diff options
Diffstat (limited to 'src/eloop.c')
| -rw-r--r-- | src/eloop.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/src/eloop.c b/src/eloop.c index a0581fc4..6785b316 100644 --- a/src/eloop.c +++ b/src/eloop.c @@ -26,6 +26,25 @@ * SUCH DAMAGE. */ +/* NOTES: + * Basically for a small number of fd's (total, not max fd) + * of say a few hundred, ppoll(2) performs just fine, if not faster than others. + * It also has the smallest memory and binary size footprint. + * ppoll(2) is available on all modern OS my software runs on. + * If ppoll is not available, then pselect(2) can be used instead. + * + * Both epoll(7) and kqueue(2) require an extra fd per process to manage + * their respective list of interest AND syscalls to manage it. + * So for a small number of fd's, these are more resource intensive, + * especially when used with more than one process. + * + * epoll avoids the resource limit RLIMIT_NOFILE Linux poll stupidly applies. + * kqueue avoids the same limit on OpenBSD. + * ppoll can still be secured in both by using SEECOMP or pledge. + * + * Taking this all into account, ppoll(2) is the default mechanism used here. + */ + #if (defined(__unix__) || defined(unix)) && !defined(USG) #include <sys/param.h> #endif @@ -51,10 +70,10 @@ #if defined(HAVE_KQUEUE) || defined(HAVE_EPOLL) || defined(HAVE_PPOLL) #elif defined(HAVE_POLLTS) #define ppoll pollts -#elif !defined(HAVE_PSELECT) -#pragma message("Compiling eloop with pselect(2) support.") -#define HAVE_PSELECT +#elif defined(HAVE_PSELECT) #define ppoll eloop_ppoll +#else +#define HAVE_PPOLL #endif #if defined(HAVE_KQUEUE) |