diff options
| -rw-r--r-- | ev.pod | 5 |
1 files changed, 3 insertions, 2 deletions
@@ -465,8 +465,9 @@ epoll scales either O(1) or O(active_fds). The epoll mechanism deserves honorable mention as the most misdesigned of the more advanced event mechanisms: mere annoyances include silently dropping file descriptors, requiring a system call per change per file -descriptor (and unnecessary guessing of parameters), problems with dup and -so on. The biggest issue is fork races, however - if a program forks then +descriptor (and unnecessary guessing of parameters), problems with dup, +returning before the timeout value requiring additional iterations and so +on. The biggest issue is fork races, however - if a program forks then I<both> parent and child process have to recreate the epoll set, which can take considerable time (one syscall per file descriptor) and is of course hard to detect. |