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);
58 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
59 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
60 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
61 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
65 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id);
66 static void *xbt_parmap_mc_worker_main(void *arg);
70 * \brief Parallel map structure
72 typedef struct s_xbt_parmap {
73 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
74 unsigned work; /**< index of the current round */
75 unsigned thread_counter; /**< number of workers that have done the work */
77 unsigned int num_workers; /**< total number of worker threads including the controller */
78 xbt_os_thread_t *workers; /**< worker thread handlers */
79 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
80 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
81 std::atomic<unsigned int> index; /**< index of the next element of data to pick */
86 int_f_pvoid_pvoid_t snapshot_compare;
92 xbt_os_cond_t ready_cond;
93 xbt_os_mutex_t ready_mutex;
94 xbt_os_cond_t done_cond;
95 xbt_os_mutex_t done_mutex;
97 /* fields that depend on the synchronization mode */
98 e_xbt_parmap_mode_t mode; /**< synchronization mode */
99 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
100 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
101 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
102 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
106 * \brief Thread data transmission structure
108 typedef struct s_xbt_parmap_thread_data{
111 } s_xbt_parmap_thread_data_t;
113 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
116 * \brief Creates a parallel map object
117 * \param num_workers number of worker threads to create
118 * \param mode how to synchronize the worker threads
119 * \return the parmap created
121 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
123 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
125 /* Initialize the thread pool data structure */
126 xbt_parmap_t parmap = new s_xbt_parmap_t();
127 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
129 parmap->num_workers = num_workers;
130 parmap->status = XBT_PARMAP_WORK;
131 xbt_parmap_set_mode(parmap, mode);
133 /* Create the pool of worker threads */
134 xbt_parmap_thread_data_t data;
135 parmap->workers[0] = NULL;
136 #ifdef HAVE_PTHREAD_SETAFFINITY
139 for (unsigned int i = 1; i < num_workers; i++) {
140 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
141 data->parmap = parmap;
143 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_worker_main, data, NULL);
144 #ifdef HAVE_PTHREAD_SETAFFINITY
145 xbt_os_thread_bind(parmap->workers[i], core_bind);
146 if (core_bind != xbt_os_get_numcores())
157 * \brief Creates a parallel map object
158 * \param num_workers number of worker threads to create
159 * \param mode how to synchronize the worker threads
160 * \return the parmap created
162 xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
166 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
168 /* Initialize the thread pool data structure */
169 xbt_parmap_t parmap = new s_xbt_parmap_t();
170 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
172 parmap->num_workers = num_workers;
173 parmap->status = XBT_PARMAP_WORK;
174 xbt_parmap_set_mode(parmap, mode);
176 /* Create the pool of worker threads */
177 xbt_parmap_thread_data_t data;
178 parmap->workers[0] = NULL;
179 for (i = 1; i < num_workers; i++) {
180 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
181 data->parmap = parmap;
183 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main,
191 * \brief Destroys a parmap
192 * \param parmap the parmap to destroy
194 void xbt_parmap_destroy(xbt_parmap_t parmap)
200 parmap->status = XBT_PARMAP_DESTROY;
201 parmap->master_signal_f(parmap);
204 for (i = 1; i < parmap->num_workers; i++)
205 xbt_os_thread_join(parmap->workers[i], NULL);
207 xbt_os_cond_destroy(parmap->ready_cond);
208 xbt_os_mutex_destroy(parmap->ready_mutex);
209 xbt_os_cond_destroy(parmap->done_cond);
210 xbt_os_mutex_destroy(parmap->done_mutex);
212 xbt_free(parmap->workers);
217 * \brief Sets the synchronization mode of a parmap.
