1 /* Copyright (c) 2004-2019. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "msg_private.hpp"
7 #include "src/simix/smx_private.hpp"
11 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
13 void s_simdata_task_t::reportMultipleUse() const
15 if (msg_global->debug_multiple_use){
16 XBT_ERROR("This task is already used in there:");
18 XBT_ERROR("<missing backtrace>");
19 XBT_ERROR("And you try to reuse it from here:");
20 xbt_backtrace_display_current();
22 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
23 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
27 /********************************* Task **************************************/
28 /** @brief Creates a new task
30 * A constructor for msg_task_t taking four arguments.
32 * @param name a name for the object. It is for user-level information and can be nullptr.
33 * @param flop_amount a value of the processing amount (in flop) needed to process this new task.
34 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
35 * @param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
36 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
37 * @param data a pointer to any data may want to attach to the new object. It is for user-level information and can
38 * be nullptr. It can be retrieved with the function @ref MSG_task_get_data.
39 * @return The new corresponding object.
41 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
43 msg_task_t task = new s_msg_task_t;
44 simdata_task_t simdata = new s_simdata_task_t();
45 task->simdata = simdata;
48 task->name = xbt_strdup(name);
52 simdata->bytes_amount = message_size;
53 simdata->flops_amount = flop_amount;
55 TRACE_msg_task_create(task);
60 /** @brief Creates a new parallel task
62 * A constructor for #msg_task_t taking six arguments.
65 * See :cpp:func:`void simgrid::s4u::this_actor::parallel_execute(int, s4u::Host**, double*, double*)` for
66 * the exact semantic of the parameters.
69 * @param name a name for the object. It is for user-level information and can be nullptr.
70 * @param host_nb the number of hosts implied in the parallel task.
71 * @param host_list an array of @p host_nb msg_host_t.
72 * @param flops_amount an array of @p host_nb doubles.
73 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
74 * @param bytes_amount an array of @p host_nb* @p host_nb doubles.
75 * @param data a pointer to any data may want to attach to the new object.
76 * It is for user-level information and can be nullptr.
77 * It can be retrieved with the function @ref MSG_task_get_data().
79 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
80 double *flops_amount, double *bytes_amount, void *data)
82 // Task's flops amount is set to an arbitrary value > 0.0 to be able to distinguish, in
83 // MSG_task_get_remaining_work_ratio(), a finished task and a task that has not started yet.
84 msg_task_t task = MSG_task_create(name, 1.0, 0, data);
85 simdata_task_t simdata = task->simdata;
87 /* Simulator Data specific to parallel tasks */
88 simdata->host_nb = host_nb;
89 simdata->host_list = new sg_host_t[host_nb];
90 std::copy_n(host_list, host_nb, simdata->host_list);
91 if (flops_amount != nullptr) {
92 simdata->flops_parallel_amount = new double[host_nb];
93 std::copy_n(flops_amount, host_nb, simdata->flops_parallel_amount);
95 if (bytes_amount != nullptr) {
96 simdata->bytes_parallel_amount = new double[host_nb * host_nb];
97 std::copy_n(bytes_amount, host_nb * host_nb, simdata->bytes_parallel_amount);
103 /** @brief Return the user data of the given task */
104 void *MSG_task_get_data(msg_task_t task)
109 /** @brief Sets the user data of a given task */
110 void MSG_task_set_data(msg_task_t task, void *data)
115 /** @brief Sets a function to be called when a task has just been copied.
116 * @param callback a callback function
118 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
120 msg_global->task_copy_callback = callback;
123 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
125 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
129 /** @brief Returns the sender of the given task */
130 msg_process_t MSG_task_get_sender(msg_task_t task)
132 return task->simdata->sender;
135 /** @brief Returns the source (the sender's host) of the given task */
136 msg_host_t MSG_task_get_source(msg_task_t task)
138 return task->simdata->source;
141 /** @brief Returns the name of the given task. */
142 const char *MSG_task_get_name(msg_task_t task)
147 /** @brief Sets the name of the given task. */
148 void MSG_task_set_name(msg_task_t task, const char *name)
150 task->name = xbt_strdup(name);
153 /** @brief Destroys the given task.
