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"
10 #include <simgrid/modelchecker.h>
11 #include <simgrid/s4u/Comm.hpp>
13 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
19 /* parallel tasks only */
21 delete[] flops_parallel_amount;
22 delete[] bytes_parallel_amount;
28 this->report_multiple_use();
32 void Task::report_multiple_use() const
34 if (msg_global->debug_multiple_use){
35 XBT_ERROR("This task is already used in there:");
37 XBT_ERROR("<missing backtrace>");
38 XBT_ERROR("And you try to reuse it from here:");
39 xbt_backtrace_display_current();
41 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
42 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
46 } // namespace simgrid
48 /********************************* Task **************************************/
49 /** @brief Creates a new task
51 * A constructor for msg_task_t taking four arguments.
53 * @param name a name for the object. It is for user-level information and can be nullptr.
54 * @param flop_amount a value of the processing amount (in flop) needed to process this new task.
55 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
56 * @param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
57 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
58 * @param data a pointer to any data may want to attach to the new object. It is for user-level information and can
59 * be nullptr. It can be retrieved with the function @ref MSG_task_get_data.
60 * @return The new corresponding object.
62 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
64 static std::atomic_ullong counter{0};
66 msg_task_t task = new s_msg_task_t;
68 task->simdata = new simgrid::msg::Task(name ? name : "", flop_amount, message_size);
73 task->counter = counter++;
74 task->category = nullptr;
77 MC_ignore_heap(&(task->counter), sizeof(task->counter));
82 /** @brief Creates a new parallel task
84 * A constructor for #msg_task_t taking six arguments.
87 * See :cpp:func:`void simgrid::s4u::this_actor::parallel_execute(int, s4u::Host**, double*, double*)` for
88 * the exact semantic of the parameters.
91 * @param name a name for the object. It is for user-level information and can be nullptr.
92 * @param host_nb the number of hosts implied in the parallel task.
93 * @param host_list an array of @p host_nb msg_host_t.
94 * @param flops_amount an array of @p host_nb doubles.
95 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
96 * @param bytes_amount an array of @p host_nb* @p host_nb doubles.
97 * @param data a pointer to any data may want to attach to the new object.
98 * It is for user-level information and can be nullptr.
99 * It can be retrieved with the function @ref MSG_task_get_data().
101 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
102 double *flops_amount, double *bytes_amount, void *data)
104 // Task's flops amount is set to an arbitrary value > 0.0 to be able to distinguish, in
105 // MSG_task_get_remaining_work_ratio(), a finished task and a task that has not started yet.
106 msg_task_t task = MSG_task_create(name, 1.0, 0, data);
107 simdata_task_t simdata = task->simdata;
109 /* Simulator Data specific to parallel tasks */
110 simdata->host_nb = host_nb;
111 simdata->host_list = new sg_host_t[host_nb];
112 std::copy_n(host_list, host_nb, simdata->host_list);
113 if (flops_amount != nullptr) {
114 simdata->flops_parallel_amount = new double[host_nb];
115 std::copy_n(flops_amount, host_nb, simdata->flops_parallel_amount);
117 if (bytes_amount != nullptr) {
118 simdata->bytes_parallel_amount = new double[host_nb * host_nb];
119 std::copy_n(bytes_amount, host_nb * host_nb, simdata->bytes_parallel_amount);
125 /** @brief Return the user data of the given task */
126 void *MSG_task_get_data(msg_task_t task)
131 /** @brief Sets the user data of a given task */
132 void MSG_task_set_data(msg_task_t task, void *data)
137 /** @brief Sets a function to be called when a task has just been copied.
138 * @param callback a callback function
140 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
142 msg_global->task_copy_callback = callback;
145 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
147 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
151 /** @brief Returns the sender of the given task */
152 msg_process_t MSG_task_get_sender(msg_task_t task)
154 return task->simdata->sender;
157 /** @brief Returns the source (the sender's host) of the given task */
158 msg_host_t MSG_task_get_source(msg_task_t task)
160 return task->simdata->sender->get_host();
163 /** @brief Returns the name of the given task. */
164 const char *MSG_task_get_name(msg_task_t task)
166 return task->simdata->get_cname();
169 /** @brief Sets the name of the given task. */
170 void MSG_task_set_name(msg_task_t task, const char *name)
172 task->simdata->set_name(name);
175 /** @brief Destroys the given task.
