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");
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);
58 * \brief Parallel map structure
60 typedef struct s_xbt_parmap {
61 e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
62 unsigned work; /**< index of the current round */
63 unsigned thread_counter; /**< number of workers that have done the work */
65 unsigned int num_workers; /**< total number of worker threads including the controller */
66 void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
67 xbt_dynar_t data; /**< parameters to pass to fun in parallel */
68 unsigned int index; /**< index of the next element of data to pick */
71 xbt_os_cond_t ready_cond;
72 xbt_os_mutex_t ready_mutex;
73 xbt_os_cond_t done_cond;
74 xbt_os_mutex_t done_mutex;
76 /* fields that depend on the synchronization mode */
77 e_xbt_parmap_mode_t mode; /**< synchronization mode */
78 void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
79 void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
80 void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
81 void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
85 * \brief Thread data transmission structure
87 typedef struct s_xbt_parmap_thread_data{
90 } s_xbt_parmap_thread_data_t;
92 typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
95 * \brief Creates a parallel map object
96 * \param num_workers number of worker threads to create
97 * \param mode how to synchronize the worker threads
98 * \return the parmap created
100 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
103 xbt_os_thread_t worker = NULL;
105 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
107 /* Initialize the thread pool data structure */
108 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
110 parmap->num_workers = num_workers;
111 parmap->status = XBT_PARMAP_WORK;
112 xbt_parmap_set_mode(parmap, mode);
114 /* Create the pool of worker threads */
115 xbt_parmap_thread_data_t data;
116 for (i = 1; i < num_workers; i++) {
117 data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
118 data->parmap = parmap;
120 worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, data, NULL);
121 xbt_os_thread_detach(worker);
127 * \brief Destroys a parmap
128 * \param parmap the parmap to destroy
130 void xbt_parmap_destroy(xbt_parmap_t parmap)
136 parmap->status = XBT_PARMAP_DESTROY;
137 parmap->master_signal_f(parmap);
138 parmap->master_wait_f(parmap);
140 xbt_os_cond_destroy(parmap->ready_cond);
141 xbt_os_mutex_destroy(parmap->ready_mutex);
142 xbt_os_cond_destroy(parmap->done_cond);
143 xbt_os_mutex_destroy(parmap->done_mutex);
149 * \brief Sets the synchronization mode of a parmap.
150 * \param parmap a parallel map object
151 * \param mode the synchronization mode
153 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
155 if (mode == XBT_PARMAP_DEFAULT) {
157 mode = XBT_PARMAP_FUTEX;
159 mode = XBT_PARMAP_POSIX;
166 case XBT_PARMAP_POSIX:
167 parmap->master_wait_f = xbt_parmap_posix_master_wait;
168 parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
169 parmap->master_signal_f = xbt_parmap_posix_master_signal;
170 parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
172 parmap->ready_cond = xbt_os_cond_init();
173 parmap->ready_mutex = xbt_os_mutex_init();
174 parmap->done_cond = xbt_os_cond_init();
175 parmap->done_mutex = xbt_os_mutex_init();
179 case XBT_PARMAP_FUTEX:
181 parmap->master_wait_f = xbt_parmap_futex_master_wait;
182 parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
183 parmap->master_signal_f = xbt_parmap_futex_master_signal;
184 parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
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);
192 xbt_die("Futex is not available on this OS.");
195 case XBT_PARMAP_BUSY_WAIT:
196 parmap->master_wait_f = xbt_parmap_busy_master_wait;
197 parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
198 parmap->master_signal_f = xbt_parmap_busy_master_signal;
199 parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
201 xbt_os_cond_destroy(parmap->ready_cond);
202 xbt_os_mutex_destroy(parmap->ready_mutex);
203 xbt_os_cond_destroy(parmap->done_cond);
204 xbt_os_mutex_destroy(parmap->done_mutex);
207 case XBT_PARMAP_DEFAULT:
214 * \brief Applies a list of tasks in parallel.
215 * \param parmap a parallel map object
216 * \param fun the function to call in parallel
217 * \param data each element of this dynar will be passed as an argument to fun
219 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
221 /* Assign resources to worker threads */
225 parmap->master_signal_f(parmap);
226 xbt_parmap_work(parmap);
227 parmap->master_wait_f(parmap);
228 XBT_DEBUG("Job done");
232 * \brief Returns a next task to process.
234 * Worker threads call this function to get more work.
236 * \return the next task to process, or NULL if there is no more work
238 void* xbt_parmap_next(xbt_parmap_t parmap)
240 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
241 if (index < xbt_dynar_length(parmap->data)) {
242 return xbt_dynar_get_as(parmap->data, index, void*);
247 static void xbt_parmap_work(xbt_parmap_t parmap)
250 while ((index = __sync_fetch_and_add(&parmap->index, 1))
251 < xbt_dynar_length(parmap->data))
252 parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
256 * \brief Main function of a worker thread.
