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);
35 static void xbt_parmap_posix_start(xbt_parmap_t parmap);
36 static void xbt_parmap_posix_end(xbt_parmap_t parmap);
37 static void xbt_parmap_posix_signal(xbt_parmap_t parmap);
38 static void xbt_parmap_posix_wait(xbt_parmap_t parmap);
41 static void xbt_parmap_futex_start(xbt_parmap_t parmap);
42 static void xbt_parmap_futex_end(xbt_parmap_t parmap);
43 static void xbt_parmap_futex_signal(xbt_parmap_t parmap);
44 static void xbt_parmap_futex_wait(xbt_parmap_t parmap);
45 static void futex_wait(int *uaddr, int val);
46 static void futex_wake(int *uaddr, int val);
49 static void xbt_parmap_busy_start(xbt_parmap_t parmap);
50 static void xbt_parmap_busy_end(xbt_parmap_t parmap);
51 static void xbt_parmap_busy_signal(xbt_parmap_t parmap);
52 static void xbt_parmap_busy_wait(xbt_parmap_t parmap);
55 * \brief Parallel map structure
57 typedef struct s_xbt_parmap {
58 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
59 int work; /**< index of the current round (1 is the first) */
60 int done; /**< number of rounds already done (futexes only) */
61 unsigned int thread_counter; /**< number of threads currently working */
62 unsigned int num_workers; /**< total number of worker threads including the controller */
63 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
64 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
65 unsigned int index; /**< index of the next element of data to pick */
68 xbt_os_cond_t ready_cond;
69 xbt_os_mutex_t ready_mutex;
70 xbt_os_cond_t done_cond;
71 xbt_os_mutex_t done_mutex;
73 /* fields that depend on the synchronization mode */
74 e_xbt_parmap_mode_t mode; /**< synchronization mode */
75 void (*start_f)(xbt_parmap_t); /**< initializes the worker threads */
76 void (*end_f)(xbt_parmap_t); /**< finalizes the worker threads */
77 void (*signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
78 void (*wait_f)(xbt_parmap_t); /**< waits for more work */
82 * \brief Creates a parallel map object
83 * \param num_workers number of worker threads to create
84 * \param mode how to synchronize the worker threads
85 * \return the parmap created
87 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
90 xbt_os_thread_t worker = NULL;
92 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
94 /* Initialize the thread pool data structure */
95 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
97 parmap->num_workers = num_workers;
98 parmap->status = XBT_PARMAP_WORK;
99 xbt_parmap_set_mode(parmap, mode);
101 /* Create the pool of worker threads */
102 for (i = 0; i < num_workers - 1; i++) {
103 worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL);
104 xbt_os_thread_detach(worker);
106 parmap->start_f(parmap);
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->signal_f(parmap);
123 xbt_os_cond_destroy(parmap->ready_cond);
124 xbt_os_mutex_destroy(parmap->ready_mutex);
125 xbt_os_cond_destroy(parmap->done_cond);
126 xbt_os_mutex_destroy(parmap->done_mutex);
132 * \brief Sets the synchronization mode of a parmap.
133 * \param parmap a parallel map object
134 * \param mode the synchronization mode
136 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
138 if (mode == XBT_PARMAP_DEFAULT) {
140 mode = XBT_PARMAP_FUTEX;
142 mode = XBT_PARMAP_POSIX;
149 case XBT_PARMAP_POSIX:
150 parmap->start_f = xbt_parmap_posix_start;
151 parmap->end_f = xbt_parmap_posix_end;
152 parmap->signal_f = xbt_parmap_posix_signal;
153 parmap->wait_f = xbt_parmap_posix_wait;
155 parmap->ready_cond = xbt_os_cond_init();
156 parmap->ready_mutex = xbt_os_mutex_init();
157 parmap->done_cond = xbt_os_cond_init();
158 parmap->done_mutex = xbt_os_mutex_init();
162 case XBT_PARMAP_FUTEX:
164 parmap->start_f = xbt_parmap_futex_start;
165 parmap->end_f = xbt_parmap_futex_end;
166 parmap->signal_f = xbt_parmap_futex_signal;
167 parmap->wait_f = xbt_parmap_futex_wait;
169 xbt_os_cond_destroy(parmap->ready_cond);
170 xbt_os_mutex_destroy(parmap->ready_mutex);
171 xbt_os_cond_destroy(parmap->done_cond);
172 xbt_os_mutex_destroy(parmap->done_mutex);
175 xbt_die("Futex is not available on this OS.");
178 case XBT_PARMAP_BUSY_WAIT:
179 parmap->start_f = xbt_parmap_busy_start;
180 parmap->end_f = xbt_parmap_busy_end;
181 parmap->signal_f = xbt_parmap_busy_signal;
182 parmap->wait_f = xbt_parmap_busy_wait;
184 xbt_os_cond_destroy(parmap->ready_cond);
185 xbt_os_mutex_destroy(parmap->ready_mutex);
186 xbt_os_cond_destroy(parmap->done_cond);
187 xbt_os_mutex_destroy(parmap->done_mutex);
190 case XBT_PARMAP_DEFAULT:
197 * \brief Applies a list of tasks in parallel.
