… | |
… | |
8 | |
8 | |
9 | =head2 EXAMPLE PROGRAM |
9 | =head2 EXAMPLE PROGRAM |
10 | |
10 | |
11 | // a single header file is required |
11 | // a single header file is required |
12 | #include <ev.h> |
12 | #include <ev.h> |
|
|
13 | |
|
|
14 | #include <stdio.h> // for puts |
13 | |
15 | |
14 | // every watcher type has its own typedef'd struct |
16 | // every watcher type has its own typedef'd struct |
15 | // with the name ev_TYPE |
17 | // with the name ev_TYPE |
16 | ev_io stdin_watcher; |
18 | ev_io stdin_watcher; |
17 | ev_timer timeout_watcher; |
19 | ev_timer timeout_watcher; |
… | |
… | |
418 | starting a watcher (without re-setting it) also usually doesn't cause |
420 | starting a watcher (without re-setting it) also usually doesn't cause |
419 | extra overhead. A fork can both result in spurious notifications as well |
421 | extra overhead. A fork can both result in spurious notifications as well |
420 | as in libev having to destroy and recreate the epoll object, which can |
422 | as in libev having to destroy and recreate the epoll object, which can |
421 | take considerable time and thus should be avoided. |
423 | take considerable time and thus should be avoided. |
422 | |
424 | |
423 | All this means that, in practise, C<EVBACKEND_SELECT> can be as fast or |
425 | All this means that, in practice, C<EVBACKEND_SELECT> can be as fast or |
424 | faster then epoll for maybe up to a hundred file descriptors, depending on |
426 | faster than epoll for maybe up to a hundred file descriptors, depending on |
425 | the usage. So sad. |
427 | the usage. So sad. |
426 | |
428 | |
427 | While nominally embeddable in other event loops, this feature is broken in |
429 | While nominally embeddable in other event loops, this feature is broken in |
428 | all kernel versions tested so far. |
430 | all kernel versions tested so far. |
429 | |
431 | |
… | |
… | |
1419 | else |
1421 | else |
1420 | { |
1422 | { |
1421 | // callback was invoked, but there was some activity, re-arm |
1423 | // callback was invoked, but there was some activity, re-arm |
1422 | // the watcher to fire in last_activity + 60, which is |
1424 | // the watcher to fire in last_activity + 60, which is |
1423 | // guaranteed to be in the future, so "again" is positive: |
1425 | // guaranteed to be in the future, so "again" is positive: |
1424 | w->again = timeout - now; |
1426 | w->repeat = timeout - now; |
1425 | ev_timer_again (EV_A_ w); |
1427 | ev_timer_again (EV_A_ w); |
1426 | } |
1428 | } |
1427 | } |
1429 | } |
1428 | |
1430 | |
1429 | To summarise the callback: first calculate the real timeout (defined |
1431 | To summarise the callback: first calculate the real timeout (defined |
… | |
… | |
2997 | Tony Arcieri has written a ruby extension that offers access to a subset |
2999 | Tony Arcieri has written a ruby extension that offers access to a subset |
2998 | of the libev API and adds file handle abstractions, asynchronous DNS and |
3000 | of the libev API and adds file handle abstractions, asynchronous DNS and |
2999 | more on top of it. It can be found via gem servers. Its homepage is at |
3001 | more on top of it. It can be found via gem servers. Its homepage is at |
3000 | L<http://rev.rubyforge.org/>. |
3002 | L<http://rev.rubyforge.org/>. |
3001 | |
3003 | |
|
|
3004 | Roger Pack reports that using the link order C<-lws2_32 -lmsvcrt-ruby-190> |
|
|
3005 | makes rev work even on mingw. |
|
|
3006 | |
3002 | =item D |
3007 | =item D |
3003 | |
3008 | |
3004 | Leandro Lucarella has written a D language binding (F<ev.d>) for libev, to |
3009 | Leandro Lucarella has written a D language binding (F<ev.d>) for libev, to |
3005 | be found at L<http://proj.llucax.com.ar/wiki/evd>. |
3010 | be found at L<http://proj.llucax.com.ar/wiki/evd>. |
3006 | |
3011 | |
… | |
… | |
3182 | keeps libev from including F<config.h>, and it also defines dummy |
3187 | keeps libev from including F<config.h>, and it also defines dummy |
3183 | implementations for some libevent functions (such as logging, which is not |
3188 | implementations for some libevent functions (such as logging, which is not |
3184 | supported). It will also not define any of the structs usually found in |
3189 | supported). It will also not define any of the structs usually found in |
3185 | F<event.h> that are not directly supported by the libev core alone. |
3190 | F<event.h> that are not directly supported by the libev core alone. |
3186 | |
3191 | |
|
|
3192 | In stanbdalone mode, libev will still try to automatically deduce the |
|
|
3193 | configuration, but has to be more conservative. |
|
|
3194 | |
3187 | =item EV_USE_MONOTONIC |
3195 | =item EV_USE_MONOTONIC |
3188 | |
3196 | |
3189 | If defined to be C<1>, libev will try to detect the availability of the |
