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-rw-r--r--tevent_queue.c462
1 files changed, 462 insertions, 0 deletions
diff --git a/tevent_queue.c b/tevent_queue.c
new file mode 100644
index 0000000..8f0e6a5
--- /dev/null
+++ b/tevent_queue.c
@@ -0,0 +1,462 @@
+/*
+ Unix SMB/CIFS implementation.
+ Infrastructure for async requests
+ Copyright (C) Volker Lendecke 2008
+ 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"
+#include "tevent.h"
+#include "tevent_internal.h"
+#include "tevent_util.h"
+
+#undef tevent_queue_add
+#undef tevent_queue_add_entry
+#undef tevent_queue_add_optimize_empty
+
+struct tevent_queue_entry {
+ struct tevent_queue_entry *prev, *next;
+ struct tevent_queue *queue;
+
+ bool triggered;
+
+ struct tevent_req *req;
+ struct tevent_context *ev;
+
+ tevent_queue_trigger_fn_t trigger;
+ const char *trigger_name;
+ void *private_data;
+ uint64_t tag;
+};
+
+struct tevent_queue {
+ const char *name;
+ const char *location;
+
+ bool running;
+ struct tevent_immediate *immediate;
+
+ size_t length;
+ struct tevent_queue_entry *list;
+};
+
+static void tevent_queue_immediate_trigger(struct tevent_context *ev,
+ struct tevent_immediate *im,
+ void *private_data);
+
+static int tevent_queue_entry_destructor(struct tevent_queue_entry *e)
+{
+ struct tevent_queue *q = e->queue;
+
+ if (!q) {
+ return 0;
+ }
+
+ tevent_trace_queue_callback(q->list->ev, e, TEVENT_EVENT_TRACE_DETACH);
+ tevent_thread_call_depth_notify(TEVENT_CALL_FLOW_REQ_QUEUE_LEAVE,
+ q->list->req,
+ q->list->req->internal.call_depth,
+ e->trigger_name);
+ DLIST_REMOVE(q->list, e);
+ q->length--;
+
+ if (!q->running) {
+ return 0;
+ }
+
+ if (!q->list) {
+ return 0;
+ }
+
+ if (q->list->triggered) {
+ return 0;
+ }
+
+ tevent_schedule_immediate(q->immediate,
+ q->list->ev,
+ tevent_queue_immediate_trigger,
+ q);
+
+ return 0;
+}
+
+static int tevent_queue_destructor(struct tevent_queue *q)
+{
+ q->running = false;
+
+ while (q->list) {
+ struct tevent_queue_entry *e = q->list;
+ talloc_free(e);
+ }
+
+ return 0;
+}
+
+struct tevent_queue *_tevent_queue_create(TALLOC_CTX *mem_ctx,
+ const char *name,
+ const char *location)
+{
+ struct tevent_queue *queue;
+
+ queue = talloc_zero(mem_ctx, struct tevent_queue);
+ if (!queue) {
+ return NULL;
+ }
+
+ queue->name = talloc_strdup(queue, name);
+ if (!queue->name) {
+ talloc_free(queue);
+ return NULL;
+ }
+ queue->immediate = tevent_create_immediate(queue);
+ if (!queue->immediate) {
+ talloc_free(queue);
+ return NULL;
+ }
+
+ queue->location = location;
+
+ /* queue is running by default */
+ queue->running = true;
+
+ talloc_set_destructor(queue, tevent_queue_destructor);
+ return queue;
+}
+
+static void tevent_queue_immediate_trigger(struct tevent_context *ev,
+ struct tevent_immediate *im,
+ void *private_data)
+{
+ struct tevent_queue *q =
+ talloc_get_type_abort(private_data,
+ struct tevent_queue);
+
+ if (!q->running) {
+ return;
+ }
+
+ if (!q->list) {
+ return;
+ }
+
+ tevent_trace_queue_callback(ev, q->list,
+ TEVENT_EVENT_TRACE_BEFORE_HANDLER);
+ /* Set the call depth of the request coming from the queue. */
+ tevent_thread_call_depth_notify(TEVENT_CALL_FLOW_REQ_QUEUE_TRIGGER,
+ q->list->req,
+ q->list->req->internal.call_depth,
+ q->list->trigger_name);
+ q->list->triggered = true;
+ q->list->trigger(q->list->req, q->list->private_data);
+}
+
+static void tevent_queue_noop_trigger(struct tevent_req *req,
+ void *_private_data)
+{
+ /* this is doing nothing but blocking the queue */
+}
+
+static struct tevent_queue_entry *tevent_queue_add_internal(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ const char *trigger_name,
+ void *private_data,
+ bool allow_direct)
+{
+ struct tevent_queue_entry *e;
+
+ e = talloc_zero(req, struct tevent_queue_entry);
+ if (e == NULL) {
+ return NULL;
+ }
+
+ /*
+ * if there is no trigger, it is just a blocker
+ */
+ if (trigger == NULL) {
+ trigger = tevent_queue_noop_trigger;
+ }
+
+ e->queue = queue;
+ e->req = req;
+ e->ev = ev;
+ e->trigger = trigger;
+ e->trigger_name = trigger_name;
+ e->private_data = private_data;
+
+ if (queue->length > 0) {
+ /*
+ * if there are already entries in the
+ * queue do not optimize.
+ */
+ allow_direct = false;
+ }
+
+ if (req->async.fn != NULL) {
+ /*
+ * If the caller wants to optimize for the
+ * empty queue case, call the trigger only
+ * if there is no callback defined for the
+ * request yet.
