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. */
7 #include "internal_config.h"
11 #include <sys/syscall.h>
15 #include <linux/futex.h>
19 #include "xbt/parmap.h"
21 #include "xbt/function_types.h"
22 #include "xbt/dynar.h"
23 #include "xbt/xbt_os_thread.h"
24 #include "xbt/sysdep.h"
25 #include "simix/smx_private.h"
27 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
32 } e_xbt_parmap_flag_t;
34 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
35 static void *xbt_parmap_worker_main(void *parmap);
36 static void xbt_parmap_work(xbt_parmap_t parmap);
38 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
39 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
40 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
41 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
44 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
45 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
46 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
47 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
48 static void futex_wait(unsigned *uaddr, unsigned val);
49 static void futex_wake(unsigned *uaddr, unsigned val);
52 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
53 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
54 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
55 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
58 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id);
59 static void *xbt_parmap_mc_worker_main(void *arg);
63 * \brief Parallel map structure
65 typedef struct s_xbt_parmap {
66 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
67 unsigned work; /**< index of the current round */
68 unsigned thread_counter; /**< number of workers that have done the work */
70 unsigned int num_workers; /**< total number of worker threads including the controller */
71 xbt_os_thread_t *workers; /**< worker thread handlers */
72 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
73 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
74 unsigned int index; /**< index of the next element of data to pick */
79 int_f_pvoid_pvoid_t snapshot_compare;
85 xbt_os_cond_t ready_cond;
86 xbt_os_mutex_t ready_mutex;
87 xbt_os_cond_t done_cond;
88 xbt_os_mutex_t done_mutex;
90 /* fields that depend on the synchronization mode */
91 e_xbt_parmap_mode_t mode; /**< synchronization mode */
92 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
93 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
94 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
95 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
99 * \brief Thread data transmission structure
101 typedef struct s_xbt_parmap_thread_data{
104 } s_xbt_parmap_thread_data_t;
106 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
109 * \brief Creates a parallel map object
110 * \param num_workers number of worker threads to create
111 * \param mode how to synchronize the worker threads
112 * \return the parmap created
114 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
118 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
120 /* Initialize the thread pool data structure */
121 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
122 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
124 parmap->num_workers = num_workers;
125 parmap->status = XBT_PARMAP_WORK;
126 xbt_parmap_set_mode(parmap, mode);
128 /* Create the pool of worker threads */
129 xbt_parmap_thread_data_t data;
130 parmap->workers[0] = NULL;
131 for (i = 1; i < num_workers; i++) {
132 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
133 data->parmap = parmap;
135 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_worker_main,
143 * \brief Creates a parallel map object
144 * \param num_workers number of worker threads to create
145 * \param mode how to synchronize the worker threads
146 * \return the parmap created
148 xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
152 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
154 /* Initialize the thread pool data structure */
155 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
156 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
158 parmap->num_workers = num_workers;
159 parmap->status = XBT_PARMAP_WORK;
160 xbt_parmap_set_mode(parmap, mode);
162 /* Create the pool of worker threads */
163 xbt_parmap_thread_data_t data;
164 parmap->workers[0] = NULL;
165 for (i = 1; i < num_workers; i++) {
166 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
167 data->parmap = parmap;
169 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main,
177 * \brief Destroys a parmap
178 * \param parmap the parmap to destroy
180 void xbt_parmap_destroy(xbt_parmap_t parmap)
186 parmap->status = XBT_PARMAP_DESTROY;
187 parmap->master_signal_f(parmap);
190 for (i = 1; i < parmap->num_workers; i++)
191 xbt_os_thread_join(parmap->workers[i], NULL);
193 xbt_os_cond_destroy(parmap->ready_cond);
194 xbt_os_mutex_destroy(parmap->ready_mutex);
195 xbt_os_cond_destroy(parmap->done_cond);
196 xbt_os_mutex_destroy(parmap->done_mutex);
198 xbt_free(parmap->workers);
203 * \brief Sets the synchronization mode of a parmap.
