From 3254e392208ac06c7cce3d89ca6369a224f7f481 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Wed, 9 Feb 2011 15:28:10 +0100 Subject: tevent: Add a poll backend --- lib/tevent/libtevent.m4 | 1 + lib/tevent/tevent.c | 1 + lib/tevent/tevent_internal.h | 1 + lib/tevent/tevent_poll.c | 306 +++++++++++++++++++++++++++++++++++++++++++ lib/tevent/wscript | 1 + 5 files changed, 310 insertions(+) create mode 100644 lib/tevent/tevent_poll.c diff --git a/lib/tevent/libtevent.m4 b/lib/tevent/libtevent.m4 index 4162ba30f9..5c5969b0df 100644 --- a/lib/tevent/libtevent.m4 +++ b/lib/tevent/libtevent.m4 @@ -30,6 +30,7 @@ TEVENT_OBJ="tevent.o tevent_debug.o tevent_util.o" TEVENT_OBJ="$TEVENT_OBJ tevent_fd.o tevent_timed.o tevent_immediate.o tevent_signal.o" TEVENT_OBJ="$TEVENT_OBJ tevent_req.o tevent_wakeup.o tevent_queue.o" TEVENT_OBJ="$TEVENT_OBJ tevent_standard.o tevent_select.o" +TEVENT_OBJ="$TEVENT_OBJ tevent_poll.o" AC_CHECK_HEADERS(sys/epoll.h) AC_CHECK_FUNCS(epoll_create) diff --git a/lib/tevent/tevent.c b/lib/tevent/tevent.c index 4849bc162f..87e5aff034 100644 --- a/lib/tevent/tevent.c +++ b/lib/tevent/tevent.c @@ -113,6 +113,7 @@ void tevent_set_default_backend(const char *backend) static void tevent_backend_init(void) { tevent_select_init(); + tevent_poll_init(); tevent_standard_init(); #ifdef HAVE_EPOLL tevent_epoll_init(); diff --git a/lib/tevent/tevent_internal.h b/lib/tevent/tevent_internal.h index 7f5fd64854..3d71bfd034 100644 --- a/lib/tevent/tevent_internal.h +++ b/lib/tevent/tevent_internal.h @@ -303,6 +303,7 @@ void tevent_cleanup_pending_signal_handlers(struct tevent_signal *se); bool tevent_standard_init(void); bool tevent_select_init(void); +bool tevent_poll_init(void); #ifdef HAVE_EPOLL bool tevent_epoll_init(void); #endif diff --git a/lib/tevent/tevent_poll.c b/lib/tevent/tevent_poll.c new file mode 100644 index 0000000000..c133194072 --- /dev/null +++ b/lib/tevent/tevent_poll.c @@ -0,0 +1,306 @@ +/* + Unix SMB/CIFS implementation. + main select loop and event handling + Copyright (C) Andrew Tridgell 2003-2005 + Copyright (C) Stefan Metzmacher 2005-2009 + + ** NOTE! The following LGPL license applies to the tevent + ** library. This does NOT imply that all of Samba is released + ** under the LGPL + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see . +*/ + +#include "replace.h" +#include "system/filesys.h" +#include "system/select.h" +#include "tevent.h" +#include "tevent_util.h" +#include "tevent_internal.h" + +struct poll_event_context { + /* + * These two arrays are maintained together. + */ + struct pollfd *fds; + struct tevent_fd **fd_events; + int num_fds; + + /* information for exiting from the event loop */ + int exit_code; +}; + +/* + create a select_event_context structure. +*/ +static int poll_event_context_init(struct tevent_context *ev) +{ + struct poll_event_context *poll_ev; + + poll_ev = talloc_zero(ev, struct poll_event_context); + if (poll_ev == NULL) { + return -1; + } + ev->additional_data = poll_ev; + return 0; +} + +/* + destroy an fd_event +*/ +static int poll_event_fd_destructor(struct tevent_fd *fde) +{ + struct tevent_context *ev = fde->event_ctx; + struct poll_event_context *poll_ev = NULL; + struct tevent_fd *moved_fde; + int del_idx; + + if (ev == NULL) { + goto done; + } + + poll_ev = talloc_get_type_abort( + ev->additional_data, struct poll_event_context); + + /* + * Assume a void * can carry enough bits to hold num_fds. + */ + del_idx = (int)(fde->additional_data); + + moved_fde = poll_ev->fd_events[poll_ev->num_fds-1]; + poll_ev->fd_events[del_idx] = moved_fde; + poll_ev->fds[del_idx] = poll_ev->fds[poll_ev->num_fds-1]; + moved_fde->additional_data = (void *)del_idx; + + poll_ev->num_fds -= 1; +done: + return tevent_common_fd_destructor(fde); +} + +/* + add a fd based event + return NULL on failure (memory allocation error) +*/ +static struct tevent_fd *poll_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 poll_event_context *poll_ev = talloc_get_type_abort( + ev->additional_data, struct poll_event_context); + struct pollfd *pfd; + struct tevent_fd *fde; + + fde = tevent_common_add_fd(ev, mem_ctx, fd, flags, + handler, private_data, + handler_name, location); + if (fde == NULL) { + return NULL; + } + + /* we allocate 16 slots to avoid a lot of reallocations */ + if (talloc_array_length(poll_ev->fds) == poll_ev->num_fds) { + struct pollfd *tmp_fds; + struct tevent_fd **tmp_fd_events; + tmp_fds = talloc_realloc( + poll_ev, poll_ev->fds, struct pollfd, + poll_ev->num_fds + 16); + if (tmp_fds == NULL) { + TALLOC_FREE(fde); + return NULL; + } + poll_ev->fds = tmp_fds; + + tmp_fd_events = talloc_realloc( + poll_ev, poll_ev->fd_events, struct tevent_fd *, + poll_ev->num_fds + 16); + if (tmp_fd_events == NULL) { + TALLOC_FREE(fde); + return NULL; + } + poll_ev->fd_events = tmp_fd_events; + } + + pfd = &poll_ev->fds[poll_ev->num_fds]; + + pfd->fd = fd; + + pfd->events = 0; + pfd->revents = 0; + + if (flags & TEVENT_FD_READ) { + pfd->events |= (POLLIN|POLLHUP); + } + if (flags & TEVENT_FD_WRITE) { + pfd->events |= (POLLOUT); + } + + /* + * Assume a void * can carry enough bits to hold num_fds. + */ + fde->additional_data = (void *)poll_ev->num_fds; + poll_ev->fd_events[poll_ev->num_fds] = fde; + + poll_ev->num_fds += 1; + + talloc_set_destructor(fde, poll_event_fd_destructor); + + return fde; +} + +/* + set the fd event flags +*/ +static void poll_event_set_fd_flags(struct tevent_fd *fde, uint16_t flags) +{ + struct poll_event_context *poll_ev = talloc_get_type_abort( + fde->event_ctx->additional_data, struct poll_event_context); + int idx; + uint16_t pollflags = 0; + + if (flags & TEVENT_FD_READ) { + pollflags |= (POLLIN|POLLHUP); + } + if (flags & TEVENT_FD_WRITE) { + pollflags |= (POLLOUT); + } + + idx = (int)(fde->additional_data); + poll_ev->fds[idx].events = pollflags; + + fde->flags = flags; +} + +/* + event loop handling using select() +*/ +static int poll_event_loop_poll(struct tevent_context *ev, + struct timeval *tvalp) +{ + struct poll_event_context *poll_ev = talloc_get_type_abort( + ev->additional_data, struct poll_event_context); + struct tevent_fd *fde; + int pollrtn; + int timeout = -1; + + if (ev->signal_events && tevent_common_check_signal(ev)) { + return 0; + } + + if (tvalp != NULL) { + timeout = tvalp->tv_sec * 1000; + timeout += (tvalp->tv_usec + 999) / 1000; + } + + pollrtn = poll(poll_ev->fds, poll_ev->num_fds, timeout); + + if (pollrtn == -1 && errno == EINTR && ev->signal_events) { + tevent_common_check_signal(ev); + return 0; + } + + if (pollrtn == -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(ev, TEVENT_DEBUG_FATAL, + "ERROR: EBADF on poll_event_loop_once\n"); + poll_ev->exit_code = EBADF; + return -1; + } + + if (pollrtn == 0 && tvalp) { + /* we don't care about a possible delay here */ + tevent_common_loop_timer_delay(ev); + return 0; + } + + if (pollrtn > 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 = ev->fd_events; fde; fde = fde->next) { + struct pollfd *pfd; + int pfd_idx; + uint16_t flags = 0; + + pfd_idx = (int)(fde->additional_data); + + pfd = &poll_ev->fds[pfd_idx]; + + if (pfd->revents & (POLLIN|POLLHUP|POLLERR)) { + flags |= TEVENT_FD_READ; + } + if (pfd->revents & POLLOUT) { + flags |= TEVENT_FD_WRITE; + } + if (flags != 0) { + fde->handler(ev, fde, flags, + fde->private_data); + break; + } + } + } + + return 0; +} + +/* + do a single event loop using the events defined in ev +*/ +static int poll_event_loop_once(struct tevent_context *ev, + const char *location) +{ + 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; + } + + return poll_event_loop_poll(ev, &tval); +} + +static const struct tevent_ops poll_event_ops = { + .context_init = poll_event_context_init, + .add_fd = poll_event_add_fd, + .set_fd_close_fn = tevent_common_fd_set_close_fn, + .get_fd_flags = tevent_common_fd_get_flags, + .set_fd_flags = poll_event_set_fd_flags, + .add_timer = tevent_common_add_timer, + .schedule_immediate = tevent_common_schedule_immediate, + .add_signal = tevent_common_add_signal, + .loop_once = poll_event_loop_once, + .loop_wait = tevent_common_loop_wait, +}; + +_PRIVATE_ bool tevent_poll_init(void) +{ + return tevent_register_backend("poll", &poll_event_ops); +} diff --git a/lib/tevent/wscript b/lib/tevent/wscript index 6074a3e863..b82a41f573 100644 --- a/lib/tevent/wscript +++ b/lib/tevent/wscript @@ -61,6 +61,7 @@ def build(bld): SRC = '''tevent.c tevent_debug.c tevent_fd.c tevent_immediate.c tevent_queue.c tevent_req.c tevent_select.c + tevent_poll.c tevent_signal.c tevent_standard.c tevent_timed.c tevent_util.c tevent_wakeup.c''' if bld.CONFIG_SET('HAVE_EPOLL'): -- cgit