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/s4u/Comm.hpp>
12 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
18 /* parallel tasks only */
20 delete[] flops_parallel_amount;
21 delete[] bytes_parallel_amount;
27 this->report_multiple_use();
31 void Task::report_multiple_use() const
33 if (msg_global->debug_multiple_use){
34 XBT_ERROR("This task is already used in there:");
36 XBT_ERROR("<missing backtrace>");
37 XBT_ERROR("And you try to reuse it from here:");
38 xbt_backtrace_display_current();
40 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
41 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
45 } // namespace simgrid
47 /********************************* Task **************************************/
48 /** @brief Creates a new task
50 * A constructor for msg_task_t taking four arguments.
52 * @param name a name for the object. It is for user-level information and can be nullptr.
53 * @param flop_amount a value of the processing amount (in flop) needed to process this new task.
54 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
55 * @param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
56 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
57 * @param data a pointer to any data may want to attach to the new object. It is for user-level information and can
58 * be nullptr. It can be retrieved with the function @ref MSG_task_get_data.
59 * @return The new corresponding object.
61 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
63 return new simgrid::msg::Task(name ? name : "", flop_amount, message_size, data);
66 /** @brief Creates a new parallel task
68 * A constructor for #msg_task_t taking six arguments.
71 * See :cpp:func:`void simgrid::s4u::this_actor::parallel_execute(int, s4u::Host**, double*, double*)` for
72 * the exact semantic of the parameters.
75 * @param name a name for the object. It is for user-level information and can be nullptr.
76 * @param host_nb the number of hosts implied in the parallel task.
77 * @param host_list an array of @p host_nb msg_host_t.
78 * @param flops_amount an array of @p host_nb doubles.
79 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
80 * @param bytes_amount an array of @p host_nb* @p host_nb doubles.
81 * @param data a pointer to any data may want to attach to the new object.
82 * It is for user-level information and can be nullptr.
83 * It can be retrieved with the function @ref MSG_task_get_data().
85 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
86 double *flops_amount, double *bytes_amount, void *data)
88 // Task's flops amount is set to an arbitrary value > 0.0 to be able to distinguish, in
89 // MSG_task_get_remaining_work_ratio(), a finished task and a task that has not started yet.
90 msg_task_t task = MSG_task_create(name, 1.0, 0, data);
92 /* Simulator Data specific to parallel tasks */
93 task->host_nb = host_nb;
94 host_list = new sg_host_t[host_nb];
95 std::copy_n(host_list, host_nb, task->host_list);
96 if (flops_amount != nullptr) {
97 task->flops_parallel_amount = new double[host_nb];
98 std::copy_n(flops_amount, host_nb, task->flops_parallel_amount);
100 if (bytes_amount != nullptr) {
101 task->bytes_parallel_amount = new double[host_nb * host_nb];
102 std::copy_n(bytes_amount, host_nb * host_nb, task->bytes_parallel_amount);
108 /** @brief Return the user data of the given task */
109 void* MSG_task_get_data(msg_task_t task)
111 return task->get_user_data();
114 /** @brief Sets the user data of a given task */
115 void MSG_task_set_data(msg_task_t task, void *data)
117 task->set_user_data(data);
120 /** @brief Sets a function to be called when a task has just been copied.
121 * @param callback a callback function
123 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
125 msg_global->task_copy_callback = callback;
128 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
130 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
134 /** @brief Returns the sender of the given task */
135 msg_process_t MSG_task_get_sender(msg_task_t task)
140 /** @brief Returns the source (the sender's host) of the given task */
141 msg_host_t MSG_task_get_source(msg_task_t task)
143 return task->sender->get_host();
146 /** @brief Returns the name of the given task. */
147 const char *MSG_task_get_name(msg_task_t task)
149 return task->get_cname();
152 /** @brief Sets the name of the given task. */
153 void MSG_task_set_name(msg_task_t task, const char *name)
155 task->set_name(name);
158 /** @brief Destroys the given task.
160 * You should free user data, if any, @b before calling this destructor.
162 * Only the process that owns the task can destroy it.
163 * The owner changes after a successful send.
164 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
166 * If the task failed to be sent, the sender remains the owner of the task.
168 msg_error_t MSG_task_destroy(msg_task_t task)
171 /* the task is being sent or executed: cancel it first */
172 MSG_task_cancel(task);
175 /* free main structures */
181 /** @brief Cancel the given task
183 * If it was currently executed or transfered, the working process is stopped.
185 msg_error_t MSG_task_cancel(msg_task_t task)
187 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
190 simgrid::simix::simcall([task] { task->compute->cancel(); });
191 } else if (task->comm) {
192 task->comm->cancel();
194 task->set_not_used();
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");
208 return task->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->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->compute != nullptr) {
224 return task->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->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->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->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->comm.get());
261 return task->comm->get_remaining();
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, "Invalid parameter");
268 return task->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->priority = 1 / priority;
279 xbt_assert(std::isfinite(task->priority), "priority is not finite!");
282 /** @brief Changes the maximum CPU utilization of a computation task (in flops/s).
284 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
286 void MSG_task_set_bound(msg_task_t task, double bound)
288 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
289 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");