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 */
78 int_f_pvoid_pvoid_t snapshot_compare;
84 xbt_os_cond_t ready_cond;
85 xbt_os_mutex_t ready_mutex;
86 xbt_os_cond_t done_cond;
87 xbt_os_mutex_t done_mutex;
89 /* fields that depend on the synchronization mode */
90 e_xbt_parmap_mode_t mode; /**< synchronization mode */
91 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
92 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
93 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
94 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
98 * \brief Thread data transmission structure
100 typedef struct s_xbt_parmap_thread_data{
103 } s_xbt_parmap_thread_data_t;
105 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
108 * \brief Creates a parallel map object
109 * \param num_workers number of worker threads to create
110 * \param mode how to synchronize the worker threads
111 * \return the parmap created
113 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
117 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
119 /* Initialize the thread pool data structure */
120 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
121 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
123 parmap->num_workers = num_workers;
124 parmap->status = XBT_PARMAP_WORK;
125 xbt_parmap_set_mode(parmap, mode);
127 /* Create the pool of worker threads */
128 xbt_parmap_thread_data_t data;
129 parmap->workers[0] = NULL;
130 for (i = 1; i < num_workers; i++) {
131 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
132 data->parmap = parmap;
134 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_worker_main,
142 * \brief Creates a parallel map object
143 * \param num_workers number of worker threads to create
144 * \param mode how to synchronize the worker threads
145 * \return the parmap created
147 xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
151 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
153 /* Initialize the thread pool data structure */
154 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
155 parmap->workers = xbt_new(xbt_os_thread_t, num_workers);
157 parmap->num_workers = num_workers;
158 parmap->status = XBT_PARMAP_WORK;
159 xbt_parmap_set_mode(parmap, mode);
161 /* Create the pool of worker threads */
162 xbt_parmap_thread_data_t data;
163 parmap->workers[0] = NULL;
164 for (i = 1; i < num_workers; i++) {
165 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
166 data->parmap = parmap;
168 parmap->workers[i] = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main,
176 * \brief Destroys a parmap
177 * \param parmap the parmap to destroy
179 void xbt_parmap_destroy(xbt_parmap_t parmap)
185 parmap->status = XBT_PARMAP_DESTROY;
186 parmap->master_signal_f(parmap);
189 for (i = 1; i < parmap->num_workers; i++)
190 xbt_os_thread_join(parmap->workers[i], NULL);
192 xbt_os_cond_destroy(parmap->ready_cond);
193 xbt_os_mutex_destroy(parmap->ready_mutex);
194 xbt_os_cond_destroy(parmap->done_cond);
195 xbt_os_mutex_destroy(parmap->done_mutex);
197 xbt_free(parmap->workers);
202 * \brief Sets the synchronization mode of a parmap.
203 * \param parmap a parallel map object
204 * \param mode the synchronization mode
206 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
208 if (mode == XBT_PARMAP_DEFAULT) {
210 mode = XBT_PARMAP_FUTEX;
212 mode = XBT_PARMAP_POSIX;
219 case XBT_PARMAP_POSIX:
220 parmap->master_wait_f = xbt_parmap_posix_master_wait;
221 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
222 parmap->master_signal_f = xbt_parmap_posix_master_signal;
223 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
225 parmap->ready_cond = xbt_os_cond_init();
226 parmap->ready_mutex = xbt_os_mutex_init();
227 parmap->done_cond = xbt_os_cond_init();
228 parmap->done_mutex = xbt_os_mutex_init();
232 case XBT_PARMAP_FUTEX:
234 parmap->master_wait_f = xbt_parmap_futex_master_wait;
235 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
236 parmap->master_signal_f = xbt_parmap_futex_master_signal;
237 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
239 xbt_os_cond_destroy(parmap->ready_cond);
240 xbt_os_mutex_destroy(parmap->ready_mutex);
241 xbt_os_cond_destroy(parmap->done_cond);
242 xbt_os_mutex_destroy(parmap->done_mutex);
245 xbt_die("Futex is not available on this OS.");
248 case XBT_PARMAP_BUSY_WAIT:
249 parmap->master_wait_f = xbt_parmap_busy_master_wait;
250 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
251 parmap->master_signal_f = xbt_parmap_busy_master_signal;
252 parmap->worker_wait_f = xbt_parmap_busy_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 case XBT_PARMAP_DEFAULT:
267 * \brief Applies a list of tasks in parallel.
