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Comparing libev/ev.pod (file contents):
Revision 1.323 by root, Sun Oct 24 18:01:26 2010 UTC vs.
Revision 1.333 by root, Mon Oct 25 09:31:47 2010 UTC

300An event loop is described by a C<struct ev_loop *> (the C<struct> is 300An event loop is described by a C<struct ev_loop *> (the C<struct> is
301I<not> optional in this case unless libev 3 compatibility is disabled, as 301I<not> optional in this case unless libev 3 compatibility is disabled, as
302libev 3 had an C<ev_loop> function colliding with the struct name). 302libev 3 had an C<ev_loop> function colliding with the struct name).
303 303
304The library knows two types of such loops, the I<default> loop, which 304The library knows two types of such loops, the I<default> loop, which
305supports signals and child events, and dynamically created event loops 305supports child process events, and dynamically created event loops which
306which do not. 306do not.
307 307
308=over 4 308=over 4
309 309
310=item struct ev_loop *ev_default_loop (unsigned int flags) 310=item struct ev_loop *ev_default_loop (unsigned int flags)
311 311
1112=item C<EV_FORK> 1112=item C<EV_FORK>
1113 1113
1114The event loop has been resumed in the child process after fork (see 1114The event loop has been resumed in the child process after fork (see
1115C<ev_fork>). 1115C<ev_fork>).
1116 1116
1117=item C<EV_CLEANUP>
1118
1119The event loop is about to be destroyed (see C<ev_cleanup>).
1120
1117=item C<EV_ASYNC> 1121=item C<EV_ASYNC>
1118 1122
1119The given async watcher has been asynchronously notified (see C<ev_async>). 1123The given async watcher has been asynchronously notified (see C<ev_async>).
1120 1124
1121=item C<EV_CUSTOM> 1125=item C<EV_CUSTOM>
3090 3094
3091=head3 Watcher-Specific Functions and Data Members 3095=head3 Watcher-Specific Functions and Data Members
3092 3096
3093=over 4 3097=over 4
3094 3098
3095=item ev_fork_init (ev_signal *, callback) 3099=item ev_fork_init (ev_fork *, callback)
3096 3100
3097Initialises and configures the fork watcher - it has no parameters of any 3101Initialises and configures the fork watcher - it has no parameters of any
3098kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, 3102kind. There is a C<ev_fork_set> macro, but using it is utterly pointless,
3099believe me. 3103really.
3100 3104
3101=back 3105=back
3106
3107
3108=head2 C<ev_cleanup> - even the best things end
3109
3110Cleanup watchers are called just before the event loop is being destroyed
3111by a call to C<ev_loop_destroy>.
3112
3113While there is no guarantee that the event loop gets destroyed, cleanup
3114watchers provide a convenient method to install cleanup hooks for your
3115program, worker threads and so on - you just to make sure to destroy the
3116loop when you want them to be invoked.
3117
3118Cleanup watchers are invoked in the same way as any other watcher. Unlike
3119all other watchers, they do not keep a reference to the event loop (which
3120makes a lot of sense if you think about it). Like all other watchers, you
3121can call libev functions in the callback, except C<ev_cleanup_start>.
3122
3123=head3 Watcher-Specific Functions and Data Members
3124
3125=over 4
3126
3127=item ev_cleanup_init (ev_cleanup *, callback)
3128
3129Initialises and configures the cleanup watcher - it has no parameters of
3130any kind. There is a C<ev_cleanup_set> macro, but using it is utterly
3131pointless, I assure you.
3132
3133=back
3134
3135Example: Register an atexit handler to destroy the default loop, so any
3136cleanup functions are called.
3137
3138 static void
3139 program_exits (void)
3140 {
3141 ev_loop_destroy (EV_DEFAULT_UC);
3142 }
3143
3144 ...
