static smx_context_t smx_current_context_serial;
static int smx_parallel_contexts = 1;
static int smx_parallel_threshold = 2;
+static e_xbt_parmap_mode_t smx_parallel_synchronization_mode = XBT_PARMAP_FUTEX;
/**
* This function is called by SIMIX_global_init() to initialize the context module.
xbt_dict_remove((xbt_dict_t) _surf_cfg_set,"contexts/factory");
}
+/**
+ * \brief Returns whether some parallel threads are used
+ * for the user contexts.
+ * \return 1 if parallelism is used
+ */
+XBT_INLINE int SIMIX_context_is_parallel(void) {
+ return smx_parallel_contexts > 1;
+}
+
+/**
+ * \brief Returns the number of parallel threads used
+ * for the user contexts.
+ * \return the number of threads (1 means no parallelism)
+ */
+XBT_INLINE int SIMIX_context_get_nthreads(void) {
+ return smx_parallel_contexts;
+}
+
/**
* \brief Sets the number of parallel threads to use
* for the user contexts.
}
/**
- * \brief Returns the number of parallel threads used
- * for the user contexts.
- * \return the number of threads (1 means no parallelism)
- */
-XBT_INLINE int SIMIX_context_get_nthreads(void) {
- return smx_parallel_contexts;
-}
-
-/**
- * \brief Returns whether some parallel threads are used
- * for the user contexts.
- * \return 1 if parallelism is used
+ * \brief Returns the threshold above which user processes are run in parallel.
+ *
+ * If the number of threads is set to 1, there is no parallelism and this
+ * threshold has no effect.
+ *
+ * \return when the number of user processes ready to run is above
+ * this threshold, they are run in parallel
*/
-XBT_INLINE int SIMIX_context_is_parallel(void) {
- return smx_parallel_contexts > 1;
+XBT_INLINE int SIMIX_context_get_parallel_threshold(void) {
+ return smx_parallel_threshold;
}
/**
}
/**
- * \brief Returns the threshold above which user processes are run in parallel.
- *
- * If the number of threads is set to 1, there is no parallelism and this
- * threshold has no effect.
- *
- * \return when the number of user processes ready to run is above
- * this threshold, they are run in parallel
+ * \brief Returns the synchronization mode used when processes are run in
+ * parallel.
+ * \return how threads are synchronized if processes are run in parallel
*/
-XBT_INLINE int SIMIX_context_get_parallel_threshold(void) {
- return smx_parallel_threshold;
+XBT_INLINE e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode(void) {
+ return smx_parallel_synchronization_mode;
+}
+
+/**
+ * \brief Sets the synchronization mode to use when processes are run in
+ * parallel.
+ * \param mode how to synchronize threads if processes are run in parallel
+ */
+XBT_INLINE void SIMIX_context_set_parallel_mode(e_xbt_parmap_mode_t mode) {
+ smx_parallel_synchronization_mode = mode;
}
/**
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 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 */
+ 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;
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 - 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;
}
*/
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)
+{
+ 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:
+ 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;
+
+ 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;
+ }
+}
+
/**
* \brief Applies a list of tasks in parallel.
* \param parmap a parallel map object
parmap->fun = fun;
parmap->data = data;
parmap->index = 0;
- xbt_parmap_signal(parmap);
+ parmap->signal_f(parmap);
XBT_DEBUG("Job done");
}
/* 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 got a job");
/* We are destroying the parmap */
} else {
- xbt_parmap_end(parmap);
+ parmap->end_f(parmap);
XBT_DEBUG("Shutting down worker");
return NULL;
}
}
#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.
*
*
* \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);
+ }
}
/**
*
* \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++;
/* wake all workers */
futex_wake(&parmap->work, parmap->num_workers);
- if (parmap->status == PARMAP_WORK) {
+ if (parmap->status == XBT_PARMAP_WORK) {
/* also work myself */
void* work = xbt_parmap_next(parmap);
- if (work != NULL) {
+ while (work != NULL) {
parmap->fun(work);
+ work = xbt_parmap_next(parmap);
}
}
/* some workers have not finished yet */
futex_wait(&parmap->done, myflag);
}
-
-#endif
}
/**
* \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;
/* 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();
+ }
}
/**
*
* \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