198 * \param parmap a parallel map object
199 * \param fun the function to call in parallel
200 * \param data each element of this dynar will be passed as an argument to fun
202 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
204 /* Assign resources to worker threads */
208 parmap->signal_f(parmap);
209 XBT_DEBUG("Job done");
213 * \brief Returns a next task to process.
215 * Worker threads call this function to get more work.
217 * \return the next task to process, or NULL if there is no more work
219 void* xbt_parmap_next(xbt_parmap_t parmap)
221 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
222 if (index < xbt_dynar_length(parmap->data)) {
223 return xbt_dynar_get_as(parmap->data, index, void*);
229 * \brief Main function of a worker thread.
230 * \param arg the parmap
232 static void *xbt_parmap_worker_main(void *arg)
234 xbt_parmap_t parmap = (xbt_parmap_t) arg;
236 XBT_DEBUG("New worker thread created");
238 /* Worker's main loop */
240 parmap->wait_f(parmap);
241 if (parmap->status == XBT_PARMAP_WORK) {
243 XBT_DEBUG("Worker got a job");
245 void* work = xbt_parmap_next(parmap);
246 while (work != NULL) {
248 work = xbt_parmap_next(parmap);
251 XBT_DEBUG("Worker has finished");
253 /* We are destroying the parmap */
255 parmap->end_f(parmap);
262 static void futex_wait(int *uaddr, int val)
264 XBT_VERB("Waiting on futex %p", uaddr);
265 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
268 static void futex_wake(int *uaddr, int val)
270 XBT_VERB("Waking futex %p", uaddr);
271 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
276 * \brief Starts the parmap: waits for all workers to be ready and returns.
278 * This function is called by the controller thread.
280 * \param parmap a parmap
282 static void xbt_parmap_posix_start(xbt_parmap_t parmap)
284 unsigned int counter = __sync_fetch_and_add(&parmap->thread_counter, 1);
285 if (counter < parmap->num_workers) {
286 /* wait for all workers to be initialized */
287 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
292 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
294 * This function is called by all worker threads when they end (not including
297 * \param parmap a parmap
299 static void xbt_parmap_posix_end(xbt_parmap_t parmap)
301 unsigned int counter = __sync_add_and_fetch(&parmap->thread_counter, 1);
302 XBT_DEBUG("Shutting down worker %d", counter);
303 if (counter == parmap->num_workers) {
304 /* all workers have finished, wake the controller */
305 xbt_os_cond_signal(parmap->done_cond);
310 * \brief Wakes all workers and waits for them to finish the tasks.
312 * This function is called by the controller thread.
314 * \param parmap a parmap
316 static void xbt_parmap_posix_signal(xbt_parmap_t parmap)
318 parmap->thread_counter = 0;
320 XBT_DEBUG("Starting work %d", parmap->work);
322 /* wake all workers */
323 xbt_os_cond_broadcast(parmap->ready_cond);
325 if (parmap->status == XBT_PARMAP_WORK) {
326 /* also work myself */
327 void* work = xbt_parmap_next(parmap);
328 while (work != NULL) {
330 work = xbt_parmap_next(parmap);
334 unsigned int counter = __sync_add_and_fetch(&parmap->thread_counter, 1);
335 if (counter < parmap->num_workers) {
336 /* some workers have not finished yet */
337 XBT_DEBUG("Some workers have not finished yet, waiting for them");
338 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
343 * \brief Waits for some work to process.
345 * This function is called by each worker thread (not including the controller)
346 * when it has no more work to do.
348 * \param parmap a parmap
350 static void xbt_parmap_posix_wait(xbt_parmap_t parmap)
352 int work = parmap->work;
353 unsigned int counter = __sync_add_and_fetch(&parmap->thread_counter, 1);
354 if (counter == parmap->num_workers) {
355 /* all workers have finished, wake the controller */
357 XBT_DEBUG("Last worker has finished, waking the controller");
358 xbt_os_cond_signal(parmap->done_cond);
361 /* wait for more work */
362 XBT_DEBUG("Worker %d waiting for more work", counter);
363 if (parmap->work == work) {
364 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
370 * \brief Starts the parmap: waits for all workers to be ready and returns.
