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Comparing libev/ev.pod (file contents):
Revision 1.126 by root, Fri Feb 1 13:46:26 2008 UTC vs.
Revision 1.128 by root, Fri Feb 1 13:53:56 2008 UTC

… …
2697=item EV_ATOMIC_T 2697=item EV_ATOMIC_T
2698 2698
2699Libev requires an integer type (suitable for storing C<0> or C<1>) whose 2699Libev requires an integer type (suitable for storing C<0> or C<1>) whose
2700access is atomic with respect to other threads or signal contexts. No such 2700access is atomic with respect to other threads or signal contexts. No such
2701type is easily found in the C language, so you can provide your own type 2701type is easily found in the C language, so you can provide your own type
2702that you know is safe for your purposes. 2702that you know is safe for your purposes. It is used both for signal handler "locking"
2703as well as for signal and thread safety in C<ev_async> watchers.
2703 2704
2704In the absense of this define, libev will use C<sig_atomic_t volatile> 2705In the absense of this define, libev will use C<sig_atomic_t volatile>
2705(from F<signal.h>), which is usually good enough on most platforms. 2706(from F<signal.h>), which is usually good enough on most platforms.
2706 2707
2707=item EV_H 2708=item EV_H
… …
2911=item Changing timer/periodic watchers (by autorepeat or calling again): O(log skipped_other_timers) 2912=item Changing timer/periodic watchers (by autorepeat or calling again): O(log skipped_other_timers)
2912 2913
2913That means that changing a timer costs less than removing/adding them 2914That means that changing a timer costs less than removing/adding them
2914as only the relative motion in the event queue has to be paid for. 2915as only the relative motion in the event queue has to be paid for.
2915 2916
2916=item Starting io/check/prepare/idle/signal/child watchers: O(1) 2917=item Starting io/check/prepare/idle/signal/child/fork/async watchers: O(1)
2917 2918
2918These just add the watcher into an array or at the head of a list. 2919These just add the watcher into an array or at the head of a list.
2919 2920
2920=item Stopping check/prepare/idle watchers: O(1) 2921=item Stopping check/prepare/idle/fork/async watchers: O(1)
2921 2922
2922=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) 2923=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))
2923 2924
2924These watchers are stored in lists then need to be walked to find the 2925These watchers are stored in lists then need to be walked to find the
2925correct watcher to remove. The lists are usually short (you don't usually 2926correct watcher to remove. The lists are usually short (you don't usually
… …
2942 2943
2943Priorities are implemented by allocating some space for each 2944Priorities are implemented by allocating some space for each
2944priority. When doing priority-based operations, libev usually has to 2945priority. When doing priority-based operations, libev usually has to
2945linearly search all the priorities, but starting/stopping and activating 2946linearly search all the priorities, but starting/stopping and activating
2946watchers becomes O(1) w.r.t. prioritiy handling. 2947watchers becomes O(1) w.r.t. prioritiy handling.
2948
2949=item Sending an ev_async: O(1)
2950
2951=item Processing ev_async_send: O(number_of_async_watchers)
2952
2953=item Processing signals: O(max_signal_number)
2954
2955Sending involves a syscall I<iff> there were no other C<ev_async_send>
2956calls in the current loop iteration. Checking for async and signal events
2957involves iterating over all running async watchers or all signal numbers.
2947 2958
2948=back 2959=back
2949 2960
2950 2961
2951=head1 Win32 platform limitations and workarounds 2962=head1 Win32 platform limitations and workarounds

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