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);
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 int work; /**< index of the current round (1 is the first) */
61 int done; /**< number of rounds already done (futexes only) */
62 unsigned int thread_counter; /**< number of threads currently working */
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 */
68 /* fields that depend on the synchronization mode */
69 e_xbt_parmap_mode_t mode; /**< synchronization mode */
70 void (*start_f)(xbt_parmap_t); /**< initializes the worker threads */
71 void (*end_f)(xbt_parmap_t); /**< finalizes the worker threads */
72 void (*signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
73 void (*wait_f)(xbt_parmap_t); /**< waits for more work */
77 * \brief Creates a parallel map object
78 * \param num_workers number of worker threads to create
79 * \param mode how to synchronize the worker threads
80 * \return the parmap created
82 xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
85 xbt_os_thread_t worker = NULL;
87 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
89 /* Initialize the thread pool data structure */
90 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
92 parmap->num_workers = num_workers;
93 parmap->status = XBT_PARMAP_WORK;
94 xbt_parmap_set_mode(parmap, mode);
96 /* Create the pool of worker threads */
97 for (i = 0; i < num_workers - 1; i++) {
98 worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL);
99 xbt_os_thread_detach(worker);
101 parmap->start_f(parmap);
106 * \brief Destroys a parmap
107 * \param parmap the parmap to destroy
109 void xbt_parmap_destroy(xbt_parmap_t parmap)
111 parmap->status = XBT_PARMAP_DESTROY;
112 parmap->signal_f(parmap);
117 * \brief Sets the synchronization mode of a parmap.
118 * \param parmap a parallel map object
119 * \param mode the synchronization mode
121 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
127 case XBT_PARMAP_POSIX:
128 parmap->start_f = xbt_parmap_posix_start;
129 parmap->end_f = xbt_parmap_posix_end;
130 parmap->signal_f = xbt_parmap_posix_signal;
131 parmap->wait_f = xbt_parmap_posix_wait;
135 case XBT_PARMAP_FUTEX:
137 parmap->start_f = xbt_parmap_futex_start;
138 parmap->end_f = xbt_parmap_futex_end;
139 parmap->signal_f = xbt_parmap_futex_signal;
140 parmap->wait_f = xbt_parmap_futex_wait;
142 xbt_die("Impossible to use futex on Mac");
145 case XBT_PARMAP_BUSY_WAIT:
146 parmap->start_f = xbt_parmap_busy_start;
147 parmap->end_f = xbt_parmap_busy_end;
148 parmap->signal_f = xbt_parmap_busy_signal;
149 parmap->wait_f = xbt_parmap_busy_wait;
155 * \brief Applies a list of tasks in parallel.
156 * \param parmap a parallel map object
157 * \param fun the function to call in parallel
158 * \param data each element of this dynar will be passed as an argument to fun
160 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
162 /* Assign resources to worker threads */
166 parmap->signal_f(parmap);
167 XBT_DEBUG("Job done");
171 * \brief Returns a next task to process.
173 * Worker threads call this function to get more work.
175 * \return the next task to process, or NULL if there is no more work
177 void* xbt_parmap_next(xbt_parmap_t parmap)
179 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
180 if (index < xbt_dynar_length(parmap->data)) {
181 return xbt_dynar_get_as(parmap->data, index, void*);
187 * \brief Main function of a worker thread.
188 * \param arg the parmap
190 static void *xbt_parmap_worker_main(void *arg)
192 xbt_parmap_t parmap = (xbt_parmap_t) arg;
194 XBT_DEBUG("New worker thread created");
196 /* Worker's main loop */
198 parmap->wait_f(parmap);
199 if (parmap->status == XBT_PARMAP_WORK) {
201 XBT_DEBUG("Worker got a job");
203 void* work = xbt_parmap_next(parmap);
204 while (work != NULL) {
206 work = xbt_parmap_next(parmap);
209 XBT_DEBUG("Worker has finished");
211 /* We are destroying the parmap */
213 parmap->end_f(parmap);
214 XBT_DEBUG("Shutting down worker");
221 static void futex_wait(int *uaddr, int val)
223 XBT_VERB("Waiting on futex %p", uaddr);
224 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
227 static void futex_wake(int *uaddr, int val)
229 XBT_VERB("Waking futex %p", uaddr);
230 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
234 static void xbt_parmap_posix_start(xbt_parmap_t parmap)
239 static void xbt_parmap_posix_end(xbt_parmap_t parmap)
244 static void xbt_parmap_posix_signal(xbt_parmap_t parmap)
249 static void xbt_parmap_posix_wait(xbt_parmap_t parmap)
256 * \brief Starts the parmap: waits for all workers to be ready and returns.
