4 * Copyright(c) 2015 Intel Corporation. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * * Neither the name of Intel Corporation nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 * Some portions of this software is derived from the
36 * https://github.com/halayli/lthread which carrys the following license.
38 * Copyright (C) 2012, Hasan Alayli <halayli@gmail.com>
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
49 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
80 #include "lthread_api.h"
82 #include "lthread_timer.h"
83 #include "lthread_tls.h"
84 #include "lthread_objcache.h"
85 #include "lthread_diag.h"
89 * This function gets called after an lthread function has returned.
91 void _lthread_exit_handler(struct lthread *lt)
94 lt->state |= BIT(ST_LT_EXITED);
96 if (!(lt->state & BIT(ST_LT_DETACH))) {
97 /* thread is this not explicitly detached
98 * it must be joinable, so we call lthread_exit().
103 /* if we get here the thread is detached so we can reschedule it,
104 * allowing the scheduler to free it
111 * Free resources allocated to an lthread
113 void _lthread_free(struct lthread *lt)
116 DIAG_EVENT(lt, LT_DIAG_LTHREAD_FREE, lt, 0);
118 /* invoke any user TLS destructor functions */
119 _lthread_tls_destroy(lt);
121 /* free memory allocated for TLS defined using RTE_PER_LTHREAD macros */
122 if (sizeof(void *) < (uint64_t)RTE_PER_LTHREAD_SECTION_SIZE)
123 _lthread_objcache_free(lt->tls->root_sched->per_lthread_cache,
124 lt->per_lthread_data);
126 /* free pthread style TLS memory */
127 _lthread_objcache_free(lt->tls->root_sched->tls_cache, lt->tls);
130 _lthread_objcache_free(lt->stack_container->root_sched->stack_cache,
131 lt->stack_container);
133 /* now free the thread */
134 _lthread_objcache_free(lt->root_sched->lthread_cache, lt);
139 * Allocate a stack and maintain a cache of stacks
141 struct lthread_stack *_stack_alloc(void)
143 struct lthread_stack *s;
145 s = _lthread_objcache_alloc((THIS_SCHED)->stack_cache);
146 RTE_ASSERT(s != NULL);
148 s->root_sched = THIS_SCHED;
149 s->stack_size = LTHREAD_MAX_STACK_SIZE;
154 * Execute a ctx by invoking the start function
155 * On return call an exit handler if the user has provided one
157 static void _lthread_exec(void *arg)
159 struct lthread *lt = (struct lthread *)arg;
161 /* invoke the contexts function */
163 /* do exit handling */
164 if (lt->exit_handler != NULL)
165 lt->exit_handler(lt);
169 * Initialize an lthread
170 * Set its function, args, and exit handler
173 _lthread_init(struct lthread *lt,
174 lthread_func_t fun, void *arg, lthread_exit_func exit_handler)
177 /* set ctx func and args */
180 lt->exit_handler = exit_handler;
182 /* set initial state */
183 lt->birth = _sched_now();
184 lt->state = BIT(ST_LT_INIT);
185 lt->join = LT_JOIN_INITIAL;
189 * set the lthread stack
191 void _lthread_set_stack(struct lthread *lt, void *stack, size_t stack_size)
193 char *stack_top = (char *)stack + stack_size;
194 void **s = (void **)stack_top;
198 lt->stack_size = stack_size;
200 /* set initial context */
203 lt->ctx.rsp = (void *)(stack_top - (4 * sizeof(void *)));
204 lt->ctx.rbp = (void *)(stack_top - (3 * sizeof(void *)));
205 lt->ctx.rip = (void *)_lthread_exec;
209 * Create an lthread on the current scheduler
210 * If there is no current scheduler on this pthread then first create one
213 lthread_create(struct lthread **new_lt, int lcore_id,
214 lthread_func_t fun, void *arg)
216 if ((new_lt == NULL) || (fun == NULL))
217 return POSIX_ERRNO(EINVAL);
220 lcore_id = rte_lcore_id();
221 else if (lcore_id > LTHREAD_MAX_LCORES)
222 return POSIX_ERRNO(EINVAL);
224 struct lthread *lt = NULL;
226 if (THIS_SCHED == NULL) {
227 THIS_SCHED = _lthread_sched_create(0);
228 if (THIS_SCHED == NULL) {
229 perror("Failed to create scheduler");
230 return POSIX_ERRNO(EAGAIN);
234 /* allocate a thread structure */
235 lt = _lthread_objcache_alloc((THIS_SCHED)->lthread_cache);
237 return POSIX_ERRNO(EAGAIN);
239 bzero(lt, sizeof(struct lthread));
240 lt->root_sched = THIS_SCHED;
242 /* set the function args and exit handlder */
243 _lthread_init(lt, fun, arg, _lthread_exit_handler);
245 /* put it in the ready queue */
249 lcore_id = rte_lcore_id();
251 DIAG_CREATE_EVENT(lt, LT_DIAG_LTHREAD_CREATE);
254 _ready_queue_insert(_lthread_sched_get(lcore_id), lt);
259 * Schedules lthread to sleep for `nsecs`
260 * setting the lthread state to LT_ST_SLEEPING.
