1 /* Copyright (c) 2004-2005, 2007, 2009-2013. 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. */
6 #include "internal_config.h"
10 #include <sys/syscall.h>
14 #include <linux/futex.h>
18 #include "xbt/parmap.h"
20 #include "xbt/function_types.h"
21 #include "xbt/dynar.h"
22 #include "xbt/xbt_os_thread.h"
23 #include "xbt/sysdep.h"
24 #include "simix/smx_private.h"
26 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
31 } e_xbt_parmap_flag_t;
33 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
34 static void *xbt_parmap_worker_main(void *parmap);
35 static void xbt_parmap_work(xbt_parmap_t parmap);
37 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
38 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
39 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
40 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
43 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
44 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
45 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
46 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
47 static void futex_wait(unsigned *uaddr, unsigned val);
48 static void futex_wake(unsigned *uaddr, unsigned val);
51 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
52 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
53 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
54 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
57 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id);
58 static void *xbt_parmap_mc_worker_main(void *arg);
62 * \brief Parallel map structure
64 typedef struct s_xbt_parmap {
65 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
66 unsigned work; /**< index of the current round */
67 unsigned thread_counter; /**< number of workers that have done the work */
69 unsigned int num_workers; /**< total number of worker threads including the controller */
70 xbt_os_thread_t *workers; /**< worker thread handlers */
71 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
72 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
73 unsigned int index; /**< index of the next element of data to pick */
80 int_f_pvoid_pvoid_t snapshot_compare;
86 xbt_os_cond_t ready_cond;
87 xbt_os_mutex_t ready_mutex;
88 xbt_os_cond_t done_cond;
89 xbt_os_mutex_t done_mutex;
91 /* fields that depend on the synchronization mode */
92 e_xbt_parmap_mode_t mode; /**< synchronization mode */
93 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
94 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
95 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
96 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
100 * \brief Thread data transmission structure
102 typedef struct s_xbt_parmap_thread_data{
105 } s_xbt_parmap_thread_data_t;
107 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
110 * \brief Creates a parallel map object
111 * \param num_workers number of worker threads to create
112 * \param mode how to synchronize the worker threads
113 * \return the parmap created
115 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
119 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
121 /* Initialize the thread pool data structure */
122 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
123 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
125 parmap->num_workers = num_workers;
126 parmap->status = XBT_PARMAP_WORK;
127 xbt_parmap_set_mode(parmap, mode);
129 /* Create the pool of worker threads */
130 xbt_parmap_thread_data_t data;
131 parmap->workers[0] = NULL;
132 for (i = 1; i < num_workers; i++) {
133 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
134 data->parmap = parmap;
136 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_worker_main,
144 * \brief Creates a parallel map object
145 * \param num_workers number of worker threads to create
146 * \param mode how to synchronize the worker threads
147 * \return the parmap created
149 xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
153 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
155 /* Initialize the thread pool data structure */
156 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
157 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
159 parmap->num_workers = num_workers;
160 parmap->status = XBT_PARMAP_WORK;
161 xbt_parmap_set_mode(parmap, mode);
163 /* Create the pool of worker threads */
164 xbt_parmap_thread_data_t data;
165 parmap->workers[0] = NULL;
166 for (i = 1; i < num_workers; i++) {
167 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
168 data->parmap = parmap;
170 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main,
178 * \brief Destroys a parmap
179 * \param parmap the parmap to destroy
181 void xbt_parmap_destroy(xbt_parmap_t parmap)
187 parmap->status = XBT_PARMAP_DESTROY;
188 parmap->master_signal_f(parmap);
191 for (i = 1; i < parmap->num_workers; i++)
192 xbt_os_thread_join(parmap->workers[i], NULL);
194 xbt_os_cond_destroy(parmap->ready_cond);
195 xbt_os_mutex_destroy(parmap->ready_mutex);
196 xbt_os_cond_destroy(parmap->done_cond);
197 xbt_os_mutex_destroy(parmap->done_mutex);
199 xbt_free(parmap->workers);
204 * \brief Sets the synchronization mode of a parmap.
