#ifdef HAVE_FUTEX_H
#include <linux/futex.h>
+#include <limits.h>
#endif
#include "xbt/parmap.h"
XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing");
typedef enum {
- PARMAP_WORK = 0,
- PARMAP_DESTROY
+ XBT_PARMAP_WORK,
+ XBT_PARMAP_DESTROY
} e_xbt_parmap_flag_t;
-static void xbt_parmap_start(xbt_parmap_t parmap);
-static void xbt_parmap_signal(xbt_parmap_t parmap);
-static void xbt_parmap_wait(xbt_parmap_t parmap);
-static void xbt_parmap_end(xbt_parmap_t parmap);
+static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
static void *xbt_parmap_worker_main(void *parmap);
+static void xbt_parmap_work(xbt_parmap_t parmap);
+
+static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
+static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
+static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
+static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
#ifdef HAVE_FUTEX_H
-static void futex_wait(int *uaddr, int val);
-static void futex_wake(int *uaddr, int val);
+static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
+static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
+static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
+static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
+static void futex_wait(unsigned *uaddr, unsigned val);
+static void futex_wake(unsigned *uaddr, unsigned val);
#endif
+static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
+static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
+static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
+static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
+
/**
* \brief Parallel map structure
*/
typedef struct s_xbt_parmap {
- e_xbt_parmap_flag_t status; /* is the parmap active or being destroyed? */
-
- int work; /* index of the current round (1 is the first) */
- int done; /* number of rounds already done */
- unsigned int thread_counter; /* number of threads currently working */
- unsigned int num_workers; /* total number of worker threads */
- unsigned int workers_max_id; /* id of the next worker thread to create */
- void_f_pvoid_t fun; /* function to run in parallel on each element of data */
- xbt_dynar_t data; /* parameters to pass to fun in parallel */
- unsigned int index; /* index of the next element of data to pick */
+ e_xbt_parmap_flag_t status; /**< is the parmap active or being destroyed? */
+ unsigned work; /**< index of the current round */
+ unsigned thread_counter; /**< number of workers that have done the work */
+
+ unsigned int num_workers; /**< total number of worker threads including the controller */
+ void_f_pvoid_t fun; /**< function to run in parallel on each element of data */
+ xbt_dynar_t data; /**< parameters to pass to fun in parallel */
+ unsigned int index; /**< index of the next element of data to pick */
+
+ /* posix only */
+ xbt_os_cond_t ready_cond;
+ xbt_os_mutex_t ready_mutex;
+ xbt_os_cond_t done_cond;
+ xbt_os_mutex_t done_mutex;
+
+ /* fields that depend on the synchronization mode */
+ e_xbt_parmap_mode_t mode; /**< synchronization mode */
+ void (*master_wait_f)(xbt_parmap_t); /**< wait for the workers to have done the work */
+ void (*worker_signal_f)(xbt_parmap_t); /**< signal the master that a worker has done the work */
+ void (*master_signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */
+ void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
} s_xbt_parmap_t;
/**
* \brief Creates a parallel map object
* \param num_workers number of worker threads to create
+ * \param mode how to synchronize the worker threads
* \return the parmap created
*/
-xbt_parmap_t xbt_parmap_new(unsigned int num_workers)
+xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
{
unsigned int i;
xbt_os_thread_t worker = NULL;
xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
parmap->num_workers = num_workers;
- parmap->status = PARMAP_WORK;
+ parmap->status = XBT_PARMAP_WORK;
+ xbt_parmap_set_mode(parmap, mode);
/* Create the pool of worker threads */
- for (i = 0; i < num_workers; i++) {
+ for (i = 1; i < num_workers; i++) {
worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL);
xbt_os_thread_detach(worker);
}
- xbt_parmap_start(parmap);
return parmap;
}
*/
void xbt_parmap_destroy(xbt_parmap_t parmap)
{
- parmap->status = PARMAP_DESTROY;
- xbt_parmap_signal(parmap);
+ if (!parmap) {
+ return;
+ }
+
+ parmap->status = XBT_PARMAP_DESTROY;
+ parmap->master_signal_f(parmap);
+ parmap->master_wait_f(parmap);
+
+ xbt_os_cond_destroy(parmap->ready_cond);
+ xbt_os_mutex_destroy(parmap->ready_mutex);
+ xbt_os_cond_destroy(parmap->done_cond);
+ xbt_os_mutex_destroy(parmap->done_mutex);
+
xbt_free(parmap);
}
+/**
+ * \brief Sets the synchronization mode of a parmap.