261 * lthread state is cleared upon resumption or expiry.
263 static inline void _lthread_sched_sleep(struct lthread *lt, uint64_t nsecs)
265 uint64_t state = lt->state;
266 uint64_t clks = _ns_to_clks(nsecs);
269 _timer_start(lt, clks);
270 lt->state = state | BIT(ST_LT_SLEEPING);
272 DIAG_EVENT(lt, LT_DIAG_LTHREAD_SLEEP, clks, 0);
279 * Cancels any running timer.
280 * This can be called multiple times on the same lthread regardless if it was
283 int _lthread_desched_sleep(struct lthread *lt)
285 uint64_t state = lt->state;
287 if (state & BIT(ST_LT_SLEEPING)) {
289 state &= (CLEARBIT(ST_LT_SLEEPING) & CLEARBIT(ST_LT_EXPIRED));
290 lt->state = state | BIT(ST_LT_READY);
297 * set user data pointer in an lthread
299 void lthread_set_data(void *data)
301 if (sizeof(void *) == RTE_PER_LTHREAD_SECTION_SIZE)
302 THIS_LTHREAD->per_lthread_data = data;
306 * Retrieve user data pointer from an lthread
308 void *lthread_get_data(void)
310 return THIS_LTHREAD->per_lthread_data;
314 * Return the current lthread handle
316 struct lthread *lthread_current(void)
318 struct lthread_sched *sched = THIS_SCHED;
321 return sched->current_lthread;
328 * Tasklet to cancel a thread
333 struct lthread *lt = (struct lthread *) arg;
335 lt->state |= BIT(ST_LT_CANCELLED);
341 * Mark the specified as canceled
343 int lthread_cancel(struct lthread *cancel_lt)
347 if ((cancel_lt == NULL) || (cancel_lt == THIS_LTHREAD))
348 return POSIX_ERRNO(EINVAL);
350 DIAG_EVENT(cancel_lt, LT_DIAG_LTHREAD_CANCEL, cancel_lt, 0);
352 if (cancel_lt->sched != THIS_SCHED) {
354 /* spawn task-let to cancel the thread */
356 cancel_lt->sched->lcore_id,
361 cancel_lt->state |= BIT(ST_LT_CANCELLED);
366 * Suspend the current lthread for specified time
368 void lthread_sleep(uint64_t nsecs)
370 struct lthread *lt = THIS_LTHREAD;
372 _lthread_sched_sleep(lt, nsecs);
377 * Suspend the current lthread for specified time
379 void lthread_sleep_clks(uint64_t clks)
381 struct lthread *lt = THIS_LTHREAD;
382 uint64_t state = lt->state;
385 _timer_start(lt, clks);
386 lt->state = state | BIT(ST_LT_SLEEPING);
388 DIAG_EVENT(lt, LT_DIAG_LTHREAD_SLEEP, clks, 0);
393 * Requeue the current thread to the back of the ready queue
395 void lthread_yield(void)
397 struct lthread *lt = THIS_LTHREAD;
399 DIAG_EVENT(lt, LT_DIAG_LTHREAD_YIELD, 0, 0);
401 _ready_queue_insert(THIS_SCHED, lt);
402 ctx_switch(&(THIS_SCHED)->ctx, <->ctx);
406 * Exit the current lthread
407 * If a thread is joining pass the user pointer to it
409 void lthread_exit(void *ptr)
411 struct lthread *lt = THIS_LTHREAD;
413 /* if thread is detached (this is not valid) just exit */
414 if (lt->state & BIT(ST_LT_DETACH))
417 /* There is a race between lthread_join() and lthread_exit()
418 * - if exit before join then we suspend and resume on join