257 * \param arg the parmap
259 static void *xbt_parmap_worker_main(void *arg)
261 xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
262 xbt_parmap_t parmap = data->parmap;
264 smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
265 SIMIX_context_set_current(context);
267 XBT_DEBUG("New worker thread created");
269 /* Worker's main loop */
271 parmap->worker_wait_f(parmap, ++round);
272 if (parmap->status == XBT_PARMAP_WORK) {
274 XBT_DEBUG("Worker %d got a job", data->worker_id);
276 xbt_parmap_work(parmap);
277 parmap->worker_signal_f(parmap);
279 XBT_DEBUG("Worker %d has finished", data->worker_id);
281 /* We are destroying the parmap */
284 parmap->worker_signal_f(parmap);
291 static void futex_wait(unsigned *uaddr, unsigned val)
293 XBT_VERB("Waiting on futex %p", uaddr);
294 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
297 static void futex_wake(unsigned *uaddr, unsigned val)
299 XBT_VERB("Waking futex %p", uaddr);
300 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
305 * \brief Starts the parmap: waits for all workers to be ready and returns.
307 * This function is called by the controller thread.
309 * \param parmap a parmap
311 static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
313 xbt_os_mutex_acquire(parmap->done_mutex);
314 if (parmap->thread_counter < parmap->num_workers) {
315 /* wait for all workers to be ready */
316 xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
318 xbt_os_mutex_release(parmap->done_mutex);
322 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
324 * This function is called by all worker threads when they end (not including
327 * \param parmap a parmap
329 static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
331 xbt_os_mutex_acquire(parmap->done_mutex);
332 if (++parmap->thread_counter == parmap->num_workers) {
333 /* all workers have finished, wake the controller */
334 xbt_os_cond_signal(parmap->done_cond);
336 xbt_os_mutex_release(parmap->done_mutex);
340 * \brief Wakes all workers and waits for them to finish the tasks.
342 * This function is called by the controller thread.
344 * \param parmap a parmap
346 static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
348 xbt_os_mutex_acquire(parmap->ready_mutex);
349 parmap->thread_counter = 1;
351 /* wake all workers */
352 xbt_os_cond_broadcast(parmap->ready_cond);
353 xbt_os_mutex_release(parmap->ready_mutex);
357 * \brief Waits for some work to process.
359 * This function is called by each worker thread (not including the controller)
360 * when it has no more work to do.
362 * \param parmap a parmap
363 * \param round the expected round number
365 static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
367 xbt_os_mutex_acquire(parmap->ready_mutex);
368 /* wait for more work */
369 if (parmap->work != round) {
370 xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
372 xbt_os_mutex_release(parmap->ready_mutex);
377 * \brief Starts the parmap: waits for all workers to be ready and returns.
379 * This function is called by the controller thread.
381 * \param parmap a parmap
383 static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
385 unsigned count = parmap->thread_counter;
386 while (count < parmap->num_workers) {
387 /* wait for all workers to be ready */
388 futex_wait(&parmap->thread_counter, count);
389 count = parmap->thread_counter;
394 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
396 * This function is called by all worker threads when they end (not including
399 * \param parmap a parmap
401 static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
403 unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
404 if (count == parmap->num_workers) {
405 /* all workers have finished, wake the controller */
406 futex_wake(&parmap->thread_counter, INT_MAX);
411 * \brief Wakes all workers and waits for them to finish the tasks.
413 * This function is called by the controller thread.
415 * \param parmap a parmap
417 static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
419 parmap->thread_counter = 1;
420 __sync_add_and_fetch(&parmap->work, 1);
421 /* wake all workers */
422 futex_wake(&parmap->work, INT_MAX);
426 * \brief Waits for some work to process.
428 * This function is called by each worker thread (not including the controller)
429 * when it has no more work to do.
431 * \param parmap a parmap
432 * \param round the expected round number
434 static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
436 unsigned work = parmap->work;
437 /* wait for more work */
438 while (work != round) {
439 futex_wait(&parmap->work, work);
446 * \brief Starts the parmap: waits for all workers to be ready and returns.
448 * This function is called by the controller thread.
450 * \param parmap a parmap
452 static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
454 while (parmap->thread_counter < parmap->num_workers) {
455 xbt_os_thread_yield();
460 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
462 * This function is called by all worker threads when they end.
464 * \param parmap a parmap
466 static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
468 __sync_add_and_fetch(&parmap->thread_counter, 1);
472 * \brief Wakes all workers and waits for them to finish the tasks.
474 * This function is called by the controller thread.
476 * \param parmap a parmap
478 static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
480 parmap->thread_counter = 1;
481 __sync_add_and_fetch(&parmap->work, 1);
485 * \brief Waits for some work to process.
487 * This function is called by each worker thread (not including the controller)
488 * when it has no more work to do.
490 * \param parmap a parmap
491 * \param round the expected round number
493 static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
495 /* wait for more work */
496 while (parmap->work != round) {
497 xbt_os_thread_yield();