/**
* \brief Returns an approximative estimation of the execution time of a task.
*
* The estimation is very approximative because the value returned is the time the task would take if it was executed
* now and if it was the only task.
*
* \param task the task to evaluate
* \param workstation_nb number of workstations on which the task would be executed
* \param workstation_list the workstations on which the task would be executed
* \param flops_amount computation amount for each workstation (i.e., an array of workstation_nb doubles)
* \param bytes_amount communication amount between each pair of workstations (i.e., a matrix of
* workstation_nb*workstation_nb doubles)
* \see SD_schedule()
*/
double SD_task_get_execution_time(SD_task_t task, int workstation_nb, const sg_host_t *workstation_list,
const double *flops_amount, const double *bytes_amount)
{
xbt_assert(workstation_nb > 0, "Invalid parameter");
double max_time = 0.0;
/* the task execution time is the maximum execution time of the parallel tasks */
for (int i = 0; i < workstation_nb; i++) {
double time = 0.0;
if (flops_amount != nullptr)
time = flops_amount[i] / workstation_list[i]->speed();
if (bytes_amount != nullptr)
for (int j = 0; j < workstation_nb; j++) {
if (bytes_amount[i * workstation_nb + j] !=0 ) {
time += (SD_route_get_latency(workstation_list[i], workstation_list[j]) +
bytes_amount[i * workstation_nb + j] /
SD_route_get_bandwidth(workstation_list[i], workstation_list[j]));
}
}
if (time > max_time) {
max_time = time;
}
}
return max_time;
}
int main(int argc, char **argv)
{
unsigned int ctr;
SD_task_t task;
xbt_dynar_t changed_tasks;
SD_init(&argc, argv);
SD_create_environment(argv[1]);
const sg_host_t *hosts = sg_host_list();
SD_task_t t1 = SD_task_create_comp_seq("t1", NULL, 25000000);
SD_task_t c1 = SD_task_create_comm_e2e("c1", NULL, 125000000);
SD_task_t t2 = SD_task_create_comp_seq("t2", NULL, 25000000);
SD_task_t c2 = SD_task_create_comm_e2e("c2", NULL, 62500000);
SD_task_t t3 = SD_task_create_comp_seq("t3", NULL, 25000000);
SD_task_t c3 = SD_task_create_comm_e2e("c3", NULL, 31250000);
SD_task_t t4 = SD_task_create_comp_seq("t4", NULL, 25000000);
/* Add dependencies: t1->c1->t2->c2->t3 */
SD_task_dependency_add(NULL, NULL, t1, c1);
SD_task_dependency_add(NULL, NULL, c1, t2);
SD_task_dependency_add(NULL, NULL, t2, c2);
SD_task_dependency_add(NULL, NULL, c2, t3);
SD_task_dependency_add(NULL, NULL, t3, c3);
SD_task_dependency_add(NULL, NULL, c3, t4);
/* Schedule tasks t1 and w3 on first host, t2 on second host */
/* Transfers are auto-scheduled */
SD_task_schedulel(t1, 1, hosts[0]);
SD_task_schedulel(t2, 1, hosts[1]);
SD_task_schedulel(t3, 1, hosts[0]);
SD_task_schedulel(t4, 1, hosts[1]);
/* Add some watchpoint upon task completion */
SD_task_watch(t1, SD_DONE);
SD_task_watch(c1, SD_DONE);
SD_task_watch(t2, SD_DONE);
SD_task_watch(c2, SD_DONE);
SD_task_watch(t3, SD_DONE);
SD_task_watch(c3, SD_DONE);
SD_task_watch(t4, SD_DONE);
while (!xbt_dynar_is_empty((changed_tasks = SD_simulate(-1.0)))) {
XBT_INFO("link1: bw=%.0f, lat=%f", SD_route_get_bandwidth(hosts[0], hosts[1]),
SD_route_get_latency(hosts[0], hosts[1]));
XBT_INFO("Jupiter: speed=%.0f", sg_host_speed(hosts[0])* sg_host_get_available_speed(hosts[0]));
XBT_INFO("Tremblay: speed=%.0f", sg_host_speed(hosts[1])* sg_host_get_available_speed(hosts[1]));
