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"
9 #include <sys/syscall.h>
13 #include <linux/futex.h>
15 #include "xbt/xbt_os_thread.h"
18 #include "parmap_private.h"
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
21 XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing");
23 static void *_xbt_parmap_worker_main(void *parmap);
25 static void futex_wait(int *uaddr, int val);
26 static void futex_wake(int *uaddr, int val);
28 xbt_parmap_t xbt_parmap_new(unsigned int num_workers)
31 xbt_os_thread_t worker = NULL;
33 XBT_DEBUG("Create new parmap (%u workers)", num_workers);
35 /* Initialize the thread pool data structure */
36 xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
37 parmap->sync_event = xbt_new0(s_xbt_event_t, 1);
38 parmap->num_workers = num_workers;
39 parmap->status = PARMAP_WORK;
40 parmap->sync_event->threads_to_wait = num_workers;
42 /* Create the pool of worker threads */
43 for(i=0; i < num_workers; i++){
44 worker = xbt_os_thread_create(NULL, _xbt_parmap_worker_main, parmap, NULL);
45 xbt_os_thread_detach(worker);
48 xbt_event_init(parmap->sync_event);
52 void xbt_parmap_destroy(xbt_parmap_t parmap)
54 XBT_DEBUG("Destroy parmap %p", parmap);
55 parmap->status = PARMAP_DESTROY;
56 xbt_event_signal(parmap->sync_event);
57 xbt_free(parmap->sync_event);
61 void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
63 /* Assign resources to worker threads*/
67 xbt_event_signal(parmap->sync_event);
69 XBT_DEBUG("Job done");
72 static void *_xbt_parmap_worker_main(void *arg)
74 unsigned int data_start, data_end, data_size, worker_id;
75 xbt_parmap_t parmap = (xbt_parmap_t)arg;
77 /* Fetch a worker id */
78 worker_id = __sync_fetch_and_add(&parmap->workers_max_id, 1);
79 xbt_os_thread_set_extra_data((void *)(unsigned long)worker_id);
81 XBT_DEBUG("New worker thread created (%u)", worker_id);
83 /* Worker's main loop */
85 xbt_event_wait(parmap->sync_event);
86 if(parmap->status == PARMAP_WORK){
87 XBT_DEBUG("Worker %u got a job", worker_id);
89 /* Compute how much data does every worker gets */
90 data_size = (xbt_dynar_length(parmap->data) / parmap->num_workers)
91 + ((xbt_dynar_length(parmap->data) % parmap->num_workers) ? 1 : 0);
93 /* Each worker data segment starts in a position associated with its id*/
94 data_start = data_size * worker_id;
96 /* The end of the worker data segment must be bounded by the end of the data vector */
97 data_end = MIN(data_start + data_size, xbt_dynar_length(parmap->data));
99 XBT_DEBUG("Worker %u: data_start=%u data_end=%u (data_size=%u)",
100 worker_id, data_start, data_end, data_size);
102 /* While the worker don't pass the end of it data segment apply the function */
103 while(data_start < data_end){
104 parmap->fun(*(void **)xbt_dynar_get_ptr(parmap->data, data_start));
108 /* We are destroying the parmap */
110 xbt_event_end(parmap->sync_event);
111 XBT_DEBUG("Shutting down worker %u", worker_id);
118 static void futex_wait(int *uaddr, int val)
120 XBT_VERB("Waiting on futex %p", uaddr);
121 syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
124 static void futex_wake(int *uaddr, int val)
126 XBT_VERB("Waking futex %p", uaddr);
127 syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
130 void xbt_event_init(xbt_event_t event)
132 int myflag = event->done;
133 if(event->thread_counter < event->threads_to_wait)
134 futex_wait(&event->done, myflag);
137 void xbt_event_signal(xbt_event_t event)
139 int myflag = event->done;
140 event->thread_counter = 0;
142 futex_wake(&event->work, event->threads_to_wait);
143 futex_wait(&event->done, myflag);
146 void xbt_event_wait(xbt_event_t event)
149 unsigned int mycount;
151 myflag = event->work;
152 mycount = __sync_add_and_fetch(&event->thread_counter, 1);
153 if(mycount == event->threads_to_wait){
155 futex_wake(&event->done, 1);
158 futex_wait(&event->work, myflag);
161 void xbt_event_end(xbt_event_t event)
164 unsigned int mycount;
166 myflag = event->work;
167 mycount = __sync_add_and_fetch(&event->thread_counter, 1);
168 if(mycount == event->threads_to_wait){
170 futex_wake(&event->done, 1);
179 XBT_TEST_SUITE("parmap", "Parallel Map");
180 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
190 //XBT_INFO("I'm job %lu", (unsigned long)arg);
193 XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
195 xbt_test_add("Create the parmap");
198 xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
200 /* Create the parallel map */
201 parmap = xbt_parmap_new(10);
203 for(j=0; j < 100; j++){
204 xbt_dynar_push_as(data, void *, (void *)j);
208 xbt_parmap_apply(parmap, fun, data);
210 /* Destroy the parmap */
211 xbt_parmap_destroy(parmap);
212 xbt_dynar_free(&data);
215 #endif /* SIMGRID_TEST */