1 /* Copyright (c) 2004-2005, 2007, 2009-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
9 #include "src/internal_config.h"
15 #include <sys/syscall.h>
19 #include <linux/futex.h>
23 #include "xbt/parmap.h"
25 #include "xbt/function_types.h"
26 #include "xbt/dynar.h"
27 #include "xbt/xbt_os_thread.h"
28 #include "xbt/sysdep.h"
29 #include "src/simix/smx_private.h"
30 #include "src/simix/smx_private.hpp"
32 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
37 } e_xbt_parmap_flag_t;
39 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
40 static void *xbt_parmap_worker_main(void *parmap);
41 static void xbt_parmap_work(xbt_parmap_t parmap);
43 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
44 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
45 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
46 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
49 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
50 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
51 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
52 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
53 static void futex_wait(unsigned *uaddr, unsigned val);
54 static void futex_wake(unsigned *uaddr, unsigned val);
57 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
58 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
59 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
60 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
63 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id);
64 static void *xbt_parmap_mc_worker_main(void *arg);
68 * \brief Parallel map structure
70 typedef struct s_xbt_parmap {
71 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
72 unsigned work; /**< index of the current round */
73 unsigned thread_counter; /**< number of workers that have done the work */
75 unsigned int num_workers; /**< total number of worker threads including the controller */
76 xbt_os_thread_t *workers; /**< worker thread handlers */
77 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
78 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
79 std::atomic<unsigned int> index; /**< index of the next element of data to pick */
84 int_f_pvoid_pvoid_t snapshot_compare;
90 xbt_os_cond_t ready_cond;
91 xbt_os_mutex_t ready_mutex;
92 xbt_os_cond_t done_cond;
93 xbt_os_mutex_t done_mutex;
95 /* fields that depend on the synchronization mode */
96 e_xbt_parmap_mode_t mode; /**< synchronization mode */
97 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
98 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
99 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
100 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
104 * \brief Thread data transmission structure
106 typedef struct s_xbt_parmap_thread_data{
109 } s_xbt_parmap_thread_data_t;
111 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
114 * \brief Creates a parallel map object
115 * \param num_workers number of worker threads to create
116 * \param mode how to synchronize the worker threads
117 * \return the parmap created
119 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
121 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
123 /* Initialize the thread pool data structure */
124 xbt_parmap_t parmap = new s_xbt_parmap_t();
125 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
127 parmap->num_workers = num_workers;
128 parmap->status = XBT_PARMAP_WORK;
129 xbt_parmap_set_mode(parmap, mode);
131 /* Create the pool of worker threads */
132 xbt_parmap_thread_data_t data;
133 parmap->workers[0] = NULL;
134 #if HAVE_PTHREAD_SETAFFINITY
137 for (unsigned int i = 1; i < num_workers; i++) {
138 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
139 data->parmap = parmap;
141 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_worker_main, data, NULL);
142 #if HAVE_PTHREAD_SETAFFINITY
143 xbt_os_thread_bind(parmap->workers[i], core_bind);
144 if (core_bind != xbt_os_get_numcores())
155 * \brief Creates a parallel map object
156 * \param num_workers number of worker threads to create
157 * \param mode how to synchronize the worker threads
158 * \return the parmap created
160 xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
164 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
166 /* Initialize the thread pool data structure */
167 xbt_parmap_t parmap = new s_xbt_parmap_t();
168 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
170 parmap->num_workers = num_workers;
171 parmap->status = XBT_PARMAP_WORK;
172 xbt_parmap_set_mode(parmap, mode);
174 /* Create the pool of worker threads */
175 xbt_parmap_thread_data_t data;
176 parmap->workers[0] = NULL;
177 for (i = 1; i < num_workers; i++) {
178 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
179 data->parmap = parmap;
181 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main, data, NULL);
188 * \brief Destroys a parmap
189 * \param parmap the parmap to destroy
191 void xbt_parmap_destroy(xbt_parmap_t parmap)
197 parmap->status = XBT_PARMAP_DESTROY;
198 parmap->master_signal_f(parmap);
201 for (i = 1; i < parmap->num_workers; i++)
202 xbt_os_thread_join(parmap->workers[i], NULL);
204 xbt_os_cond_destroy(parmap->ready_cond);
205 xbt_os_mutex_destroy(parmap->ready_mutex);
206 xbt_os_cond_destroy(parmap->done_cond);
207 xbt_os_mutex_destroy(parmap->done_mutex);
209 xbt_free(parmap->workers);
214 * \brief Sets the synchronization mode of a parmap.
