2 * Copyright (c) 2019 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #include <vppinfra/fifo.h>
17 #include <vppinfra/pool.h>
18 #include <vppinfra/hash.h>
19 #include <vnet/api_errno.h>
21 #include <vcl/vcl_event.h>
24 * @brief VPP Communications Library (VCL) event handler.
26 * Definitions for generic event handling in VCL.
30 vce_generate_event (vce_event_thread_t *evt, u32 ev_idx)
35 pthread_mutex_lock (&(evt->generator_lock));
37 /* Check there is event data for this event */
39 clib_spinlock_lock (&(evt->events_lockp));
40 p = pool_elt_at_index (evt->vce_events, ev_idx);
43 elts = (int) clib_fifo_free_elts (evt->event_index_fifo);
44 if (PREDICT_TRUE (elts))
46 /* Add event to queue */
47 clib_fifo_add1 (evt->event_index_fifo, ev_idx);
48 pthread_cond_signal (&(evt->generator_cond));
52 rv = VNET_API_ERROR_QUEUE_FULL;
55 clib_spinlock_unlock (&(evt->events_lockp));
56 pthread_mutex_unlock (&(evt->generator_lock));
62 vce_clear_event (vce_event_thread_t *evt, u32 ev_idx)
64 clib_spinlock_lock (&(evt->events_lockp));
65 pool_put_index (evt->vce_events, ev_idx);
66 clib_spinlock_unlock (&(evt->events_lockp));
70 vce_get_event_from_index(vce_event_thread_t *evt, u32 ev_idx)
73 /* Assumes caller has obtained the spinlock (evt->events_lockp) */
75 if ( ! pool_is_free_index (evt->vce_events, ev_idx))
76 ev = pool_elt_at_index (evt->vce_events, ev_idx);
81 vce_event_handler_reg_t *
82 vce_get_event_handler (vce_event_thread_t *evt, vce_event_key_t *evk)
84 vce_event_handler_reg_t *handler = 0;
87 clib_spinlock_lock (&evt->handlers_lockp);
88 p = hash_get (evt->handlers_index_by_event_key, evk->as_u64);
90 handler = pool_elt_at_index (evt->vce_event_handlers, p[0]);
91 clib_spinlock_unlock (&evt->handlers_lockp);
96 vce_event_handler_reg_t *
97 vce_register_handler (vce_event_thread_t *evt, vce_event_key_t *evk,
98 vce_event_callback_t cb, void *cb_args)
100 vce_event_handler_reg_t *handler;
101 vce_event_handler_reg_t *old_handler = 0;
105 /* TODO - multiple handler support. For now we can replace
106 * and re-instate, which is useful for event recycling */
108 clib_spinlock_lock (&evt->handlers_lockp);
110 p = hash_get (evt->handlers_index_by_event_key, evk->as_u64);
113 old_handler = pool_elt_at_index (evt->vce_event_handlers, p[0]);
114 /* If we are just re-registering, ignore and move on
115 * else store the old handler_fn for unregister to re-instate */
116 if (old_handler->handler_fn == cb)
119 clib_spinlock_unlock (&evt->handlers_lockp);
121 /* Signal event thread that a handler exists in case any
122 * recycled events requiring this handler are pending */
123 pthread_mutex_lock (&(evt->generator_lock));
124 pthread_cond_signal (&(evt->generator_cond));
125 pthread_mutex_unlock (&(evt->generator_lock));
130 pool_get (evt->vce_event_handlers, handler);
131 handler_index = (u32) (handler - evt->vce_event_handlers);
133 handler->handler_fn = cb;
134 handler->replaced_handler_idx = (u32) ((p) ? p[0] : ~0);
135 handler->ev_idx = (u32) ~0; //This will be set by the event thread if event happens
136 handler->evk = evk->as_u64;
137 handler->handler_fn_args = cb_args;
139 hash_set (evt->handlers_index_by_event_key, evk->as_u64, handler_index);
141 pthread_cond_init (&(handler->handler_cond), NULL);
142 pthread_mutex_init (&(handler->handler_lock), NULL);
144 clib_spinlock_unlock (&evt->handlers_lockp);
146 /* Signal event thread that a new handler exists in case any
147 * recycled events requiring this handler are pending */
148 pthread_mutex_lock (&(evt->generator_lock));
