X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f57edc1d5b4f497883b451fc85d2d653d27a8247..bc07ec1b28653016934209a9e84e249eebf703f0:/src/xbt/parmap.c diff --git a/src/xbt/parmap.c b/src/xbt/parmap.c index 19dcb58027..8a86b36384 100644 --- a/src/xbt/parmap.c +++ b/src/xbt/parmap.c @@ -5,26 +5,61 @@ * under the terms of the license (GNU LGPL) which comes with this package. */ #include "gras_config.h" #include + #ifndef _XBT_WIN32 #include #endif #ifdef HAVE_FUTEX_H - #include -#else - #include "xbt/xbt_os_thread.h" +#include #endif -#include -#include "parmap_private.h" + +#include "xbt/parmap.h" +#include "xbt/log.h" +#include "xbt/function_types.h" +#include "xbt/dynar.h" +#include "xbt/xbt_os_thread.h" +#include "xbt/sysdep.h" XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map"); XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing"); -static void *_xbt_parmap_worker_main(void *parmap); +typedef enum { + PARMAP_WORK = 0, + 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_worker_main(void *parmap); + #ifdef HAVE_FUTEX_H - static void futex_wait(int *uaddr, int val); - static void futex_wake(int *uaddr, int val); +static void futex_wait(int *uaddr, int val); +static void futex_wake(int *uaddr, int val); #endif + +/** + * \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 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 */ +} s_xbt_parmap_t; + +/** + * \brief Creates a parallel map object + * \param num_workers number of worker threads to create + * \return the parmap created + */ xbt_parmap_t xbt_parmap_new(unsigned int num_workers) { unsigned int i; @@ -34,49 +69,55 @@ xbt_parmap_t xbt_parmap_new(unsigned int num_workers) /* Initialize the thread pool data structure */ xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1); -#ifdef HAVE_FUTEX_H - parmap->sync_event = xbt_new0(s_xbt_event_t, 1); -#endif + parmap->num_workers = num_workers; parmap->status = PARMAP_WORK; -#ifdef HAVE_FUTEX_H - parmap->sync_event->threads_to_wait = num_workers; -#endif + /* Create the pool of worker threads */ - for(i=0; i < num_workers; i++){ - worker = xbt_os_thread_create(NULL, _xbt_parmap_worker_main, parmap, NULL); + for (i = 0; i < num_workers - 1; i++) { + worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL); xbt_os_thread_detach(worker); } -#ifdef HAVE_FUTEX_H - xbt_event_init(parmap->sync_event); -#endif + xbt_parmap_start(parmap); return parmap; } +/** + * \brief Destroys a parmap + * \param parmap the parmap to destroy + */ void xbt_parmap_destroy(xbt_parmap_t parmap) -{ +{ parmap->status = PARMAP_DESTROY; -#ifdef HAVE_FUTEX_H - xbt_event_signal(parmap->sync_event); - xbt_free(parmap->sync_event); -#endif + xbt_parmap_signal(parmap); xbt_free(parmap); } - void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data) +/** + * \brief Applies a list of tasks in parallel. + * \param parmap a parallel map object + * \param fun the function to call in parallel + * \param data each element of this dynar will be passed as an argument to fun + */ +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; -#ifdef HAVE_FUTEX_H - xbt_event_signal(parmap->sync_event); -#endif + xbt_parmap_signal(parmap); XBT_DEBUG("Job done"); } -void* xbt_parmap_next(xbt_parmap_t parmap) { - +/** + * \brief Returns a next task to process. + * + * Worker threads call this function to get more work. + * + * \return the next task to process, or NULL if there is no more work + */ +void* xbt_parmap_next(xbt_parmap_t parmap) +{ unsigned int index = __sync_fetch_and_add(&parmap->index, 1); if (index < xbt_dynar_length(parmap->data)) { return xbt_dynar_get_as(parmap->data, index, void*); @@ -84,43 +125,35 @@ void* xbt_parmap_next(xbt_parmap_t parmap) { return NULL; } -unsigned long xbt_parmap_get_worker_id(xbt_parmap_t parmap) { - return (unsigned long) xbt_os_thread_get_extra_data(); -} - -static void *_xbt_parmap_worker_main(void *arg) +/** + * \brief Main function of a worker thread. + * \param arg the parmap + */ +static void *xbt_parmap_worker_main(void *arg) { - unsigned int worker_id; xbt_parmap_t parmap = (xbt_parmap_t) arg; - /* 