419 * - if join before exit then we resume the joining thread
421 if ((lt->join == LT_JOIN_INITIAL)
422 && rte_atomic64_cmpset(<->join, LT_JOIN_INITIAL,
425 DIAG_EVENT(lt, LT_DIAG_LTHREAD_EXIT, 1, 0);
427 /* set the exit value */
428 if ((ptr != NULL) && (lt->lt_join->lt_exit_ptr != NULL))
429 *(lt->lt_join->lt_exit_ptr) = ptr;
431 /* let the joining thread know we have set the exit value */
432 lt->join = LT_JOIN_EXIT_VAL_SET;
435 DIAG_EVENT(lt, LT_DIAG_LTHREAD_EXIT, 0, 0);
436 /* set the exit value */
437 if ((ptr != NULL) && (lt->lt_join->lt_exit_ptr != NULL))
438 *(lt->lt_join->lt_exit_ptr) = ptr;
439 /* let the joining thread know we have set the exit value */
440 lt->join = LT_JOIN_EXIT_VAL_SET;
441 _ready_queue_insert(lt->lt_join->sched,
442 (struct lthread *)lt->lt_join);
446 /* wait until the joinging thread has collected the exit value */
447 while (lt->join != LT_JOIN_EXIT_VAL_READ)
450 /* reset join state */
451 lt->join = LT_JOIN_INITIAL;
453 /* detach it so its resources can be released */
454 lt->state |= (BIT(ST_LT_DETACH) | BIT(ST_LT_EXITED));
459 * Suspend until the joined thread returns
461 int lthread_join(struct lthread *lt, void **ptr)
464 return POSIX_ERRNO(EINVAL);
466 struct lthread *current = THIS_LTHREAD;
467 uint64_t lt_state = lt->state;
469 /* invalid to join a detached thread, or a thread that is joined */
470 if ((lt_state & BIT(ST_LT_DETACH)) || (lt->join == LT_JOIN_THREAD_SET))
471 return POSIX_ERRNO(EINVAL);
472 /* pointer to the joining thread and a poingter to return a value */
473 lt->lt_join = current;
474 current->lt_exit_ptr = ptr;
475 /* There is a race between lthread_join() and lthread_exit()
476 * - if join before exit we suspend and will resume when exit is called
477 * - if exit before join we resume the exiting thread
479 if ((lt->join == LT_JOIN_INITIAL)
480 && rte_atomic64_cmpset(<->join, LT_JOIN_INITIAL,
481 LT_JOIN_THREAD_SET)) {
483 DIAG_EVENT(current, LT_DIAG_LTHREAD_JOIN, lt, 1);
486 DIAG_EVENT(current, LT_DIAG_LTHREAD_JOIN, lt, 0);
487 _ready_queue_insert(lt->sched, lt);
490 /* wait for exiting thread to set return value */
491 while (lt->join != LT_JOIN_EXIT_VAL_SET)
494 /* collect the return value */
496 *ptr = *current->lt_exit_ptr;
498 /* let the exiting thread proceed to exit */
499 lt->join = LT_JOIN_EXIT_VAL_READ;
505 * Detach current lthread
506 * A detached thread cannot be joined
508 void lthread_detach(void)
510 struct lthread *lt = THIS_LTHREAD;
512 DIAG_EVENT(lt, LT_DIAG_LTHREAD_DETACH, 0, 0);
514 uint64_t state = lt->state;
516 lt->state = state | BIT(ST_LT_DETACH);
520 * Set function name of an lthread
521 * this is a debug aid
523 void lthread_set_funcname(const char *f)
525 struct lthread *lt = THIS_LTHREAD;
527 strncpy(lt->funcname, f, sizeof(lt->funcname));
528 lt->funcname[sizeof(lt->funcname)-1] = 0;