diff options
Diffstat (limited to 'README')
| -rw-r--r-- | README | 58 |
1 files changed, 54 insertions, 4 deletions
@@ -2,8 +2,58 @@ libev is modelled after libevent (http://monkey.org/~provos/libevent/), but aims to be faster and more correct, and also more featureful. Examples: - multiple watchers can wait for the same event without deregistering others. -- fork() is supported and can be handled. -- timers are handled as a priority queue (faster) -- watchers use less memory (faster) -- less calls to epoll_ctl (faster) + (registering two read events on fd 10 and unregistering one will not + break the other) + +- fork() is supported and can be handled + (there is no way to recover from a fork when libevent is active) + +- timers are handled as a priority queue + (libevent uses a less efficient red-black tree) + +- supports absolute (wallclock-based) timers in addition to relative ones, + i.e. can schedule timers to occur after n seconds, or at a specific time. + +- timers can be repeating (both absolute and relative ones) + +- detects time jumps and adjusts timers + (works for both forward and backward time jumps and also for absolute timers) + +- can correctly remove timers while executing callbacks + (libevent doesn't handle this reliably and can crash) + +- less calls to epoll_ctl + (stopping and starting an io watcher between two loop iterations will now + result in spuriois epoll_ctl calls) + +- usually less calls to gettimeofday and clock_gettime + (libevent calls it on every timer event change, libev twice per iteration) + +- watchers use less memory + (libevent on amd64: 152 bytes, libev: <= 56 bytes) + +- library uses less memory + (libevent allocates large data structures wether used or not, libev + scales all its data structures dynamically) + +- no hardcoded arbitrary limits + (libevent contains an off-by-one bug and sometimes hardcodes a limit of + 32000 fds) + +- libev separates timer, signal and io watchers from each other + (libevent combines them, but with libev you can combine them yourself + by reusing the same callback and still save memory) + +- simpler design, backends are potentially much simpler + (in libevent, backends have to deal with watchers, thus the problems) + (epoll backend in libevent: 366 lines, libev: 89 lines, and more features) + +whats missing? + +- evdns, evhttp, bufferevent are missing, libev is only an even library at + the moment. + +- no priority support at the moment. + +- kqueue, poll (libev currently implements epoll and select). |