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;
143 xbt_die("Futex is not available on this OS (maybe you are on a Mac).");
146 case XBT_PARMAP_BUSY_WAIT:
147 parmap->start_f = xbt_parmap_busy_start;
148 parmap->end_f = xbt_parmap_busy_end;
149 parmap->signal_f = xbt_parmap_busy_signal;
150 parmap->wait_f = xbt_parmap_busy_wait;
156 * \brief Applies a list of tasks in parallel.
157 * \param parmap a parallel map object
158 * \param fun the function to call in parallel
159 * \param data each element of this dynar will be passed as an argument to fun
161 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
163 /* Assign resources to worker threads */
167 parmap->signal_f(parmap);
168 XBT_DEBUG("Job done");
172 * \brief Returns a next task to process.
174 * Worker threads call this function to get more work.
176 * \return the next task to process, or NULL if there is no more work
178 void* xbt_parmap_next(xbt_parmap_t parmap)
180 unsigned int index = __sync_fetch_and_add(&parmap->index, 1);
181 if (index < xbt_dynar_length(parmap->data)) {
182 return xbt_dynar_get_as(parmap->data, index, void*);
188 * \brief Main function of a worker thread.
189 * \param arg the parmap
191 static void *xbt_parmap_worker_main(void *arg)
193 xbt_parmap_t parmap = (xbt_parmap_t) arg;
195 XBT_DEBUG("New worker thread created");
197 /* Worker's main loop */
199 parmap->wait_f(parmap);
200 if (parmap->status == XBT_PARMAP_WORK) {
202 XBT_DEBUG("Worker got a job");
204 void* work = xbt_parmap_next(parmap);
205 while (work != NULL) {
207 work = xbt_parmap_next(parmap);
210 XBT_DEBUG("Worker has finished");
212 /* We are destroying the parmap */
214 parmap->end_f(parmap);
215 XBT_DEBUG("Shutting down worker");
222 static void futex_wait(int *uaddr, int val)
224 XBT_VERB("Waiting on futex %p", uaddr);
225 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
228 static void futex_wake(int *uaddr, int val)
230 XBT_VERB("Waking futex %p", uaddr);
231 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
235 static void xbt_parmap_posix_start(xbt_parmap_t parmap)
240 static void xbt_parmap_posix_end(xbt_parmap_t parmap)
245 static void xbt_parmap_posix_signal(xbt_parmap_t parmap)
250 static void xbt_parmap_posix_wait(xbt_parmap_t parmap)
257 * \brief Starts the parmap: waits for all workers to be ready and returns.
259 * This function is called by the controller thread.
261 * \param parmap a parmap
263 static void xbt_parmap_futex_start(xbt_parmap_t parmap)
265 int myflag = parmap->done;
266 __sync_fetch_and_add(&parmap->thread_counter, 1);
267 if (parmap->thread_counter < parmap->num_workers) {
268 /* wait for all workers to be ready */
269 futex_wait(&parmap->done, myflag);
274 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
276 * This function is called by all worker threads when they end (not including
279 * \param parmap a parmap
281 static void xbt_parmap_futex_end(xbt_parmap_t parmap)
283 unsigned int mycount;
285 mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
286 if (mycount == parmap->num_workers) {
287 /* all workers have finished, wake the controller */
289 futex_wake(&parmap->done, 1);
294 * \brief Wakes all workers and waits for them to finish the tasks.
296 * This function is called by the controller thread.
298 * \param parmap a parmap
300 static void xbt_parmap_futex_signal(xbt_parmap_t parmap)
302 int myflag = parmap->done;
303 parmap->thread_counter = 0;
306 /* wake all workers */
307 futex_wake(&parmap->work, parmap->num_workers);
309 if (parmap->status == XBT_PARMAP_WORK) {
310 /* also work myself */
311 void* work = xbt_parmap_next(parmap);
312 while (work != NULL) {
314 work = xbt_parmap_next(parmap);
318 unsigned int mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
319 if (mycount < parmap->num_workers) {
320 /* some workers have not finished yet */
321 futex_wait(&parmap->done, myflag);
326 * \brief Waits for some work to process.
328 * This function is called by each worker thread (not including the controller)
329 * when it has no more work to do.
331 * \param parmap a parmap
333 static void xbt_parmap_futex_wait(xbt_parmap_t parmap)
336 unsigned int mycount;
338 myflag = parmap->work;
339 mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
340 if (mycount == parmap->num_workers) {
341 /* all workers have finished, wake the controller */
343 futex_wake(&parmap->done, 1);
346 /* wait for more work */
347 futex_wait(&parmap->work, myflag);
352 * \brief Starts the parmap: waits for all workers to be ready and returns.
354 * This function is called by the controller thread.
356 * \param parmap a parmap
358 static void xbt_parmap_busy_start(xbt_parmap_t parmap)
360 __sync_fetch_and_add(&parmap->thread_counter, 1);
361 while (parmap->thread_counter < parmap->num_workers) {
362 xbt_os_thread_yield();
367 * \brief Ends the parmap: wakes the controller thread when all workers terminate.
369 * This function is called by all worker threads when they end.
371 * \param parmap a parmap
373 static void xbt_parmap_busy_end(xbt_parmap_t parmap)
375 __sync_add_and_fetch(&parmap->thread_counter, 1);
379 * \brief Wakes all workers and waits for them to finish the tasks.
381 * This function is called by the controller thread.
383 * \param parmap a parmap
385 static void xbt_parmap_busy_signal(xbt_parmap_t parmap)
387 parmap->thread_counter = 0;
390 if (parmap->status == XBT_PARMAP_WORK) {
391 /* also work myself */
392 void* work = xbt_parmap_next(parmap);
393 while (work != NULL) {
395 work = xbt_parmap_next(parmap);
399 /* I have finished, wait for the others */
400 __sync_add_and_fetch(&parmap->thread_counter, 1);
401 while (parmap->thread_counter < parmap->num_workers) {
402 xbt_os_thread_yield();
407 * \brief Waits for some work to process.
409 * This function is called by each worker thread (not including the controller)
410 * when it has no more work to do.
412 * \param parmap a parmap
414 static void xbt_parmap_busy_wait(xbt_parmap_t parmap)
416 int work = parmap->work;
417 __sync_add_and_fetch(&parmap->thread_counter, 1);
419 /* wait for more work */
420 while (parmap->work == work) {
421 xbt_os_thread_yield();
429 XBT_TEST_SUITE("parmap", "Parallel Map");
430 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
438 //XBT_INFO("I'm job %lu", (unsigned long)arg);
441 XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
443 xbt_test_add("Create the parmap");
446 xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
448 /* Create the parallel map */
450 parmap = xbt_parmap_new(10, XBT_PARMAP_FUTEX);
452 parmap = xbt_parmap_new(10, XBT_PARMAP_BUSY_WAIT);
454 for (j = 0; j < 100; j++) {
455 xbt_dynar_push_as(data, void *, (void *)j);
458 for (i = 0; i < 5; i++) {
459 xbt_parmap_apply(parmap, fun, data);
462 /* Destroy the parmap */
463 xbt_parmap_destroy(parmap);
464 xbt_dynar_free(&data);
467 #endif /* SIMGRID_TEST */