X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/9b605c24eb28349bfb6d61da080733e19a7cb9a2..ccc485f3688249e70503ad250cb065b5b6d7748f:/src/xbt/parmap.c diff --git a/src/xbt/parmap.c b/src/xbt/parmap.c index 25de341a47..9f2f35bd49 100644 --- a/src/xbt/parmap.c +++ b/src/xbt/parmap.c @@ -25,43 +25,61 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map"); XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing"); typedef enum { - PARMAP_WORK = 0, - PARMAP_DESTROY + XBT_PARMAP_WORK = 0, + 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_posix_start(xbt_parmap_t parmap); +static void xbt_parmap_posix_end(xbt_parmap_t parmap); +static void xbt_parmap_posix_signal(xbt_parmap_t parmap); +static void xbt_parmap_posix_wait(xbt_parmap_t parmap); + #ifdef HAVE_FUTEX_H +static void xbt_parmap_futex_start(xbt_parmap_t parmap); +static void xbt_parmap_futex_end(xbt_parmap_t parmap); +static void xbt_parmap_futex_signal(xbt_parmap_t parmap); +static void xbt_parmap_futex_wait(xbt_parmap_t parmap); static void futex_wait(int *uaddr, int val); static void futex_wake(int *uaddr, int val); #endif +static void xbt_parmap_busy_start(xbt_parmap_t parmap); +static void xbt_parmap_busy_end(xbt_parmap_t parmap); +static void xbt_parmap_busy_signal(xbt_parmap_t parmap); +static void xbt_parmap_busy_wait(xbt_parmap_t parmap); + + /** * \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? */ + int work; /**< index of the current round (1 is the first) */ + int done; /**< number of rounds already done (futexes only) */ + 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 */ + + /* fields that depend on the synchronization mode */ + e_xbt_parmap_mode_t mode; /**< synchronization mode */ + void (*start_f)(xbt_parmap_t); /**< initializes the worker threads */ + void (*end_f)(xbt_parmap_t); /**< finalizes the worker threads */ + void (*signal_f)(xbt_parmap_t); /**< wakes the workers threads to process tasks */ + void (*wait_f)(xbt_parmap_t); /**< 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; @@ -72,14 +90,15 @@ xbt_parmap_t xbt_parmap_new(unsigned int num_workers) 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 = 0; i < num_workers - 1; i++) { worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL); xbt_os_thread_detach(worker); } - xbt_parmap_start(parmap); + parmap->start_f(parmap); return parmap; } @@ -89,11 +108,61 @@ xbt_parmap_t xbt_parmap_new(unsigned int num_workers) */ void xbt_parmap_destroy(xbt_parmap_t parmap) { - parmap->status = PARMAP_DESTROY; - xbt_parmap_signal(parmap); + parmap->status = XBT_PARMAP_DESTROY; + parmap->signal_f(parmap); 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->start_f = xbt_parmap_posix_start; + parmap->end_f = xbt_parmap_posix_end; + parmap->signal_f = xbt_parmap_posix_signal; + parmap->wait_f = xbt_parmap_posix_wait; + break; + + + case XBT_PARMAP_FUTEX: +#ifdef HAVE_FUTEX_H + parmap->start_f = xbt_parmap_futex_start; + parmap->end_f = xbt_parmap_futex_end; + parmap->signal_f = xbt_parmap_futex_signal; + parmap->wait_f = xbt_parmap_futex_wait; + break; +#else + xbt_die("Futex is not available on this OS (maybe you are on a Mac)."); +#endif + + case XBT_PARMAP_BUSY_WAIT: + parmap->start_f = xbt_parmap_busy_start; + parmap->end_f = xbt_parmap_busy_end; + parmap->signal_f = xbt_parmap_busy_signal; + parmap->wait_f = xbt_parmap_busy_wait; + break; + + case XBT_PARMAP_DEFAULT: + THROW_IMPOSSIBLE; + break; + } +} + /** * \brief Applies a list of tasks in parallel. * \param parmap a parallel map object @@ -102,11 +171,11 @@ void xbt_parmap_destroy(xbt_parmap_t parmap) */ 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->signal_f(parmap); XBT_DEBUG("Job done"); } @@ -126,49 +195,35 @@ void* xbt_parmap_next(xbt_parmap_t parmap) 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) -{ - return (unsigned long) xbt_os_thread_get_extra_data(); -} - /** * \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) { - xbt_parmap_wait(parmap); - if (parmap->status == PARMAP_WORK) { + parmap->wait_f(parmap); + 