205 * \param parmap a parallel map object
206 * \param mode the synchronization mode
208 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
210 if (mode == XBT_PARMAP_DEFAULT) {
212 mode = XBT_PARMAP_FUTEX;
214 mode = XBT_PARMAP_POSIX;
221 case XBT_PARMAP_POSIX:
222 parmap->master_wait_f = xbt_parmap_posix_master_wait;
223 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
224 parmap->master_signal_f = xbt_parmap_posix_master_signal;
225 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
227 parmap->ready_cond = xbt_os_cond_init();
228 parmap->ready_mutex = xbt_os_mutex_init();
229 parmap->done_cond = xbt_os_cond_init();
230 parmap->done_mutex = xbt_os_mutex_init();
234 case XBT_PARMAP_FUTEX:
236 parmap->master_wait_f = xbt_parmap_futex_master_wait;
237 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
238 parmap->master_signal_f = xbt_parmap_futex_master_signal;
239 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
241 xbt_os_cond_destroy(parmap->ready_cond);
242 xbt_os_mutex_destroy(parmap->ready_mutex);
243 xbt_os_cond_destroy(parmap->done_cond);
244 xbt_os_mutex_destroy(parmap->done_mutex);
247 xbt_die("Futex is not available on this OS.");
250 case XBT_PARMAP_BUSY_WAIT:
251 parmap->master_wait_f = xbt_parmap_busy_master_wait;
252 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
253 parmap->master_signal_f = xbt_parmap_busy_master_signal;
254 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
256 xbt_os_cond_destroy(parmap->ready_cond);
257 xbt_os_mutex_destroy(parmap->ready_mutex);
258 xbt_os_cond_destroy(parmap->done_cond);
259 xbt_os_mutex_destroy(parmap->done_mutex);
262 case XBT_PARMAP_DEFAULT:
269 * \brief Applies a list of tasks in parallel.
270 * \param parmap a parallel map object
271 * \param fun the function to call in parallel
272 * \param data each element of this dynar will be passed as an argument to fun
274 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun,
275 xbt_dynar_t data, unsigned stride, int once)
277 /* Assign resources to worker threads */
281 parmap->stride = stride;
282 parmap->apply_once = once;
283 parmap->master_signal_f(parmap);
284 xbt_parmap_work(parmap);
285 parmap->master_wait_f(parmap);
286 XBT_DEBUG("Job done");
290 * \brief Returns a next task to process.
292 * Worker threads call this function to get more work.
294 * \return the next task to process, or NULL if there is no more work
296 void* xbt_parmap_next(xbt_parmap_t parmap, unsigned *index)
299 if (i % parmap->stride == 0)
300 i = __sync_fetch_and_add(&parmap->index, parmap->stride);
302 return i < xbt_dynar_length(parmap->data) ?
303 xbt_dynar_get_as(parmap->data, i, void*) : NULL;
306 static void xbt_parmap_work(xbt_parmap_t parmap)
308 if (parmap->apply_once) {
315 index = __sync_fetch_and_add(&parmap->index, parmap->stride);
316 next = index + parmap->stride;
317 if (next >= xbt_dynar_length(parmap->data)) {
318 next = xbt_dynar_length(parmap->data);
321 while (index < next) {
322 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
330 * \brief Main function of a worker thread.
331 * \param arg the parmap
333 static void *xbt_parmap_worker_main(void *arg)
335 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
336 xbt_parmap_t parmap = data->parmap;
338 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
339 SIMIX_context_set_current(context);
341 XBT_DEBUG("New worker thread created");
343 /* Worker's main loop */
345 parmap->worker_wait_f(parmap, ++round);
346 if (parmap->status == XBT_PARMAP_WORK) {
348 XBT_DEBUG("Worker %d got a job", data->worker_id);
350 xbt_parmap_work(parmap);
351 parmap->worker_signal_f(parmap);
353 XBT_DEBUG("Worker %d has finished", data->worker_id);
355 /* We are destroying the parmap */
357 SIMIX_context_free(context);
367 * \brief Applies a list of tasks in parallel.
368 * \param parmap a parallel map object
369 * \param fun the function to call in parallel
370 * \param data each element of this dynar will be passed as an argument to fun
372 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun,
373 void* data, unsigned int length, void* ref_snapshot)
375 /* Assign resources to worker threads */
376 parmap->snapshot_compare = fun;
377 parmap->mc_data = data;
380 parmap->length = length;
381 parmap->ref_snapshot = ref_snapshot;
382 parmap->master_signal_f(parmap);
383 xbt_parmap_mc_work(parmap, 0);
384 parmap->master_wait_f(parmap);
385 XBT_DEBUG("Job done");
386 return parmap->finish;
389 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
391 unsigned int data_size = (parmap->length / parmap->num_workers) +
392 ((parmap->length % parmap->num_workers) ? 1 :0);
393 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
394 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
396 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
398 while ( start < end && parmap->finish == -1) {
399 //XBT_CRITICAL("Starting with %p", start);
400 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
401 start = (char *)start + sizeof(start);
404 parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
405 //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
412 * \brief Main function of a worker thread.
