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 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
71 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
72 unsigned int index; /**< index of the next element of data to pick */
77 int_f_pvoid_pvoid_t snapshot_compare;
83 xbt_os_cond_t ready_cond;
84 xbt_os_mutex_t ready_mutex;
85 xbt_os_cond_t done_cond;
86 xbt_os_mutex_t done_mutex;
88 /* fields that depend on the synchronization mode */
89 e_xbt_parmap_mode_t mode; /**< synchronization mode */
90 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
91 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
92 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
93 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
97 * \brief Thread data transmission structure
99 typedef struct s_xbt_parmap_thread_data{
102 } s_xbt_parmap_thread_data_t;
104 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
107 * \brief Creates a parallel map object
108 * \param num_workers number of worker threads to create
109 * \param mode how to synchronize the worker threads
110 * \return the parmap created
112 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
115 xbt_os_thread_t worker = NULL;
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);
122 parmap->num_workers = num_workers;
123 parmap->status = XBT_PARMAP_WORK;
124 xbt_parmap_set_mode(parmap, mode);
126 /* Create the pool of worker threads */
127 xbt_parmap_thread_data_t data;
128 for (i = 1; i < num_workers; i++) {
129 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
130 data->parmap = parmap;
132 worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, data, NULL);
133 xbt_os_thread_detach(worker);
140 * \brief Creates a parallel map object
141 * \param num_workers number of worker threads to create
142 * \param mode how to synchronize the worker threads
143 * \return the parmap created
145 xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
148 xbt_os_thread_t worker = NULL;
150 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
152 /* Initialize the thread pool data structure */
153 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
155 parmap->num_workers = num_workers;
156 parmap->status = XBT_PARMAP_WORK;
157 xbt_parmap_set_mode(parmap, mode);
159 /* Create the pool of worker threads */
160 xbt_parmap_thread_data_t data;
161 for (i = 1; i < num_workers; i++) {
162 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
163 data->parmap = parmap;
165 worker = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main, data, NULL);
166 xbt_os_thread_detach(worker);
173 * \brief Destroys a parmap
174 * \param parmap the parmap to destroy
176 void xbt_parmap_destroy(xbt_parmap_t parmap)
182 parmap->status = XBT_PARMAP_DESTROY;
183 parmap->master_signal_f(parmap);
184 parmap->master_wait_f(parmap);
186 xbt_os_cond_destroy(parmap->ready_cond);
187 xbt_os_mutex_destroy(parmap->ready_mutex);
188 xbt_os_cond_destroy(parmap->done_cond);
189 xbt_os_mutex_destroy(parmap->done_mutex);
195 * \brief Sets the synchronization mode of a parmap.
196 * \param parmap a parallel map object
197 * \param mode the synchronization mode
199 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
201 if (mode == XBT_PARMAP_DEFAULT) {
203 mode = XBT_PARMAP_FUTEX;
205 mode = XBT_PARMAP_POSIX;
212 case XBT_PARMAP_POSIX:
213 parmap->master_wait_f = xbt_parmap_posix_master_wait;
214 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
215 parmap->master_signal_f = xbt_parmap_posix_master_signal;
216 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
218 parmap->ready_cond = xbt_os_cond_init();
219 parmap->ready_mutex = xbt_os_mutex_init();
220 parmap->done_cond = xbt_os_cond_init();
221 parmap->done_mutex = xbt_os_mutex_init();
225 case XBT_PARMAP_FUTEX:
227 parmap->master_wait_f = xbt_parmap_futex_master_wait;
228 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
229 parmap->master_signal_f = xbt_parmap_futex_master_signal;
230 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
232 xbt_os_cond_destroy(parmap->ready_cond);
233 xbt_os_mutex_destroy(parmap->ready_mutex);
234 xbt_os_cond_destroy(parmap->done_cond);
235 xbt_os_mutex_destroy(parmap->done_mutex);
238 xbt_die("Futex is not available on this OS.");
241 case XBT_PARMAP_BUSY_WAIT:
242 parmap->master_wait_f = xbt_parmap_busy_master_wait;
243 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
244 parmap->master_signal_f = xbt_parmap_busy_master_signal;
245 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
247 xbt_os_cond_destroy(parmap->ready_cond);
248 xbt_os_mutex_destroy(parmap->ready_mutex);
249 xbt_os_cond_destroy(parmap->done_cond);
250 xbt_os_mutex_destroy(parmap->done_mutex);
253 case XBT_PARMAP_DEFAULT:
260 * \brief Applies a list of tasks in parallel.