258 * This function is called by the controller thread.
260 * \param parmap a parmap
262 static void xbt_parmap_futex_start(xbt_parmap_t parmap)
264 int myflag = parmap->done;
265 __sync_fetch_and_add(&parmap->thread_counter, 1);
266 if (parmap->thread_counter < parmap->num_workers) {
267 /* wait for all workers to be ready */
268 futex_wait(&parmap->done, myflag);
273 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
275 * This function is called by all worker threads when they end (not including
278 * \param parmap a parmap
280 static void xbt_parmap_futex_end(xbt_parmap_t parmap)
282 unsigned int mycount;
284 mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
285 if (mycount == parmap->num_workers) {
286 /* all workers have finished, wake the controller */
288 futex_wake(&parmap->done, 1);
293 * \brief Wakes all workers and waits for them to finish the tasks.
295 * This function is called by the controller thread.
297 * \param parmap a parmap
299 static void xbt_parmap_futex_signal(xbt_parmap_t parmap)
301 int myflag = parmap->done;
302 parmap->thread_counter = 0;
305 /* wake all workers */
306 futex_wake(&parmap->work, parmap->num_workers);
308 if (parmap->status == XBT_PARMAP_WORK) {
309 /* also work myself */
310 void* work = xbt_parmap_next(parmap);
311 while (work != NULL) {
313 work = xbt_parmap_next(parmap);
317 unsigned int mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
318 if (mycount < parmap->num_workers) {
319 /* some workers have not finished yet */
320 futex_wait(&parmap->done, myflag);
325 * \brief Waits for some work to process.
327 * This function is called by each worker thread (not including the controller)
328 * when it has no more work to do.
330 * \param parmap a parmap
332 static void xbt_parmap_futex_wait(xbt_parmap_t parmap)
335 unsigned int mycount;
337 myflag = parmap->work;
338 mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
339 if (mycount == parmap->num_workers) {
340 /* all workers have finished, wake the controller */
342 futex_wake(&parmap->done, 1);
345 /* wait for more work */
346 futex_wait(&parmap->work, myflag);
351 * \brief Starts the parmap: waits for all workers to be ready and returns.
353 * This function is called by the controller thread.
355 * \param parmap a parmap
357 static void xbt_parmap_busy_start(xbt_parmap_t parmap)
359 __sync_fetch_and_add(&parmap->thread_counter, 1);
360 while (parmap->thread_counter < parmap->num_workers) {
361 xbt_os_thread_yield();
366 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
368 * This function is called by all worker threads when they end.
370 * \param parmap a parmap
372 static void xbt_parmap_busy_end(xbt_parmap_t parmap)
374 __sync_add_and_fetch(&parmap->thread_counter, 1);
378 * \brief Wakes all workers and waits for them to finish the tasks.
380 * This function is called by the controller thread.
382 * \param parmap a parmap
384 static void xbt_parmap_busy_signal(xbt_parmap_t parmap)
386 parmap->thread_counter = 0;
389 if (parmap->status == XBT_PARMAP_WORK) {
390 /* also work myself */
391 void* work = xbt_parmap_next(parmap);
392 while (work != NULL) {
394 work = xbt_parmap_next(parmap);
398 /* I have finished, wait for the others */
399 __sync_add_and_fetch(&parmap->thread_counter, 1);
400 while (parmap->thread_counter < parmap->num_workers) {
401 xbt_os_thread_yield();
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
413 static void xbt_parmap_busy_wait(xbt_parmap_t parmap)
415 int work = parmap->work;
416 __sync_add_and_fetch(&parmap->thread_counter, 1);
418 /* wait for more work */
419 while (parmap->work == work) {
420 xbt_os_thread_yield();
428 XBT_TEST_SUITE("parmap", "Parallel Map");
429 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
437 //XBT_INFO("I'm job %lu", (unsigned long)arg);
440 XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
442 xbt_test_add("Create the parmap");
445 xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
447 /* Create the parallel map */
449 parmap = xbt_parmap_new(10, XBT_PARMAP_FUTEX);
451 parmap = xbt_parmap_new(10, XBT_PARMAP_BUSY_WAIT);
453 for (j = 0; j < 100; j++) {
454 xbt_dynar_push_as(data, void *, (void *)j);
457 for (i = 0; i < 5; i++) {
458 xbt_parmap_apply(parmap, fun, data);
461 /* Destroy the parmap */
462 xbt_parmap_destroy(parmap);
463 xbt_dynar_free(&data);
466 #endif /* SIMGRID_TEST */