diff options
Diffstat (limited to 'tevent/tevent_epoll.c')
| -rw-r--r-- | tevent/tevent_epoll.c | 482 |
1 files changed, 0 insertions, 482 deletions
diff --git a/tevent/tevent_epoll.c b/tevent/tevent_epoll.c deleted file mode 100644 index 1d03b7dbf..000000000 --- a/tevent/tevent_epoll.c +++ /dev/null @@ -1,482 +0,0 @@ -/* - Unix SMB/CIFS implementation. - - main select loop and event handling - epoll implementation - - Copyright (C) Andrew Tridgell 2003-2005 - Copyright (C) Stefan Metzmacher 2005 - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ - -#include "replace.h" -#include "system/filesys.h" -#include "system/network.h" -#include "tevent.h" -#include "tevent_internal.h" -#include "tevent_util.h" -#include <sys/epoll.h> - -struct epoll_event_context { - /* a pointer back to the generic event_context */ - struct event_context *ev; - - /* list of filedescriptor events */ - struct fd_event *fd_events; - - /* number of registered fd event handlers */ - int num_fd_events; - - /* this is changed by the destructors for the fd event - type. It is used to detect event destruction by event - handlers, which means the code that is calling the event - handler needs to assume that the linked list is no longer - valid - */ - uint32_t destruction_count; - - /* when using epoll this is the handle from epoll_create */ - int epoll_fd; - - pid_t pid; -}; - -/* - called when a epoll call fails, and we should fallback - to using select -*/ -static void epoll_panic(struct epoll_event_context *epoll_ev, const char *reason) -{ - ev_debug(epoll_ev->ev, EV_DEBUG_FATAL, - "%s (%s) - calling abort()\n", reason, strerror(errno)); - abort(); -} - -/* - map from EVENT_FD_* to EPOLLIN/EPOLLOUT -*/ -static uint32_t epoll_map_flags(uint16_t flags) -{ - uint32_t ret = 0; - if (flags & EVENT_FD_READ) ret |= (EPOLLIN | EPOLLERR | EPOLLHUP); - if (flags & EVENT_FD_WRITE) ret |= (EPOLLOUT | EPOLLERR | EPOLLHUP); - return ret; -} - -/* - free the epoll fd -*/ -static int epoll_ctx_destructor(struct epoll_event_context *epoll_ev) -{ - close(epoll_ev->epoll_fd); - epoll_ev->epoll_fd = -1; - return 0; -} - -/* - init the epoll fd -*/ -static int epoll_init_ctx(struct epoll_event_context *epoll_ev) -{ - epoll_ev->epoll_fd = epoll_create(64); - epoll_ev->pid = getpid(); - talloc_set_destructor(epoll_ev, epoll_ctx_destructor); - if (epoll_ev->epoll_fd == -1) { - return -1; - } - return 0; -} - -static void epoll_add_event(struct epoll_event_context *epoll_ev, struct fd_event *fde); - -/* - reopen the epoll handle when our pid changes - see http://junkcode.samba.org/ftp/unpacked/junkcode/epoll_fork.c for an - demonstration of why this is needed - */ -static void epoll_check_reopen(struct epoll_event_context *epoll_ev) -{ - struct fd_event *fde; - - if (epoll_ev->pid == getpid()) { - return; - } - - close(epoll_ev->epoll_fd); - epoll_ev->epoll_fd = epoll_create(64); - if (epoll_ev->epoll_fd == -1) { - ev_debug(epoll_ev->ev, EV_DEBUG_FATAL, - "Failed to recreate epoll handle after fork\n"); - return; - } - epoll_ev->pid = getpid(); - for (fde=epoll_ev->fd_events;fde;fde=fde->next) { - epoll_add_event(epoll_ev, fde); - } -} - -#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 -*/ -static void epoll_add_event(struct epoll_event_context *epoll_ev, struct fd_event *fde) -{ - struct epoll_event event; - - if (epoll_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(epoll_ev->epoll_fd, EPOLL_CTL_ADD, fde->fd, &event) != 