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Diffstat (limited to '')
| -rw-r--r-- | tevent_immediate.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/tevent_immediate.c b/tevent_immediate.c new file mode 100644 index 0000000..82f92f1 --- /dev/null +++ b/tevent_immediate.c @@ -0,0 +1,261 @@ +/* + Unix SMB/CIFS implementation. + + common events code for immediate events + + Copyright (C) Stefan Metzmacher 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 <http://www.gnu.org/licenses/>. +*/ + +#include "replace.h" +#define TEVENT_DEPRECATED 1 +#include "tevent.h" +#include "tevent_internal.h" +#include "tevent_util.h" + +static void tevent_common_immediate_cancel(struct tevent_immediate *im) +{ + const char *create_location = im->create_location; + bool busy = im->busy; + uint64_t tag = im->tag; + struct tevent_context *detach_ev_ctx = NULL; + + if (im->destroyed) { + tevent_abort(im->event_ctx, "tevent_immediate use after free"); + return; + } + + if (im->detach_ev_ctx != NULL) { + detach_ev_ctx = im->detach_ev_ctx; + im->detach_ev_ctx = NULL; + tevent_trace_immediate_callback(detach_ev_ctx, + im, + TEVENT_EVENT_TRACE_DETACH); + return; + } + + if (!im->event_ctx) { + return; + } + + if (im->handler_name != NULL) { + TEVENT_DEBUG(im->event_ctx, TEVENT_DEBUG_TRACE, + "Cancel immediate event %p \"%s\"\n", + im, im->handler_name); + } + + /* let the backend free im->additional_data */ + if (im->cancel_fn) { + im->cancel_fn(im); + } + + if (busy && im->handler_name == NULL) { + detach_ev_ctx = im->event_ctx; + } else { + tevent_trace_immediate_callback(im->event_ctx, + im, + TEVENT_EVENT_TRACE_DETACH); + } + DLIST_REMOVE(im->event_ctx->immediate_events, im); + + *im = (struct tevent_immediate) { + .create_location = create_location, + .busy = busy, + .tag = tag, + .detach_ev_ctx = detach_ev_ctx, + }; + + if (!busy) { + talloc_set_destructor(im, NULL); + } +} + +/* + destroy an immediate event +*/ +static int tevent_common_immediate_destructor(struct tevent_immediate *im) +{ + if (im->destroyed) { + tevent_common_check_double_free(im, + "tevent_immediate double free"); + goto done; + } + + tevent_common_immediate_cancel(im); + + im->destroyed = true; + +done: + if (im->busy) { + return -1; + } + + return 0; +} + +/* + * schedule an immediate event on + */ +void tevent_common_schedule_immediate(struct tevent_immediate *im, + struct tevent_context *ev, + tevent_immediate_handler_t handler, + void *private_data, + const char *handler_name, + const char *location) +{ + const char *create_location = im->create_location; + bool busy = im->busy; + uint64_t tag = im->tag; + struct tevent_wrapper_glue *glue = im->wrapper; + + tevent_common_immediate_cancel(im); + + if (!handler) { + return; + } + + *im = (struct tevent_immediate) { + .event_ctx = ev, + .wrapper = glue, + .handler = handler, + .private_data = private_data, + .handler_name = handler_name, + .create_location = create_location, + .schedule_location = location, + .busy = busy, + .tag = tag, + }; + + tevent_trace_immediate_callback(im->event_ctx, im, TEVENT_EVENT_TRACE_ATTACH); + DLIST_ADD_END(ev->immediate_events, im); + talloc_set_destructor(im, tevent_common_immediate_destructor); + + TEVENT_DEBUG(ev, TEVENT_DEBUG_TRACE, + "Schedule immediate event \"%s\": %p\n", + handler_name, im); +} + +int tevent_common_invoke_immediate_handler(struct tevent_immediate *im, + bool *removed) +{ + struct tevent_context *handler_ev = im->event_ctx; + struct tevent_context *ev = im->event_ctx; + struct tevent_immediate cur = *im; + + if (removed != NULL) { + *removed = false; + } + + TEVENT_DEBUG(ev, TEVENT_DEBUG_TRACE, + "Run immediate event \"%s\": %p\n", + im->handler_name, im); + + /* + * remember the handler and then clear the event + * the handler might reschedule the event + */ + + im->busy = true; + im->handler_name = NULL; + tevent_common_immediate_cancel(im); + if (cur.wrapper != NULL) { + handler_ev = cur.wrapper->wrap_ev; + + tevent_wrapper_push_use_internal(handler_ev, cur.wrapper); + cur.wrapper->ops->before_immediate_handler( + cur.wrapper->wrap_ev, + cur.wrapper->private_state, + cur.wrapper->main_ev, + im, + cur.handler_name, + cur.schedule_location); + } + tevent_trace_immediate_callback(cur.event_ctx, im, TEVENT_EVENT_TRACE_BEFORE_HANDLER); + cur.handler(handler_ev, im, cur.private_data); + if (cur.wrapper != NULL) { + cur.wrapper->ops->after_immediate_handler( + cur.wrapper->wrap_ev, + cur.wrapper->private_state, + cur.wrapper->main_ev, + im, + cur.handler_name, + cur.schedule_location); + tevent_wrapper_pop_use_internal(handler_ev, cur.wrapper); + } + im->busy = false; + + /* The event was removed in tevent_common_immediate_cancel(). */ + if (im->detach_ev_ctx != NULL) { + struct tevent_context *detach_ev_ctx = im->detach_ev_ctx; + im->detach_ev_ctx = NULL; + tevent_trace_immediate_callback(detach_ev_ctx, + im, + TEVENT_EVENT_TRACE_DETACH); + } + + if (im->destroyed) { + talloc_set_destructor(im, NULL); + TALLOC_FREE(im); + if (removed != NULL) { + *removed = true; + } + } + + return 0; +} + +/* + trigger the first immediate event and return true + if no event was triggered return false +*/ +bool tevent_common_loop_immediate(struct tevent_context *ev) +{ + struct tevent_immediate *im = ev->immediate_events; + int ret; + + if (!im) { + return false; + } + + ret = tevent_common_invoke_immediate_handler(im, NULL); + if (ret != 0) { + tevent_abort(ev, "tevent_common_invoke_immediate_handler() failed"); + } + + return true; +} + + +void tevent_immediate_set_tag(struct tevent_immediate *im, uint64_t tag) +{ + if (im == NULL) { + return; + } + + im->tag = tag; +} + +uint64_t tevent_immediate_get_tag(const struct tevent_immediate *im) +{ + if (im == NULL) { + return 0; + } + + return im->tag; +} |