… | |
… | |
2632 | |
2632 | |
2633 | =item Starting and stopping timer/periodic watchers: O(log skipped_other_timers) |
2633 | =item Starting and stopping timer/periodic watchers: O(log skipped_other_timers) |
2634 | |
2634 | |
2635 | This means that, when you have a watcher that triggers in one hour and |
2635 | This means that, when you have a watcher that triggers in one hour and |
2636 | there are 100 watchers that would trigger before that then inserting will |
2636 | there are 100 watchers that would trigger before that then inserting will |
2637 | have to skip those 100 watchers. |
2637 | have to skip roughly seven (C<ld 100>) of these watchers. |
2638 | |
2638 | |
2639 | =item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers) |
2639 | =item Changing timer/periodic watchers (by autorepeat or calling again): O(log skipped_other_timers) |
2640 | |
2640 | |
2641 | That means that for changing a timer costs less than removing/adding them |
2641 | That means that changing a timer costs less than removing/adding them |
2642 | as only the relative motion in the event queue has to be paid for. |
2642 | as only the relative motion in the event queue has to be paid for. |
2643 | |
2643 | |
2644 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
2644 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
2645 | |
2645 | |
2646 | These just add the watcher into an array or at the head of a list. |
2646 | These just add the watcher into an array or at the head of a list. |
|
|
2647 | |
2647 | =item Stopping check/prepare/idle watchers: O(1) |
2648 | =item Stopping check/prepare/idle watchers: O(1) |
2648 | |
2649 | |
2649 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) |
2650 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) |
2650 | |
2651 | |
2651 | These watchers are stored in lists then need to be walked to find the |
2652 | These watchers are stored in lists then need to be walked to find the |
2652 | correct watcher to remove. The lists are usually short (you don't usually |
2653 | correct watcher to remove. The lists are usually short (you don't usually |
2653 | have many watchers waiting for the same fd or signal). |
2654 | have many watchers waiting for the same fd or signal). |
2654 | |
2655 | |
2655 | =item Finding the next timer per loop iteration: O(1) |
2656 | =item Finding the next timer in each loop iteration: O(1) |
|
|
2657 | |
|
|
2658 | By virtue of using a binary heap, the next timer is always found at the |
|
|
2659 | beginning of the storage array. |
2656 | |
2660 | |
2657 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
2661 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
2658 | |
2662 | |
2659 | A change means an I/O watcher gets started or stopped, which requires |
2663 | A change means an I/O watcher gets started or stopped, which requires |
2660 | libev to recalculate its status (and possibly tell the kernel). |
2664 | libev to recalculate its status (and possibly tell the kernel, depending |
|
|
2665 | on backend and wether C<ev_io_set> was used). |
2661 | |
2666 | |
2662 | =item Activating one watcher: O(1) |
2667 | =item Activating one watcher (putting it into the pending state): O(1) |
2663 | |
2668 | |
2664 | =item Priority handling: O(number_of_priorities) |
2669 | =item Priority handling: O(number_of_priorities) |
2665 | |
2670 | |
2666 | Priorities are implemented by allocating some space for each |
2671 | Priorities are implemented by allocating some space for each |
2667 | priority. When doing priority-based operations, libev usually has to |
2672 | priority. When doing priority-based operations, libev usually has to |
2668 | linearly search all the priorities. |
2673 | linearly search all the priorities, but starting/stopping and activating |
|
|
2674 | watchers becomes O(1) w.r.t. prioritiy handling. |
2669 | |
2675 | |
2670 | =back |
2676 | =back |
2671 | |
2677 | |
2672 | |
2678 | |
2673 | =head1 AUTHOR |
2679 | =head1 AUTHOR |