177 * You should free user data, if any, @b before calling this destructor.
179 * Only the process that owns the task can destroy it.
180 * The owner changes after a successful send.
181 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
183 * If the task failed to be sent, the sender remains the owner of the task.
185 msg_error_t MSG_task_destroy(msg_task_t task)
187 if (task->simdata->is_used) {
188 /* the task is being sent or executed: cancel it first */
189 MSG_task_cancel(task);
192 xbt_free(task->category);
194 /* free main structures */
195 delete task->simdata;
201 /** @brief Cancel the given task
203 * If it was currently executed or transfered, the working process is stopped.
205 msg_error_t MSG_task_cancel(msg_task_t task)
207 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
209 simdata_task_t simdata = task->simdata;
210 if (simdata->compute) {
211 simgrid::simix::simcall([simdata] { simdata->compute->cancel(); });
212 } else if (simdata->comm) {
213 simdata->comm->cancel();
215 simdata->set_not_used();
219 /** @brief Returns a value in ]0,1[ that represent the task remaining work
220 * to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
222 * It works for either parallel or sequential tasks.
224 double MSG_task_get_remaining_work_ratio(msg_task_t task) {
226 xbt_assert((task != nullptr), "Cannot get information from a nullptr task");
227 if (task->simdata->compute) {
229 return task->simdata->compute->get_remaining_ratio();
231 // Task not started (flops_amount is > 0.0) or finished (flops_amount is set to 0.0)
232 return task->simdata->flops_amount > 0.0 ? 1.0 : 0.0;
236 /** @brief Returns the amount of flops that remain to be computed
238 * The returned value is initially the cost that you defined for the task, then it decreases until it reaches 0
240 * It works for sequential tasks, but the remaining amount of work is not a scalar value for parallel tasks.
241 * So you will get an exception if you call this function on parallel tasks. Just don't do it.
243 double MSG_task_get_flops_amount(msg_task_t task) {
244 if (task->simdata->compute != nullptr) {
245 return task->simdata->compute->get_remaining();
247 // Not started or already done.
248 // - Before starting, flops_amount is initially the task cost
249 // - After execution, flops_amount is set to 0 (until someone uses MSG_task_set_flops_amount, if any)
250 return task->simdata->flops_amount;
254 /** @brief set the computation amount needed to process the given task.
256 * @warning If the computation is ongoing (already started and not finished),
257 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
258 * zero, overriding any value set during the execution.
260 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
262 task->simdata->flops_amount = flops_amount;
265 /** @brief set the amount data attached with the given task.
267 * @warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
269 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
271 task->simdata->bytes_amount = data_size;
274 /** @brief Returns the total amount received by the given task
276 * If the communication does not exist it will return 0.
277 * So, if the communication has FINISHED or FAILED it returns zero.
279 double MSG_task_get_remaining_communication(msg_task_t task)
281 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm.get());
282 return task->simdata->comm->get_remaining();
285 /** @brief Returns the size of the data attached to the given task. */
286 double MSG_task_get_bytes_amount(msg_task_t task)
288 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
289 return task->simdata->bytes_amount;
292 /** @brief Changes the priority of a computation task.
294 * This priority doesn't affect the transfer rate. A priority of 2
295 * will make a task receive two times more cpu power than regular tasks.
297 void MSG_task_set_priority(msg_task_t task, double priority)
299 task->simdata->priority = 1 / priority;
300 xbt_assert(std::isfinite(task->simdata->priority), "priority is not finite!");
303 /** @brief Changes the maximum CPU utilization of a computation task (in flops/s).
305 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
307 void MSG_task_set_bound(msg_task_t task, double bound)
309 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
310 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
311 task->simdata->bound = bound;