+ * \param parmap a parallel map object
+ * \param mode the synchronization mode
+ */
+static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
+{
+ if (mode == XBT_PARMAP_DEFAULT) {
+#ifdef HAVE_FUTEX_H
+ mode = XBT_PARMAP_FUTEX;
+#else
+ mode = XBT_PARMAP_POSIX;
+#endif
+ }
+ parmap->mode = mode;
+
+ switch (mode) {
+
+ case XBT_PARMAP_POSIX:
+ parmap->master_wait_f = xbt_parmap_posix_master_wait;
+ parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
+ parmap->master_signal_f = xbt_parmap_posix_master_signal;
+ parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
+
+ parmap->ready_cond = xbt_os_cond_init();
+ parmap->ready_mutex = xbt_os_mutex_init();
+ parmap->done_cond = xbt_os_cond_init();
+ parmap->done_mutex = xbt_os_mutex_init();
+ break;
+
+
+ case XBT_PARMAP_FUTEX:
+#ifdef HAVE_FUTEX_H
+ parmap->master_wait_f = xbt_parmap_futex_master_wait;
+ parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
+ parmap->master_signal_f = xbt_parmap_futex_master_signal;
+ parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
+
+ xbt_os_cond_destroy(parmap->ready_cond);
+ xbt_os_mutex_destroy(parmap->ready_mutex);
+ xbt_os_cond_destroy(parmap->done_cond);
+ xbt_os_mutex_destroy(parmap->done_mutex);
+ break;
+#else
+ xbt_die("Futex is not available on this OS.");
+#endif
+
+ case XBT_PARMAP_BUSY_WAIT:
+ parmap->master_wait_f = xbt_parmap_busy_master_wait;
+ parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
+ parmap->master_signal_f = xbt_parmap_busy_master_signal;
+ parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
+
+ xbt_os_cond_destroy(parmap->ready_cond);
+ xbt_os_mutex_destroy(parmap->ready_mutex);
+ xbt_os_cond_destroy(parmap->done_cond);
+ xbt_os_mutex_destroy(parmap->done_mutex);
+ break;
+
+ case XBT_PARMAP_DEFAULT:
+ THROW_IMPOSSIBLE;
+ break;
+ }
+}
+
/**
* \brief Applies a list of tasks in parallel.
* \param parmap a parallel map object
*/
void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
{
- /* Assign resources to worker threads*/
+ /* Assign resources to worker threads */
parmap->fun = fun;
parmap->data = data;
parmap->index = 0;
- xbt_parmap_signal(parmap);
+ parmap->master_signal_f(parmap);
+ xbt_parmap_work(parmap);
+ parmap->master_wait_f(parmap);
XBT_DEBUG("Job done");
}
return NULL;
}
-/**
- * \brief Returns the worker id of the current thread.
