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,
189 * \brief Destroys a parmap
190 * \param parmap the parmap to destroy
192 void xbt_parmap_destroy(xbt_parmap_t parmap)
198 parmap->status = XBT_PARMAP_DESTROY;
199 parmap->master_signal_f(parmap);
202 for (i = 1; i < parmap->num_workers; i++)
203 xbt_os_thread_join(parmap->workers[i], NULL);
205 xbt_os_cond_destroy(parmap->ready_cond);
206 xbt_os_mutex_destroy(parmap->ready_mutex);
207 xbt_os_cond_destroy(parmap->done_cond);
208 xbt_os_mutex_destroy(parmap->done_mutex);
210 xbt_free(parmap->workers);
215 * \brief Sets the synchronization mode of a parmap.
216 * \param parmap a parallel map object
217 * \param mode the synchronization mode
219 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
221 if (mode == XBT_PARMAP_DEFAULT) {
223 mode = XBT_PARMAP_FUTEX;
225 mode = XBT_PARMAP_POSIX;
232 case XBT_PARMAP_POSIX:
233 parmap->master_wait_f = xbt_parmap_posix_master_wait;
234 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
235 parmap->master_signal_f = xbt_parmap_posix_master_signal;
236 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
238 parmap->ready_cond = xbt_os_cond_init();
239 parmap->ready_mutex = xbt_os_mutex_init();
240 parmap->done_cond = xbt_os_cond_init();
241 parmap->done_mutex = xbt_os_mutex_init();
245 case XBT_PARMAP_FUTEX:
247 parmap->master_wait_f = xbt_parmap_futex_master_wait;
248 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
249 parmap->master_signal_f = xbt_parmap_futex_master_signal;
250 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
252 xbt_os_cond_destroy(parmap->ready_cond);
253 xbt_os_mutex_destroy(parmap->ready_mutex);
254 xbt_os_cond_destroy(parmap->done_cond);
255 xbt_os_mutex_destroy(parmap->done_mutex);
258 xbt_die("Futex is not available on this OS.");
261 case XBT_PARMAP_BUSY_WAIT:
263 parmap->master_wait_f = xbt_parmap_busy_master_wait;
264 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
265 parmap->master_signal_f = xbt_parmap_busy_master_signal;
266 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
268 xbt_os_cond_destroy(parmap->ready_cond);
269 xbt_os_mutex_destroy(parmap->ready_mutex);
270 xbt_os_cond_destroy(parmap->done_cond);
271 xbt_os_mutex_destroy(parmap->done_mutex);
274 xbt_die("Busy waiting not implemented on Windows yet.");
277 case XBT_PARMAP_DEFAULT:
284 * \brief Applies a list of tasks in parallel.
285 * \param parmap a parallel map object
286 * \param fun the function to call in parallel
287 * \param data each element of this dynar will be passed as an argument to fun
289 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
291 /* Assign resources to worker threads (we are maestro here)*/
295 parmap->master_signal_f(parmap); // maestro runs futex_wait to wake all the minions (the working threads)
296 xbt_parmap_work(parmap); // maestro works with its minions
297 parmap->master_wait_f(parmap); // When there is no more work to do, then maestro waits for the last minion to stop
298 XBT_DEBUG("Job done"); // ... and proceeds
302 * \brief Returns a next task to process.
304 * Worker threads call this function to get more work.
306 * \return the next task to process, or NULL if there is no more work
308 void* xbt_parmap_next(xbt_parmap_t parmap)
310 unsigned int index = parmap->index++;
311 if (index < xbt_dynar_length(parmap->data)) {
312 return xbt_dynar_get_as(parmap->data, index, void*);
317 static void xbt_parmap_work(xbt_parmap_t parmap)
320 while ((index = parmap->index++)
321 < xbt_dynar_length(parmap->data))
322 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
326 * \brief Main function of a worker thread.
327 * \param arg the parmap
329 static void *xbt_parmap_worker_main(void *arg)
331 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
332 xbt_parmap_t parmap = data->parmap;
334 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
335 SIMIX_context_set_current(context);
337 XBT_DEBUG("New worker thread created");
339 /* Worker's main loop */
341 parmap->worker_wait_f(parmap, ++round);
342 if (parmap->status == XBT_PARMAP_WORK) {
344 XBT_DEBUG("Worker %d got a job", data->worker_id);
346 xbt_parmap_work(parmap);
347 parmap->worker_signal_f(parmap);
349 XBT_DEBUG("Worker %d has finished", data->worker_id);
351 /* We are destroying the parmap */
353 SIMIX_context_free(context);
363 * \brief Applies a list of tasks in parallel.
364 * \param parmap a parallel map object
365 * \param fun the function to call in parallel
366 * \param data each element of this dynar will be passed as an argument to fun
368 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun,
369 void* data, unsigned int length, void* ref_snapshot)
371 /* Assign resources to worker threads */
372 parmap->snapshot_compare = fun;
373 parmap->mc_data = data;
376 parmap->length = length;
377 parmap->ref_snapshot = ref_snapshot;
378 parmap->master_signal_f(parmap);
379 xbt_parmap_mc_work(parmap, 0);
380 parmap->master_wait_f(parmap);
381 XBT_DEBUG("Job done");
382 return parmap->finish;
385 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
387 unsigned int data_size = (parmap->length / parmap->num_workers) +
388 ((parmap->length % parmap->num_workers) ? 1 :0);
389 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
390 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
392 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
394 while ( start < end && parmap->finish == -1) {
395 //XBT_CRITICAL("Starting with %p", start);
396 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
397 start = (char *)start + sizeof(start);
400 parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
401 //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
408 * \brief Main function of a worker thread.
