1 /* Copyright (c) 2004, 2005, 2007, 2009, 2010. 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 "gras_config.h"
10 #include <sys/syscall.h>
14 #include <linux/futex.h>
17 #include "xbt/parmap.h"
19 #include "xbt/function_types.h"
20 #include "xbt/dynar.h"
21 #include "xbt/xbt_os_thread.h"
22 #include "xbt/sysdep.h"
24 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
25 XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing");
30 } e_xbt_parmap_flag_t;
32 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
33 static void *xbt_parmap_worker_main(void *parmap);
34 static void xbt_parmap_work(xbt_parmap_t parmap);
36 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
37 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
38 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
39 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
42 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
43 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
44 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
45 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
46 static void futex_wait(unsigned *uaddr, unsigned val);
47 static void futex_wake(unsigned *uaddr, unsigned val);
50 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
51 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
52 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
53 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
56 * \brief Parallel map structure
58 typedef struct s_xbt_parmap {
59 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
60 unsigned work; /**< index of the current round */
61 unsigned thread_counter; /**< number of workers that have done the work */
63 unsigned int num_workers; /**< total number of worker threads including the controller */
64 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
65 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
66 unsigned int index; /**< index of the next element of data to pick */
69 xbt_os_cond_t ready_cond;
70 xbt_os_mutex_t ready_mutex;
71 xbt_os_cond_t done_cond;
72 xbt_os_mutex_t done_mutex;
74 /* fields that depend on the synchronization mode */
75 e_xbt_parmap_mode_t mode; /**< synchronization mode */
76 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
77 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
78 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
79 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
83 * \brief Creates a parallel map object
84 * \param num_workers number of worker threads to create
85 * \param mode how to synchronize the worker threads
86 * \return the parmap created
88 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
91 xbt_os_thread_t worker = NULL;
93 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
95 /* Initialize the thread pool data structure */
96 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
98 parmap->num_workers = num_workers;
99 parmap->status = XBT_PARMAP_WORK;
100 xbt_parmap_set_mode(parmap, mode);
102 /* Create the pool of worker threads */
103 for (i = 1; i < num_workers; i++) {
104 worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL);
105 xbt_os_thread_detach(worker);
111 * \brief Destroys a parmap
112 * \param parmap the parmap to destroy
114 void xbt_parmap_destroy(xbt_parmap_t parmap)
120 parmap->status = XBT_PARMAP_DESTROY;
121 parmap->master_signal_f(parmap);
122 parmap->master_wait_f(parmap);
124 xbt_os_cond_destroy(parmap->ready_cond);
125 xbt_os_mutex_destroy(parmap->ready_mutex);
126 xbt_os_cond_destroy(parmap->done_cond);
127 xbt_os_mutex_destroy(parmap->done_mutex);
133 * \brief Sets the synchronization mode of a parmap.
134 * \param parmap a parallel map object
135 * \param mode the synchronization mode
137 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
139 if (mode == XBT_PARMAP_DEFAULT) {
141 mode = XBT_PARMAP_FUTEX;
143 mode = XBT_PARMAP_POSIX;
150 case XBT_PARMAP_POSIX:
151 parmap->master_wait_f = xbt_parmap_posix_master_wait;
152 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
153 parmap->master_signal_f = xbt_parmap_posix_master_signal;
154 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
156 parmap->ready_cond = xbt_os_cond_init();
157 parmap->ready_mutex = xbt_os_mutex_init();
158 parmap->done_cond = xbt_os_cond_init();
159 parmap->done_mutex = xbt_os_mutex_init();
163 case XBT_PARMAP_FUTEX:
165 parmap->master_wait_f = xbt_parmap_futex_master_wait;
166 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
167 parmap->master_signal_f = xbt_parmap_futex_master_signal;
168 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
170 xbt_os_cond_destroy(parmap->ready_cond);
171 xbt_os_mutex_destroy(parmap->ready_mutex);
172 xbt_os_cond_destroy(parmap->done_cond);
173 xbt_os_mutex_destroy(parmap->done_mutex);
176 xbt_die("Futex is not available on this OS.");
179 case XBT_PARMAP_BUSY_WAIT:
180 parmap->master_wait_f = xbt_parmap_busy_master_wait;
181 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
182 parmap->master_signal_f = xbt_parmap_busy_master_signal;
183 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
185 xbt_os_cond_destroy(parmap->ready_cond);
186 xbt_os_mutex_destroy(parmap->ready_mutex);
187 xbt_os_cond_destroy(parmap->done_cond);
188 xbt_os_mutex_destroy(parmap->done_mutex);
191 case XBT_PARMAP_DEFAULT:
198 * \brief Applies a list of tasks in parallel.
199 * \param parmap a parallel map object
200 * \param fun the function to call in parallel
201 * \param data each element of this dynar will be passed as an argument to fun
203 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
205 /* Assign resources to worker threads */
209 parmap->master_signal_f(parmap);
210 xbt_parmap_work(parmap);
211 parmap->master_wait_f(parmap);
212 XBT_DEBUG("Job done");
216 * \brief Returns a next task to process.