- * \param parmap a parmap
- * \return the worker id
- */
-unsigned long xbt_parmap_get_worker_id(xbt_parmap_t parmap)
+static void xbt_parmap_work(xbt_parmap_t parmap)
{
- return (unsigned long) xbt_os_thread_get_extra_data();
+ unsigned index;
+ while ((index = __sync_fetch_and_add(&parmap->index, 1))
+ < xbt_dynar_length(parmap->data))
+ parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
}
/**
*/
static void *xbt_parmap_worker_main(void *arg)
{
- unsigned int worker_id;
xbt_parmap_t parmap = (xbt_parmap_t) arg;
+ unsigned round = 0;
- /* Fetch a worker id */
- worker_id = __sync_fetch_and_add(&parmap->workers_max_id, 1);
- xbt_os_thread_set_extra_data((void*) (unsigned long) worker_id);
+ XBT_DEBUG("New worker thread created");
- XBT_DEBUG("New worker thread created (%u)", worker_id);
-
/* Worker's main loop */
while (1) {
- xbt_parmap_wait(parmap);
- if (parmap->status == PARMAP_WORK) {
+ parmap->worker_wait_f(parmap, ++round);
+ if (parmap->status == XBT_PARMAP_WORK) {
- XBT_DEBUG("Worker %u got a job", worker_id);
+ XBT_DEBUG("Worker got a job");
- void* work = xbt_parmap_next(parmap);
- if (work != NULL) {
- parmap->fun(work);
- }
+ xbt_parmap_work(parmap);
+ parmap->worker_signal_f(parmap);
- XBT_DEBUG("Worker %u has finished", worker_id);
+ XBT_DEBUG("Worker has finished");
/* We are destroying the parmap */
} else {
- xbt_parmap_end(parmap);
- XBT_DEBUG("Shutting down worker %u", worker_id);
+ parmap->worker_signal_f(parmap);
return NULL;
}
}
}
#ifdef HAVE_FUTEX_H
-static void futex_wait(int *uaddr, int val)
+static void futex_wait(unsigned *uaddr, unsigned val)
{
XBT_VERB("Waiting on futex %p", uaddr);
syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
}
-static void futex_wake(int *uaddr, int val)
+static void futex_wake(unsigned *uaddr, unsigned val)
{
XBT_VERB("Waking futex %p", uaddr);
syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
*
* \param parmap a parmap
*/
-static void xbt_parmap_start(xbt_parmap_t parmap)
+static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
{
-#ifdef HAVE_FUTEX_H
- int myflag = parmap->done;
+ xbt_os_mutex_acquire(parmap->done_mutex);
if (parmap->thread_counter < parmap->num_workers) {
/* wait for all workers to be ready */
- futex_wait(&parmap->done, myflag);
+ xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
}
-#endif
+ xbt_os_mutex_release(parmap->done_mutex);
+}
+
+/**
+ * \brief Ends the parmap: wakes the controller thread when all workers terminate.
+ *
+ * This function is called by all worker threads when they end (not including
+ * the controller).
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
+{
+ xbt_os_mutex_acquire(parmap->done_mutex);
+ if (++parmap->thread_counter == parmap->num_workers) {
+ /* all workers have finished, wake the controller */
+ xbt_os_cond_signal(parmap->done_cond);
+ }
+ xbt_os_mutex_release(parmap->done_mutex);
}
/**
*
* \param parmap a parmap
*/
-static void xbt_parmap_signal(xbt_parmap_t parmap)
+static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
{
-#ifdef HAVE_FUTEX_H
- int myflag = parmap->done;
- parmap->thread_counter = 0;
+ xbt_os_mutex_acquire(parmap->ready_mutex);
+ parmap->thread_counter = 1;
parmap->work++;
-
/* wake all workers */
- futex_wake(&parmap->work, parmap->num_workers);
-
- /* wait for all of them to finish */
- futex_wait(&parmap->done, myflag);
-#endif
+ xbt_os_cond_broadcast(parmap->ready_cond);
+ xbt_os_mutex_release(parmap->ready_mutex);
}
/**
* \brief Waits for some work to process.
*
- * This function is called by each worker when it has no more work to do.
+ * This function is called by each worker thread (not including the controller)
+ * when it has no more work to do.
*
* \param parmap a parmap
+ * \param round the expected round number
*/
-static void xbt_parmap_wait(xbt_parmap_t parmap)
+static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
{
+ xbt_os_mutex_acquire(parmap->ready_mutex);
+ /* wait for more work */
+ if (parmap->work != round) {
+ xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
+ }
+ xbt_os_mutex_release(parmap->ready_mutex);
+}
+
#ifdef HAVE_FUTEX_H
- int myflag;
- unsigned int mycount;
+/**
+ * \brief Starts the parmap: waits for all workers to be ready and returns.
+ *
+ * This function is called by the controller thread.
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
+{
+ unsigned count = parmap->thread_counter;
+ while (count < parmap->num_workers) {
+ /* wait for all workers to be ready */
+ futex_wait(&parmap->thread_counter, count);
+ count = parmap->thread_counter;
+ }
+}
- myflag = parmap->work;
- mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
- if (mycount == parmap->num_workers) {
+/**
+ * \brief Ends the parmap: wakes the controller thread when all workers terminate.
+ *
+ * This function is called by all worker threads when they end (not including
+ * the controller).
