/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <linux/futex.h>
+#include <errno.h>
+#include "parmap_private.h"
-#include "threadpool_private.h"
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
+XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing");
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_threadpool, xbt,
- "threadpool: pool of worker threads");
+static void *_xbt_parmap_worker_main(void *parmap);
-static void *_xbt_tpool_worker_main(void *tpool);
+static void futex_wait(int *uaddr, int val);
+static void futex_wake(int *uaddr, int val);
-unsigned long tpoolcounter = 0; /* Debug purposes */
-
-xbt_tpool_t xbt_tpool_new(unsigned int num_workers, unsigned int max_jobs)
+xbt_parmap_t xbt_parmap_new(unsigned int num_workers)
{
unsigned int i;
xbt_os_thread_t worker = NULL;
- DEBUG2("Create new thread pool (%u, %u)", num_workers, max_jobs);
-
- /* Initialize thread pool data structure */
- xbt_tpool_t tpool = xbt_new0(s_xbt_tpool_t, 1);
- tpool->mutex = xbt_os_mutex_init();
- tpool->job_posted = xbt_os_cond_init();
- tpool->job_taken = xbt_os_cond_init();
- tpool->idle_worker = xbt_os_cond_init();
- tpool->jobs_queue = xbt_dynar_new(sizeof(s_xbt_tpool_job_t), NULL);
- tpool->num_workers = num_workers;
- tpool->num_idle_workers = 0;
- tpool->max_jobs = max_jobs;
-
+ DEBUG1("Create new parmap (%u workers)", num_workers);
+
+ /* Initialize the thread pool data structure */
+ xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
+ parmap->num_workers = num_workers;
+ parmap->status = PARMAP_WORK;
+
+ parmap->workers_ready = xbt_new0(s_xbt_barrier_t, 1);
+ xbt_barrier_init(parmap->workers_ready, num_workers + 1);
+ parmap->workers_done = xbt_new0(s_xbt_barrier_t, 1);
+ xbt_barrier_init(parmap->workers_done, num_workers + 1);
+
/* Create the pool of worker threads */
for(i=0; i < num_workers; i++){
- worker = xbt_os_thread_create(NULL, _xbt_tpool_worker_main, tpool, NULL);
+ worker = xbt_os_thread_create(NULL, _xbt_parmap_worker_main, parmap, NULL);
xbt_os_thread_detach(worker);
}
- return tpool;
+ return parmap;
}
-void xbt_tpool_destroy(xbt_tpool_t tpool)
+void xbt_parmap_destroy(xbt_parmap_t parmap)
{
- DEBUG1("Destroy thread pool %p", tpool);
+ DEBUG1("Destroy parmap %p", parmap);
- /* Lock the pool, then signal every worker an wait for each to finish */
- xbt_os_mutex_acquire(tpool->mutex);
- tpool->flags = TPOOL_DESTROY;
+ parmap->status = PARMAP_DESTROY;
- while(tpool->num_workers){
- DEBUG1("Still %u workers, waiting...", tpool->num_workers);
- xbt_os_cond_signal(tpool->job_posted);
- xbt_os_cond_wait(tpool->job_taken, tpool->mutex);
- }
+ xbt_barrier_wait(parmap->workers_ready);
+ DEBUG0("Kill job sent");
+ xbt_barrier_wait(parmap->workers_done);
- /* Destroy pool's data structures */
- xbt_os_cond_destroy(tpool->job_posted);
- xbt_os_cond_destroy(tpool->job_taken);
- xbt_os_cond_destroy(tpool->idle_worker);
- xbt_os_mutex_release(tpool->mutex);
- xbt_os_mutex_destroy(tpool->mutex);
- xbt_free(tpool);
+ xbt_free(parmap->workers_ready);
+ xbt_free(parmap->workers_done);
+ xbt_free(parmap);
}
-void xbt_tpool_queue_job(xbt_tpool_t tpool, void_f_pvoid_t fun, void* fun_arg)