204 * \param parmap a parallel map object
205 * \param mode the synchronization mode
207 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
209 if (mode == XBT_PARMAP_DEFAULT) {
211 mode = XBT_PARMAP_FUTEX;
213 mode = XBT_PARMAP_POSIX;
220 case XBT_PARMAP_POSIX:
221 parmap->master_wait_f = xbt_parmap_posix_master_wait;
222 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
223 parmap->master_signal_f = xbt_parmap_posix_master_signal;
224 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
226 parmap->ready_cond = xbt_os_cond_init();
227 parmap->ready_mutex = xbt_os_mutex_init();
228 parmap->done_cond = xbt_os_cond_init();
229 parmap->done_mutex = xbt_os_mutex_init();
233 case XBT_PARMAP_FUTEX:
235 parmap->master_wait_f = xbt_parmap_futex_master_wait;
236 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
237 parmap->master_signal_f = xbt_parmap_futex_master_signal;
238 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
240 xbt_os_cond_destroy(parmap->ready_cond);
241 xbt_os_mutex_destroy(parmap->ready_mutex);
242 xbt_os_cond_destroy(parmap->done_cond);
243 xbt_os_mutex_destroy(parmap->done_mutex);
246 xbt_die("Futex is not available on this OS.");
249 case XBT_PARMAP_BUSY_WAIT:
250 parmap->master_wait_f = xbt_parmap_busy_master_wait;
251 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
252 parmap->master_signal_f = xbt_parmap_busy_master_signal;
253 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
255 xbt_os_cond_destroy(parmap->ready_cond);
256 xbt_os_mutex_destroy(parmap->ready_mutex);
257 xbt_os_cond_destroy(parmap->done_cond);
258 xbt_os_mutex_destroy(parmap->done_mutex);
261 case XBT_PARMAP_DEFAULT:
268 * \brief Applies a list of tasks in parallel.
269 * \param parmap a parallel map object
270 * \param fun the function to call in parallel
271 * \param data each element of this dynar will be passed as an argument to fun
273 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
275 /* Assign resources to worker threads (we are maestro here)*/
279 parmap->master_signal_f(parmap); // maestro runs futex_wait to wake all the minions (the working threads)
280 xbt_parmap_work(parmap); // maestro works with its minions
281 parmap->master_wait_f(parmap); // When there is no more work to do, then maestro waits for the last minion to stop
282 XBT_DEBUG("Job done"); // ... and proceeds
286 * \brief Returns a next task to process.
288 * Worker threads call this function to get more work.
290 * \return the next task to process, or NULL if there is no more work
292 void* xbt_parmap_next(xbt_parmap_t parmap)
294 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
295 if (index < xbt_dynar_length(parmap->data)) {
296 return xbt_dynar_get_as(parmap->data, index, void*);
301 static void xbt_parmap_work(xbt_parmap_t parmap)
304 while ((index = __sync_fetch_and_add(&parmap->index, 1))
305 < xbt_dynar_length(parmap->data))
306 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
310 * \brief Main function of a worker thread.
311 * \param arg the parmap
313 static void *xbt_parmap_worker_main(void *arg)
315 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
316 xbt_parmap_t parmap = data->parmap;
318 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
319 SIMIX_context_set_current(context);
321 XBT_DEBUG("New worker thread created");
323 /* Worker's main loop */
325 parmap->worker_wait_f(parmap, ++round);
326 if (parmap->status == XBT_PARMAP_WORK) {
328 XBT_DEBUG("Worker %d got a job", data->worker_id);
330 xbt_parmap_work(parmap);
331 parmap->worker_signal_f(parmap);
333 XBT_DEBUG("Worker %d has finished", data->worker_id);
335 /* We are destroying the parmap */
337 SIMIX_context_free(context);
347 * \brief Applies a list of tasks in parallel.
348 * \param parmap a parallel map object
349 * \param fun the function to call in parallel
350 * \param data each element of this dynar will be passed as an argument to fun
352 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun,
353 void* data, unsigned int length, void* ref_snapshot)
355 /* Assign resources to worker threads */
356 parmap->snapshot_compare = fun;
357 parmap->mc_data = data;
360 parmap->length = length;
361 parmap->ref_snapshot = ref_snapshot;
362 parmap->master_signal_f(parmap);
363 xbt_parmap_mc_work(parmap, 0);
364 parmap->master_wait_f(parmap);
365 XBT_DEBUG("Job done");
366 return parmap->finish;
369 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
371 unsigned int data_size = (parmap->length / parmap->num_workers) +
372 ((parmap->length % parmap->num_workers) ? 1 :0);
373 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
374 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
376 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
378 while ( start < end && parmap->finish == -1) {
379 //XBT_CRITICAL("Starting with %p", start);
380 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
381 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) {
410 XBT_DEBUG("Worker %d got a job", data->worker_id);
412 xbt_parmap_mc_work(parmap, data->worker_id);
413 parmap->worker_signal_f(parmap);
415 XBT_DEBUG("Worker %d has finished", data->worker_id);
417 /* We are destroying the parmap */
427 static void futex_wait(unsigned *uaddr, unsigned val)
429 XBT_VERB("Waiting on futex %p", uaddr);
430 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
433 static void futex_wake(unsigned *uaddr, unsigned val)
435 XBT_VERB("Waking futex %p", uaddr);
436 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
441 * \brief Starts the parmap: waits for all workers to be ready and returns.