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
+{
+ unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
+ if (count == parmap->num_workers) {
/* all workers have finished, wake the controller */
- parmap->done++;
- futex_wake(&parmap->done, 1);
+ futex_wake(&parmap->thread_counter, INT_MAX);
}
+}
+/**
+ * \brief Wakes all workers and waits for them to finish the tasks.
+ *
+ * This function is called by the controller thread.
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
+{
+ parmap->thread_counter = 1;
+ __sync_add_and_fetch(&parmap->work, 1);
+ /* wake all workers */
+ futex_wake(&parmap->work, INT_MAX);
+}
+
+/**
+ * \brief Waits for some work to process.
+ *
+ * This function is called by each worker thread (not including the controller)
+ * when it has no more work to do.
+ *
+ * \param parmap a parmap
+ * \param round the expected round number
+ */
+static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
+{
+ unsigned work = parmap->work;
/* wait for more work */
- futex_wait(&parmap->work, myflag);
+ while (work != round) {
+ futex_wait(&parmap->work, work);
+ work = parmap->work;
+ }
+}
#endif
+
+/**
+ * \brief Starts the parmap: waits for all workers to be ready and returns.
+ *
+ * This function is called by the controller thread.
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
+{
+ while (parmap->thread_counter < parmap->num_workers) {
+ xbt_os_thread_yield();
+ }
}
/**
*
* \param parmap a parmap
*/
-static void xbt_parmap_end(xbt_parmap_t parmap)
+static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
{
-#ifdef HAVE_FUTEX_H
- unsigned int mycount;
+ __sync_add_and_fetch(&parmap->thread_counter, 1);
+}
- mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
- if (mycount == parmap->num_workers) {
- /* all workers have finished, wake the controller */
- parmap->done++;
- futex_wake(&parmap->done, 1);
+/**
+ * \brief Wakes all workers and waits for them to finish the tasks.
+ *
+ * This function is called by the controller thread.
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
+{
+ parmap->thread_counter = 1;
+ __sync_add_and_fetch(&parmap->work, 1);
+}
+
+/**
+ * \brief Waits for some work to process.
+ *
+ * This function is called by each worker thread (not including the controller)
+ * when it has no more work to do.
+ *
+ * \param parmap a parmap
+ * \param round the expected round number
+ */
+static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
+{
+ /* wait for more work */
+ while (parmap->work != round) {
+ xbt_os_thread_yield();
}
-#endif
}
#ifdef SIMGRID_TEST
#include "xbt.h"
#include "xbt/ex.h"
+#include "xbt/xbt_os_thread.h"
+#include "xbt/xbt_os_time.h"
+#include "gras_config.h" /* HAVE_FUTEX_H */
XBT_TEST_SUITE("parmap", "Parallel Map");
XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
-xbt_parmap_t parmap;
+#ifdef HAVE_FUTEX_H
+#define TEST_PARMAP_SKIP_TEST(mode) 0
+#else
+#define TEST_PARMAP_SKIP_TEST(mode) ((mode) == XBT_PARMAP_FUTEX)
+#endif
-void fun(void *arg);
+#define TEST_PARMAP_VALIDATE_MODE(mode) \
+ if (TEST_PARMAP_SKIP_TEST(mode)) { xbt_test_skip(); return; } else ((void)0)
-void fun(void *arg)
+static void fun_double(void *arg)
{
- //XBT_INFO("I'm job %lu", (unsigned long)arg);
+ unsigned *u = arg;
+ *u = 2 * *u + 1;
}
-XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
+/* Check that the computations are correctly done. */