261 * \param parmap a parallel map object
262 * \param fun the function to call in parallel
263 * \param data each element of this dynar will be passed as an argument to fun
265 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
267 /* Assign resources to worker threads */
271 parmap->master_signal_f(parmap);
272 xbt_parmap_work(parmap);
273 parmap->master_wait_f(parmap);
274 XBT_DEBUG("Job done");
278 * \brief Returns a next task to process.
280 * Worker threads call this function to get more work.
282 * \return the next task to process, or NULL if there is no more work
284 void* xbt_parmap_next(xbt_parmap_t parmap)
286 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
287 if (index < xbt_dynar_length(parmap->data)) {
288 return xbt_dynar_get_as(parmap->data, index, void*);
293 static void xbt_parmap_work(xbt_parmap_t parmap)
296 while ((index = __sync_fetch_and_add(&parmap->index, 1))
297 < xbt_dynar_length(parmap->data))
298 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
302 * \brief Main function of a worker thread.
303 * \param arg the parmap
305 static void *xbt_parmap_worker_main(void *arg)
307 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
308 xbt_parmap_t parmap = data->parmap;
310 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
311 SIMIX_context_set_current(context);
313 XBT_DEBUG("New worker thread created");
315 /* Worker's main loop */
317 parmap->worker_wait_f(parmap, ++round);
318 if (parmap->status == XBT_PARMAP_WORK) {
320 XBT_DEBUG("Worker %d got a job", data->worker_id);
322 xbt_parmap_work(parmap);
323 parmap->worker_signal_f(parmap);
325 XBT_DEBUG("Worker %d has finished", data->worker_id);
327 /* We are destroying the parmap */
330 parmap->worker_signal_f(parmap);
339 * \brief Applies a list of tasks in parallel.
340 * \param parmap a parallel map object
341 * \param fun the function to call in parallel
342 * \param data each element of this dynar will be passed as an argument to fun
344 int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun,
345 void* data, unsigned int length, void* ref_snapshot)
347 /* Assign resources to worker threads */
348 parmap->snapshot_compare = fun;
349 parmap->mc_data = data;
352 parmap->length = length;
353 parmap->ref_snapshot = ref_snapshot;
354 parmap->master_signal_f(parmap);
355 xbt_parmap_mc_work(parmap, 0);
356 parmap->master_wait_f(parmap);
357 XBT_DEBUG("Job done");
358 return parmap->finish;
361 static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
363 unsigned int data_size = (parmap->length / parmap->num_workers) +
364 ((parmap->length % parmap->num_workers) ? 1 :0);
365 void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
366 void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
368 //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
370 while ( start < end && parmap->finish == -1) {
371 //XBT_CRITICAL("Starting with %p", start);
372 int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
373 start = (char *)start + sizeof(start);
376 parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
377 //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
384 * \brief Main function of a worker thread.
385 * \param arg the parmap
387 static void *xbt_parmap_mc_worker_main(void *arg)
389 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
390 xbt_parmap_t parmap = data->parmap;
392 /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
393 /* SIMIX_context_set_current(context); */
395 XBT_DEBUG("New worker thread created");
397 /* Worker's main loop */
399 parmap->worker_wait_f(parmap, ++round);
400 if (parmap->status == XBT_PARMAP_WORK) {
402 XBT_DEBUG("Worker %d got a job", data->worker_id);
404 xbt_parmap_mc_work(parmap, data->worker_id);
405 parmap->worker_signal_f(parmap);
407 XBT_DEBUG("Worker %d has finished", data->worker_id);
409 /* We are destroying the parmap */
412 parmap->worker_signal_f(parmap);
420 static void futex_wait(unsigned *uaddr, unsigned val)
422 XBT_VERB("Waiting on futex %p", uaddr);
423 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
426 static void futex_wake(unsigned *uaddr, unsigned val)
428 XBT_VERB("Waking futex %p", uaddr);
429 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
434 * \brief Starts the parmap: waits for all workers to be ready and returns.