215 * \param parmap a parallel map object
216 * \param mode the synchronization mode
218 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
220 if (mode == XBT_PARMAP_DEFAULT) {
222 mode = XBT_PARMAP_FUTEX;
224 mode = XBT_PARMAP_POSIX;
230 case XBT_PARMAP_POSIX:
231 parmap->master_wait_f = xbt_parmap_posix_master_wait;
232 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
233 parmap->master_signal_f = xbt_parmap_posix_master_signal;
234 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
236 parmap->ready_cond = xbt_os_cond_init();
237 parmap->ready_mutex = xbt_os_mutex_init();
238 parmap->done_cond = xbt_os_cond_init();
239 parmap->done_mutex = xbt_os_mutex_init();
241 case XBT_PARMAP_FUTEX:
243 parmap->master_wait_f = xbt_parmap_futex_master_wait;
244 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
245 parmap->master_signal_f = xbt_parmap_futex_master_signal;
246 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
248 xbt_os_cond_destroy(parmap->ready_cond);
249 xbt_os_mutex_destroy(parmap->ready_mutex);
250 xbt_os_cond_destroy(parmap->done_cond);
251 xbt_os_mutex_destroy(parmap->done_mutex);
254 xbt_die("Futex is not available on this OS.");
256 case XBT_PARMAP_BUSY_WAIT:
257 parmap->master_wait_f = xbt_parmap_busy_master_wait;
258 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
259 parmap->master_signal_f = xbt_parmap_busy_master_signal;
260 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
262 xbt_os_cond_destroy(parmap->ready_cond);
263 xbt_os_mutex_destroy(parmap->ready_mutex);
264 xbt_os_cond_destroy(parmap->done_cond);
265 xbt_os_mutex_destroy(parmap->done_mutex);
267 case XBT_PARMAP_DEFAULT:
274 * \brief Applies a list of tasks in parallel.
275 * \param parmap a parallel map object
276 * \param fun the function to call in parallel
277 * \param data each element of this dynar will be passed as an argument to fun
279 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
281 /* Assign resources to worker threads (we are maestro here)*/
285 parmap->master_signal_f(parmap); // maestro runs futex_wait to wake all the minions (the working threads)
286 xbt_parmap_work(parmap); // maestro works with its minions
287 parmap->master_wait_f(parmap); // When there is no more work to do, then maestro waits for the last minion to stop
288 XBT_DEBUG("Job done"); // ... and proceeds
292 * \brief Returns a next task to process.
294 * Worker threads call this function to get more work.
296 * \return the next task to process, or NULL if there is no more work
298 void* xbt_parmap_next(xbt_parmap_t parmap)
300 unsigned int index = parmap->index++;
301 if (index < xbt_dynar_length(parmap->data)) {
302 return xbt_dynar_get_as(parmap->data, index, void*);
307 static void xbt_parmap_work(xbt_parmap_t parmap)
310 while ((index = parmap->index++) < xbt_dynar_length(parmap->data))
311 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
315 * \brief Main function of a worker thread.
316 * \param arg the parmap
318 static void *xbt_parmap_worker_main(void *arg)
320 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
321 xbt_parmap_t parmap = data->parmap;
323 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
324 SIMIX_context_set_current(context);
326 XBT_DEBUG("New worker thread created");
328 /* Worker's main loop */
330 parmap->worker_wait_f(parmap, ++round);
331 if (parmap->status == XBT_PARMAP_WORK) {
332 XBT_DEBUG("Worker %d got a job", data->worker_id);
334 xbt_parmap_work(parmap);
335 parmap->worker_signal_f(parmap);
337 XBT_DEBUG("Worker %d has finished", data->worker_id);
338 /* We are destroying the parmap */
340 SIMIX_context_free(context);
349 * \brief Applies a list of tasks in parallel.
350 * \param parmap a parallel map object
351 * \param fun the function to call in parallel
352 * \param data each element of this dynar will be passed as an argument to fun
354 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun, void* data, unsigned int length,
357 /* Assign resources to worker threads */
358 parmap->snapshot_compare = fun;
359 parmap->mc_data = data;
362 parmap->length = length;
363 parmap->ref_snapshot = ref_snapshot;
364 parmap->master_signal_f(parmap);
365 xbt_parmap_mc_work(parmap, 0);
366 parmap->master_wait_f(parmap);
367 XBT_DEBUG("Job done");
368 return parmap->finish;
371 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
373 unsigned int data_size = (parmap->length / parmap->num_workers) + ((parmap->length % parmap->num_workers) ? 1 :0);
374 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
375 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
377 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
379 while ( start < end && parmap->finish == -1) {
380 //XBT_CRITICAL("Starting with %p", start);
381 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
382 start = (char *)start + sizeof(start);
384 parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
385 //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
392 * \brief Main function of a worker thread.