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) { + 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 { - xbt_parmap_end(parmap); - XBT_DEBUG("Shutting down worker %u", worker_id); + parmap->end_f(parmap); + XBT_DEBUG("Shutting down worker"); return NULL; } } @@ -188,6 +243,27 @@ static void futex_wake(int *uaddr, int val) } #endif +static void xbt_parmap_posix_start(xbt_parmap_t parmap) +{ + THROW_UNIMPLEMENTED; +} + +static void xbt_parmap_posix_end(xbt_parmap_t parmap) +{ + THROW_UNIMPLEMENTED; +} + +static void xbt_parmap_posix_signal(xbt_parmap_t parmap) +{ + THROW_UNIMPLEMENTED; +} + +static void xbt_parmap_posix_wait(xbt_parmap_t parmap) +{ + THROW_UNIMPLEMENTED; +} + +#ifdef HAVE_FUTEX_H /** * \brief Starts the parmap: waits for all workers to be ready and returns. * @@ -195,15 +271,34 @@ static void futex_wake(int *uaddr, int val) * * \param parmap a parmap */ -static void xbt_parmap_start(xbt_parmap_t parmap) +static void xbt_parmap_futex_start(xbt_parmap_t parmap) { -#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 +} + +/** + * \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_end(xbt_parmap_t parmap) +{ + unsigned int mycount; + + 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); + } } /** @@ -213,9 +308,8 @@ static void xbt_parmap_start(xbt_parmap_t parmap) * * \param parmap a parmap */ -static void xbt_parmap_signal(xbt_parmap_t parmap) +static void xbt_parmap_futex_signal(xbt_parmap_t parmap) { -#ifdef HAVE_FUTEX_H int myflag = parmap->done; parmap->thread_counter = 0; parmap->work++; @@ -223,21 +317,32 @@ static void xbt_parmap_signal(xbt_parmap_t parmap) /* wake all workers */ futex_wake(&parmap->work, parmap->num_workers); - /* wait for all of them to finish */ - futex_wait(&parmap->done, myflag); -#endif + if (parmap->status == XBT_PARMAP_WORK) { + /* also work myself */ + void* work = xbt_parmap_next(parmap); + while (work != NULL) { + parmap->fun(work); + work = xbt_parmap_next(parmap); + } + } + + 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); + } } /** * \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 */ -static void xbt_parmap_wait(xbt_parmap_t parmap) +static void xbt_parmap_futex_wait(xbt_parmap_t parmap) { -#ifdef HAVE_FUTEX_H int myflag; unsigned int mycount; @@ -251,7 +356,22 @@ static void xbt_parmap_wait(xbt_parmap_t parmap) /* wait for more work */ futex_wait(&parmap->work, myflag); +} #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_start(xbt_parmap_t parmap) +{ + __sync_fetch_and_add(&parmap->thread_counter, 1); + while (parmap->thread_counter < parmap->num_workers) { + xbt_os_thread_yield(); + } } /** @@ -261,18 +381,56 @@ static void xbt_parmap_wait(xbt_parmap_t parmap) * * \param parmap a parmap */ -static void xbt_parmap_end(xbt_parmap_t parmap) +static void xbt_parmap_busy_end(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_signal(xbt_parmap_t parmap) +{ + parmap->thread_counter = 0; + parmap->work++; + + if (parmap->status == XBT_PARMAP_WORK) { + /* also work myself */ + void* work = xbt_parmap_next(parmap); + while (work != NULL) { + parmap->fun(work); + work = xbt_parmap_next(parmap); + } + } + + /* I have finished, wait for the others */ + __sync_add_and_fetch(&parmap->thread_counter, 1); + while (parmap->thread_counter < parmap->num_workers) { + xbt_os_thread_yield(); + } +} + +/** + * \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 + */ +static void xbt_parmap_busy_wait(xbt_parmap_t parmap) +{ + int work = parmap->work; + __sync_add_and_fetch(&parmap->thread_counter, 1); + + /* wait for more work */ + while (parmap->work == work) { + xbt_os_thread_yield(); } -#endif } #ifdef SIMGRID_TEST @@ -299,9 +457,12 @@ XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage") 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++) { +#ifdef HAVE_FUTEX_H + parmap = xbt_parmap_new(10, XBT_PARMAP_FUTEX); +#else + parmap = xbt_parmap_new(10, XBT_PARMAP_BUSY_WAIT); +#endif + for (j = 0; j < 100; j++) { xbt_dynar_push_as(data, void *, (void *)j); }