218 * Worker threads call this function to get more work.
220 * \return the next task to process, or NULL if there is no more work
222 void* xbt_parmap_next(xbt_parmap_t parmap)
224 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
225 if (index < xbt_dynar_length(parmap->data)) {
226 return xbt_dynar_get_as(parmap->data, index, void*);
231 static void xbt_parmap_work(xbt_parmap_t parmap)
234 while ((index = __sync_fetch_and_add(&parmap->index, 1))
235 < xbt_dynar_length(parmap->data))
236 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
240 * \brief Main function of a worker thread.
241 * \param arg the parmap
243 static void *xbt_parmap_worker_main(void *arg)
245 xbt_parmap_t parmap = (xbt_parmap_t) arg;
248 XBT_DEBUG("New worker thread created");
250 /* Worker's main loop */
252 parmap->worker_wait_f(parmap, ++round);
253 if (parmap->status == XBT_PARMAP_WORK) {
255 XBT_DEBUG("Worker got a job");
257 xbt_parmap_work(parmap);
258 parmap->worker_signal_f(parmap);
260 XBT_DEBUG("Worker has finished");
262 /* We are destroying the parmap */
264 parmap->worker_signal_f(parmap);
271 static void futex_wait(unsigned *uaddr, unsigned val)
273 XBT_VERB("Waiting on futex %p", uaddr);
274 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
277 static void futex_wake(unsigned *uaddr, unsigned val)
279 XBT_VERB("Waking futex %p", uaddr);
280 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
285 * \brief Starts the parmap: waits for all workers to be ready and returns.
287 * This function is called by the controller thread.
289 * \param parmap a parmap
291 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
293 xbt_os_mutex_acquire(parmap->done_mutex);
294 if (parmap->thread_counter < parmap->num_workers) {
295 /* wait for all workers to be ready */
296 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
298 xbt_os_mutex_release(parmap->done_mutex);
302 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
304 * This function is called by all worker threads when they end (not including
307 * \param parmap a parmap
309 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
311 xbt_os_mutex_acquire(parmap->done_mutex);
312 if (++parmap->thread_counter == parmap->num_workers) {
313 /* all workers have finished, wake the controller */
314 xbt_os_cond_signal(parmap->done_cond);
316 xbt_os_mutex_release(parmap->done_mutex);
320 * \brief Wakes all workers and waits for them to finish the tasks.
322 * This function is called by the controller thread.
324 * \param parmap a parmap
326 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
328 xbt_os_mutex_acquire(parmap->ready_mutex);
329 parmap->thread_counter = 1;
331 /* wake all workers */
332 xbt_os_cond_broadcast(parmap->ready_cond);
333 xbt_os_mutex_release(parmap->ready_mutex);
337 * \brief Waits for some work to process.
339 * This function is called by each worker thread (not including the controller)
340 * when it has no more work to do.
342 * \param parmap a parmap
343 * \param round the expected round number
345 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
347 xbt_os_mutex_acquire(parmap->ready_mutex);
348 /* wait for more work */
349 if (parmap->work < round) {
350 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
352 xbt_os_mutex_release(parmap->ready_mutex);
357 * \brief Starts the parmap: waits for all workers to be ready and returns.
359 * This function is called by the controller thread.
361 * \param parmap a parmap
363 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
365 unsigned count = parmap->thread_counter;
366 while (count < parmap->num_workers) {
367 /* wait for all workers to be ready */
368 futex_wait(&parmap->thread_counter, count);
369 count = parmap->thread_counter;
374 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
376 * This function is called by all worker threads when they end (not including
379 * \param parmap a parmap
381 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
383 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
384 if (count == parmap->num_workers) {
385 /* all workers have finished, wake the controller */
386 futex_wake(&parmap->thread_counter, 1);
391 * \brief Wakes all workers and waits for them to finish the tasks.
393 * This function is called by the controller thread.
395 * \param parmap a parmap
397 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
399 parmap->thread_counter = 1;
400 __sync_add_and_fetch(&parmap->work, 1);
401 /* wake all workers */
402 futex_wake(&parmap->work, parmap->num_workers - 1);
406 * \brief Waits for some work to process.
408 * This function is called by each worker thread (not including the controller)
409 * when it has no more work to do.
411 * \param parmap a parmap
412 * \param round the expected round number
414 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
416 unsigned work = parmap->work;
417 /* wait for more work */
419 futex_wait(&parmap->work, work);
424 * \brief Starts the parmap: waits for all workers to be ready and returns.
426 * This function is called by the controller thread.
428 * \param parmap a parmap
430 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
432 while (parmap->thread_counter < parmap->num_workers) {
433 xbt_os_thread_yield();
438 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
440 * This function is called by all worker threads when they end.
442 * \param parmap a parmap
444 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
446 __sync_add_and_fetch(&parmap->thread_counter, 1);
450 * \brief Wakes all workers and waits for them to finish the tasks.
452 * This function is called by the controller thread.
