/*
Unix SMB/CIFS implementation.
main select loop and event handling
- Copyright (C) Andrew Tridgell 2003-2005
- Copyright (C) Stefan Metzmacher 2005-2013
+ Copyright (C) Stefan Metzmacher 2013
Copyright (C) Jeremy Allison 2013
** NOTE! The following LGPL license applies to the tevent
#include "tevent_util.h"
#include "tevent_internal.h"
-#if 0
-struct std_event_context {
- /* a pointer back to the generic event_context */
- struct tevent_context *ev;
-
- /* the maximum file descriptor number in fd_events */
- int maxfd;
-
- /* information for exiting from the event loop */
- int exit_code;
-
- /* when using epoll this is the handle from epoll_create */
- int epoll_fd;
-
- /* our pid at the time the epoll_fd was created */
- pid_t pid;
-};
-
-/* use epoll if it is available */
-#if HAVE_EPOLL
-/*
- called when a epoll call fails, and we should fallback
- to using select
-*/
-static void epoll_fallback_to_select(struct std_event_context *std_ev, const char *reason)
-{
- tevent_debug(std_ev->ev, TEVENT_DEBUG_FATAL,
- "%s (%s) - falling back to select()\n",
- reason, strerror(errno));
- close(std_ev->epoll_fd);
- std_ev->epoll_fd = -1;
- talloc_set_destructor(std_ev, NULL);
-}
-
-/*
- map from TEVENT_FD_* to EPOLLIN/EPOLLOUT
-*/
-static uint32_t epoll_map_flags(uint16_t flags)
-{
- uint32_t ret = 0;
- if (flags & TEVENT_FD_READ) ret |= (EPOLLIN | EPOLLERR | EPOLLHUP);
- if (flags & TEVENT_FD_WRITE) ret |= (EPOLLOUT | EPOLLERR | EPOLLHUP);
- return ret;
-}
-
-/*
- free the epoll fd
-*/
-static int epoll_ctx_destructor(struct std_event_context *std_ev)
-{
- if (std_ev->epoll_fd != -1) {
- close(std_ev->epoll_fd);
- }
- std_ev->epoll_fd = -1;
- return 0;
-}
-
-/*
- init the epoll fd
-*/
-static void epoll_init_ctx(struct std_event_context *std_ev)
-{
- std_ev->epoll_fd = epoll_create(64);
- if (std_ev->epoll_fd == -1) {
- tevent_debug(std_ev->ev, TEVENT_DEBUG_FATAL,
- "Failed to create epoll handle.\n");
- return;
- }
-
- if (!ev_set_close_on_exec(std_ev->epoll_fd)) {
- tevent_debug(std_ev->ev, TEVENT_DEBUG_WARNING,
- "Failed to set close-on-exec, file descriptor may be leaked to children.\n");
- }
-
- std_ev->pid = getpid();
- talloc_set_destructor(std_ev, epoll_ctx_destructor);
-}
-
-static void epoll_add_event(struct std_event_context *std_ev, struct tevent_fd *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 std_event_context *std_ev)
-{
- struct tevent_fd *fde;
-
- if (std_ev->pid == getpid()) {
- return;
- }
-
- close(std_ev->epoll_fd);
- std_ev->epoll_fd = epoll_create(64);
- if (std_ev->epoll_fd == -1) {
- tevent_debug(std_ev->ev, TEVENT_DEBUG_FATAL,
- "Failed to recreate epoll handle after fork\n");
- return;
- }
-
- if (!ev_set_close_on_exec(std_ev->epoll_fd)) {
- tevent_debug(std_ev->ev, TEVENT_DEBUG_WARNING,
- "Failed to set close-on-exec, file descriptor may be leaked to children.\n");
- }
-
- std_ev->pid = getpid();
- for (fde=std_ev->ev->fd_events;fde;fde=fde->next) {
- epoll_add_event(std_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 std_event_context *std_ev, struct tevent_fd *fde)
-{
- 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 & TEVENT_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 std_event_context *std_ev, struct tevent_fd *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_mod_event(struct std_event_context *std_ev, struct tevent_fd *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(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 & TEVENT_FD_READ) {
- fde->additional_flags |= EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR;
- }
-}
-
-static void epoll_change_event(struct std_event_context *std_ev, struct tevent_fd *fde)
-{
- bool got_error = (fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_GOT_ERROR);
- bool want_read = (fde->flags & TEVENT_FD_READ);
- bool want_write= (fde->flags & TEVENT_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
