1 /* Copyright (c) 2004-2018. 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 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
12 void s_simdata_task_t::reportMultipleUse() const
14 if (msg_global->debug_multiple_use){
15 XBT_ERROR("This task is already used in there:");
17 XBT_ERROR("<missing backtrace>");
18 XBT_ERROR("And you try to reuse it from here:");
19 xbt_backtrace_display_current();
21 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
22 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
26 /********************************* Task **************************************/
27 /** @brief Creates a new #msg_task_t.
29 * A constructor for #msg_task_t taking four arguments and returning the corresponding object.
30 * @param name a name for the object. It is for user-level information and can be nullptr.
31 * @param flop_amount a value of the processing amount (in flop) needed to process this new task.
32 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
33 * @param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
34 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
35 * @param data a pointer to any data may want to attach to the new object. It is for user-level information and can
36 * be nullptr. It can be retrieved with the function @ref MSG_task_get_data.
38 * @return The new corresponding object.
40 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
42 msg_task_t task = new s_msg_task_t;
43 simdata_task_t simdata = new s_simdata_task_t();
44 task->simdata = simdata;
47 task->name = xbt_strdup(name);
51 simdata->bytes_amount = message_size;
52 simdata->flops_amount = flop_amount;
54 TRACE_msg_task_create(task);
59 /** @brief Creates a new #msg_task_t (a parallel one....).
61 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
64 * See :cpp:func:`void simgrid::s4u::this_actor::parallel_execute(int, s4u::Host**, double*, double*)` for
65 * the exact semantic of the parameters.
68 * @param name a name for the object. It is for user-level information and can be nullptr.
69 * @param host_nb the number of hosts implied in the parallel task.
70 * @param host_list an array of @p host_nb msg_host_t.
71 * @param flops_amount an array of @p host_nb doubles.
72 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
73 * @param bytes_amount an array of @p host_nb* @p host_nb doubles.
74 * @param data a pointer to any data may want to attach to the new object.
75 * It is for user-level information and can be nullptr.
76 * It can be retrieved with the function @ref MSG_task_get_data().
78 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
79 double *flops_amount, double *bytes_amount, void *data)
81 // Task's flops amount is set to an arbitrary value > 0.0 to be able to distinguish, in
82 // MSG_task_get_remaining_work_ratio(), a finished task and a task that has not started yet.
83 msg_task_t task = MSG_task_create(name, 1.0, 0, data);
84 simdata_task_t simdata = task->simdata;
86 /* Simulator Data specific to parallel tasks */
87 simdata->host_nb = host_nb;
88 simdata->host_list = new sg_host_t[host_nb];
89 std::copy_n(host_list, host_nb, simdata->host_list);
90 if (flops_amount != nullptr) {
91 simdata->flops_parallel_amount = new double[host_nb];
92 std::copy_n(flops_amount, host_nb, simdata->flops_parallel_amount);
94 if (bytes_amount != nullptr) {
95 simdata->bytes_parallel_amount = new double[host_nb * host_nb];
96 std::copy_n(bytes_amount, host_nb * host_nb, simdata->bytes_parallel_amount);
102 /** @brief Return the user data of a #msg_task_t.
104 * This function checks whether @a task is a valid pointer and return the user data associated to @a task if possible.
106 void *MSG_task_get_data(msg_task_t task)
111 /** @ingroup m_task_management
112 * @brief Sets the user data of a #msg_task_t.
114 * This function allows to associate a new pointer to the user data associated of @a task.
116 void MSG_task_set_data(msg_task_t task, void *data)
121 /** @brief Sets a function to be called when a task has just been copied.
122 * @param callback a callback function
124 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
126 msg_global->task_copy_callback = callback;
129 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
131 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
135 /** @brief Return the sender of a #msg_task_t.
137 * This functions returns the #msg_process_t which sent this task
139 msg_process_t MSG_task_get_sender(msg_task_t task)
141 return task->simdata->sender;
144 /** @brief Return the source of a #msg_task_t.
146 * This functions returns the #msg_host_t from which this task was sent
148 msg_host_t MSG_task_get_source(msg_task_t task)
150 return task->simdata->source;
153 /** @brief Return the name of a #msg_task_t.