443 * This function is called by the controller thread.
445 * \param parmap a parmap
447 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
449 xbt_os_mutex_acquire(parmap->done_mutex);
450 if (parmap->thread_counter < parmap->num_workers) {
451 /* wait for all workers to be ready */
452 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
454 xbt_os_mutex_release(parmap->done_mutex);
458 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
460 * This function is called by all worker threads when they end (not including
463 * \param parmap a parmap
465 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
467 xbt_os_mutex_acquire(parmap->done_mutex);
468 if (++parmap->thread_counter == parmap->num_workers) {
469 /* all workers have finished, wake the controller */
470 xbt_os_cond_signal(parmap->done_cond);
472 xbt_os_mutex_release(parmap->done_mutex);
476 * \brief Wakes all workers and waits for them to finish the tasks.
478 * This function is called by the controller thread.
480 * \param parmap a parmap
482 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
484 xbt_os_mutex_acquire(parmap->ready_mutex);
485 parmap->thread_counter = 1;
487 /* wake all workers */
488 xbt_os_cond_broadcast(parmap->ready_cond);
489 xbt_os_mutex_release(parmap->ready_mutex);
493 * \brief Waits for some work to process.
495 * This function is called by each worker thread (not including the controller)
496 * when it has no more work to do.
498 * \param parmap a parmap
499 * \param round the expected round number
501 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
503 xbt_os_mutex_acquire(parmap->ready_mutex);
504 /* wait for more work */
505 if (parmap->work != round) {
506 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
508 xbt_os_mutex_release(parmap->ready_mutex);
513 * \brief Starts the parmap: waits for all workers to be ready and returns.
515 * This function is called by the controller thread.
517 * \param parmap a parmap
519 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
521 unsigned count = parmap->thread_counter;
522 while (count < parmap->num_workers) {
523 /* wait for all workers to be ready */
524 futex_wait(&parmap->thread_counter, count);
525 count = parmap->thread_counter;
530 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
532 * This function is called by all worker threads when they end (not including
535 * \param parmap a parmap
537 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
539 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
540 if (count == parmap->num_workers) {
541 /* all workers have finished, wake the controller */
542 futex_wake(&parmap->thread_counter, INT_MAX);
547 * \brief Wakes all workers and waits for them to finish the tasks.
549 * This function is called by the controller thread.
551 * \param parmap a parmap
553 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
555 parmap->thread_counter = 1;
556 __sync_add_and_fetch(&parmap->work, 1);
557 /* wake all workers */
558 futex_wake(&parmap->work, INT_MAX);
562 * \brief Waits for some work to process.
564 * This function is called by each worker thread (not including the controller)
565 * when it has no more work to do.
567 * \param parmap a parmap
568 * \param round the expected round number
570 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
572 unsigned work = parmap->work;
573 /* wait for more work */
574 while (work != round) {
575 futex_wait(&parmap->work, work);
582 * \brief Starts the parmap: waits for all workers to be ready and returns.
584 * This function is called by the controller thread.
586 * \param parmap a parmap
588 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
590 while (parmap->thread_counter < parmap->num_workers) {
591 xbt_os_thread_yield();
596 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
598 * This function is called by all worker threads when they end.
600 * \param parmap a parmap
602 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
604 __sync_add_and_fetch(&parmap->thread_counter, 1);
608 * \brief Wakes all workers and waits for them to finish the tasks.
610 * This function is called by the controller thread.
612 * \param parmap a parmap
614 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
616 parmap->thread_counter = 1;
617 __sync_add_and_fetch(&parmap->work, 1);
621 * \brief Waits for some work to process.
623 * This function is called by each worker thread (not including the controller)
624 * when it has no more work to do.
626 * \param parmap a parmap
627 * \param round the expected round number
629 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
631 /* wait for more work */
632 while (parmap->work != round) {
633 xbt_os_thread_yield();