diff options
| -rw-r--r-- | Changes | 7 | ||||
| -rw-r--r-- | ev.c | 35 | ||||
| -rw-r--r-- | ev_epoll.c | 24 | ||||
| -rw-r--r-- | ev_poll.c | 2 |
4 files changed, 38 insertions, 30 deletions
@@ -1,6 +1,13 @@ Revision history for libev, a high-performance and full-featured event loop. WISH? monotonic clocks times/GetTickCount for coarse corrections? + + - further optimise away the EPOLL_CTL_ADD/MOD combo in the epoll + backend by assuming the kernel event mask hasn't changed if + ADD fails with EEXIST. + - use memset to initialise most arrays now and do away with the + init functions. + 3.45 Tue Oct 21 21:59:26 CEST 2008 - disable inotify usage on linux <2.6.25, as it is broken (reported by Yoann Vandoorselaere). @@ -451,6 +451,8 @@ typedef struct WL head; unsigned char events; unsigned char reify; + unsigned char emask; /* the epoll backend stores the actual kernel mask in here */ + unsigned char unused; /* currently unused padding */ #if EV_SELECT_IS_WINSOCKET SOCKET handle; #endif @@ -613,6 +615,9 @@ array_realloc (int elem, void *base, int *cur, int cnt) return ev_realloc (base, elem * *cur); } +#define array_init_zero(base,count) \ + memset ((void *)(base), 0, sizeof (*(base)) * (count)) + #define array_needsize(type,base,cur,cnt,init) \ if (expect_false ((cnt) > (cur))) \ { \ @@ -665,19 +670,6 @@ queue_events (EV_P_ W *events, int eventcnt, int type) /*****************************************************************************/ -void inline_size -anfds_init (ANFD *base, int count) -{ - while (count--) - { - base->head = 0; - base->events = EV_NONE; - base->reify = 0; - - ++base; - } -} - void inline_speed fd_event (EV_P_ int fd, int revents) { @@ -977,18 +969,6 @@ static int signalmax; static EV_ATOMIC_T gotsig; -void inline_size -signals_init (ANSIG *base, int count) -{ - while (count--) - { - base->head = 0; - base->gotsig = 0; - - ++base; - } -} - /*****************************************************************************/ void inline_speed @@ -2141,11 +2121,12 @@ ev_io_start (EV_P_ ev_io *w) return; assert (("ev_io_start called with negative fd", fd >= 0)); + assert (("ev_io start called with illegal event mask", !(w->events & ~(EV_IOFDSET | EV_READ | EV_WRITE)))); EV_FREQUENT_CHECK; ev_start (EV_A_ (W)w, 1); - array_needsize (ANFD, anfds, anfdmax, fd + 1, anfds_init); + array_needsize (ANFD, anfds, anfdmax, fd + 1, array_init_zero); wlist_add (&anfds[fd].head, (WL)w); fd_change (EV_A_ fd, w->events & EV_IOFDSET | 1); @@ -2347,7 +2328,7 @@ ev_signal_start (EV_P_ ev_signal *w) sigprocmask (SIG_SETMASK, &full, &prev); #endif - array_needsize (ANSIG, signals, signalmax, w->signum, signals_init); + array_needsize (ANSIG, signals, signalmax, w->signum, array_init_zero); #ifndef _WIN32 sigprocmask (SIG_SETMASK, &prev, 0); @@ -57,20 +57,34 @@ #include <sys/epoll.h> +void inline_size +unsigned_char_init (unsigned char *base, int count) +{ + /* memset might be overkill */ + while (count--) + *base++ = 0; +} + static void epoll_modify (EV_P_ int fd, int oev, int nev) { struct epoll_event ev; + unsigned char oldmask; /* * we handle EPOLL_CTL_DEL by ignoring it here * on the assumption that the fd is gone anyways * if that is wrong, we have to handle the spurious * event in epoll_poll. + * the fd is later added, we try to ADD it, and, if that + * fails, we assume it still has the same eventmask. */ if (!nev) return; + oldmask = anfds [fd].emask; + anfds [fd].emask = nev; + ev.data.u64 = fd; /* use u64 to fully initialise the struct, for nicer strace etc. */ ev.events = (nev & EV_READ ? EPOLLIN : 0) | (nev & EV_WRITE ? EPOLLOUT : 0); @@ -80,7 +94,7 @@ epoll_modify (EV_P_ int fd, int oev, int nev) if (expect_true (errno == ENOENT)) { - /* on ENOENT the fd went away, so try to do the right thing */ + /* if ENOENT then the fd went away, so try to do the right thing */ if (!nev) return; @@ -89,8 +103,9 @@ epoll_modify (EV_P_ int fd, int oev, int nev) } else if (expect_true (errno == EEXIST)) { - /* on EEXIST we ignored a previous DEL */ - if (!epoll_ctl (backend_fd, EPOLL_CTL_MOD, fd, &ev)) + /* EEXIST means we ignored a previous DEL, but the fd is still active */ + /* if the kernel mask is the same as the new mask, we assume it hasn't changed */ + if (oldmask == nev || !epoll_ctl (backend_fd, EPOLL_CTL_MOD, fd, &ev)) return; } @@ -122,7 +137,10 @@ epoll_poll (EV_P_ ev_tstamp timeout) if (expect_false (got & ~want)) { + anfds [fd].emask = want; + /* we received an event but are not interested in it, try mod or del */ + /* I don't think we ever need MOD, but let's handle it anyways */ ev->events = (want & EV_READ ? EPOLLIN : 0) | (want & EV_WRITE ? EPOLLOUT : 0); @@ -42,6 +42,8 @@ void inline_size pollidx_init (int *base, int count) { + /* consider using memset (.., -1, ...), which is pratically guarenteed + * to work on all systems implementing poll */ while (count--) *base++ = -1; } |