1 /* Copyright (c) 2004-2017. 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"
12 /** @addtogroup m_task_management
14 * Since most scheduling algorithms rely on a concept of task that can be either <em>computed</em> locally or
15 * <em>transferred</em> on another processor, it seems to be the right level of abstraction for our purposes.
16 * A <em>task</em> may then be defined by a <em>computing amount</em>, a <em>message size</em> and
17 * some <em>private data</em>.
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
22 void s_simdata_task_t::reportMultipleUse() const
24 if (msg_global->debug_multiple_use){
25 XBT_ERROR("This task is already used in there:");
27 XBT_ERROR("<missing backtrace>");
28 XBT_ERROR("And you try to reuse it from here:");
29 xbt_backtrace_display_current();
31 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
32 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
36 /********************************* Task **************************************/
37 /** \ingroup m_task_management
38 * \brief Creates a new #msg_task_t.
40 * A constructor for #msg_task_t taking four arguments and returning the corresponding object.
41 * \param name a name for the object. It is for user-level information and can be nullptr.
42 * \param flop_amount a value of the processing amount (in flop) needed to process this new task.
43 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
44 * \param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
45 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
46 * \param data a pointer to any data may want to attach to the new object. It is for user-level information and can
47 * be nullptr. It can be retrieved with the function \ref MSG_task_get_data.
49 * \return The new corresponding object.
51 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
53 msg_task_t task = new s_msg_task_t;
54 simdata_task_t simdata = new s_simdata_task_t();
55 task->simdata = simdata;
58 task->name = xbt_strdup(name);
62 simdata->bytes_amount = message_size;
63 simdata->flops_amount = flop_amount;
65 TRACE_msg_task_create(task);
70 /** \ingroup m_task_management
71 * \brief Creates a new #msg_task_t (a parallel one....).
73 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
74 * \param name a name for the object. It is for user-level information and can be nullptr.
75 * \param host_nb the number of hosts implied in the parallel task.
76 * \param host_list an array of \p host_nb msg_host_t.
77 * \param flops_amount an array of \p host_nb doubles.
78 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
79 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
80 * \param data a pointer to any data may want to attach to the new object.
81 * It is for user-level information and can be nullptr.
82 * It can be retrieved with the function \ref MSG_task_get_data.
84 * \return The new corresponding object.
86 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
87 double *flops_amount, double *bytes_amount, void *data)
89 msg_task_t task = MSG_task_create(name, 0, 0, data);
90 simdata_task_t simdata = task->simdata;
92 /* Simulator Data specific to parallel tasks */
93 simdata->host_nb = host_nb;
94 simdata->host_list = new sg_host_t[host_nb];
95 std::copy_n(host_list, host_nb, simdata->host_list);
96 if (flops_amount != nullptr) {
97 simdata->flops_parallel_amount = new double[host_nb];
98 std::copy_n(flops_amount, host_nb, simdata->flops_parallel_amount);
100 if (bytes_amount != nullptr) {
101 simdata->bytes_parallel_amount = new double[host_nb * host_nb];
102 std::copy_n(bytes_amount, host_nb * host_nb, simdata->bytes_parallel_amount);
108 /** \ingroup m_task_management
109 * \brief Return the user data of a #msg_task_t.
111 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
113 void *MSG_task_get_data(msg_task_t task)
118 /** \ingroup m_task_management
119 * \brief Sets the user data of a #msg_task_t.
121 * This function allows to associate a new pointer to the user data associated of \a task.
123 void MSG_task_set_data(msg_task_t task, void *data)
128 /** \ingroup m_task_management
129 * \brief Sets a function to be called when a task has just been copied.
130 * \param callback a callback function
132 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
134 msg_global->task_copy_callback = callback;
137 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
139 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
143 /** \ingroup m_task_management
144 * \brief Return the sender of a #msg_task_t.
146 * This functions returns the #msg_process_t which sent this task
148 msg_process_t MSG_task_get_sender(msg_task_t task)
150 return task->simdata->sender;
153 /** \ingroup m_task_management
154 * \brief Return the source of a #msg_task_t.
156 * This functions returns the #msg_host_t from which this task was sent
158 msg_host_t MSG_task_get_source(msg_task_t task)
160 return task->simdata->source;
163 /** \ingroup m_task_management
164 * \brief Return the name of a #msg_task_t.