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) { -#ifdef HAVE_FUTEX_H - xbt_event_wait(parmap->sync_event); -#endif + xbt_parmap_wait(parmap); if (parmap->status == 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) { + while (work != NULL) { parmap->fun(work); + work = xbt_parmap_next(parmap); } - XBT_DEBUG("Worker %u has finished", worker_id); + XBT_DEBUG("Worker has finished"); /* We are destroying the parmap */ } else { -#ifdef HAVE_FUTEX_H - xbt_event_end(parmap->sync_event); -#endif - XBT_DEBUG("Shutting down worker %u", worker_id); + xbt_parmap_end(parmap); + XBT_DEBUG("Shutting down worker"); return NULL; } } @@ -138,49 +171,107 @@ static void futex_wake(int *uaddr, int val) XBT_VERB("Waking futex %p", uaddr); syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0); } +#endif -void xbt_event_init(xbt_event_t event) +/** + * \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_start(xbt_parmap_t parmap) { - int myflag = event->done; - if(event->thread_counter < event->threads_to_wait) - futex_wait(&event->done, myflag); +#ifdef HAVE_FUTEX_H + int myflag = parmap->done; + __sync_fetch_and_add(&parmap->thread_counter, 1); + if (parmap->thread_counter < parmap->num_workers) { + /* wait for all workers to be ready */ + futex_wait(&parmap->done, myflag); + } +#endif } -void xbt_event_signal(xbt_event_t event) +/** + * \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_signal(xbt_parmap_t parmap) { - int myflag = event->done; - event->thread_counter = 0; - event->work++; - futex_wake(&event->work, event->threads_to_wait); - futex_wait(&event->done, myflag); +#ifdef HAVE_FUTEX_H + int myflag = parmap->done; + parmap->thread_counter = 0; + parmap->work++; + + /* wake all workers */ + futex_wake(&parmap->work, parmap->num_workers); + + if (parmap->status == PARMAP_WORK) { + /* also work myself */ + void* work = xbt_parmap_next(parmap); + if (work != NULL) { + parmap->fun(work); + } + } + + unsigned int mycount = __sync_add_and_fetch(&parmap->thread_counter, 1); + if (mycount < parmap->num_workers) { + /* some workers have not finished yet */ + futex_wait(&parmap->done, myflag); + } + +#endif } -void xbt_event_wait(xbt_event_t event) +/** + * \brief Waits for some work to process. + * + * This function is called by each worker when it has no more work to do. + * + * \param parmap a parmap + */ +static void xbt_parmap_wait(xbt_parmap_t parmap) { +#ifdef HAVE_FUTEX_H int myflag; unsigned int mycount; - myflag = event->work; - mycount = __sync_add_and_fetch(&event->thread_counter, 1); - if(mycount == event->threads_to_wait){ - event->done++; - futex_wake(&event->done, 1); + myflag = parmap->work; + 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); } - futex_wait(&event->work, myflag); + /* wait for more work */ + futex_wait(&parmap->work, myflag); +#endif } -void xbt_event_end(xbt_event_t event) +/** + * \brief Ends the parmap: wakes the controller thread when all workers terminate. + * + * This function is called by all worker threads when they end. + * + * \param parmap a parmap + */ +static void xbt_parmap_end(xbt_parmap_t parmap) { +#ifdef HAVE_FUTEX_H unsigned int mycount; - mycount = __sync_add_and_fetch(&event->thread_counter, 1); - if(mycount == event->threads_to_wait){ - event->done++; - futex_wake(&event->done, 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); } -} #endif +} #ifdef SIMGRID_TEST #include "xbt.h" @@ -189,8 +280,6 @@ void xbt_event_end(xbt_event_t event) XBT_TEST_SUITE("parmap", "Parallel Map"); XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit); - - xbt_parmap_t parmap; void fun(void *arg); @@ -204,18 +293,19 @@ XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage") { xbt_test_add("Create the parmap"); - unsigned long i,j; + unsigned long i, j; xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL); /* Create the parallel map */ parmap = xbt_parmap_new(10); - for(j=0; j < 100; j++){ + for (j = 0; j < 100; j++) { xbt_dynar_push_as(data, void *, (void *)j); } - for(i=0; i < 5; i++) + for (i = 0; i < 5; i++) { xbt_parmap_apply(parmap, fun, data); + } /* Destroy the parmap */ xbt_parmap_destroy(parmap);