268 * \param parmap a parallel map object
269 * \param fun the function to call in parallel
270 * \param data each element of this dynar will be passed as an argument to fun
272 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
274 /* Assign resources to worker threads */
278 parmap->master_signal_f(parmap);
279 xbt_parmap_work(parmap);
280 parmap->master_wait_f(parmap);
281 XBT_DEBUG("Job done");
285 * \brief Returns a next task to process.
287 * Worker threads call this function to get more work.
289 * \return the next task to process, or NULL if there is no more work
291 void* xbt_parmap_next(xbt_parmap_t parmap)
293 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
294 if (index < xbt_dynar_length(parmap->data)) {
295 return xbt_dynar_get_as(parmap->data, index, void*);
300 static void xbt_parmap_work(xbt_parmap_t parmap)
303 while ((index = __sync_fetch_and_add(&parmap->index, 1))
304 < xbt_dynar_length(parmap->data))
305 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
309 * \brief Main function of a worker thread.
310 * \param arg the parmap
312 static void *xbt_parmap_worker_main(void *arg)
314 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
315 xbt_parmap_t parmap = data->parmap;
317 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
318 SIMIX_context_set_current(context);
320 XBT_DEBUG("New worker thread created");
322 /* Worker's main loop */
324 parmap->worker_wait_f(parmap, ++round);
325 if (parmap->status == XBT_PARMAP_WORK) {
327 XBT_DEBUG("Worker %d got a job", data->worker_id);
329 xbt_parmap_work(parmap);
330 parmap->worker_signal_f(parmap);
332 XBT_DEBUG("Worker %d has finished", data->worker_id);
334 /* We are destroying the parmap */
336 SIMIX_context_free(context);
346 * \brief Applies a list of tasks in parallel.
347 * \param parmap a parallel map object
348 * \param fun the function to call in parallel
349 * \param data each element of this dynar will be passed as an argument to fun
351 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun,
352 void* data, unsigned int length, void* ref_snapshot)
354 /* Assign resources to worker threads */
355 parmap->snapshot_compare = fun;
356 parmap->mc_data = data;
359 parmap->length = length;
360 parmap->ref_snapshot = ref_snapshot;
361 parmap->master_signal_f(parmap);
362 xbt_parmap_mc_work(parmap, 0);
363 parmap->master_wait_f(parmap);
364 XBT_DEBUG("Job done");
365 return parmap->finish;
368 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
370 unsigned int data_size = (parmap->length / parmap->num_workers) +
371 ((parmap->length % parmap->num_workers) ? 1 :0);
372 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
373 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
375 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
377 while ( start < end && parmap->finish == -1) {
378 //XBT_CRITICAL("Starting with %p", start);
379 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
380 start = (char *)start + sizeof(start);
383 parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
384 //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
391 * \brief Main function of a worker thread.
392 * \param arg the parmap
394 static void *xbt_parmap_mc_worker_main(void *arg)
396 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
397 xbt_parmap_t parmap = data->parmap;
399 /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
400 /* SIMIX_context_set_current(context); */
402 XBT_DEBUG("New worker thread created");
404 /* Worker's main loop */
406 parmap->worker_wait_f(parmap, ++round);
407 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);
416 /* We are destroying the parmap */
426 static void futex_wait(unsigned *uaddr, unsigned val)
428 XBT_VERB("Waiting on futex %p", uaddr);
429 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
432 static void futex_wake(unsigned *uaddr, unsigned val)
434 XBT_VERB("Waking futex %p", uaddr);
435 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
440 * \brief Starts the parmap: waits for all workers to be ready and returns.