372 * This function is called by the controller thread.
374 * \param parmap a parmap
376 static void xbt_parmap_futex_start(xbt_parmap_t parmap)
378 int myflag = parmap->done;
379 __sync_fetch_and_add(&parmap->thread_counter, 1);
380 if (parmap->thread_counter < parmap->num_workers) {
381 /* wait for all workers to be ready */
382 futex_wait(&parmap->done, myflag);
387 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
389 * This function is called by all worker threads when they end (not including
392 * \param parmap a parmap
394 static void xbt_parmap_futex_end(xbt_parmap_t parmap)
396 unsigned int mycount;
398 mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
399 if (mycount == parmap->num_workers) {
400 /* all workers have finished, wake the controller */
402 futex_wake(&parmap->done, 1);
407 * \brief Wakes all workers and waits for them to finish the tasks.
409 * This function is called by the controller thread.
411 * \param parmap a parmap
413 static void xbt_parmap_futex_signal(xbt_parmap_t parmap)
415 int myflag = parmap->done;
416 parmap->thread_counter = 0;
419 /* wake all workers */
420 futex_wake(&parmap->work, parmap->num_workers);
422 if (parmap->status == XBT_PARMAP_WORK) {
423 /* also work myself */
424 void* work = xbt_parmap_next(parmap);
425 while (work != NULL) {
427 work = xbt_parmap_next(parmap);
431 unsigned int mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
432 if (mycount < parmap->num_workers) {
433 /* some workers have not finished yet */
434 futex_wait(&parmap->done, myflag);
439 * \brief Waits for some work to process.
441 * This function is called by each worker thread (not including the controller)
442 * when it has no more work to do.
444 * \param parmap a parmap
446 static void xbt_parmap_futex_wait(xbt_parmap_t parmap)
449 unsigned int mycount;
451 myflag = parmap->work;
452 mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
453 if (mycount == parmap->num_workers) {
454 /* all workers have finished, wake the controller */
456 futex_wake(&parmap->done, 1);
459 /* wait for more work */
460 futex_wait(&parmap->work, myflag);
465 * \brief Starts the parmap: waits for all workers to be ready and returns.
467 * This function is called by the controller thread.
469 * \param parmap a parmap
471 static void xbt_parmap_busy_start(xbt_parmap_t parmap)
473 __sync_fetch_and_add(&parmap->thread_counter, 1);
474 while (parmap->thread_counter < parmap->num_workers) {
475 xbt_os_thread_yield();
480 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
482 * This function is called by all worker threads when they end.
484 * \param parmap a parmap
486 static void xbt_parmap_busy_end(xbt_parmap_t parmap)
488 __sync_add_and_fetch(&parmap->thread_counter, 1);
492 * \brief Wakes all workers and waits for them to finish the tasks.
494 * This function is called by the controller thread.
496 * \param parmap a parmap
498 static void xbt_parmap_busy_signal(xbt_parmap_t parmap)
500 parmap->thread_counter = 0;
503 if (parmap->status == XBT_PARMAP_WORK) {
504 /* also work myself */
505 void* work = xbt_parmap_next(parmap);
506 while (work != NULL) {
508 work = xbt_parmap_next(parmap);
512 /* I have finished, wait for the others */
513 __sync_add_and_fetch(&parmap->thread_counter, 1);
514 while (parmap->thread_counter < parmap->num_workers) {
515 xbt_os_thread_yield();
520 * \brief Waits for some work to process.
522 * This function is called by each worker thread (not including the controller)
523 * when it has no more work to do.
525 * \param parmap a parmap
527 static void xbt_parmap_busy_wait(xbt_parmap_t parmap)
529 int work = parmap->work;
530 __sync_add_and_fetch(&parmap->thread_counter, 1);
532 /* wait for more work */
533 while (parmap->work == work) {
534 xbt_os_thread_yield();
542 XBT_TEST_SUITE("parmap", "Parallel Map");
543 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
551 //XBT_INFO("I'm job %lu", (unsigned long)arg);
554 XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
556 xbt_test_add("Create the parmap");
559 xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
561 /* Create the parallel map */
563 parmap = xbt_parmap_new(10, XBT_PARMAP_FUTEX);
565 parmap = xbt_parmap_new(10, XBT_PARMAP_BUSY_WAIT);
567 for (j = 0; j < 100; j++) {
568 xbt_dynar_push_as(data, void *, (void *)j);
571 for (i = 0; i < 5; i++) {
572 xbt_parmap_apply(parmap, fun, data);
575 /* Destroy the parmap */
576 xbt_parmap_destroy(parmap);
577 xbt_dynar_free(&data);
580 #endif /* SIMGRID_TEST */