436 * This function is called by the controller thread.
438 * \param parmap a parmap
440 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
442 xbt_os_mutex_acquire(parmap->done_mutex);
443 if (parmap->thread_counter < parmap->num_workers) {
444 /* wait for all workers to be ready */
445 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
447 xbt_os_mutex_release(parmap->done_mutex);
451 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
453 * This function is called by all worker threads when they end (not including
456 * \param parmap a parmap
458 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
460 xbt_os_mutex_acquire(parmap->done_mutex);
461 if (++parmap->thread_counter == parmap->num_workers) {
462 /* all workers have finished, wake the controller */
463 xbt_os_cond_signal(parmap->done_cond);
465 xbt_os_mutex_release(parmap->done_mutex);
469 * \brief Wakes all workers and waits for them to finish the tasks.
471 * This function is called by the controller thread.
473 * \param parmap a parmap
475 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
477 xbt_os_mutex_acquire(parmap->ready_mutex);
478 parmap->thread_counter = 1;
480 /* wake all workers */
481 xbt_os_cond_broadcast(parmap->ready_cond);
482 xbt_os_mutex_release(parmap->ready_mutex);
486 * \brief Waits for some work to process.
488 * This function is called by each worker thread (not including the controller)
489 * when it has no more work to do.
491 * \param parmap a parmap
492 * \param round the expected round number
494 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
496 xbt_os_mutex_acquire(parmap->ready_mutex);
497 /* wait for more work */
498 if (parmap->work != round) {
499 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
501 xbt_os_mutex_release(parmap->ready_mutex);
506 * \brief Starts the parmap: waits for all workers to be ready and returns.
508 * This function is called by the controller thread.
510 * \param parmap a parmap
512 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
514 unsigned count = parmap->thread_counter;
515 while (count < parmap->num_workers) {
516 /* wait for all workers to be ready */
517 futex_wait(&parmap->thread_counter, count);
518 count = parmap->thread_counter;
523 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
525 * This function is called by all worker threads when they end (not including
528 * \param parmap a parmap
530 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
532 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
533 if (count == parmap->num_workers) {
534 /* all workers have finished, wake the controller */
535 futex_wake(&parmap->thread_counter, INT_MAX);
540 * \brief Wakes all workers and waits for them to finish the tasks.
542 * This function is called by the controller thread.
544 * \param parmap a parmap
546 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
548 parmap->thread_counter = 1;
549 __sync_add_and_fetch(&parmap->work, 1);
550 /* wake all workers */
551 futex_wake(&parmap->work, INT_MAX);
555 * \brief Waits for some work to process.
557 * This function is called by each worker thread (not including the controller)
558 * when it has no more work to do.
560 * \param parmap a parmap
561 * \param round the expected round number
563 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
565 unsigned work = parmap->work;
566 /* wait for more work */
567 while (work != round) {
568 futex_wait(&parmap->work, work);
575 * \brief Starts the parmap: waits for all workers to be ready and returns.
577 * This function is called by the controller thread.
579 * \param parmap a parmap
581 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
583 while (parmap->thread_counter < parmap->num_workers) {
584 xbt_os_thread_yield();
589 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
591 * This function is called by all worker threads when they end.
593 * \param parmap a parmap
595 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
597 __sync_add_and_fetch(&parmap->thread_counter, 1);
601 * \brief Wakes all workers and waits for them to finish the tasks.
603 * This function is called by the controller thread.
605 * \param parmap a parmap
607 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
609 parmap->thread_counter = 1;
610 __sync_add_and_fetch(&parmap->work, 1);
614 * \brief Waits for some work to process.
616 * This function is called by each worker thread (not including the controller)
617 * when it has no more work to do.
619 * \param parmap a parmap
620 * \param round the expected round number
622 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
624 /* wait for more work */
625 while (parmap->work != round) {
626 xbt_os_thread_yield();