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"
9 /** @addtogroup m_task_management
11 * Since most scheduling algorithms rely on a concept of task that can be either <em>computed</em> locally or
12 * <em>transferred</em> on another processor, it seems to be the right level of abstraction for our purposes.
13 * A <em>task</em> may then be defined by a <em>computing amount</em>, a <em>message size</em> and
14 * some <em>private data</em>.
17 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
19 void simdata_task::reportMultipleUse() const
21 if (msg_global->debug_multiple_use){
22 XBT_ERROR("This task is already used in there:");
24 XBT_ERROR("<missing backtrace>");
25 XBT_ERROR("And you try to reuse it from here:");
26 xbt_backtrace_display_current();
28 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
29 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
33 /********************************* Task **************************************/
34 /** \ingroup m_task_management
35 * \brief Creates a new #msg_task_t.
37 * A constructor for #msg_task_t taking four arguments and returning the corresponding object.
38 * \param name a name for the object. It is for user-level information and can be nullptr.
39 * \param flop_amount a value of the processing amount (in flop) needed to process this new task.
40 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
41 * \param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
42 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
43 * \param data a pointer to any data may want to attach to the new object. It is for user-level information and can
44 * be nullptr. It can be retrieved with the function \ref MSG_task_get_data.
46 * \return The new corresponding object.
48 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
50 msg_task_t task = xbt_new(s_msg_task_t, 1);
51 simdata_task_t simdata = new s_simdata_task_t();
52 task->simdata = simdata;
55 task->name = xbt_strdup(name);
59 simdata->compute = nullptr;
60 simdata->comm = nullptr;
61 simdata->bytes_amount = message_size;
62 simdata->flops_amount = flop_amount;
63 simdata->sender = nullptr;
64 simdata->receiver = nullptr;
65 simdata->source = nullptr;
66 simdata->priority = 1.0;
72 simdata->host_list = nullptr;
73 simdata->flops_parallel_amount = nullptr;
74 simdata->bytes_parallel_amount = nullptr;
75 TRACE_msg_task_create(task);
80 /** \ingroup m_task_management
81 * \brief Creates a new #msg_task_t (a parallel one....).
83 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
84 * \param name a name for the object. It is for user-level information and can be nullptr.
85 * \param host_nb the number of hosts implied in the parallel task.
86 * \param host_list an array of \p host_nb msg_host_t.
87 * \param flops_amount an array of \p host_nb doubles.
88 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
89 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
90 * \param data a pointer to any data may want to attach to the new object.
91 * It is for user-level information and can be nullptr.
92 * It can be retrieved with the function \ref MSG_task_get_data.
94 * \return The new corresponding object.
96 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
97 double *flops_amount, double *bytes_amount, void *data)
99 msg_task_t task = MSG_task_create(name, 0, 0, data);
100 simdata_task_t simdata = task->simdata;
102 /* Simulator Data specific to parallel tasks */
103 simdata->host_nb = host_nb;
104 simdata->host_list = xbt_new0(sg_host_t, host_nb);
105 simdata->flops_parallel_amount = flops_amount;
106 simdata->bytes_parallel_amount = bytes_amount;
108 for (int i = 0; i < host_nb; i++)
109 simdata->host_list[i] = host_list[i];
114 /** \ingroup m_task_management
115 * \brief Return the user data of a #msg_task_t.
117 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
119 void *MSG_task_get_data(msg_task_t task)
124 /** \ingroup m_task_management
125 * \brief Sets the user data of a #msg_task_t.
127 * This function allows to associate a new pointer to the user data associated of \a task.
129 void MSG_task_set_data(msg_task_t task, void *data)
134 /** \ingroup m_task_management
135 * \brief Sets a function to be called when a task has just been copied.
136 * \param callback a callback function
138 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
140 msg_global->task_copy_callback = callback;
143 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
145 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
149 /** \ingroup m_task_management
150 * \brief Return the sender of a #msg_task_t.
152 * This functions returns the #msg_process_t which sent this task
154 msg_process_t MSG_task_get_sender(msg_task_t task)
156 return task->simdata->sender;
159 /** \ingroup m_task_management
160 * \brief Return the source of a #msg_task_t.
162 * This functions returns the #msg_host_t from which this task was sent
164 msg_host_t MSG_task_get_source(msg_task_t task)
166 return task->simdata->source;
169 /** \ingroup m_task_management
170 * \brief Return the name of a #msg_task_t.
172 * This functions returns the name of a #msg_task_t as specified on creation
174 const char *MSG_task_get_name(msg_task_t task)
179 /** \ingroup m_task_management
180 * \brief Sets the name of a #msg_task_t.
182 * This functions allows to associate a name to a task
184 void MSG_task_set_name(msg_task_t task, const char *name)
186 task->name = xbt_strdup(name);
189 /** \ingroup m_task_management
190 * \brief Destroy a #msg_task_t.
192 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
194 * Only the process that owns the task can destroy it.
195 * The owner changes after a successful send.
196 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
198 * If the task failed to be sent, the sender remains the owner of the task.
200 msg_error_t MSG_task_destroy(msg_task_t task)
202 if (task->simdata->isused) {
203 /* the task is being sent or executed: cancel it first */
204 MSG_task_cancel(task);
206 TRACE_msg_task_destroy(task);
208 xbt_free(task->name);
210 /* free main structures */
211 delete task->simdata;
217 /** \ingroup m_task_usage
218 * \brief Cancel a #msg_task_t.
219 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
221 msg_error_t MSG_task_cancel(msg_task_t task)
223 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
225 if (task->simdata->compute) {
226 simcall_execution_cancel(task->simdata->compute);
228 else if (task->simdata->comm) {
229 simdata_task_t simdata = task->simdata;
230 simcall_comm_cancel(simdata->comm);
231 simdata->setNotUsed();
236 /** \ingroup m_task_management
237 * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
239 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
240 * #MSG_task_set_flops_amount before restarting the task.
242 double MSG_task_get_flops_amount(msg_task_t task) {
243 if (task->simdata->compute) {
244 return task->simdata->compute->remains();
246 return task->simdata->flops_amount;
250 /** \ingroup m_task_management
251 * \brief set the computation amount needed to process a task #msg_task_t.
253 * \warning If the computation is ongoing (already started and not finished),
254 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
255 * zero, overriding any value set during the execution.
257 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
259 task->simdata->flops_amount = flops_amount;
262 /** \ingroup m_task_management
263 * \brief set the amount data attached with a task #msg_task_t.
265 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
267 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
269 task->simdata->bytes_amount = data_size;
272 /** \ingroup m_task_management
273 * \brief Returns the total amount received by a task #msg_task_t.
274 * If the communication does not exist it will return 0.
275 * So, if the communication has FINISHED or FAILED it returns zero.
277 double MSG_task_get_remaining_communication(msg_task_t task)
279 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm);
280 return task->simdata->comm->remains();
283 /** \ingroup m_task_management
284 * \brief Returns the size of the data attached to a task #msg_task_t.
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 /** \ingroup m_task_management
293 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
294 * will make a task receive two times more cpu power than the other ones.
296 void MSG_task_set_priority(msg_task_t task, double priority)
298 task->simdata->priority = 1 / priority;
299 if (task->simdata->compute)
300 simcall_execution_set_priority(task->simdata->compute, task->simdata->priority);
303 /** \ingroup m_task_management
304 * \brief Changes the maximum CPU utilization of a computation task.
307 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
309 void MSG_task_set_bound(msg_task_t task, double bound)
311 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
312 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
314 task->simdata->bound = bound;
315 if (task->simdata->compute)
316 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);