413 * \param arg the parmap
415 static void *xbt_parmap_mc_worker_main(void *arg)
417 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
418 xbt_parmap_t parmap = data->parmap;
420 /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
421 /* SIMIX_context_set_current(context); */
423 XBT_DEBUG("New worker thread created");
425 /* Worker's main loop */
427 parmap->worker_wait_f(parmap, ++round);
428 if (parmap->status == XBT_PARMAP_WORK) {
430 XBT_DEBUG("Worker %d got a job", data->worker_id);
432 xbt_parmap_mc_work(parmap, data->worker_id);
433 parmap->worker_signal_f(parmap);
435 XBT_DEBUG("Worker %d has finished", data->worker_id);
437 /* We are destroying the parmap */
447 static void futex_wait(unsigned *uaddr, unsigned val)
449 XBT_VERB("Waiting on futex %p", uaddr);
450 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
453 static void futex_wake(unsigned *uaddr, unsigned val)
455 XBT_VERB("Waking futex %p", uaddr);
456 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
461 * \brief Starts the parmap: waits for all workers to be ready and returns.
463 * This function is called by the controller thread.
465 * \param parmap a parmap
467 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
469 xbt_os_mutex_acquire(parmap->done_mutex);
470 if (parmap->thread_counter < parmap->num_workers) {
471 /* wait for all workers to be ready */
472 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
474 xbt_os_mutex_release(parmap->done_mutex);
478 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
480 * This function is called by all worker threads when they end (not including
483 * \param parmap a parmap
485 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
487 xbt_os_mutex_acquire(parmap->done_mutex);
488 if (++parmap->thread_counter == parmap->num_workers) {
489 /* all workers have finished, wake the controller */
490 xbt_os_cond_signal(parmap->done_cond);
492 xbt_os_mutex_release(parmap->done_mutex);
496 * \brief Wakes all workers and waits for them to finish the tasks.
498 * This function is called by the controller thread.
500 * \param parmap a parmap
502 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
504 xbt_os_mutex_acquire(parmap->ready_mutex);
505 parmap->thread_counter = 1;
507 /* wake all workers */
508 xbt_os_cond_broadcast(parmap->ready_cond);
509 xbt_os_mutex_release(parmap->ready_mutex);
513 * \brief Waits for some work to process.
515 * This function is called by each worker thread (not including the controller)
516 * when it has no more work to do.
518 * \param parmap a parmap
519 * \param round the expected round number
521 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
523 xbt_os_mutex_acquire(parmap->ready_mutex);
524 /* wait for more work */
525 if (parmap->work != round) {
526 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
528 xbt_os_mutex_release(parmap->ready_mutex);
533 * \brief Starts the parmap: waits for all workers to be ready and returns.
535 * This function is called by the controller thread.
537 * \param parmap a parmap
539 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
541 unsigned count = parmap->thread_counter;
542 while (count < parmap->num_workers) {
543 /* wait for all workers to be ready */
544 futex_wait(&parmap->thread_counter, count);
545 count = parmap->thread_counter;
550 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
552 * This function is called by all worker threads when they end (not including
555 * \param parmap a parmap
557 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
559 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
560 if (count == parmap->num_workers) {
561 /* all workers have finished, wake the controller */
562 futex_wake(&parmap->thread_counter, INT_MAX);
567 * \brief Wakes all workers and waits for them to finish the tasks.
569 * This function is called by the controller thread.
571 * \param parmap a parmap
573 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
575 parmap->thread_counter = 1;
576 __sync_add_and_fetch(&parmap->work, 1);
577 /* wake all workers */
578 futex_wake(&parmap->work, INT_MAX);
582 * \brief Waits for some work to process.
584 * This function is called by each worker thread (not including the controller)
585 * when it has no more work to do.
587 * \param parmap a parmap
588 * \param round the expected round number
590 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
592 unsigned work = parmap->work;
593 /* wait for more work */
594 while (work != round) {
595 futex_wait(&parmap->work, work);
602 * \brief Starts the parmap: waits for all workers to be ready and returns.
604 * This function is called by the controller thread.
606 * \param parmap a parmap
608 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
610 while (parmap->thread_counter < parmap->num_workers) {
611 xbt_os_thread_yield();
616 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
618 * This function is called by all worker threads when they end.
620 * \param parmap a parmap
622 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
624 __sync_add_and_fetch(&parmap->thread_counter, 1);
628 * \brief Wakes all workers and waits for them to finish the tasks.
630 * This function is called by the controller thread.
632 * \param parmap a parmap
634 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
636 parmap->thread_counter = 1;
637 __sync_add_and_fetch(&parmap->work, 1);
641 * \brief Waits for some work to process.
643 * This function is called by each worker thread (not including the controller)
644 * when it has no more work to do.
646 * \param parmap a parmap
647 * \param round the expected round number
649 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
651 /* wait for more work */
652 while (parmap->work != round) {
653 xbt_os_thread_yield();