218 * \param parmap a parallel map object
219 * \param mode the synchronization mode
221 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
223 if (mode == XBT_PARMAP_DEFAULT) {
225 mode = XBT_PARMAP_FUTEX;
227 mode = XBT_PARMAP_POSIX;
234 case XBT_PARMAP_POSIX:
235 parmap->master_wait_f = xbt_parmap_posix_master_wait;
236 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
237 parmap->master_signal_f = xbt_parmap_posix_master_signal;
238 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
240 parmap->ready_cond = xbt_os_cond_init();
241 parmap->ready_mutex = xbt_os_mutex_init();
242 parmap->done_cond = xbt_os_cond_init();
243 parmap->done_mutex = xbt_os_mutex_init();
247 case XBT_PARMAP_FUTEX:
249 parmap->master_wait_f = xbt_parmap_futex_master_wait;
250 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
251 parmap->master_signal_f = xbt_parmap_futex_master_signal;
252 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
254 xbt_os_cond_destroy(parmap->ready_cond);
255 xbt_os_mutex_destroy(parmap->ready_mutex);
256 xbt_os_cond_destroy(parmap->done_cond);
257 xbt_os_mutex_destroy(parmap->done_mutex);
260 xbt_die("Futex is not available on this OS.");
263 case XBT_PARMAP_BUSY_WAIT:
265 parmap->master_wait_f = xbt_parmap_busy_master_wait;
266 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
267 parmap->master_signal_f = xbt_parmap_busy_master_signal;
268 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
270 xbt_os_cond_destroy(parmap->ready_cond);
271 xbt_os_mutex_destroy(parmap->ready_mutex);
272 xbt_os_cond_destroy(parmap->done_cond);
273 xbt_os_mutex_destroy(parmap->done_mutex);
276 xbt_die("Busy waiting not implemented on Windows yet.");
279 case XBT_PARMAP_DEFAULT:
286 * \brief Applies a list of tasks in parallel.
287 * \param parmap a parallel map object
288 * \param fun the function to call in parallel
289 * \param data each element of this dynar will be passed as an argument to fun
291 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
293 /* Assign resources to worker threads (we are maestro here)*/
297 parmap->master_signal_f(parmap); // maestro runs futex_wait to wake all the minions (the working threads)
298 xbt_parmap_work(parmap); // maestro works with its minions
299 parmap->master_wait_f(parmap); // When there is no more work to do, then maestro waits for the last minion to stop
300 XBT_DEBUG("Job done"); // ... and proceeds
304 * \brief Returns a next task to process.
306 * Worker threads call this function to get more work.
308 * \return the next task to process, or NULL if there is no more work
310 void* xbt_parmap_next(xbt_parmap_t parmap)
312 unsigned int index = parmap->index++;
313 if (index < xbt_dynar_length(parmap->data)) {
314 return xbt_dynar_get_as(parmap->data, index, void*);
319 static void xbt_parmap_work(xbt_parmap_t parmap)
322 while ((index = parmap->index++)
323 < xbt_dynar_length(parmap->data))
324 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
328 * \brief Main function of a worker thread.
329 * \param arg the parmap
331 static void *xbt_parmap_worker_main(void *arg)
333 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
334 xbt_parmap_t parmap = data->parmap;
336 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
337 SIMIX_context_set_current(context);
339 XBT_DEBUG("New worker thread created");
341 /* Worker's main loop */
343 parmap->worker_wait_f(parmap, ++round);
344 if (parmap->status == XBT_PARMAP_WORK) {
346 XBT_DEBUG("Worker %d got a job", data->worker_id);
348 xbt_parmap_work(parmap);
349 parmap->worker_signal_f(parmap);
351 XBT_DEBUG("Worker %d has finished", data->worker_id);
353 /* We are destroying the parmap */
355 SIMIX_context_free(context);
365 * \brief Applies a list of tasks in parallel.
366 * \param parmap a parallel map object
367 * \param fun the function to call in parallel
368 * \param data each element of this dynar will be passed as an argument to fun
370 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun,
371 void* data, unsigned int length, void* ref_snapshot)
373 /* Assign resources to worker threads */
374 parmap->snapshot_compare = fun;
375 parmap->mc_data = data;
378 parmap->length = length;
379 parmap->ref_snapshot = ref_snapshot;
380 parmap->master_signal_f(parmap);
381 xbt_parmap_mc_work(parmap, 0);
382 parmap->master_wait_f(parmap);
383 XBT_DEBUG("Job done");
384 return parmap->finish;
387 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
389 unsigned int data_size = (parmap->length / parmap->num_workers) +
390 ((parmap->length % parmap->num_workers) ? 1 :0);
391 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
392 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
394 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
396 while ( start < end && parmap->finish == -1) {
397 //XBT_CRITICAL("Starting with %p", start);
398 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
399 start = (char *)start + sizeof(start);
402 parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
403 //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
410 * \brief Main function of a worker thread.