454 * \param parmap a parmap
456 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
458 parmap->thread_counter = 1;
459 __sync_add_and_fetch(&parmap->work, 1);
463 * \brief Waits for some work to process.
465 * This function is called by each worker thread (not including the controller)
466 * when it has no more work to do.
468 * \param parmap a parmap
469 * \param round the expected round number
471 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
473 /* wait for more work */
474 while (parmap->work < round) {
475 xbt_os_thread_yield();
482 #include "xbt/xbt_os_thread.h"
483 #include "xbt/xbt_os_time.h"
484 #include "gras_config.h" /* HAVE_FUTEX_H */
486 XBT_TEST_SUITE("parmap", "Parallel Map");
487 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
490 #define TEST_PARMAP_SKIP_TEST(mode) 0
492 #define TEST_PARMAP_SKIP_TEST(mode) ((mode) == XBT_PARMAP_FUTEX)
495 #define TEST_PARMAP_VALIDATE_MODE(mode) \
496 if (TEST_PARMAP_SKIP_TEST(mode)) { xbt_test_skip(); return; } else ((void)0)
498 static void fun_double(void *arg)
504 /* Check that the computations are correctly done. */
505 static void test_parmap_basic(e_xbt_parmap_mode_t mode)
507 unsigned num_workers;
509 for (num_workers = 1 ; num_workers <= 16 ; num_workers *= 2) {
510 const unsigned len = 1033;
511 const unsigned num = 5;
517 xbt_test_add("Basic parmap usage (%u workers)", num_workers);
519 TEST_PARMAP_VALIDATE_MODE(mode);
520 parmap = xbt_parmap_new(num_workers, mode);
522 a = xbt_malloc(len * sizeof *a);
523 data = xbt_dynar_new(sizeof a, NULL);
524 for (i = 0; i < len; i++) {
526 xbt_dynar_push_as(data, void *, &a[i]);
529 for (i = 0; i < num; i++)
530 xbt_parmap_apply(parmap, fun_double, data);
532 for (i = 0; i < len; i++) {
533 unsigned expected = (1U << num) * (i + 1) - 1;
534 xbt_test_assert(a[i] == expected,
535 "a[%u]: expected %u, got %u", i, expected, a[i]);
538 xbt_dynar_free(&data);
540 xbt_parmap_destroy(parmap);
544 XBT_TEST_UNIT("basic_posix", test_parmap_basic_posix, "Basic usage: posix")
546 test_parmap_basic(XBT_PARMAP_POSIX);
549 XBT_TEST_UNIT("basic_futex", test_parmap_basic_futex, "Basic usage: futex")
551 test_parmap_basic(XBT_PARMAP_FUTEX);
554 XBT_TEST_UNIT("basic_busy_wait", test_parmap_basic_busy_wait, "Basic usage: busy_wait")
556 test_parmap_basic(XBT_PARMAP_BUSY_WAIT);
559 static void fun_get_id(void *arg)
561 *(uintptr_t *)arg = (uintptr_t)xbt_os_thread_self();
565 static int fun_compare(const void *pa, const void *pb)
567 uintptr_t a = *(uintptr_t *)pa;
568 uintptr_t b = *(uintptr_t *)pb;
569 return a < b ? -1 : a > b ? 1 : 0;
572 /* Check that all threads are working. */
573 static void test_parmap_extended(e_xbt_parmap_mode_t mode)
575 unsigned num_workers;
577 for (num_workers = 1 ; num_workers <= 16 ; num_workers *= 2) {
578 const unsigned len = 2 * num_workers;
585 xbt_test_add("Extended parmap usage (%u workers)", num_workers);
587 TEST_PARMAP_VALIDATE_MODE(mode);
588 parmap = xbt_parmap_new(num_workers, mode);
590 a = xbt_malloc(len * sizeof *a);
591 data = xbt_dynar_new(sizeof a, NULL);
592 for (i = 0; i < len; i++)
593 xbt_dynar_push_as(data, void *, &a[i]);
595 xbt_parmap_apply(parmap, fun_get_id, data);
597 qsort(a, len, sizeof a[0], fun_compare);
599 for (i = 1; i < len; i++)
600 if (a[i] != a[i - 1])
602 xbt_test_assert(count == num_workers,
603 "only %u/%u threads did some work", count, num_workers);
605 xbt_dynar_free(&data);
607 xbt_parmap_destroy(parmap);
611 XBT_TEST_UNIT("extended_posix", test_parmap_extended_posix, "Extended usage: posix")
613 test_parmap_extended(XBT_PARMAP_POSIX);
616 XBT_TEST_UNIT("extended_futex", test_parmap_extended_futex, "Extended usage: futex")
618 test_parmap_extended(XBT_PARMAP_FUTEX);
621 XBT_TEST_UNIT("extended_busy_wait", test_parmap_extended_busy_wait, "Extended usage: busy_wait")
623 test_parmap_extended(XBT_PARMAP_BUSY_WAIT);
626 #endif /* SIMGRID_TEST */