+ void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
{
- s_xbt_tpool_job_t job;
- job.fun = fun;
- job.fun_arg = fun_arg;
-
- /* Wait until we can lock on the pool with some space on it for the job */
- xbt_os_mutex_acquire(tpool->mutex);
- while(xbt_dynar_length(tpool->jobs_queue) == tpool->max_jobs)
- xbt_os_cond_wait(tpool->job_taken, tpool->mutex);
-
- DEBUG3("Queue job %p (%p) to thread pool %p", fun, fun_arg, tpool);
-
- /* Push the job in the queue, signal the workers and unlock the pool */
- xbt_dynar_push_as(tpool->jobs_queue, s_xbt_tpool_job_t, job);
- xbt_os_cond_signal(tpool->job_posted);
- xbt_os_mutex_release(tpool->mutex);
- return;
+ /* Assign resources to worker threads*/
+ parmap->fun = fun;
+ parmap->data = data;
+
+ /* Notify workers that there is a job */
+ xbt_barrier_wait(parmap->workers_ready);
+ DEBUG0("Job dispatched, lets wait...");
+ xbt_barrier_wait(parmap->workers_done);
+
+ DEBUG0("Job done");
+ parmap->fun = NULL;
+ parmap->data = NULL;
}
-void xbt_tpool_wait_all(xbt_tpool_t tpool)
+static void *_xbt_parmap_worker_main(void *arg)
{
- DEBUG1("Wait all workers in thread pool %p", tpool);
- xbt_os_mutex_acquire(tpool->mutex);
-
- while(tpool->num_idle_workers < tpool->num_workers
- || xbt_dynar_length(tpool->jobs_queue) > 0)
- xbt_os_cond_wait(tpool->idle_worker, tpool->mutex);
+ unsigned int data_start, data_end, data_size, worker_id;
+ xbt_parmap_t parmap = (xbt_parmap_t)arg;
- xbt_os_mutex_release(tpool->mutex);
- DEBUG1("Wait all workers done in thread pool %p", tpool);
- return;
-}
+ /* Fetch a worker id */
+ worker_id = __sync_fetch_and_add(&parmap->workers_max_id, 1);
-static void *_xbt_tpool_worker_main(void *arg)
-{
- s_xbt_tpool_job_t job;
- xbt_tpool_t tpool = (xbt_tpool_t)arg;
-
- unsigned long i = tpoolcounter++; /* Debug purposes */
- DEBUG1("New worker thread created (%lu)", i);
+ DEBUG1("New worker thread created (%u)", worker_id);
-
/* Worker's main loop */
while(1){
- xbt_os_mutex_acquire(tpool->mutex);
+ xbt_barrier_wait(parmap->workers_ready);
- tpool->num_idle_workers++;
- xbt_os_cond_signal(tpool->idle_worker);
+ if(parmap->status == PARMAP_WORK){
+ DEBUG1("Worker %u got a job", worker_id);
- /* If there are no jobs in the queue wait for one */
- while(xbt_dynar_length(tpool->jobs_queue) == 0
- && tpool->flags != TPOOL_DESTROY){
- DEBUG1("Worker %lu waiting for a job", i);
- xbt_os_cond_wait(tpool->job_posted, tpool->mutex);
- }
+ /* Compute how much data does every worker gets */
+ data_size = (xbt_dynar_length(parmap->data) / parmap->num_workers)
+ + ((xbt_dynar_length(parmap->data) % parmap->num_workers) ? 1 : 0);
+
+ /* Each worker data segment starts in a position associated with its id*/
+ data_start = data_size * worker_id;
- DEBUG1("Worker %lu got a job", i);
+ /* The end of the worker data segment must be bounded by the end of the data vector */
+ data_end = MIN(data_start + data_size, xbt_dynar_length(parmap->data));
- /* If we are shutting down, signal the destroyer so it can kill the other */
- /* workers, unlock the pool and return */
- if(tpool->flags == TPOOL_DESTROY){
- DEBUG1("Shutting down worker %lu", i);
