diff options
Diffstat (limited to 'ev_epoll.c')
| -rw-r--r-- | ev_epoll.c | 24 |
1 files changed, 21 insertions, 3 deletions
@@ -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); |