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 "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");
27 XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing");
32 } e_xbt_parmap_flag_t;
34 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
35 static void *xbt_parmap_worker_main(void *parmap);
36 static void xbt_parmap_work(xbt_parmap_t parmap);
38 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
39 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
40 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
41 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
44 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
45 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
46 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
47 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
48 static void futex_wait(unsigned *uaddr, unsigned val);
49 static void futex_wake(unsigned *uaddr, unsigned val);
52 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
53 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
54 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
55 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
59 * \brief Parallel map structure
61 typedef struct s_xbt_parmap {
62 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
63 unsigned work; /**< index of the current round */
64 unsigned thread_counter; /**< number of workers that have done the work */
66 unsigned int num_workers; /**< total number of worker threads including the controller */
67 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
68 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
69 unsigned int index; /**< index of the next element of data to pick */
72 xbt_os_cond_t ready_cond;
73 xbt_os_mutex_t ready_mutex;
74 xbt_os_cond_t done_cond;
75 xbt_os_mutex_t done_mutex;
77 /* fields that depend on the synchronization mode */
78 e_xbt_parmap_mode_t mode; /**< synchronization mode */
79 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
80 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
81 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
82 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
86 * \brief Thread data transmission structure
88 typedef struct s_xbt_parmap_thread_data{
91 } s_xbt_parmap_thread_data_t;
93 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
96 * \brief Creates a parallel map object
97 * \param num_workers number of worker threads to create
98 * \param mode how to synchronize the worker threads
99 * \return the parmap created
101 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
104 xbt_os_thread_t worker = NULL;
106 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
108 /* Initialize the thread pool data structure */
109 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
111 parmap->num_workers = num_workers;
112 parmap->status = XBT_PARMAP_WORK;
113 xbt_parmap_set_mode(parmap, mode);
115 /* Create the pool of worker threads */
116 xbt_parmap_thread_data_t data;
117 for (i = 1; i < num_workers; i++) {
118 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
119 data->parmap = parmap;
121 worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, data, NULL);
122 xbt_os_thread_detach(worker);
128 * \brief Destroys a parmap
129 * \param parmap the parmap to destroy
131 void xbt_parmap_destroy(xbt_parmap_t parmap)
137 parmap->status = XBT_PARMAP_DESTROY;
138 parmap->master_signal_f(parmap);
139 parmap->master_wait_f(parmap);
141 xbt_os_cond_destroy(parmap->ready_cond);
142 xbt_os_mutex_destroy(parmap->ready_mutex);
143 xbt_os_cond_destroy(parmap->done_cond);
144 xbt_os_mutex_destroy(parmap->done_mutex);
150 * \brief Sets the synchronization mode of a parmap.
151 * \param parmap a parallel map object
152 * \param mode the synchronization mode
154 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
156 if (mode == XBT_PARMAP_DEFAULT) {
158 mode = XBT_PARMAP_FUTEX;
160 mode = XBT_PARMAP_POSIX;
167 case XBT_PARMAP_POSIX:
168 parmap->master_wait_f = xbt_parmap_posix_master_wait;
169 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
170 parmap->master_signal_f = xbt_parmap_posix_master_signal;
171 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
173 parmap->ready_cond = xbt_os_cond_init();
174 parmap->ready_mutex = xbt_os_mutex_init();
175 parmap->done_cond = xbt_os_cond_init();
176 parmap->done_mutex = xbt_os_mutex_init();
180 case XBT_PARMAP_FUTEX:
182 parmap->master_wait_f = xbt_parmap_futex_master_wait;
183 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
184 parmap->master_signal_f = xbt_parmap_futex_master_signal;
185 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
187 xbt_os_cond_destroy(parmap->ready_cond);
188 xbt_os_mutex_destroy(parmap->ready_mutex);
189 xbt_os_cond_destroy(parmap->done_cond);
190 xbt_os_mutex_destroy(parmap->done_mutex);
193 xbt_die("Futex is not available on this OS.");
196 case XBT_PARMAP_BUSY_WAIT:
197 parmap->master_wait_f = xbt_parmap_busy_master_wait;
198 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
199 parmap->master_signal_f = xbt_parmap_busy_master_signal;
200 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
202 xbt_os_cond_destroy(parmap->ready_cond);
203 xbt_os_mutex_destroy(parmap->ready_mutex);
204 xbt_os_cond_destroy(parmap->done_cond);
205 xbt_os_mutex_destroy(parmap->done_mutex);
208 case XBT_PARMAP_DEFAULT:
215 * \brief Applies a list of tasks in parallel.
216 * \param parmap a parallel map object
217 * \param fun the function to call in parallel
218 * \param data each element of this dynar will be passed as an argument to fun
220 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
222 /* Assign resources to worker threads */
226 parmap->master_signal_f(parmap);
227 xbt_parmap_work(parmap);
228 parmap->master_wait_f(parmap);
229 XBT_DEBUG("Job done");
233 * \brief Returns a next task to process.
235 * Worker threads call this function to get more work.