3145 atexit (program_exits);
3102 3146
3103 3147
3104=head2 C<ev_async> - how to wake up an event loop 3148=head2 C<ev_async> - how to wake up an event loop
3105 3149
3106In general, you cannot use an C<ev_run> from multiple threads or other 3150In general, you cannot use an C<ev_run> from multiple threads or other
4713structure (guaranteed by POSIX but not by ISO C for example), but it also 4757structure (guaranteed by POSIX but not by ISO C for example), but it also
4714assumes that the same (machine) code can be used to call any watcher 4758assumes that the same (machine) code can be used to call any watcher
4715callback: The watcher callbacks have different type signatures, but libev 4759callback: The watcher callbacks have different type signatures, but libev
4716calls them using an C<ev_watcher *> internally. 4760calls them using an C<ev_watcher *> internally.
4717 4761
4762=item pointer accesses must be thread-atomic
4763
4764Accessing a pointer value must be atomic, it must both be readable and
4765writable in one piece - this is the case on all current architectures.
4766
4718=item C<sig_atomic_t volatile> must be thread-atomic as well 4767=item C<sig_atomic_t volatile> must be thread-atomic as well
4719 4768
4720The type C<sig_atomic_t volatile> (or whatever is defined as 4769The type C<sig_atomic_t volatile> (or whatever is defined as
4721C<EV_ATOMIC_T>) must be atomic with respect to accesses from different 4770C<EV_ATOMIC_T>) must be atomic with respect to accesses from different
4722threads. This is not part of the specification for C<sig_atomic_t>, but is 4771threads. This is not part of the specification for C<sig_atomic_t>, but is
4828=back 4877=back
4829 4878
4830 4879
4831=head1 PORTING FROM LIBEV 3.X TO 4.X 4880=head1 PORTING FROM LIBEV 3.X TO 4.X
4832 4881
4833The major version 4 introduced some minor incompatible changes to the API. 4882The major version 4 introduced some incompatible changes to the API.
4834 4883
4835At the moment, the C<ev.h> header file tries to implement superficial 4884At the moment, the C<ev.h> header file provides compatibility definitions
4836compatibility, so most programs should still compile. Those might be 4885for all changes, so most programs should still compile. The compatibility
4837removed in later versions of libev, so better update early than late. 4886layer might be removed in later versions of libev, so better update to the
4887new API early than late.
4838 4888
4839=over 4 4889=over 4
4840 4890
4891=item C<EV_COMPAT3> backwards compatibility mechanism
4892
4893The backward compatibility mechanism can be controlled by
4894C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
4895section.
4896
4841=item C<ev_default_destroy> and C<ev_default_fork> have been removed 4897=item C<ev_default_destroy> and C<ev_default_fork> have been removed
4842 4898
4843These calls can be replaced easily by their C<ev_loop_xxx> counterparts: 4899These calls can be replaced easily by their C<ev_loop_xxx> counterparts:
4844 4900
4845 ev_loop_destroy (EV_DEFAULT); 4901 ev_loop_destroy (EV_DEFAULT_UC);
4846 ev_loop_fork (EV_DEFAULT); 4902 ev_loop_fork (EV_DEFAULT);
4847 4903
4848=item function/symbol renames 4904=item function/symbol renames
4849 4905
4850A number of functions and symbols have been renamed: 4906A number of functions and symbols have been renamed:
4870ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme 4926ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme
4871as all other watcher types. Note that C<ev_loop_fork> is still called 4927as all other watcher types. Note that C<ev_loop_fork> is still called
4872C<ev_loop_fork> because it would otherwise clash with the C<ev_fork> 4928C<ev_loop_fork> because it would otherwise clash with the C<ev_fork>
4873typedef. 4929typedef.
4874 4930
4875=item C<EV_COMPAT3> backwards compatibility mechanism
4876
4877The backward compatibility mechanism can be controlled by
4878C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
4879section.
4880
4881=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES> 4931=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>
4882 4932
4883The preprocessor symbol C<EV_MINIMAL> has been replaced by a different 4933The preprocessor symbol C<EV_MINIMAL> has been replaced by a different
4884mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile 4934mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile
4885and work, but the library code will of course be larger. 4935and work, but the library code will of course be larger.
4959 5009
4960=back 5010=back
4961 5011
4962=head1 AUTHOR 5012=head1 AUTHOR
4963 5013
4964Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson. 5014Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael
5015Magnusson and Emanuele Giaquinta.
4965 5016

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