-*/
-static int epoll_event_loop(struct std_event_context *std_ev, struct timeval *tvalp)
-{
- int ret, i;
-#define MAXEVENTS 1
- struct epoll_event events[MAXEVENTS];
- int timeout = -1;
-
- if (std_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 (std_ev->ev->signal_events &&
- tevent_common_check_signal(std_ev->ev)) {
- return 0;
- }
-
- tevent_trace_point_callback(std_ev->ev, TEVENT_TRACE_BEFORE_WAIT);
- ret = epoll_wait(std_ev->epoll_fd, events, MAXEVENTS, timeout);
- tevent_trace_point_callback(std_ev->ev, TEVENT_TRACE_AFTER_WAIT);
-
- if (ret == -1 && errno == EINTR && std_ev->ev->signal_events) {
- if (tevent_common_check_signal(std_ev->ev)) {
- return 0;
- }
- }
-
- if (ret == -1 && errno != EINTR) {
- epoll_fallback_to_select(std_ev, "epoll_wait() failed");
- return -1;
- }
-
- if (ret == 0 && tvalp) {
- /* we don't care about a possible delay here */
- tevent_common_loop_timer_delay(std_ev->ev);
- return 0;
- }
-
- for (i=0;i<ret;i++) {
- struct tevent_fd *fde = talloc_get_type(events[i].data.ptr,
- struct tevent_fd);
- uint16_t flags = 0;
-
- if (fde == NULL) {
- epoll_fallback_to_select(std_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 TEVENT_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 |= TEVENT_FD_READ;
- }
- if (events[i].events & EPOLLIN) flags |= TEVENT_FD_READ;
- if (events[i].events & EPOLLOUT) flags |= TEVENT_FD_WRITE;
- if (flags) {
- fde->handler(std_ev->ev, fde, flags, fde->private_data);
- break;
- }
- }
-
- return 0;
-}
-#else
-#define epoll_init_ctx(std_ev)
-#define epoll_add_event(std_ev,fde)
-#define epoll_del_event(std_ev,fde)
-#define epoll_change_event(std_ev,fde)
-#define epoll_event_loop(std_ev,tvalp) (-1)
-#define epoll_check_reopen(std_ev)
-#endif
-
-/*
- create a std_event_context structure.
-*/
-static int std_event_context_init(struct tevent_context *ev)
-{
- struct std_event_context *std_ev;
-
- /*
- * We might be called during tevent_re_initialise()
- * which means we need to free our old additional_data.
- */
- TALLOC_FREE(ev->additional_data);
-
- std_ev = talloc_zero(ev, struct std_event_context);
- if (!std_ev) return -1;
- std_ev->ev = ev;
- std_ev->epoll_fd = -1;
-
- epoll_init_ctx(std_ev);
-
- ev->additional_data = std_ev;
- return 0;
-}
-
-/*
- recalculate the maxfd
-*/
-static void calc_maxfd(struct std_event_context *std_ev)
-{
- struct tevent_fd *fde;
-
- std_ev->maxfd = 0;
- for (fde = std_ev->ev->fd_events; fde; fde = fde->next) {
- if (fde->fd > std_ev->maxfd) {
- std_ev->maxfd = fde->fd;
- }
- }
-}
-
-
-/* to mark the ev->maxfd invalid
- * this means we need to recalculate it
- */
-#define EVENT_INVALID_MAXFD (-1)
-
-/*
- destroy an fd_event
-*/
-static int std_event_fd_destructor(struct tevent_fd *fde)
-{
- struct tevent_context *ev = fde->event_ctx;
- struct std_event_context *std_ev = NULL;
-
- if (ev) {
- std_ev = talloc_get_type(ev->additional_data,
- struct std_event_context);
-
- epoll_check_reopen(std_ev);
-
- if (std_ev->maxfd == fde->fd) {
- std_ev->maxfd = EVENT_INVALID_MAXFD;
- }
-
- epoll_del_event(std_ev, fde);
- }
-
- return tevent_common_fd_destructor(fde);
-}
-
-/*
- add a fd based event
- return NULL on failure (memory allocation error)
-*/
-static struct tevent_fd *std_event_add_fd(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
- int fd, uint16_t flags,
- tevent_fd_handler_t handler,
- void *private_data,
- const char *handler_name,
- const char *location)
-{
- struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
- struct std_event_context);
- struct tevent_fd *fde;
-
- epoll_check_reopen(std_ev);
-
- fde = tevent_common_add_fd(ev, mem_ctx, fd, flags,
- handler, private_data,
- handler_name, location);
- if (!fde) return NULL;
-
- if ((std_ev->maxfd != EVENT_INVALID_MAXFD)
- && (fde->fd > std_ev->maxfd)) {
- std_ev->maxfd = fde->fd;
- }