411 * \param arg the parmap
413 static void *xbt_parmap_mc_worker_main(void *arg)
415 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
416 xbt_parmap_t parmap = data->parmap;
418 /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
419 /* SIMIX_context_set_current(context); */
421 XBT_DEBUG("New worker thread created");
423 /* Worker's main loop */
425 parmap->worker_wait_f(parmap, ++round);
426 if (parmap->status == XBT_PARMAP_WORK) {
428 XBT_DEBUG("Worker %d got a job", data->worker_id);
430 xbt_parmap_mc_work(parmap, data->worker_id);
431 parmap->worker_signal_f(parmap);
433 XBT_DEBUG("Worker %d has finished", data->worker_id);
435 /* We are destroying the parmap */
445 static void futex_wait(unsigned *uaddr, unsigned val)
447 XBT_VERB("Waiting on futex %p", uaddr);
448 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
451 static void futex_wake(unsigned *uaddr, unsigned val)
453 XBT_VERB("Waking futex %p", uaddr);
454 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
459 * \brief Starts the parmap: waits for all workers to be ready and returns.
461 * This function is called by the controller thread.
463 * \param parmap a parmap
465 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
467 xbt_os_mutex_acquire(parmap->done_mutex);
468 if (parmap->thread_counter < parmap->num_workers) {
469 /* wait for all workers to be ready */
470 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
472 xbt_os_mutex_release(parmap->done_mutex);
476 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
478 * This function is called by all worker threads when they end (not including
481 * \param parmap a parmap
483 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
485 xbt_os_mutex_acquire(parmap->done_mutex);
486 if (++parmap->thread_counter == parmap->num_workers) {
487 /* all workers have finished, wake the controller */
488 xbt_os_cond_signal(parmap->done_cond);
490 xbt_os_mutex_release(parmap->done_mutex);
494 * \brief Wakes all workers and waits for them to finish the tasks.
496 * This function is called by the controller thread.
498 * \param parmap a parmap
500 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
502 xbt_os_mutex_acquire(parmap->ready_mutex);
503 parmap->thread_counter = 1;
505 /* wake all workers */
506 xbt_os_cond_broadcast(parmap->ready_cond);
507 xbt_os_mutex_release(parmap->ready_mutex);
511 * \brief Waits for some work to process.
513 * This function is called by each worker thread (not including the controller)
514 * when it has no more work to do.
516 * \param parmap a parmap
517 * \param round the expected round number
519 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
521 xbt_os_mutex_acquire(parmap->ready_mutex);
522 /* wait for more work */
523 if (parmap->work != round) {
524 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
526 xbt_os_mutex_release(parmap->ready_mutex);
531 * \brief Starts the parmap: waits for all workers to be ready and returns.
533 * This function is called by the controller thread.
535 * \param parmap a parmap
537 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
539 unsigned count = parmap->thread_counter;
540 while (count < parmap->num_workers) {
541 /* wait for all workers to be ready */
542 futex_wait(&parmap->thread_counter, count);
543 count = parmap->thread_counter;
548 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
550 * This function is called by all worker threads when they end (not including
553 * \param parmap a parmap
555 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
557 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
558 if (count == parmap->num_workers) {
559 /* all workers have finished, wake the controller */
560 futex_wake(&parmap->thread_counter, INT_MAX);
565 * \brief Wakes all workers and waits for them to finish the tasks.
567 * This function is called by the controller thread.
569 * \param parmap a parmap
571 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
573 parmap->thread_counter = 1;
574 __sync_add_and_fetch(&parmap->work, 1);
575 /* wake all workers */
576 futex_wake(&parmap->work, INT_MAX);
580 * \brief Waits for some work to process.
582 * This function is called by each worker thread (not including the controller)
583 * when it has no more work to do.
585 * \param parmap a parmap
586 * \param round the expected round number
588 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
590 unsigned work = parmap->work;
591 /* wait for more work */
592 while (work != round) {
593 futex_wait(&parmap->work, work);
601 * \brief Starts the parmap: waits for all workers to be ready and returns.
603 * This function is called by the controller thread.
605 * \param parmap a parmap
607 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
609 while (parmap->thread_counter < parmap->num_workers) {
610 xbt_os_thread_yield();
615 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
617 * This function is called by all worker threads when they end.
619 * \param parmap a parmap
621 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
623 __sync_add_and_fetch(&parmap->thread_counter, 1);
627 * \brief Wakes all workers and waits for them to finish the tasks.
629 * This function is called by the controller thread.
631 * \param parmap a parmap
633 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
635 parmap->thread_counter = 1;
636 __sync_add_and_fetch(&parmap->work, 1);
640 * \brief Waits for some work to process.
642 * This function is called by each worker thread (not including the controller)
643 * when it has no more work to do.
645 * \param parmap a parmap
646 * \param round the expected round number
648 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
650 /* wait for more work */
651 while (parmap->work != round) {
652 xbt_os_thread_yield();
655 #endif /* ! _MSC_VER */