1 /* Copyright (c) 2004-2016. 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.h"
7 #include "src/simix/smx_private.h"
11 /** @addtogroup m_task_management
13 * Since most scheduling algorithms rely on a concept of task that can be either <em>computed</em> locally or
14 * <em>transferred</em> on another processor, it seems to be the right level of abstraction for our purposes.
15 * A <em>task</em> may then be defined by a <em>computing amount</em>, a <em>message size</em> and
16 * some <em>private data</em>.
19 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
21 void simdata_task::reportMultipleUse() const
23 if (msg_global->debug_multiple_use){
24 XBT_ERROR("This task is already used in there:");
26 XBT_ERROR("<missing backtrace>");
27 XBT_ERROR("And you try to reuse it from here:");
28 xbt_backtrace_display_current();
30 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
31 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
35 /********************************* Task **************************************/
36 /** \ingroup m_task_management
37 * \brief Creates a new #msg_task_t.
39 * A constructor for #msg_task_t taking four arguments and returning the corresponding object.
40 * \param name a name for the object. It is for user-level information and can be nullptr.
41 * \param flop_amount a value of the processing amount (in flop) needed to process this new task.
42 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
43 * \param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
44 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
45 * \param data a pointer to any data may want to attach to the new object. It is for user-level information and can
46 * be nullptr. It can be retrieved with the function \ref MSG_task_get_data.
48 * \return The new corresponding object.
50 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
52 msg_task_t task = xbt_new(s_msg_task_t, 1);
53 simdata_task_t simdata = new s_simdata_task_t();
54 task->simdata = simdata;
57 task->name = xbt_strdup(name);
61 simdata->bytes_amount = message_size;
62 simdata->flops_amount = flop_amount;
64 TRACE_msg_task_create(task);
69 /** \ingroup m_task_management
70 * \brief Creates a new #msg_task_t (a parallel one....).
72 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
73 * \param name a name for the object. It is for user-level information and can be nullptr.
74 * \param host_nb the number of hosts implied in the parallel task.
75 * \param host_list an array of \p host_nb msg_host_t.
76 * \param flops_amount an array of \p host_nb doubles.
77 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
78 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
79 * \param data a pointer to any data may want to attach to the new object.
80 * It is for user-level information and can be nullptr.
81 * It can be retrieved with the function \ref MSG_task_get_data.
83 * \return The new corresponding object.
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 msg_task_t task = MSG_task_create(name, 0, 0, data);
89 simdata_task_t simdata = task->simdata;
91 /* Simulator Data specific to parallel tasks */
92 simdata->host_nb = host_nb;
93 simdata->host_list = xbt_new0(sg_host_t, host_nb);
94 simdata->flops_parallel_amount = flops_amount;
95 simdata->bytes_parallel_amount = bytes_amount;
97 for (int i = 0; i < host_nb; i++)
98 simdata->host_list[i] = host_list[i];
103 /** \ingroup m_task_management
104 * \brief Return the user data of a #msg_task_t.
106 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
108 void *MSG_task_get_data(msg_task_t task)
113 /** \ingroup m_task_management
114 * \brief Sets the user data of a #msg_task_t.
116 * This function allows to associate a new pointer to the user data associated of \a task.
118 void MSG_task_set_data(msg_task_t task, void *data)
123 /** \ingroup m_task_management
124 * \brief Sets a function to be called when a task has just been copied.
125 * \param callback a callback function
127 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
129 msg_global->task_copy_callback = callback;
132 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
134 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
138 /** \ingroup m_task_management
139 * \brief Return the sender of a #msg_task_t.
141 * This functions returns the #msg_process_t which sent this task
143 msg_process_t MSG_task_get_sender(msg_task_t task)
145 return task->simdata->sender;
148 /** \ingroup m_task_management
149 * \brief Return the source of a #msg_task_t.
151 * This functions returns the #msg_host_t from which this task was sent
153 msg_host_t MSG_task_get_source(msg_task_t task)
155 return task->simdata->source;
158 /** \ingroup m_task_management
159 * \brief Return the name of a #msg_task_t.
161 * This functions returns the name of a #msg_task_t as specified on creation
163 const char *MSG_task_get_name(msg_task_t task)
168 /** \ingroup m_task_management
169 * \brief Sets the name of a #msg_task_t.
171 * This functions allows to associate a name to a task
173 void MSG_task_set_name(msg_task_t task, const char *name)
175 task->name = xbt_strdup(name);
178 /** \ingroup m_task_management
179 * \brief Destroy a #msg_task_t.
181 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
183 * Only the process that owns the task can destroy it.
184 * The owner changes after a successful send.
185 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
187 * If the task failed to be sent, the sender remains the owner of the task.
189 msg_error_t MSG_task_destroy(msg_task_t task)
191 if (task->simdata->isused) {
192 /* the task is being sent or executed: cancel it first */
193 MSG_task_cancel(task);
195 TRACE_msg_task_destroy(task);
197 xbt_free(task->name);
199 /* free main structures */
200 delete task->simdata;
206 /** \ingroup m_task_usage
207 * \brief Cancel a #msg_task_t.
208 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
210 msg_error_t MSG_task_cancel(msg_task_t task)
212 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
214 if (task->simdata->compute) {
215 simcall_execution_cancel(task->simdata->compute);
217 else if (task->simdata->comm) {
218 simdata_task_t simdata = task->simdata;
219 simcall_comm_cancel(simdata->comm);
220 simdata->setNotUsed();
225 /** \ingroup m_task_management
226 * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
228 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
229 * #MSG_task_set_flops_amount before restarting the task.
231 double MSG_task_get_flops_amount(msg_task_t task) {
232 if (task->simdata->compute) {
233 return task->simdata->compute->remains();
235 return task->simdata->flops_amount;
239 /** \ingroup m_task_management
240 * \brief set the computation amount needed to process a task #msg_task_t.
242 * \warning If the computation is ongoing (already started and not finished),
243 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
244 * zero, overriding any value set during the execution.
246 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
248 task->simdata->flops_amount = flops_amount;
251 /** \ingroup m_task_management
252 * \brief set the amount data attached with a task #msg_task_t.
254 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
256 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
258 task->simdata->bytes_amount = data_size;
261 /** \ingroup m_task_management
262 * \brief Returns the total amount received by a task #msg_task_t.
263 * If the communication does not exist it will return 0.
264 * So, if the communication has FINISHED or FAILED it returns zero.
266 double MSG_task_get_remaining_communication(msg_task_t task)
268 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm.get());
269 return task->simdata->comm->remains();
272 /** \ingroup m_task_management
273 * \brief Returns the size of the data attached to a task #msg_task_t.
275 double MSG_task_get_bytes_amount(msg_task_t task)
277 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
278 return task->simdata->bytes_amount;
281 /** \ingroup m_task_management
282 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
283 * will make a task receive two times more cpu power than the other ones.
285 void MSG_task_set_priority(msg_task_t task, double priority)
287 task->simdata->priority = 1 / priority;
288 if (task->simdata->compute)
289 simcall_execution_set_priority(task->simdata->compute, task->simdata->priority);
292 /** \ingroup m_task_management
293 * \brief Changes the maximum CPU utilization of a computation task.
296 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
298 void MSG_task_set_bound(msg_task_t task, double bound)
300 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
301 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
303 task->simdata->bound = bound;
304 if (task->simdata->compute)
305 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);