xbt_dynar_foreach(changed_tasks, ctr, task) {
XBT_INFO("Task '%s' start time: %f, finish time: %f", SD_task_get_name(task),
SD_task_get_start_time(task), SD_task_get_finish_time(task));
if (SD_task_get_state(task)==SD_DONE)
SD_task_destroy(task);
}
}
static double finish_on_at(SD_task_t task, sg_host_t host)
{
double result;
unsigned int i;
double data_available = 0.;
double redist_time = 0;
double last_data_available;
xbt_dynar_t parents = SD_task_get_parents(task);
if (!xbt_dynar_is_empty(parents)) {
/* compute last_data_available */
SD_task_t parent;
last_data_available = -1.0;
xbt_dynar_foreach(parents, i, parent) {
/* normal case */
if (SD_task_get_kind(parent) == SD_TASK_COMM_E2E) {
xbt_dynar_t grand_parents = SD_task_get_parents(parent);
SD_task_t grand_parent;
xbt_assert(xbt_dynar_length(grand_parents) <2, "Error: transfer %s has 2 parents", SD_task_get_name(parent));
xbt_dynar_get_cpy(grand_parents, 0, &grand_parent);
sg_host_t * grand_parent_host_list = SD_task_get_workstation_list(grand_parent);
/* Estimate the redistribution time from this parent */
if (SD_task_get_amount(parent) <= 1e-6){
redist_time= 0;
} else {
redist_time = SD_route_get_latency(grand_parent_host_list[0], host) +
SD_task_get_amount(parent) / SD_route_get_bandwidth(grand_parent_host_list[0], host);
}
data_available = SD_task_get_finish_time(grand_parent) + redist_time;
xbt_dynar_free_container(&grand_parents);
}
/* no transfer, control dependency */
if (SD_task_get_kind(parent) == SD_TASK_COMP_SEQ) {
data_available = SD_task_get_finish_time(parent);
}
if (last_data_available < data_available)
last_data_available = data_available;
}
xbt_dynar_free_container(&parents);
result = MAX(sg_host_get_available_at(host), last_data_available) + SD_task_get_amount(task)/sg_host_speed(host);
} else {
int main(int argc, char **argv)
{
sg_host_t host_list[2];
double computation_amount[2];
double communication_amount[4] = { 0 };
/* initialization of SD */
SD_init(&argc, argv);
xbt_assert(argc > 1, "Usage: %s platform_file\n\nExample: %s two_clusters.xml", argv[0], argv[0]);
SD_create_environment(argv[1]);
/* test the estimation functions */
const sg_host_t *hosts = sg_host_list();
sg_host_t h1 = hosts[0];
sg_host_t h2 = hosts[1];
const char *name1 = sg_host_get_name(h1);
const char *name2 = sg_host_get_name(h2);
double comp_amount1 = 2000000;
double comp_amount2 = 1000000;
double comm_amount12 = 2000000;
double comm_amount21 = 3000000;
XBT_INFO("Computation time for %f flops on %s: %f", comp_amount1, name1, comp_amount1/sg_host_speed(h1));
XBT_INFO("Computation time for %f flops on %s: %f", comp_amount2, name2, comp_amount2/sg_host_speed(h2));
XBT_INFO("Route between %s and %s:", name1, name2);
SD_link_t *route = SD_route_get_list(h1, h2);
int route_size = SD_route_get_size(h1, h2);
for (int i = 0; i < route_size; i++)
XBT_INFO(" Link %s: latency = %f, bandwidth = %f", sg_link_name(route[i]), sg_link_latency(route[i]),
sg_link_bandwidth(route[i]));
xbt_free(route);
XBT_INFO("Route latency = %f, route bandwidth = %f", SD_route_get_latency(h1, h2), SD_route_get_bandwidth(h1, h2));
XBT_INFO("Communication time for %f bytes between %s and %s: %f", comm_amount12, name1, name2,
SD_route_get_latency(h1, h2) + comm_amount12 / SD_route_get_bandwidth(h1, h2));