- talloc_set_destructor(fde, std_event_fd_destructor);
-
- epoll_add_event(std_ev, fde);
-
- return fde;
-}
-
-/*
- set the fd event flags
-*/
-static void std_event_set_fd_flags(struct tevent_fd *fde, uint16_t flags)
-{
- struct tevent_context *ev;
- struct std_event_context *std_ev;
-
- if (fde->flags == flags) return;
-
- ev = fde->event_ctx;
- std_ev = talloc_get_type(ev->additional_data, struct std_event_context);
-
- fde->flags = flags;
-
- epoll_check_reopen(std_ev);
-
- epoll_change_event(std_ev, fde);
-}
-
-/*
- event loop handling using select()
-*/
-static int std_event_loop_select(struct std_event_context *std_ev, struct timeval *tvalp)
-{
- fd_set r_fds, w_fds;
- struct tevent_fd *fde;
- int selrtn;
-
- /* we maybe need to recalculate the maxfd */
- if (std_ev->maxfd == EVENT_INVALID_MAXFD) {
- calc_maxfd(std_ev);
- }
-
- FD_ZERO(&r_fds);
- FD_ZERO(&w_fds);
-
- /* setup any fd events */
- for (fde = std_ev->ev->fd_events; fde; fde = fde->next) {
- if (fde->fd < 0 || fde->fd >= FD_SETSIZE) {
- std_ev->exit_code = EBADF;
- return -1;
- }
- if (fde->flags & TEVENT_FD_READ) {
- FD_SET(fde->fd, &r_fds);
- }
- if (fde->flags & TEVENT_FD_WRITE) {
- FD_SET(fde->fd, &w_fds);
- }
- }
-
- if (std_ev->ev->signal_events &&
- tevent_common_check_signal(std_ev->ev)) {
- return 0;
- }
-
- selrtn = select(std_ev->maxfd+1, &r_fds, &w_fds, NULL, tvalp);
-
- if (selrtn == -1 && errno == EINTR &&
- std_ev->ev->signal_events) {
- tevent_common_check_signal(std_ev->ev);
- return 0;
- }
-
- if (selrtn == -1 && errno == EBADF) {
- /* the socket is dead! this should never
- happen as the socket should have first been
- made readable and that should have removed
- the event, so this must be a bug. This is a
- fatal error. */
- tevent_debug(std_ev->ev, TEVENT_DEBUG_FATAL,
- "ERROR: EBADF on std_event_loop_once\n");
- std_ev->exit_code = EBADF;
- return -1;
- }
-
- if (selrtn == 0 && tvalp) {
- /* we don't care about a possible delay here */
- tevent_common_loop_timer_delay(std_ev->ev);
- return 0;
- }
-
- if (selrtn > 0) {
- /* at least one file descriptor is ready - check
- which ones and call the handler, being careful to allow
- the handler to remove itself when called */
- for (fde = std_ev->ev->fd_events; fde; fde = fde->next) {
- uint16_t flags = 0;
-
- if (FD_ISSET(fde->fd, &r_fds)) flags |= TEVENT_FD_READ;
- if (FD_ISSET(fde->fd, &w_fds)) flags |= TEVENT_FD_WRITE;
- if (flags & fde->flags) {
- fde->handler(std_ev->ev, fde, flags, fde->private_data);
- break;
- }
- }
- }
-
- return 0;
-}
-
-/*
- do a single event loop using the events defined in ev
-*/
-static int std_event_loop_once(struct tevent_context *ev, const char *location)
-{
- struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
- struct std_event_context);
- struct timeval tval;
-
- if (ev->signal_events &&
- tevent_common_check_signal(ev)) {
- return 0;
- }
-
- if (ev->immediate_events &&
- tevent_common_loop_immediate(ev)) {
- return 0;
- }
-
- tval = tevent_common_loop_timer_delay(ev);
- if (tevent_timeval_is_zero(&tval)) {
- return 0;
- }
-
- epoll_check_reopen(std_ev);
-
- if (epoll_event_loop(std_ev, &tval) == 0) {
- return 0;
- }
-
- return std_event_loop_select(std_ev, &tval);
-}
-
-static const struct tevent_ops std_event_ops = {
- .context_init = std_event_context_init,
- .add_fd = std_event_add_fd,
- .set_fd_close_fn = tevent_common_fd_set_close_fn,
- .get_fd_flags = tevent_common_fd_get_flags,
- .set_fd_flags = std_event_set_fd_flags,
- .add_timer = tevent_common_add_timer,
- .schedule_immediate = tevent_common_schedule_immediate,
- .add_signal = tevent_common_add_signal,
- .loop_once = std_event_loop_once,
- .loop_wait = tevent_common_loop_wait,
-};
-#endif
-
struct std_event_glue {
const struct tevent_ops *epoll_ops;
const struct tevent_ops *poll_ops;
git.samba.org / obnox / samba / samba-obnox.git / commitdiff