0) { - epoll_panic(epoll_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; - } -} - -/* - delete the epoll event for given fd_event -*/ -static void epoll_del_event(struct epoll_event_context *epoll_ev, struct fd_event *fde) -{ - struct epoll_event event; - - if (epoll_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; - if (epoll_ctl(epoll_ev->epoll_fd, EPOLL_CTL_DEL, fde->fd, &event) != 0) { - ev_debug(epoll_ev->ev, EV_DEBUG_FATAL, - "epoll_del_event failed! probable early close bug (%s)\n", - strerror(errno)); - } - fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_HAS_EVENT; -} - -/* - change the epoll event to the given fd_event -*/ -static void epoll_mod_event(struct epoll_event_context *epoll_ev, struct fd_event *fde) -{ - struct epoll_event event; - if (epoll_ev->epoll_fd == -1) return; - - fde->additional_flags &= ~EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR; - - ZERO_STRUCT(event); - event.events = epoll_map_flags(fde->flags); - event.data.ptr = fde; - if (epoll_ctl(epoll_ev->epoll_fd, EPOLL_CTL_MOD, fde->fd, &event) != 0) { - epoll_panic(epoll_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 epoll_event_context *epoll_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 (epoll_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(epoll_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(epoll_ev, fde); - return; - } - - /* there's no epoll_event attached to the fde */ - if (want_read || (want_write && !got_error)) { - epoll_add_event(epoll_ev, fde); - return; - } -} - -/* - event loop handling using epoll -*/ -static int epoll_event_loop(struct epoll_event_context *epoll_ev, struct timeval *tvalp) -{ - int ret, i; -#define MAXEVENTS 32 - struct epoll_event events[MAXEVENTS]; - uint32_t destruction_count = ++epoll_ev->destruction_count; - int timeout = -1; - - if (epoll_ev->epoll_fd == -1) return -1; - - if (tvalp) { - /* it's better to trigger timed events a bit later than to early */ - timeout = ((tvalp->tv_usec+999) / 1000) + (tvalp->tv_sec*1000); - } - - if (epoll_ev->ev->num_signal_handlers && - common_event_check_signal(epoll_ev->ev)) { - return 0; - } - - ret = epoll_wait(epoll_ev->epoll_fd, events, MAXEVENTS, timeout); - - if (ret == -1 && errno == EINTR && epoll_ev->ev->num_signal_handlers) { - if (common_event_check_signal(epoll_ev->ev)) { - return 0; - } - } - - if (ret == -1 && errno != EINTR) { - epoll_panic(epoll_ev, "epoll_wait() failed"); - return -1; - } - - if (ret == 0 && tvalp) { - /* we don't care about a possible delay here */ - common_event_loop_timer_delay(epoll_ev->ev); - return 0; - } - - for (i=0;i<ret;i++) { - struct fd_event *fde = talloc_get_type(events[i].data.ptr, - struct fd_event); - uint16_t flags = 0; - - if (fde == NULL) { - epoll_panic(epoll_ev, "epoll_wait() gave bad data"); - return -1; - } - 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(epoll_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) { - fde->handler(epoll_ev->ev, fde, flags, fde->private_data); - if (destruction_count != epoll_ev->destruction_count) { - break; - } - } - } - - return 0; -} - -/* - create a epoll_event_context structure. -*/ -static int epoll_event_context_init(struct event_context *ev) -{ - int ret; - struct epoll_event_context *epoll_ev; - - epoll_ev = talloc_zero(ev, struct epoll_event_context); - if (!epoll_ev) return -1; - epoll_ev->ev = ev; - epoll_ev->epoll_fd = -1; - - ret = epoll_init_ctx(epoll_ev); - if (ret != 0) { - talloc_free(epoll_ev); - return ret; - } - - ev->additional_data = epoll_ev; - return 0; -} - -/* - destroy an fd_event -*/ -static int epoll_event_fd_destructor(struct fd_event *fde) -{ - struct event_context *ev = fde->event_ctx; - struct epoll_event_context *epoll_ev = talloc_get_type(ev->additional_data, - struct epoll_event_context); - - epoll_check_reopen(epoll_ev); - - epoll_ev->num_fd_events--; - epoll_ev->destruction_count++; - - DLIST_REMOVE(epoll_ev->fd_events, fde); - - epoll_del_event(epoll_ev, fde); - - if (fde->flags & EVENT_FD_AUTOCLOSE) { - close(fde->fd); - fde->fd = -1; - } - - return 0; -} - -/* - add a fd based event - return NULL on failure (memory allocation error) -*/ -static struct fd_event *epoll_event_add_fd(struct event_context *ev, TALLOC_CTX *mem_ctx, - int fd, uint16_t flags, - event_fd_handler_t handler, - void *private_data) -{ - struct epoll_event_context *epoll_ev = talloc_get_type(ev->additional_data, - struct epoll_event_context); - struct fd_event *fde; - - epoll_check_reopen(epoll_ev); - - fde = talloc(mem_ctx?mem_ctx:ev, struct fd_event); - if (!fde) return NULL; - - fde->event_ctx = ev; - fde->fd = fd; - fde->flags = flags; - fde->handler = handler; - fde->private_data = private_data; - fde->additional_flags = 0; - fde->additional_data = NULL; - - epoll_ev->num_fd_events++; - talloc_set_destructor(fde, epoll_event_fd_destructor); - - DLIST_ADD(epoll_ev->fd_events, fde); - epoll_add_event(epoll_ev, fde); - - return fde; -} - - -/* - return the fd event flags -*/ -static uint16_t epoll_event_get_fd_flags(struct fd_event *fde) -{ - return fde->flags; -} - -/* - set the fd event flags -*/ -static void epoll_event_set_fd_flags(struct fd_event *fde, uint16_t flags) -{ - struct event_context *ev; - struct epoll_event_context *epoll_ev; - - if (fde->flags == flags) return; - - ev = fde->event_ctx; - epoll_ev = talloc_get_type(ev->additional_data, struct epoll_event_context); - - fde->flags = flags; - - epoll_check_reopen(epoll_ev); - - epoll_change_event(epoll_ev, fde); -} - -/* - do a single event loop using the events defined in ev -*/ -static int epoll_event_loop_once(struct event_context *ev) -{ - struct epoll_event_context *epoll_ev = talloc_get_type(ev->additional_data, - struct epoll_event_context); - struct timeval tval; - - tval = common_event_loop_timer_delay(ev); - if (ev_timeval_is_zero(&tval)) { - return 0; - } - - epoll_check_reopen(epoll_ev); - - return epoll_event_loop(epoll_ev, &tval); -} - -/* - return on failure or (with 0) if all fd events are removed -*/ -static int epoll_event_loop_wait(struct event_context *ev) -{ - struct epoll_event_context *epoll_ev = talloc_get_type(ev->additional_data, - struct epoll_event_context); - while (epoll_ev->num_fd_events) { - if (epoll_event_loop_once(ev) != 0) { - break; - } - } - - return 0; -} - -static const struct event_ops epoll_event_ops = { - .context_init = epoll_event_context_init, - .add_fd = epoll_event_add_fd, - .get_fd_flags = epoll_event_get_fd_flags, - .set_fd_flags = epoll_event_set_fd_flags, - .add_timed = common_event_add_timed, - .add_signal = common_event_add_signal, - .loop_once = epoll_event_loop_once, - .loop_wait = epoll_event_loop_wait, -}; - -bool events_epoll_init(void) -{ - return event_register_backend("epoll", &epoll_event_ops); -} |