+static void test_parmap_basic(e_xbt_parmap_mode_t mode)
{
- xbt_test_add("Create the parmap");
+ unsigned num_workers;
+
+ for (num_workers = 1 ; num_workers <= 16 ; num_workers *= 2) {
+ const unsigned len = 1033;
+ const unsigned num = 5;
+ unsigned *a;
+ xbt_dynar_t data;
+ xbt_parmap_t parmap;
+ unsigned i;
+
+ xbt_test_add("Basic parmap usage (%u workers)", num_workers);
+
+ TEST_PARMAP_VALIDATE_MODE(mode);
+ parmap = xbt_parmap_new(num_workers, mode);
+
+ a = xbt_malloc(len * sizeof *a);
+ data = xbt_dynar_new(sizeof a, NULL);
+ for (i = 0; i < len; i++) {
+ a[i] = i;
+ xbt_dynar_push_as(data, void *, &a[i]);
+ }
- unsigned long i, j;
- xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
+ for (i = 0; i < num; i++)
+ xbt_parmap_apply(parmap, fun_double, data);
- /* Create the parallel map */
- parmap = xbt_parmap_new(10);
+ for (i = 0; i < len; i++) {
+ unsigned expected = (1U << num) * (i + 1) - 1;
+ xbt_test_assert(a[i] == expected,
+ "a[%u]: expected %u, got %u", i, expected, a[i]);
+ }
- for(j = 0; j < 100; j++) {
- xbt_dynar_push_as(data, void *, (void *)j);
+ xbt_dynar_free(&data);
+ xbt_free(a);
+ xbt_parmap_destroy(parmap);
}
+}
+
+XBT_TEST_UNIT("basic_posix", test_parmap_basic_posix, "Basic usage: posix")
+{
+ test_parmap_basic(XBT_PARMAP_POSIX);
+}
+
+XBT_TEST_UNIT("basic_futex", test_parmap_basic_futex, "Basic usage: futex")
+{
+ test_parmap_basic(XBT_PARMAP_FUTEX);
+}
- for (i = 0; i < 5; i++) {
- xbt_parmap_apply(parmap, fun, data);
+XBT_TEST_UNIT("basic_busy_wait", test_parmap_basic_busy_wait, "Basic usage: busy_wait")
+{
+ test_parmap_basic(XBT_PARMAP_BUSY_WAIT);
+}
+
+static void fun_get_id(void *arg)
+{
+ *(uintptr_t *)arg = (uintptr_t)xbt_os_thread_self();
+ xbt_os_sleep(0.5);
+}
+
+static int fun_compare(const void *pa, const void *pb)
+{
+ uintptr_t a = *(uintptr_t *)pa;
+ uintptr_t b = *(uintptr_t *)pb;
+ return a < b ? -1 : a > b ? 1 : 0;
+}
+
+/* Check that all threads are working. */
+static void test_parmap_extended(e_xbt_parmap_mode_t mode)
+{
+ unsigned num_workers;
+
+ for (num_workers = 1 ; num_workers <= 16 ; num_workers *= 2) {
+ const unsigned len = 2 * num_workers;
+ uintptr_t *a;
+ xbt_parmap_t parmap;
+ xbt_dynar_t data;
+ unsigned i;
+ unsigned count;
+
+ xbt_test_add("Extended parmap usage (%u workers)", num_workers);
+
+ TEST_PARMAP_VALIDATE_MODE(mode);
+ parmap = xbt_parmap_new(num_workers, mode);
+
+ a = xbt_malloc(len * sizeof *a);
+ data = xbt_dynar_new(sizeof a, NULL);
+ for (i = 0; i < len; i++)
+ xbt_dynar_push_as(data, void *, &a[i]);
+
+ xbt_parmap_apply(parmap, fun_get_id, data);
+
+ qsort(a, len, sizeof a[0], fun_compare);
+ count = 1;
+ for (i = 1; i < len; i++)
+ if (a[i] != a[i - 1])
+ count++;
+ xbt_test_assert(count == num_workers,
+ "only %u/%u threads did some work", count, num_workers);
+
+ xbt_dynar_free(&data);
+ xbt_free(a);
+ xbt_parmap_destroy(parmap);
}
+}
+
+XBT_TEST_UNIT("extended_posix", test_parmap_extended_posix, "Extended usage: posix")
+{
+ test_parmap_extended(XBT_PARMAP_POSIX);
+}
- /* Destroy the parmap */
- xbt_parmap_destroy(parmap);
- xbt_dynar_free(&data);
+XBT_TEST_UNIT("extended_futex", test_parmap_extended_futex, "Extended usage: futex")
+{
+ test_parmap_extended(XBT_PARMAP_FUTEX);
+}
+
+XBT_TEST_UNIT("extended_busy_wait", test_parmap_extended_busy_wait, "Extended usage: busy_wait")
+{
+ test_parmap_extended(XBT_PARMAP_BUSY_WAIT);
}
#endif /* SIMGRID_TEST */