393 * \param arg the parmap
395 static void *xbt_parmap_mc_worker_main(void *arg)
397 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
398 xbt_parmap_t parmap = data->parmap;
400 /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
401 /* SIMIX_context_set_current(context); */
403 XBT_DEBUG("New worker thread created");
405 /* Worker's main loop */
407 parmap->worker_wait_f(parmap, ++round);
408 if (parmap->status == XBT_PARMAP_WORK) {
409 XBT_DEBUG("Worker %d got a job", data->worker_id);
411 xbt_parmap_mc_work(parmap, data->worker_id);
412 parmap->worker_signal_f(parmap);
414 XBT_DEBUG("Worker %d has finished", data->worker_id);
415 /* We are destroying the parmap */
425 static void futex_wait(unsigned *uaddr, unsigned val)
427 XBT_VERB("Waiting on futex %p", uaddr);
428 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
431 static void futex_wake(unsigned *uaddr, unsigned val)
433 XBT_VERB("Waking futex %p", uaddr);
434 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
439 * \brief Starts the parmap: waits for all workers to be ready and returns.
441 * This function is called by the controller thread.
443 * \param parmap a parmap
445 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
447 xbt_os_mutex_acquire(parmap->done_mutex);
448 if (parmap->thread_counter < parmap->num_workers) {
449 /* wait for all workers to be ready */
450 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
452 xbt_os_mutex_release(parmap->done_mutex);
456 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
458 * This function is called by all worker threads when they end (not including the controller).
460 * \param parmap a parmap
462 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
464 xbt_os_mutex_acquire(parmap->done_mutex);
465 if (++parmap->thread_counter == parmap->num_workers) {
466 /* all workers have finished, wake the controller */
467 xbt_os_cond_signal(parmap->done_cond);
469 xbt_os_mutex_release(parmap->done_mutex);
473 * \brief Wakes all workers and waits for them to finish the tasks.
475 * This function is called by the controller thread.
477 * \param parmap a parmap
479 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
481 xbt_os_mutex_acquire(parmap->ready_mutex);
482 parmap->thread_counter = 1;
484 /* wake all workers */
485 xbt_os_cond_broadcast(parmap->ready_cond);
486 xbt_os_mutex_release(parmap->ready_mutex);
490 * \brief Waits for some work to process.
492 * This function is called by each worker thread (not including the controller) when it has no more work to do.
494 * \param parmap a parmap
495 * \param round the expected round number
497 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
499 xbt_os_mutex_acquire(parmap->ready_mutex);
500 /* wait for more work */
501 if (parmap->work != round) {
502 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
504 xbt_os_mutex_release(parmap->ready_mutex);
509 * \brief Starts the parmap: waits for all workers to be ready and returns.
511 * This function is called by the controller thread.
513 * \param parmap a parmap
515 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
517 unsigned count = parmap->thread_counter;
518 while (count < parmap->num_workers) {
519 /* wait for all workers to be ready */
520 futex_wait(&parmap->thread_counter, count);
521 count = parmap->thread_counter;
526 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
528 * This function is called by all worker threads when they end (not including the controller).
530 * \param parmap a parmap
532 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
534 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
535 if (count == parmap->num_workers) {
536 /* all workers have finished, wake the controller */
537 futex_wake(&parmap->thread_counter, INT_MAX);
542 * \brief Wakes all workers and waits for them to finish the tasks.
544 * This function is called by the controller thread.
546 * \param parmap a parmap
548 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
550 parmap->thread_counter = 1;
551 __sync_add_and_fetch(&parmap->work, 1);
552 /* wake all workers */
553 futex_wake(&parmap->work, INT_MAX);
557 * \brief Waits for some work to process.
559 * This function is called by each worker thread (not including the controller) when it has no more work to do.
561 * \param parmap a parmap
562 * \param round the expected round number
564 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
566 unsigned work = parmap->work;
567 /* wait for more work */
568 while (work != round) {
569 futex_wait(&parmap->work, work);
576 * \brief Starts the parmap: waits for all workers to be ready and returns.
578 * This function is called by the controller thread.
580 * \param parmap a parmap
582 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
584 while (parmap->thread_counter < parmap->num_workers) {
585 xbt_os_thread_yield();
590 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
592 * This function is called by all worker threads when they end.
594 * \param parmap a parmap
596 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
598 __sync_add_and_fetch(&parmap->thread_counter, 1);
602 * \brief Wakes all workers and waits for them to finish the tasks.
604 * This function is called by the controller thread.
606 * \param parmap a parmap
608 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
610 parmap->thread_counter = 1;
611 __sync_add_and_fetch(&parmap->work, 1);
615 * \brief Waits for some work to process.
617 * This function is called by each worker thread (not including the controller) when it has no more work to do.
619 * \param parmap a parmap
620 * \param round the expected round number
622 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
624 /* wait for more work */
625 while (parmap->work != round) {
626 xbt_os_thread_yield();