Author: metze Date: 2005-12-09 20:42:09 +0000 (Fri, 09 Dec 2005) New Revision: 12153
WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba&rev=12153 Log: work arround the fact that epoll reports EPOLLERR and EPOLLHUP, even if you don't ask for. with this patch the epoll mode behaves like the select mode metze Modified: branches/SAMBA_4_0/source/lib/events/events_standard.c Changeset: Modified: branches/SAMBA_4_0/source/lib/events/events_standard.c =================================================================== --- branches/SAMBA_4_0/source/lib/events/events_standard.c 2005-12-09 20:28:13 UTC (rev 12152) +++ branches/SAMBA_4_0/source/lib/events/events_standard.c 2005-12-09 20:42:09 UTC (rev 12153) @@ -119,6 +119,10 @@ talloc_set_destructor(std_ev, epoll_ctx_destructor); } +#define EPOLL_ADDITIONAL_FD_FLAG_HAS_EVENT (1<<0) +#define EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR (1<<1) +#define EPOLL_ADDITIONAL_FD_FLAG_GOT_ERROR (1<<2) + /* add the epoll event to the given fd_event */ @@ -126,42 +130,102 @@ { struct epoll_event event; if (std_ev->epoll_fd == -1) return; + + fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; + + /* if we don't want events yet, don't add an epoll_event */ + if (fde->flags == 0) return; + ZERO_STRUCT(event); event.events = epoll_map_flags(fde->flags); event.data.ptr = fde; if (epoll_ctl(std_ev->epoll_fd, EPOLL_CTL_ADD, fde->fd, &event) != 0) { epoll_fallback_to_select(std_ev, "EPOLL_CTL_ADD failed"); } + fde->additional_flags |= EPOLL_ADDITIONAL_FD_FLAG_HAS_EVENT; + + /* only if we want to read we want to tell the event handler about errors */ + if (fde->flags & EVENT_FD_READ) { + fde->additional_flags |= EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; + } } /* - remove the epoll event for given fd_event + delete the epoll event for given fd_event */ -static void epoll_remove_event(struct std_event_context *std_ev, struct fd_event *fde) +static void epoll_del_event(struct std_event_context *std_ev, struct fd_event *fde) { struct epoll_event event; if (std_ev->epoll_fd == -1) return; + + fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; + + /* if there's no epoll_event, we don't need to delete it */ + if (!(fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_HAS_EVENT)) return; + ZERO_STRUCT(event); event.events = epoll_map_flags(fde->flags); event.data.ptr = fde; epoll_ctl(std_ev->epoll_fd, EPOLL_CTL_DEL, fde->fd, &event); + fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_HAS_EVENT; } /* change the epoll event to the given fd_event */ -static void epoll_change_event(struct std_event_context *std_ev, struct fd_event *fde, uint16_t flags) +static void epoll_mod_event(struct std_event_context *std_ev, struct fd_event *fde) { struct epoll_event event; if (std_ev->epoll_fd == -1) return; + + fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; + ZERO_STRUCT(event); - event.events = epoll_map_flags(flags); + event.events = epoll_map_flags(fde->flags); event.data.ptr = fde; if (epoll_ctl(std_ev->epoll_fd, EPOLL_CTL_MOD, fde->fd, &event) != 0) { epoll_fallback_to_select(std_ev, "EPOLL_CTL_MOD failed"); } + + /* only if we want to read we want to tell the event handler about errors */ + if (fde->flags & EVENT_FD_READ) { + fde->additional_flags |= EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; + } } +static void epoll_change_event(struct std_event_context *std_ev, struct fd_event *fde) +{ + BOOL got_error = (fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_GOT_ERROR); + BOOL want_read = (fde->flags & EVENT_FD_READ); + BOOL want_write= (fde->flags & EVENT_FD_WRITE); + + if (std_ev->epoll_fd == -1) return; + + fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; + + /* there's already an event */ + if (fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_HAS_EVENT) { + if (want_read || (want_write && !got_error)) { + epoll_mod_event(std_ev, fde); + return; + } + /* + * if we want to match the select behavior, we need to remove the epoll_event + * when the caller isn't interested in events. + * + * this is because epoll reports EPOLLERR and EPOLLHUP, even without asking for them + */ + epoll_del_event(std_ev, fde); + return; + } + + /* there's no epoll_event attached to the fde */ + if (want_read || (want_write && !got_error)) { + epoll_add_event(std_ev, fde); + return; + } +} + /* event loop handling using epoll */ @@ -201,7 +265,20 @@ epoll_fallback_to_select(std_ev, "epoll_wait() gave bad data"); return -1; } - if (events[i].events & (EPOLLHUP|EPOLLERR)) flags |= EVENT_FD_READ; + if (events[i].events & (EPOLLHUP|EPOLLERR)) { + fde->additional_flags |= EPOLL_ADDITIONAL_FD_FLAG_GOT_ERROR; + /* + * if we only wait for EVENT_FD_WRITE, we should not tell the + * event handler about it, and remove the epoll_event, + * as we only report errors when waiting for read events, + * to match the select() behavior + */ + if (!(fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR)) { + epoll_del_event(std_ev, fde); + continue; + } + flags |= EVENT_FD_READ; + } if (events[i].events & EPOLLIN) flags |= EVENT_FD_READ; if (events[i].events & EPOLLOUT) flags |= EVENT_FD_WRITE; if (flags) { @@ -217,8 +294,8 @@ #else #define epoll_init_ctx(std_ev,try_epoll) if (try_epoll) {/* fix unused variable warning*/} #define epoll_add_event(std_ev,fde) -#define epoll_remove_event(std_ev,fde) -#define epoll_change_event(std_ev,fde,flags) +#define epoll_del_event(std_ev,fde) +#define epoll_change_event(std_ev,fde) #define epoll_event_loop(std_ev,tvalp) (-1) #endif @@ -280,7 +357,7 @@ DLIST_REMOVE(std_ev->fd_events, fde); std_ev->destruction_count++; - epoll_remove_event(std_ev, fde); + epoll_del_event(std_ev, fde); return 0; } @@ -342,9 +419,9 @@ ev = fde->event_ctx; std_ev = talloc_get_type(ev->additional_data, struct std_event_context); - epoll_change_event(std_ev, fde, flags); + fde->flags = flags; - fde->flags = flags; + epoll_change_event(std_ev, fde); } /*
