |
1720 | .IX Subsection "AUTOCONF SUPPORT" |
1634 | .PP |
1721 | .PP |
1635 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your config in |
1722 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your config in |
1636 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
1723 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
1637 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR off. \fIev.c\fR will then include |
1724 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR undefined. \fIev.c\fR will then |
1638 | \&\fIconfig.h\fR and configure itself accordingly. |
1725 | include \fIconfig.h\fR and configure itself accordingly. |
1639 | .PP |
1726 | .PP |
1640 | For this of course you need the m4 file: |
1727 | For this of course you need the m4 file: |
1641 | .PP |
1728 | .PP |
1642 | .Vb 1 |
1729 | .Vb 1 |
1643 | \& libev.m4 |
1730 | \& libev.m4 |
… | |
… | |
1713 | otherwise another method will be used as fallback. This is the preferred |
1800 | otherwise another method will be used as fallback. This is the preferred |
1714 | backend for \s-1BSD\s0 and BSD-like systems, although on most BSDs kqueue only |
1801 | backend for \s-1BSD\s0 and BSD-like systems, although on most BSDs kqueue only |
1715 | supports some types of fds correctly (the only platform we found that |
1802 | supports some types of fds correctly (the only platform we found that |
1716 | supports ptys for example was NetBSD), so kqueue might be compiled in, but |
1803 | supports ptys for example was NetBSD), so kqueue might be compiled in, but |
1717 | not be used unless explicitly requested. The best way to use it is to find |
1804 | not be used unless explicitly requested. The best way to use it is to find |
1718 | out wether kqueue supports your type of fd properly and use an embedded |
1805 | out whether kqueue supports your type of fd properly and use an embedded |
1719 | kqueue loop. |
1806 | kqueue loop. |
1720 | .IP "\s-1EV_USE_PORT\s0" 4 |
1807 | .IP "\s-1EV_USE_PORT\s0" 4 |
1721 | .IX Item "EV_USE_PORT" |
1808 | .IX Item "EV_USE_PORT" |
1722 | If defined to be \f(CW1\fR, libev will compile in support for the Solaris |
1809 | If defined to be \f(CW1\fR, libev will compile in support for the Solaris |
1723 | 10 port style backend. Its availability will be detected at runtime, |
1810 | 10 port style backend. Its availability will be detected at runtime, |
… | |
… | |
1769 | .Vb 3 |
1856 | .Vb 3 |
1770 | \& #define EV_COMMON \e |
1857 | \& #define EV_COMMON \e |
1771 | \& SV *self; /* contains this struct */ \e |
1858 | \& SV *self; /* contains this struct */ \e |
1772 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
1859 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
1773 | .Ve |
1860 | .Ve |
1774 | .IP "\s-1EV_CB_DECLARE\s0(type)" 4 |
1861 | .IP "\s-1EV_CB_DECLARE\s0 (type)" 4 |
1775 | .IX Item "EV_CB_DECLARE(type)" |
1862 | .IX Item "EV_CB_DECLARE (type)" |
1776 | .PD 0 |
1863 | .PD 0 |
1777 | .IP "\s-1EV_CB_INVOKE\s0(watcher,revents)" 4 |
1864 | .IP "\s-1EV_CB_INVOKE\s0 (watcher, revents)" 4 |
1778 | .IX Item "EV_CB_INVOKE(watcher,revents)" |
1865 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
1779 | .IP "ev_set_cb(ev,cb)" 4 |
1866 | .IP "ev_set_cb (ev, cb)" 4 |
1780 | .IX Item "ev_set_cb(ev,cb)" |
1867 | .IX Item "ev_set_cb (ev, cb)" |
1781 | .PD |
1868 | .PD |
1782 | Can be used to change the callback member declaration in each watcher, |
1869 | Can be used to change the callback member declaration in each watcher, |
1783 | and the way callbacks are invoked and set. Must expand to a struct member |
1870 | and the way callbacks are invoked and set. Must expand to a struct member |
1784 | definition and a statement, respectively. See the \fIev.v\fR header file for |
1871 | definition and a statement, respectively. See the \fIev.v\fR header file for |
1785 | their default definitions. One possible use for overriding these is to |
1872 | their default definitions. One possible use for overriding these is to |
1786 | avoid the ev_loop pointer as first argument in all cases, or to use method |
1873 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
1787 | calls instead of plain function calls in \*(C+. |
1874 | method calls instead of plain function calls in \*(C+. |
1788 | .Sh "\s-1EXAMPLES\s0" |
1875 | .Sh "\s-1EXAMPLES\s0" |
1789 | .IX Subsection "EXAMPLES" |
1876 | .IX Subsection "EXAMPLES" |
1790 | For a real-world example of a program the includes libev |
1877 | For a real-world example of a program the includes libev |
1791 | verbatim, you can have a look at the \s-1EV\s0 perl module |
1878 | verbatim, you can have a look at the \s-1EV\s0 perl module |
1792 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
1879 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
… | |
… | |
1797 | .Sp |
1884 | .Sp |
1798 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
1885 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
1799 | that everybody includes and which overrides some autoconf choices: |
1886 | that everybody includes and which overrides some autoconf choices: |
1800 | .Sp |
1887 | .Sp |
1801 | .Vb 4 |
1888 | .Vb 4 |
1802 | \& #define EV_USE_POLL 0 |
1889 | \& #define EV_USE_POLL 0 |
1803 | \& #define EV_MULTIPLICITY 0 |
1890 | \& #define EV_MULTIPLICITY 0 |
1804 | \& #define EV_PERIODICS 0 |
1891 | \& #define EV_PERIODICS 0 |
1805 | \& #define EV_CONFIG_H <config.h> |
1892 | \& #define EV_CONFIG_H <config.h> |
1806 | .Ve |
1893 | .Ve |
1807 | .Sp |
1894 | .Sp |
1808 | .Vb 1 |
1895 | .Vb 1 |
1809 | \& #include "ev++.h" |
1896 | \& #include "ev++.h" |
1810 | .Ve |
1897 | .Ve |
1811 | .Sp |
1898 | .Sp |
1812 | And a \fIev_cpp.C\fR implementation file that contains libev proper and is compiled: |
1899 | And a \fIev_cpp.C\fR implementation file that contains libev proper and is compiled: |
1813 | .Sp |
1900 | .Sp |
1814 | .Vb 1 |
|
|
1815 | \& #include "rxvttoolkit.h" |
|
|
1816 | .Ve |
|
|
1817 | .Sp |
|
|
1818 | .Vb 2 |
1901 | .Vb 2 |
1819 | \& /* darwin has problems with its header files in C++, requiring this namespace juggling */ |
1902 | \& #include "ev_cpp.h" |
1820 | \& using namespace ev; |
|
|
1821 | .Ve |
|
|
1822 | .Sp |
|
|
1823 | .Vb 1 |
|
|
1824 | \& #include "ev.c" |
1903 | \& #include "ev.c" |
1825 | .Ve |
1904 | .Ve |
1826 | .SH "AUTHOR" |
1905 | .SH "AUTHOR" |
1827 | .IX Header "AUTHOR" |
1906 | .IX Header "AUTHOR" |
1828 | Marc Lehmann <libev@schmorp.de>. |
1907 | Marc Lehmann <libev@schmorp.de>. |