237 * \return the next task to process, or NULL if there is no more work
239 void* xbt_parmap_next(xbt_parmap_t parmap)
241 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
242 if (index < xbt_dynar_length(parmap->data)) {
243 return xbt_dynar_get_as(parmap->data, index, void*);
248 static void xbt_parmap_work(xbt_parmap_t parmap)
251 while ((index = __sync_fetch_and_add(&parmap->index, 1))
252 < xbt_dynar_length(parmap->data))
253 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
257 * \brief Main function of a worker thread.
258 * \param arg the parmap
260 static void *xbt_parmap_worker_main(void *arg)
262 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
263 xbt_parmap_t parmap = data->parmap;
265 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
266 SIMIX_context_set_current(context);
268 XBT_DEBUG("New worker thread created");
270 /* Worker's main loop */
272 parmap->worker_wait_f(parmap, ++round);
273 if (parmap->status == XBT_PARMAP_WORK) {
275 XBT_DEBUG("Worker %d got a job", data->worker_id);
277 xbt_parmap_work(parmap);
278 parmap->worker_signal_f(parmap);
280 XBT_DEBUG("Worker %d has finished", data->worker_id);
282 /* We are destroying the parmap */
285 parmap->worker_signal_f(parmap);
292 static void futex_wait(unsigned *uaddr, unsigned val)
294 XBT_VERB("Waiting on futex %p", uaddr);
295 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
298 static void futex_wake(unsigned *uaddr, unsigned val)
300 XBT_VERB("Waking futex %p", uaddr);
301 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
306 * \brief Starts the parmap: waits for all workers to be ready and returns.
308 * This function is called by the controller thread.
310 * \param parmap a parmap
312 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
314 xbt_os_mutex_acquire(parmap->done_mutex);
315 if (parmap->thread_counter < parmap->num_workers) {
316 /* wait for all workers to be ready */
317 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
319 xbt_os_mutex_release(parmap->done_mutex);
323 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
325 * This function is called by all worker threads when they end (not including
328 * \param parmap a parmap
330 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
332 xbt_os_mutex_acquire(parmap->done_mutex);
333 if (++parmap->thread_counter == parmap->num_workers) {
334 /* all workers have finished, wake the controller */
335 xbt_os_cond_signal(parmap->done_cond);
337 xbt_os_mutex_release(parmap->done_mutex);
341 * \brief Wakes all workers and waits for them to finish the tasks.
343 * This function is called by the controller thread.
345 * \param parmap a parmap
347 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
349 xbt_os_mutex_acquire(parmap->ready_mutex);
350 parmap->thread_counter = 1;
352 /* wake all workers */
353 xbt_os_cond_broadcast(parmap->ready_cond);
354 xbt_os_mutex_release(parmap->ready_mutex);
358 * \brief Waits for some work to process.
360 * This function is called by each worker thread (not including the controller)
361 * when it has no more work to do.
363 * \param parmap a parmap
364 * \param round the expected round number
366 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
368 xbt_os_mutex_acquire(parmap->ready_mutex);
369 /* wait for more work */
370 if (parmap->work != round) {
371 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
373 xbt_os_mutex_release(parmap->ready_mutex);
378 * \brief Starts the parmap: waits for all workers to be ready and returns.
380 * This function is called by the controller thread.
382 * \param parmap a parmap
384 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
386 unsigned count = parmap->thread_counter;
387 while (count < parmap->num_workers) {
388 /* wait for all workers to be ready */
389 futex_wait(&parmap->thread_counter, count);
390 count = parmap->thread_counter;
395 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
397 * This function is called by all worker threads when they end (not including
400 * \param parmap a parmap
402 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
404 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
405 if (count == parmap->num_workers) {
406 /* all workers have finished, wake the controller */
407 futex_wake(&parmap->thread_counter, INT_MAX);
412 * \brief Wakes all workers and waits for them to finish the tasks.
414 * This function is called by the controller thread.
416 * \param parmap a parmap
418 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
420 parmap->thread_counter = 1;
421 __sync_add_and_fetch(&parmap->work, 1);
422 /* wake all workers */
423 futex_wake(&parmap->work, INT_MAX);
427 * \brief Waits for some work to process.
429 * This function is called by each worker thread (not including the controller)
430 * when it has no more work to do.
432 * \param parmap a parmap
433 * \param round the expected round number
435 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
437 unsigned work = parmap->work;
438 /* wait for more work */
439 while (work != round) {
440 futex_wait(&parmap->work, work);
447 * \brief Starts the parmap: waits for all workers to be ready and returns.
449 * This function is called by the controller thread.
451 * \param parmap a parmap
453 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
455 while (parmap->thread_counter < parmap->num_workers) {
456 xbt_os_thread_yield();
461 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
463 * This function is called by all worker threads when they end.
465 * \param parmap a parmap
467 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
469 __sync_add_and_fetch(&parmap->thread_counter, 1);
473 * \brief Wakes all workers and waits for them to finish the tasks.
475 * This function is called by the controller thread.
477 * \param parmap a parmap
479 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
481 parmap->thread_counter = 1;
482 __sync_add_and_fetch(&parmap->work, 1);
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_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
496 /* wait for more work */
497 while (parmap->work != round) {
498 xbt_os_thread_yield();