442 * This function is called by the controller thread.
444 * \param parmap a parmap
446 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
448 xbt_os_mutex_acquire(parmap->done_mutex);
449 if (parmap->thread_counter < parmap->num_workers) {
450 /* wait for all workers to be ready */
451 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
453 xbt_os_mutex_release(parmap->done_mutex);
457 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
459 * This function is called by all worker threads when they end (not including
462 * \param parmap a parmap
464 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
466 xbt_os_mutex_acquire(parmap->done_mutex);
467 if (++parmap->thread_counter == parmap->num_workers) {
468 /* all workers have finished, wake the controller */
469 xbt_os_cond_signal(parmap->done_cond);
471 xbt_os_mutex_release(parmap->done_mutex);
475 * \brief Wakes all workers and waits for them to finish the tasks.
477 * This function is called by the controller thread.
479 * \param parmap a parmap
481 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
483 xbt_os_mutex_acquire(parmap->ready_mutex);
484 parmap->thread_counter = 1;
486 /* wake all workers */
487 xbt_os_cond_broadcast(parmap->ready_cond);
488 xbt_os_mutex_release(parmap->ready_mutex);
492 * \brief Waits for some work to process.
494 * This function is called by each worker thread (not including the controller)
495 * when it has no more work to do.
497 * \param parmap a parmap
498 * \param round the expected round number
500 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
502 xbt_os_mutex_acquire(parmap->ready_mutex);
503 /* wait for more work */
504 if (parmap->work != round) {
505 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
507 xbt_os_mutex_release(parmap->ready_mutex);
512 * \brief Starts the parmap: waits for all workers to be ready and returns.
514 * This function is called by the controller thread.
516 * \param parmap a parmap
518 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
520 unsigned count = parmap->thread_counter;
521 while (count < parmap->num_workers) {
522 /* wait for all workers to be ready */
523 futex_wait(&parmap->thread_counter, count);
524 count = parmap->thread_counter;
529 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
531 * This function is called by all worker threads when they end (not including
534 * \param parmap a parmap
536 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
538 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
539 if (count == parmap->num_workers) {
540 /* all workers have finished, wake the controller */
541 futex_wake(&parmap->thread_counter, INT_MAX);
546 * \brief Wakes all workers and waits for them to finish the tasks.
548 * This function is called by the controller thread.
550 * \param parmap a parmap
552 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
554 parmap->thread_counter = 1;
555 __sync_add_and_fetch(&parmap->work, 1);
556 /* wake all workers */
557 futex_wake(&parmap->work, INT_MAX);
561 * \brief Waits for some work to process.
563 * This function is called by each worker thread (not including the controller)
564 * when it has no more work to do.
566 * \param parmap a parmap
567 * \param round the expected round number
569 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
571 unsigned work = parmap->work;
572 /* wait for more work */
573 while (work != round) {
574 futex_wait(&parmap->work, work);
581 * \brief Starts the parmap: waits for all workers to be ready and returns.
583 * This function is called by the controller thread.
585 * \param parmap a parmap
587 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
589 while (parmap->thread_counter < parmap->num_workers) {
590 xbt_os_thread_yield();
595 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
597 * This function is called by all worker threads when they end.
599 * \param parmap a parmap
601 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
603 __sync_add_and_fetch(&parmap->thread_counter, 1);
607 * \brief Wakes all workers and waits for them to finish the tasks.
609 * This function is called by the controller thread.
611 * \param parmap a parmap
613 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
615 parmap->thread_counter = 1;
616 __sync_add_and_fetch(&parmap->work, 1);
620 * \brief Waits for some work to process.
622 * This function is called by each worker thread (not including the controller)
623 * when it has no more work to do.
625 * \param parmap a parmap
626 * \param round the expected round number
628 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
630 /* wait for more work */
631 while (parmap->work != round) {
632 xbt_os_thread_yield();