XBT_INFO("Communication time for %f bytes between %s and %s: %f", comm_amount21, name2, name1,
SD_route_get_latency(h2, h1) + comm_amount21 / SD_route_get_bandwidth(h2, h1));
/* creation of the tasks and their dependencies */
SD_task_t taskA = SD_task_create("Task A", NULL, 10.0);
SD_task_t taskB = SD_task_create("Task B", NULL, 40.0);
SD_task_t taskC = SD_task_create("Task C", NULL, 30.0);
SD_task_t taskD = SD_task_create("Task D", NULL, 60.0);
/* try to attach and retrieve user data to a task */
SD_task_set_data(taskA, static_cast<void*>(&comp_amount1));
if (fabs(comp_amount1 - (*(static_cast<double*>(SD_task_get_data(taskA))))) > 1e-12)
XBT_ERROR("User data was corrupted by a simple set/get");
SD_task_dependency_add(NULL, NULL, taskB, taskA);
SD_task_dependency_add(NULL, NULL, taskC, taskA);
SD_task_dependency_add(NULL, NULL, taskD, taskB);
SD_task_dependency_add(NULL, NULL, taskD, taskC);
SD_task_dependency_add(NULL, NULL, taskB, taskC);
try {
SD_task_dependency_add(NULL, NULL, taskA, taskA); /* shouldn't work and must raise an exception */
xbt_die("Hey, I can add a dependency between Task A and Task A!");
} catch (xbt_ex& ex) {
if (ex.category != arg_error)
throw; /* this is a serious error */
}
try {
SD_task_dependency_add(NULL, NULL, taskB, taskA); /* shouldn't work and must raise an exception */
xbt_die("Oh oh, I can add an already existing dependency!");
} catch (xbt_ex& ex) {
if (ex.category != arg_error)
throw;
}
try {
SD_task_dependency_remove(taskA, taskC); /* shouldn't work and must raise an exception */
xbt_die("Dude, I can remove an unknown dependency!");
} catch (xbt_ex& ex) {
if (ex.category != arg_error)
throw;
}
try {
SD_task_dependency_remove(taskC, taskC); /* shouldn't work and must raise an exception */
xbt_die("Wow, I can remove a dependency between Task C and itself!");
} catch (xbt_ex& ex) {
if (ex.category != arg_error)
throw;
}
/* if everything is ok, no exception is forwarded or rethrown by main() */
/* watch points */
SD_task_watch(taskD, SD_DONE);
SD_task_watch(taskB, SD_DONE);
SD_task_unwatch(taskD, SD_DONE);
/* scheduling parameters */
host_list[0] = h1;
host_list[1] = h2;
computation_amount[0] = comp_amount1;
computation_amount[1] = comp_amount2;
communication_amount[1] = comm_amount12;
communication_amount[2] = comm_amount21;
/* estimated time */
SD_task_t task = taskD;
XBT_INFO("Estimated time for '%s': %f", SD_task_get_name(task), SD_task_get_execution_time(task, 2, host_list,
computation_amount, communication_amount));
SD_task_schedule(taskA, 2, host_list, computation_amount, communication_amount, -1);
SD_task_schedule(taskB, 2, host_list, computation_amount, communication_amount, -1);
SD_task_schedule(taskC, 2, host_list, computation_amount, communication_amount, -1);
SD_task_schedule(taskD, 2, host_list, computation_amount, communication_amount, -1);
std::set<SD_task_t> *changed_tasks = simgrid::sd::simulate(-1.0);
for (auto task: *changed_tasks){
XBT_INFO("Task '%s' start time: %f, finish time: %f", SD_task_get_name(task),
SD_task_get_start_time(task), SD_task_get_finish_time(task));
}
XBT_DEBUG("Destroying tasks...");
SD_task_destroy(taskA);
SD_task_destroy(taskB);
SD_task_destroy(taskC);
SD_task_destroy(taskD);
XBT_DEBUG("Tasks destroyed. Exiting SimDag...");
SD_exit();
return 0;
}