3197 | If defined to be C<1>, libev will try to detect the availability of the |
3190 | monotonic clock option at both compile time and runtime. Otherwise no use |
3198 | monotonic clock option at both compile time and runtime. Otherwise no |
3191 | of the monotonic clock option will be attempted. If you enable this, you |
3199 | use of the monotonic clock option will be attempted. If you enable this, |
3192 | usually have to link against librt or something similar. Enabling it when |
3200 | you usually have to link against librt or something similar. Enabling it |
3193 | the functionality isn't available is safe, though, although you have |
3201 | when the functionality isn't available is safe, though, although you have |
3194 | to make sure you link against any libraries where the C<clock_gettime> |
3202 | to make sure you link against any libraries where the C<clock_gettime> |
3195 | function is hiding in (often F<-lrt>). |
3203 | function is hiding in (often F<-lrt>). See also C<EV_USE_CLOCK_SYSCALL>. |
3196 | |
3204 | |
3197 | =item EV_USE_REALTIME |
3205 | =item EV_USE_REALTIME |
3198 | |
3206 | |
3199 | If defined to be C<1>, libev will try to detect the availability of the |
3207 | If defined to be C<1>, libev will try to detect the availability of the |
3200 | real-time clock option at compile time (and assume its availability at |
3208 | real-time clock option at compile time (and assume its availability at |
3201 | runtime if successful). Otherwise no use of the real-time clock option will |
3209 | runtime if successful). Otherwise no use of the real-time clock option will |
3202 | be attempted. This effectively replaces C<gettimeofday> by C<clock_get |
3210 | be attempted. This effectively replaces C<gettimeofday> by C<clock_get |
3203 | (CLOCK_REALTIME, ...)> and will not normally affect correctness. See the |
3211 | (CLOCK_REALTIME, ...)> and will not normally affect correctness. See the |
3204 | note about libraries in the description of C<EV_USE_MONOTONIC>, though. |
3212 | note about libraries in the description of C<EV_USE_MONOTONIC>, though. |
3205 | |
3213 | |
|
|
3214 | =item EV_USE_CLOCK_SYSCALL |
|
|
3215 | |
|
|
3216 | If defined to be C<1>, libev will try to use a direct syscall instead |
|
|
3217 | of calling the system-provided C<clock_gettime> function. This option |
|
|
3218 | exists because on GNU/Linux, C<clock_gettime> is in C<librt>, but C<librt> |
|
|
3219 | unconditionally pulls in C<libpthread>, slowing down single-threaded |
|
|
3220 | programs needlessly. Using a direct syscall is slightly slower, because |
|
|
3221 | no optimised vdso implementation can be used, but avoids the pthread |
|
|
3222 | dependency. Defaults to C<1> on GNU/Linux with glibc 2.x or higher. |
|
|
3223 | |
3206 | =item EV_USE_NANOSLEEP |
3224 | =item EV_USE_NANOSLEEP |
3207 | |
3225 | |
3208 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
3226 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
3209 | and will use it for delays. Otherwise it will use C<select ()>. |
3227 | and will use it for delays. Otherwise it will use C<select ()>. |
3210 | |
3228 | |
… | |
… | |
3225 | |
3243 | |
3226 | =item EV_SELECT_USE_FD_SET |
3244 | =item EV_SELECT_USE_FD_SET |
3227 | |
3245 | |
3228 | If defined to C<1>, then the select backend will use the system C<fd_set> |
3246 | If defined to C<1>, then the select backend will use the system C<fd_set> |
3229 | structure. This is useful if libev doesn't compile due to a missing |
3247 | structure. This is useful if libev doesn't compile due to a missing |
3230 | C<NFDBITS> or C<fd_mask> definition or it mis-guesses the bitset layout on |
3248 | C<NFDBITS> or C<fd_mask> definition or it mis-guesses the bitset layout |
3231 | exotic systems. This usually limits the range of file descriptors to some |
3249 | on exotic systems. This usually limits the range of file descriptors to |
3232 | low limit such as 1024 or might have other limitations (winsocket only |
3250 | some low limit such as 1024 or might have other limitations (winsocket |
3233 | allows 64 sockets). The C<FD_SETSIZE> macro, set before compilation, might |
3251 | only allows 64 sockets). The C<FD_SETSIZE> macro, set before compilation, |
3234 | influence the size of the C<fd_set> used. |
3252 | configures the maximum size of the C<fd_set>. |
3235 | |
3253 | |
3236 | =item EV_SELECT_IS_WINSOCKET |
3254 | =item EV_SELECT_IS_WINSOCKET |
3237 | |
3255 | |
3238 | When defined to C<1>, the select backend will assume that |
3256 | When defined to C<1>, the select backend will assume that |
3239 | select/socket/connect etc. don't understand file descriptors but |
3257 | select/socket/connect etc. don't understand file descriptors but |