- tpool->num_idle_workers--;
- tpool->num_workers--;
- xbt_os_cond_signal(tpool->job_taken);
- xbt_os_mutex_release(tpool->mutex);
+ DEBUG4("Worker %u: data_start=%u data_end=%u (data_size=%u)",
+ worker_id, data_start, data_end, data_size);
+
+ /* While the worker don't pass the end of it data segment apply the function */
+ while(data_start < data_end){
+ parmap->fun(*(void **)xbt_dynar_get_ptr(parmap->data, data_start));
+ data_start++;
+ }
+
+ xbt_barrier_wait(parmap->workers_done);
+
+ /* We are destroying the parmap */
+ }else{
+ xbt_barrier_wait(parmap->workers_done);
+ DEBUG1("Shutting down worker %u", worker_id);
return NULL;
}
+ }
+}
- /* Get a job, signal the pool to inform jobs submitters and unlock it */
- job = xbt_dynar_pop_as(tpool->jobs_queue, s_xbt_tpool_job_t);
- xbt_os_cond_signal(tpool->job_taken);
- tpool->num_idle_workers--;
- xbt_os_mutex_release(tpool->mutex);
-
- /* Run the job and loop again ... */
- job.fun(job.fun_arg);
+static void futex_wait(int *uaddr, int val)
+{
+ DEBUG1("Waiting on futex %d", *uaddr);
+ syscall(SYS_futex, uaddr, FUTEX_WAIT, val, NULL, NULL, 0);
+}
+
+static void futex_wake(int *uaddr, int val)
+{
+ DEBUG1("Waking futex %d", *uaddr);
+ syscall(SYS_futex, uaddr, FUTEX_WAKE, val, NULL, NULL, 0);
+}
+
+/* Futex based implementation of the barrier */
+void xbt_barrier_init(xbt_barrier_t barrier, unsigned int threads_to_wait)
+{
+ barrier->threads_to_wait = threads_to_wait;
+ barrier->thread_count = 0;
+}
+
+void xbt_barrier_wait(xbt_barrier_t barrier)
+{
+ int myflag = 0;
+ unsigned int mycount = 0;
+
+ myflag = barrier->futex;
+ mycount = __sync_add_and_fetch(&barrier->thread_count, 1);
+ if(mycount < barrier->threads_to_wait){
+ futex_wait(&barrier->futex, myflag);
+ }else{
+ barrier->futex = __sync_add_and_fetch(&barrier->futex, 1);
+ barrier->thread_count = 0;
+ futex_wake(&barrier->futex, barrier->threads_to_wait);
}
}
#include "xbt.h"
#include "xbt/ex.h"
-XBT_TEST_SUITE("tpool", "Thread pool");
+XBT_TEST_SUITE("parmap", "Parallel Map");
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
+
-xbt_tpool_t tpool;
-void job(void *arg);
+xbt_parmap_t parmap;
-void job (void *arg)
+void fun(void *arg);
+
+void fun(void *arg)
{
- xbt_test_log1("I'm job %lu", (unsigned long)arg);
+ //INFO1("I'm job %lu", (unsigned long)arg);
}
-XBT_TEST_UNIT("basic", test_tpool_basic, "Basic usage")
+XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
{
- xbt_test_add0("Create thread pool");
+ xbt_test_add0("Create the parmap");
unsigned long i,j;
- /* Create thread pool */
- tpool = xbt_tpool_new(5, 10);
+ xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
- for(j=0; j < 10; j++){
- /* Queue some work */
- for(i=0; i < 20; i++){
- xbt_tpool_queue_job(tpool, job, (void*)i);
- }
- /* Wait for everyone */
- xbt_tpool_wait_all(tpool);
+ /* Create the parallel map */
+ parmap = xbt_parmap_new(10);
+
+ for(j=0; j < 100; j++){
+ xbt_dynar_push_as(data, void *, (void *)j);
}
- /* Destroy thread pool */
- xbt_tpool_destroy(tpool);
+ for(i=0; i < 5; i++)
+ xbt_parmap_apply(parmap, fun, data);
+
+ /* Destroy the parmap */
+ xbt_parmap_destroy(parmap);
}
#endif /* SIMGRID_TEST */