409 * \param arg the parmap
411 static void *xbt_parmap_mc_worker_main(void *arg)
413 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
414 xbt_parmap_t parmap = data->parmap;
416 /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
417 /* SIMIX_context_set_current(context); */
419 XBT_DEBUG("New worker thread created");
421 /* Worker's main loop */
423 parmap->worker_wait_f(parmap, ++round);
424 if (parmap->status == XBT_PARMAP_WORK) {
426 XBT_DEBUG("Worker %d got a job", data->worker_id);
428 xbt_parmap_mc_work(parmap, data->worker_id);
429 parmap->worker_signal_f(parmap);
431 XBT_DEBUG("Worker %d has finished", data->worker_id);
433 /* We are destroying the parmap */
443 static void futex_wait(unsigned *uaddr, unsigned val)
445 XBT_VERB("Waiting on futex %p", uaddr);
446 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
449 static void futex_wake(unsigned *uaddr, unsigned val)
451 XBT_VERB("Waking futex %p", uaddr);
452 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
457 * \brief Starts the parmap: waits for all workers to be ready and returns.
459 * This function is called by the controller thread.
461 * \param parmap a parmap
463 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
465 xbt_os_mutex_acquire(parmap->done_mutex);
466 if (parmap->thread_counter < parmap->num_workers) {
467 /* wait for all workers to be ready */
468 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
470 xbt_os_mutex_release(parmap->done_mutex);
474 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
476 * This function is called by all worker threads when they end (not including
479 * \param parmap a parmap
481 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
483 xbt_os_mutex_acquire(parmap->done_mutex);
484 if (++parmap->thread_counter == parmap->num_workers) {
485 /* all workers have finished, wake the controller */
486 xbt_os_cond_signal(parmap->done_cond);
488 xbt_os_mutex_release(parmap->done_mutex);
492 * \brief Wakes all workers and waits for them to finish the tasks.
494 * This function is called by the controller thread.
496 * \param parmap a parmap
498 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
500 xbt_os_mutex_acquire(parmap->ready_mutex);
501 parmap->thread_counter = 1;
503 /* wake all workers */
504 xbt_os_cond_broadcast(parmap->ready_cond);
505 xbt_os_mutex_release(parmap->ready_mutex);
509 * \brief Waits for some work to process.
511 * This function is called by each worker thread (not including the controller)
512 * when it has no more work to do.
514 * \param parmap a parmap
515 * \param round the expected round number
517 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
519 xbt_os_mutex_acquire(parmap->ready_mutex);
520 /* wait for more work */
521 if (parmap->work != round) {
522 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
524 xbt_os_mutex_release(parmap->ready_mutex);
529 * \brief Starts the parmap: waits for all workers to be ready and returns.
531 * This function is called by the controller thread.
533 * \param parmap a parmap
535 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
537 unsigned count = parmap->thread_counter;
538 while (count < parmap->num_workers) {
539 /* wait for all workers to be ready */
540 futex_wait(&parmap->thread_counter, count);
541 count = parmap->thread_counter;
546 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
548 * This function is called by all worker threads when they end (not including
551 * \param parmap a parmap
553 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
555 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
556 if (count == parmap->num_workers) {
557 /* all workers have finished, wake the controller */
558 futex_wake(&parmap->thread_counter, INT_MAX);
563 * \brief Wakes all workers and waits for them to finish the tasks.
565 * This function is called by the controller thread.
567 * \param parmap a parmap
569 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
571 parmap->thread_counter = 1;
572 __sync_add_and_fetch(&parmap->work, 1);
573 /* wake all workers */
574 futex_wake(&parmap->work, INT_MAX);
578 * \brief Waits for some work to process.
580 * This function is called by each worker thread (not including the controller)
581 * when it has no more work to do.
583 * \param parmap a parmap
584 * \param round the expected round number
586 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
588 unsigned work = parmap->work;
589 /* wait for more work */
590 while (work != round) {
591 futex_wait(&parmap->work, work);
599 * \brief Starts the parmap: waits for all workers to be ready and returns.
601 * This function is called by the controller thread.
603 * \param parmap a parmap
605 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
607 while (parmap->thread_counter < parmap->num_workers) {
608 xbt_os_thread_yield();
613 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
615 * This function is called by all worker threads when they end.
617 * \param parmap a parmap
619 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
621 __sync_add_and_fetch(&parmap->thread_counter, 1);
625 * \brief Wakes all workers and waits for them to finish the tasks.
627 * This function is called by the controller thread.
629 * \param parmap a parmap
631 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
633 parmap->thread_counter = 1;
634 __sync_add_and_fetch(&parmap->work, 1);
638 * \brief Waits for some work to process.
640 * This function is called by each worker thread (not including the controller)
641 * when it has no more work to do.
643 * \param parmap a parmap
644 * \param round the expected round number
646 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
648 /* wait for more work */
649 while (parmap->work != round) {
650 xbt_os_thread_yield();
653 #endif /* ! _MSC_VER */