155 * You should free user data, if any, @b before calling this destructor.
157 * Only the process that owns the task can destroy it.
158 * The owner changes after a successful send.
159 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
161 * If the task failed to be sent, the sender remains the owner of the task.
163 msg_error_t MSG_task_destroy(msg_task_t task)
165 if (task->simdata->isused) {
166 /* the task is being sent or executed: cancel it first */
167 MSG_task_cancel(task);
169 TRACE_msg_task_destroy(task);
171 xbt_free(task->name);
173 /* free main structures */
174 delete task->simdata;
180 /** @brief Cancel the given task
182 * If it was currently executed or transfered, the working process is stopped.
184 msg_error_t MSG_task_cancel(msg_task_t task)
186 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
188 simdata_task_t simdata = task->simdata;
189 if (simdata->compute) {
190 simgrid::simix::simcall([simdata] { simdata->compute->cancel(); });
191 } else if (simdata->comm) {
192 simcall_comm_cancel(simdata->comm);
194 simdata->setNotUsed();
198 /** @brief Returns a value in ]0,1[ that represent the task remaining work
199 * to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
201 * It works for either parallel or sequential tasks.
203 double MSG_task_get_remaining_work_ratio(msg_task_t task) {
205 xbt_assert((task != nullptr), "Cannot get information from a nullptr task");
206 if (task->simdata->compute) {
208 return task->simdata->compute->get_remaining_ratio();
210 // Task not started (flops_amount is > 0.0) or finished (flops_amount is set to 0.0)
211 return task->simdata->flops_amount > 0.0 ? 1.0 : 0.0;
215 /** @brief Returns the amount of flops that remain to be computed
217 * The returned value is initially the cost that you defined for the task, then it decreases until it reaches 0
219 * It works for sequential tasks, but the remaining amount of work is not a scalar value for parallel tasks.
220 * So you will get an exception if you call this function on parallel tasks. Just don't do it.
222 double MSG_task_get_flops_amount(msg_task_t task) {
223 if (task->simdata->compute != nullptr) {
224 return task->simdata->compute->get_remaining();
226 // Not started or already done.
227 // - Before starting, flops_amount is initially the task cost
228 // - After execution, flops_amount is set to 0 (until someone uses MSG_task_set_flops_amount, if any)
229 return task->simdata->flops_amount;
233 /** @brief set the computation amount needed to process the given task.
235 * @warning If the computation is ongoing (already started and not finished),
236 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
237 * zero, overriding any value set during the execution.
239 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
241 task->simdata->flops_amount = flops_amount;
244 /** @brief set the amount data attached with the given task.
246 * @warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
248 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
250 task->simdata->bytes_amount = data_size;
253 /** @brief Returns the total amount received by the given task
255 * If the communication does not exist it will return 0.
256 * So, if the communication has FINISHED or FAILED it returns zero.
258 double MSG_task_get_remaining_communication(msg_task_t task)
260 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm.get());
261 return task->simdata->comm->remains();
264 /** @brief Returns the size of the data attached to the given task. */
265 double MSG_task_get_bytes_amount(msg_task_t task)
267 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
268 return task->simdata->bytes_amount;
271 /** @brief Changes the priority of a computation task.
273 * This priority doesn't affect the transfer rate. A priority of 2
274 * will make a task receive two times more cpu power than regular tasks.
276 void MSG_task_set_priority(msg_task_t task, double priority)
278 task->simdata->priority = 1 / priority;
279 xbt_assert(std::isfinite(task->simdata->priority), "priority is not finite!");
280 if (task->simdata->compute)
281 simgrid::simix::simcall([task] { task->simdata->compute->set_priority(task->simdata->priority); });
284 /** @brief Changes the maximum CPU utilization of a computation task (in flops/s).
286 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
288 void MSG_task_set_bound(msg_task_t task, double bound)
290 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
291 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
293 task->simdata->bound = bound;
294 if (task->simdata->compute)
295 simgrid::simix::simcall([task, bound] { task->simdata->compute->set_bound(bound); });