166 * This functions returns the name of a #msg_task_t as specified on creation
168 const char *MSG_task_get_name(msg_task_t task)
173 /** \ingroup m_task_management
174 * \brief Sets the name of a #msg_task_t.
176 * This functions allows to associate a name to a task
178 void MSG_task_set_name(msg_task_t task, const char *name)
180 task->name = xbt_strdup(name);
183 /** \ingroup m_task_management
184 * \brief Destroy a #msg_task_t.
186 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
188 * Only the process that owns the task can destroy it.
189 * The owner changes after a successful send.
190 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
192 * If the task failed to be sent, the sender remains the owner of the task.
194 msg_error_t MSG_task_destroy(msg_task_t task)
196 if (task->simdata->isused) {
197 /* the task is being sent or executed: cancel it first */
198 MSG_task_cancel(task);
200 TRACE_msg_task_destroy(task);
202 xbt_free(task->name);
204 /* free main structures */
205 delete task->simdata;
211 /** \ingroup m_task_usage
212 * \brief Cancel a #msg_task_t.
213 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
215 msg_error_t MSG_task_cancel(msg_task_t task)
217 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
219 if (task->simdata->compute) {
220 simcall_execution_cancel(task->simdata->compute);
222 else if (task->simdata->comm) {
223 simdata_task_t simdata = task->simdata;
224 simcall_comm_cancel(simdata->comm);
225 simdata->setNotUsed();
230 /** \ingroup m_task_management
231 * \brief Returns a value in ]0,1[ that represent the task remaining work
232 * to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
234 * It works for either parallel or sequential tasks.
235 * TODO: Improve this function by returning 1 if the task has not started
237 double MSG_task_get_remaining_work_ratio(msg_task_t task) {
239 xbt_assert((task != nullptr), "Cannot get information from a nullptr task");
240 if (task->simdata->compute) {
242 return task->simdata->compute->remains();
244 //} else if ((MSG_task_get_flops_amount(task) == 0 and task->simdata->flops_parallel_amount == nullptr) //this is a sequential task
245 // or (task->simdata->flops_parallel_amount != nullptr and task->simdata->flops_parallel_amount == 0)) {
249 // Task not started or finished
254 double MSG_task_get_flops_amount(msg_task_t task) {
255 if (task->simdata->compute) {
256 return task->simdata->compute->remains();
258 return task->simdata->flops_amount;
262 /** \ingroup m_task_management
263 * \brief Returns the initial amount of flops needed to execute a task #msg_task_t.
265 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
266 * #MSG_task_set_flops_amount before restarting the task.
268 * Warning: Only work for simple task, not parallel task.
270 double MSG_task_get_initial_flops_amount(msg_task_t task) {
271 return task->simdata->flops_amount;
274 /** \ingroup m_task_management
275 * \brief set the computation amount needed to process a task #msg_task_t.
277 * \warning If the computation is ongoing (already started and not finished),
278 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
279 * zero, overriding any value set during the execution.
281 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
283 task->simdata->flops_amount = flops_amount;
286 /** \ingroup m_task_management
287 * \brief set the amount data attached with a task #msg_task_t.
289 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
291 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
293 task->simdata->bytes_amount = data_size;
296 /** \ingroup m_task_management
297 * \brief Returns the total amount received by a task #msg_task_t.
298 * If the communication does not exist it will return 0.
299 * So, if the communication has FINISHED or FAILED it returns zero.
301 double MSG_task_get_remaining_communication(msg_task_t task)
303 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm.get());
304 return task->simdata->comm->remains();
307 /** \ingroup m_task_management
308 * \brief Returns the size of the data attached to a task #msg_task_t.
310 double MSG_task_get_bytes_amount(msg_task_t task)
312 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
313 return task->simdata->bytes_amount;
316 /** \ingroup m_task_management
317 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
318 * will make a task receive two times more cpu power than the other ones.
320 void MSG_task_set_priority(msg_task_t task, double priority)
322 task->simdata->priority = 1 / priority;
323 if (task->simdata->compute)
324 simcall_execution_set_priority(task->simdata->compute, task->simdata->priority);
327 /** \ingroup m_task_management
328 * \brief Changes the maximum CPU utilization of a computation task.
331 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
333 void MSG_task_set_bound(msg_task_t task, double bound)
335 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
336 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
338 task->simdata->bound = bound;
339 if (task->simdata->compute)
340 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);