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"
8 #include "xbt/sysdep.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->compute = nullptr;
62 simdata->comm = nullptr;
63 simdata->bytes_amount = message_size;
64 simdata->flops_amount = flop_amount;
65 simdata->sender = nullptr;
66 simdata->receiver = nullptr;
67 simdata->source = nullptr;
68 simdata->priority = 1.0;
74 simdata->host_list = nullptr;
75 simdata->flops_parallel_amount = nullptr;
76 simdata->bytes_parallel_amount = nullptr;
77 TRACE_msg_task_create(task);
82 /** \ingroup m_task_management
83 * \brief Creates a new #msg_task_t (a parallel one....).
85 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
86 * \param name a name for the object. It is for user-level information and can be nullptr.
87 * \param host_nb the number of hosts implied in the parallel task.
88 * \param host_list an array of \p host_nb msg_host_t.
89 * \param flops_amount an array of \p host_nb doubles.
90 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
91 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
92 * \param data a pointer to any data may want to attach to the new object.
93 * It is for user-level information and can be nullptr.
94 * It can be retrieved with the function \ref MSG_task_get_data.
96 * \return The new corresponding object.
98 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
99 double *flops_amount, double *bytes_amount, void *data)
101 msg_task_t task = MSG_task_create(name, 0, 0, data);
102 simdata_task_t simdata = task->simdata;
104 /* Simulator Data specific to parallel tasks */
105 simdata->host_nb = host_nb;
106 simdata->host_list = xbt_new0(sg_host_t, host_nb);
107 simdata->flops_parallel_amount = flops_amount;
108 simdata->bytes_parallel_amount = bytes_amount;
110 for (int i = 0; i < host_nb; i++)
111 simdata->host_list[i] = host_list[i];
116 /** \ingroup m_task_management
117 * \brief Return the user data of a #msg_task_t.
119 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
121 void *MSG_task_get_data(msg_task_t task)
126 /** \ingroup m_task_management
127 * \brief Sets the user data of a #msg_task_t.
129 * This function allows to associate a new pointer to the user data associated of \a task.
131 void MSG_task_set_data(msg_task_t task, void *data)
136 /** \ingroup m_task_management
137 * \brief Sets a function to be called when a task has just been copied.
138 * \param callback a callback function
140 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
142 msg_global->task_copy_callback = callback;
145 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
147 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
151 /** \ingroup m_task_management
152 * \brief Return the sender of a #msg_task_t.
154 * This functions returns the #msg_process_t which sent this task
156 msg_process_t MSG_task_get_sender(msg_task_t task)
158 return task->simdata->sender;
161 /** \ingroup m_task_management
162 * \brief Return the source of a #msg_task_t.
164 * This functions returns the #msg_host_t from which this task was sent
166 msg_host_t MSG_task_get_source(msg_task_t task)
168 return task->simdata->source;
171 /** \ingroup m_task_management
172 * \brief Return the name of a #msg_task_t.
174 * This functions returns the name of a #msg_task_t as specified on creation
176 const char *MSG_task_get_name(msg_task_t task)
181 /** \ingroup m_task_management
182 * \brief Sets the name of a #msg_task_t.
184 * This functions allows to associate a name to a task
186 void MSG_task_set_name(msg_task_t task, const char *name)
188 task->name = xbt_strdup(name);
191 /** \ingroup m_task_management
192 * \brief Destroy a #msg_task_t.
194 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
196 * Only the process that owns the task can destroy it.
197 * The owner changes after a successful send.
198 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
200 * If the task failed to be sent, the sender remains the owner of the task.
202 msg_error_t MSG_task_destroy(msg_task_t task)
204 if (task->simdata->isused) {
205 /* the task is being sent or executed: cancel it first */
206 MSG_task_cancel(task);
208 TRACE_msg_task_destroy(task);
210 xbt_free(task->name);
212 /* free main structures */
213 delete task->simdata;
219 /** \ingroup m_task_usage
220 * \brief Cancel a #msg_task_t.
221 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
223 msg_error_t MSG_task_cancel(msg_task_t task)
225 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
227 if (task->simdata->compute) {
228 simcall_execution_cancel(task->simdata->compute);
230 else if (task->simdata->comm) {
231 simdata_task_t simdata = task->simdata;
232 simcall_comm_cancel(simdata->comm);
233 simdata->setNotUsed();
238 /** \ingroup m_task_management
239 * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
241 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
242 * #MSG_task_set_flops_amount before restarting the task.
244 double MSG_task_get_flops_amount(msg_task_t task) {
245 if (task->simdata->compute) {
246 return task->simdata->compute->remains();
248 return task->simdata->flops_amount;
252 /** \ingroup m_task_management
253 * \brief set the computation amount needed to process a task #msg_task_t.
255 * \warning If the computation is ongoing (already started and not finished),
256 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
257 * zero, overriding any value set during the execution.
259 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
261 task->simdata->flops_amount = flops_amount;
264 /** \ingroup m_task_management
265 * \brief set the amount data attached with a task #msg_task_t.
267 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
269 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
271 task->simdata->bytes_amount = data_size;
274 /** \ingroup m_task_management
275 * \brief Returns the total amount received by a task #msg_task_t.
276 * If the communication does not exist it will return 0.
277 * So, if the communication has FINISHED or FAILED it returns zero.
279 double MSG_task_get_remaining_communication(msg_task_t task)
281 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm);
282 return task->simdata->comm->remains();
285 /** \ingroup m_task_management
286 * \brief Returns the size of the data attached to a task #msg_task_t.
288 double MSG_task_get_bytes_amount(msg_task_t task)
290 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
291 return task->simdata->bytes_amount;
294 /** \ingroup m_task_management
295 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
296 * will make a task receive two times more cpu power than the other ones.
298 void MSG_task_set_priority(msg_task_t task, double priority)
300 task->simdata->priority = 1 / priority;
301 if (task->simdata->compute)
302 simcall_execution_set_priority(task->simdata->compute, task->simdata->priority);
305 /** \ingroup m_task_management
306 * \brief Changes the maximum CPU utilization of a computation task.
309 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
311 void MSG_task_set_bound(msg_task_t task, double bound)
313 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
314 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
316 task->simdata->bound = bound;
317 if (task->simdata->compute)
318 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);