149 pthread_cond_signal (&(evt->generator_cond));
150 pthread_mutex_unlock (&(evt->generator_lock));
156 vce_unregister_handler (vce_event_thread_t *evt,
157 vce_event_handler_reg_t *handler)
160 u64 evk = handler->evk;
161 u8 generate_signal = 0;
163 clib_spinlock_lock (&evt->handlers_lockp);
165 p = hash_get (evt->handlers_index_by_event_key, evk);
168 clib_spinlock_unlock (&evt->handlers_lockp);
169 return VNET_API_ERROR_NO_SUCH_ENTRY;
172 handler = pool_elt_at_index (evt->vce_event_handlers, p[0]);
174 /* If this handler replaced another handler, re-instate it */
175 if (handler->replaced_handler_idx != ~0)
177 hash_set (evt->handlers_index_by_event_key, evk,
178 handler->replaced_handler_idx);
183 hash_unset (evt->handlers_index_by_event_key, evk);
186 pthread_mutex_destroy (&(handler->handler_lock));
187 pthread_cond_destroy (&(handler->handler_cond));
188 pool_put (evt->vce_event_handlers, handler);
190 clib_spinlock_unlock (&evt->handlers_lockp);
194 /* Signal event thread that a new handler exists in case any
195 * recycled events requiring this handler are pending */
196 pthread_mutex_lock (&(evt->generator_lock));
197 pthread_cond_signal (&(evt->generator_cond));
198 pthread_mutex_unlock (&(evt->generator_lock));
205 vce_event_thread_fn (void *arg)
207 vce_event_thread_t *evt = (vce_event_thread_t *) arg;
210 vce_event_handler_reg_t *handler;
212 u32 recycle_count = 0;
214 pthread_mutex_lock (&(evt->generator_lock));
217 uword fifo_depth = clib_fifo_elts (evt->event_index_fifo);
218 while ((fifo_depth == 0) || (recycle_count == fifo_depth))
221 pthread_cond_wait (&(evt->generator_cond), &(evt->generator_lock));
222 fifo_depth = clib_fifo_elts (evt->event_index_fifo);
226 clib_spinlock_lock (&(evt->events_lockp));
227 clib_fifo_sub1 (evt->event_index_fifo, ev_idx);
228 ev = vce_get_event_from_index (evt, ev_idx);
230 if (recycle_count && ev->recycle)
232 clib_fifo_add1 (evt->event_index_fifo, ev_idx);
233 clib_spinlock_unlock (&(evt->events_lockp));
236 clib_spinlock_lock (&evt->handlers_lockp);
238 p = hash_get (evt->handlers_index_by_event_key, ev->evk.as_u64);
241 /* If an event falls in the woods, and there is no handler to hear it,
242 * does it make any sound?
243 * I don't know either, so lets biff the event */
244 pool_put(evt->vce_events, ev);
245 clib_spinlock_unlock (&(evt->events_lockp));
246 clib_spinlock_unlock (&evt->handlers_lockp);
247 pthread_mutex_unlock (&(evt->generator_lock));
251 u32 evt_recycle = ev->recycle;
252 handler = pool_elt_at_index (evt->vce_event_handlers, p[0]);
253 handler->ev_idx = ev_idx;
256 clib_spinlock_unlock (&(evt->events_lockp));
257 clib_spinlock_unlock (&evt->handlers_lockp);
258 pthread_mutex_unlock (&(evt->generator_lock));
260 (handler->handler_fn)(handler);
262 clib_spinlock_lock (&(evt->events_lockp));
263 ev = vce_get_event_from_index (evt, ev_idx);
264 recycle_count += (!evt_recycle && ev && ev->recycle) ? 1 : 0;
265 clib_spinlock_unlock(&(evt->events_lockp));
268 pthread_mutex_lock (&(evt->generator_lock));
274 vce_start_event_thread (vce_event_thread_t *evt, u8 max_events)
276 clib_fifo_validate (evt->event_index_fifo, max_events);
277 evt->handlers_index_by_event_key = hash_create (0, sizeof (uword));
279 pthread_cond_init (&(evt->generator_cond), NULL);
280 pthread_mutex_init (&(evt->generator_lock), NULL);
282 clib_spinlock_init (&(evt->events_lockp));
283 clib_spinlock_init (&(evt->handlers_lockp));
285 return pthread_create (&(evt->thread), NULL /* attr */ ,
286 vce_event_thread_fn, evt);