+ */
+ allow_direct = false;
+ }
+
+ DLIST_ADD_END(queue->list, e);
+ queue->length++;
+ talloc_set_destructor(e, tevent_queue_entry_destructor);
+ tevent_trace_queue_callback(ev, e, TEVENT_EVENT_TRACE_ATTACH);
+ tevent_thread_call_depth_notify(TEVENT_CALL_FLOW_REQ_QUEUE_ENTER,
+ req,
+ req->internal.call_depth,
+ e->trigger_name);
+
+ if (!queue->running) {
+ return e;
+ }
+
+ if (queue->list->triggered) {
+ return e;
+ }
+
+ /*
+ * If allowed we directly call the trigger
+ * avoiding possible delays caused by
+ * an immediate event.
+ */
+ if (allow_direct) {
+ tevent_trace_queue_callback(ev,
+ queue->list,
+ TEVENT_EVENT_TRACE_BEFORE_HANDLER);
+ queue->list->triggered = true;
+ queue->list->trigger(queue->list->req,
+ queue->list->private_data);
+ return e;
+ }
+
+ tevent_schedule_immediate(queue->immediate,
+ queue->list->ev,
+ tevent_queue_immediate_trigger,
+ queue);
+
+ return e;
+}
+
+bool tevent_queue_add(struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ void *private_data)
+{
+ return _tevent_queue_add(queue, ev, req, trigger, NULL, private_data);
+}
+
+bool _tevent_queue_add(struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ const char* trigger_name,
+ void *private_data)
+{
+ struct tevent_queue_entry *e;
+
+ e = tevent_queue_add_internal(queue, ev, req,
+ trigger, trigger_name,
+ private_data, false);
+ if (e == NULL) {
+ return false;
+ }
+
+ return true;
+}
+
+struct tevent_queue_entry *tevent_queue_add_entry(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ void *private_data)
+{
+ return _tevent_queue_add_entry(queue, ev, req,
+ trigger, NULL,
+ private_data);
+}
+
+struct tevent_queue_entry *_tevent_queue_add_entry(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ const char* trigger_name,
+ void *private_data)
+{
+ return tevent_queue_add_internal(queue, ev, req,
+ trigger, trigger_name,
+ private_data, false);
+}
+
+struct tevent_queue_entry *tevent_queue_add_optimize_empty(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ void *private_data)
+{
+ return _tevent_queue_add_optimize_empty(queue, ev, req,
+ trigger, NULL,
+ private_data);
+}
+
+struct tevent_queue_entry *_tevent_queue_add_optimize_empty(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ const char* trigger_name,
+ void *private_data)
+{
+ return tevent_queue_add_internal(queue, ev, req,
+ trigger, trigger_name,
+ private_data, true);
+}
+
+void tevent_queue_entry_untrigger(struct tevent_queue_entry *entry)
+{
+ if (entry->queue->running) {
+ abort();
+ }
+
+ if (entry->queue->list != entry) {
+ abort();
+ }
+
+ entry->triggered = false;
+}
+
+void tevent_queue_start(struct tevent_queue *queue)
+{
+ if (queue->running) {
+ /* already started */
+ return;
+ }
+
+ queue->running = true;
+
+ if (!queue->list) {
+ return;
+ }
+
+ if (queue->list->triggered) {
+ return;
+ }
+
+ tevent_schedule_immediate(queue->immediate,
+ queue->list->ev,
+ tevent_queue_immediate_trigger,
+ queue);
+}
+
+void tevent_queue_stop(struct tevent_queue *queue)
+{
+ queue->running = false;
+}
+
+size_t tevent_queue_length(struct tevent_queue *queue)
+{
+ return queue->length;
+}
+
+bool tevent_queue_running(struct tevent_queue *queue)
+{
+ return queue->running;
+}
+
+struct tevent_queue_wait_state {
+ uint8_t dummy;
+};
+
+static void tevent_queue_wait_trigger(struct tevent_req *req,
+ void *private_data);
+
+struct tevent_req *tevent_queue_wait_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ struct tevent_queue *queue)
+{
+ struct tevent_req *req;
+ struct tevent_queue_wait_state *state;
+ bool ok;
+
+ req = tevent_req_create(mem_ctx, &state,
+ struct tevent_queue_wait_state);
+ if (req == NULL) {
+ return NULL;
+ }
+
+ ok = _tevent_queue_add(queue, ev, req,
+ tevent_queue_wait_trigger,
+ "tevent_queue_wait_trigger",
+ NULL);
+ if (!ok) {
+ tevent_req_oom(req);
+ return tevent_req_post(req, ev);
+ }
+
+ return req;
+}
+
+static void tevent_queue_wait_trigger(struct tevent_req *req,
+ void *private_data)
+{
+ tevent_req_done(req);
+}
+
+bool tevent_queue_wait_recv(struct tevent_req *req)
+{
+ enum tevent_req_state state;
+ uint64_t err;
+
+ if (tevent_req_is_error(req, &state, &err)) {
+ tevent_req_received(req);
+ return false;
+ }
+
+ tevent_req_received(req);
+ return true;
+}
+
+void tevent_queue_entry_set_tag(struct tevent_queue_entry *qe, uint64_t tag)
+{
+ if (qe == NULL) {
+ return;
+ }
+
+ qe->tag = tag;
+}
+
+uint64_t tevent_queue_entry_get_tag(const struct tevent_queue_entry *qe)
+{
+ if (qe == NULL) {
+ return 0;
+ }
+
+ return qe->tag;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-07 05:05:53 +0000