155 * This functions returns the name of a #msg_task_t as specified on creation
157 const char *MSG_task_get_name(msg_task_t task)
162 /** @brief Sets the name of a #msg_task_t.
164 * This functions allows to associate a name to a task
166 void MSG_task_set_name(msg_task_t task, const char *name)
168 task->name = xbt_strdup(name);
171 /** @brief Destroy a #msg_task_t.
173 * Destructor for #msg_task_t. Note that you should free user data, if any, @b before calling this function.
175 * Only the process that owns the task can destroy it.
176 * The owner changes after a successful send.
177 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
179 * If the task failed to be sent, the sender remains the owner of the task.
181 msg_error_t MSG_task_destroy(msg_task_t task)
183 if (task->simdata->isused) {
184 /* the task is being sent or executed: cancel it first */
185 MSG_task_cancel(task);
187 TRACE_msg_task_destroy(task);
189 xbt_free(task->name);
191 /* free main structures */
192 delete task->simdata;
198 /** @brief Cancel a #msg_task_t.
199 * @param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
201 msg_error_t MSG_task_cancel(msg_task_t task)
203 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
205 simdata_task_t simdata = task->simdata;
206 if (simdata->compute) {
207 simcall_execution_cancel(simdata->compute);
208 } else if (simdata->comm) {
209 simcall_comm_cancel(simdata->comm);
211 simdata->setNotUsed();
215 /** @brief Returns a value in ]0,1[ that represent the task remaining work
216 * to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
218 * It works for either parallel or sequential tasks.
220 double MSG_task_get_remaining_work_ratio(msg_task_t task) {
222 xbt_assert((task != nullptr), "Cannot get information from a nullptr task");
223 if (task->simdata->compute) {
225 return task->simdata->compute->get_remaining_ratio();
227 // Task not started (flops_amount is > 0.0) or finished (flops_amount is set to 0.0)
228 return task->simdata->flops_amount > 0.0 ? 1.0 : 0.0;
232 /** @brief Returns the amount of flops that remain to be computed
234 * The returned value is initially the cost that you defined for the task, then it decreases until it reaches 0
236 * It works for sequential tasks, but the remaining amount of work is not a scalar value for parallel tasks.
237 * So you will get an exception if you call this function on parallel tasks. Just don't do it.
239 double MSG_task_get_flops_amount(msg_task_t task) {
240 if (task->simdata->compute != nullptr) {
241 return task->simdata->compute->get_remaining();
243 // Not started or already done.
244 // - Before starting, flops_amount is initially the task cost
245 // - After execution, flops_amount is set to 0 (until someone uses MSG_task_set_flops_amount, if any)
246 return task->simdata->flops_amount;
250 /** @brief set the computation amount needed to process a task #msg_task_t.
252 * @warning If the computation is ongoing (already started and not finished),
253 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
254 * zero, overriding any value set during the execution.
256 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
258 task->simdata->flops_amount = flops_amount;
261 /** @brief set the amount data attached with a task #msg_task_t.
263 * @warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
265 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
267 task->simdata->bytes_amount = data_size;
270 /** @brief Returns the total amount received by a task #msg_task_t.
271 * If the communication does not exist it will return 0.
272 * So, if the communication has FINISHED or FAILED it returns zero.
274 double MSG_task_get_remaining_communication(msg_task_t task)
276 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm.get());
277 return task->simdata->comm->remains();
280 /** @brief Returns the size of the data attached to a task #msg_task_t.
282 double MSG_task_get_bytes_amount(msg_task_t task)
284 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
285 return task->simdata->bytes_amount;
288 /** @brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
289 * will make a task receive two times more cpu power than the other ones.
291 void MSG_task_set_priority(msg_task_t task, double priority)
293 task->simdata->priority = 1 / priority;
294 if (task->simdata->compute)
295 simcall_execution_set_priority(task->simdata->compute, task->simdata->priority);
298 /** @brief Changes the maximum CPU utilization of a computation task.
301 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
303 void MSG_task_set_bound(msg_task_t task, double bound)
305 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
306 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
308 task->simdata->bound = bound;
309 if (task->simdata->compute)
310 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);