1 /* Copyright (c) 2004-2015. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 #include "msg_private.h"
8 #include "src/simix/smx_private.h"
9 #include "xbt/sysdep.h"
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 simdata_task::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 = xbt_new(s_msg_task_t, 1);
54 simdata_task_t simdata = new s_simdata_task_t();
55 task->simdata = simdata;
58 task->name = xbt_strdup(name);
62 simdata->compute = nullptr;
63 simdata->comm = nullptr;
64 simdata->bytes_amount = message_size;
65 simdata->flops_amount = flop_amount;
66 simdata->sender = nullptr;
67 simdata->receiver = nullptr;
68 simdata->source = nullptr;
69 simdata->priority = 1.0;
75 simdata->host_list = nullptr;
76 simdata->flops_parallel_amount = nullptr;
77 simdata->bytes_parallel_amount = nullptr;
78 TRACE_msg_task_create(task);
83 /** \ingroup m_task_management
84 * \brief Creates a new #msg_task_t (a parallel one....).
86 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
87 * \param name a name for the object. It is for user-level information and can be nullptr.
88 * \param host_nb the number of hosts implied in the parallel task.
89 * \param host_list an array of \p host_nb msg_host_t.
90 * \param flops_amount an array of \p host_nb doubles.
91 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
92 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
93 * \param data a pointer to any data may want to attach to the new object.
94 * It is for user-level information and can be nullptr.
95 * It can be retrieved with the function \ref MSG_task_get_data.
97 * \return The new corresponding object.
99 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
100 double *flops_amount, double *bytes_amount, void *data)
102 msg_task_t task = MSG_task_create(name, 0, 0, data);
103 simdata_task_t simdata = task->simdata;
106 /* Simulator Data specific to parallel tasks */
107 simdata->host_nb = host_nb;
108 simdata->host_list = xbt_new0(sg_host_t, host_nb);
109 simdata->flops_parallel_amount = flops_amount;
110 simdata->bytes_parallel_amount = bytes_amount;
112 for (i = 0; i < host_nb; i++)
113 simdata->host_list[i] = host_list[i];
118 /** \ingroup m_task_management
119 * \brief Return the user data of a #msg_task_t.
121 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
123 void *MSG_task_get_data(msg_task_t task)
125 xbt_assert((task != nullptr), "Invalid parameter");
129 /** \ingroup m_task_management
130 * \brief Sets the user data of a #msg_task_t.
132 * This function allows to associate a new pointer to the user data associated of \a task.
134 void MSG_task_set_data(msg_task_t task, void *data)
136 xbt_assert((task != nullptr), "Invalid parameter");
140 /** \ingroup m_task_management
141 * \brief Sets a function to be called when a task has just been copied.
142 * \param callback a callback function
144 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
146 msg_global->task_copy_callback = callback;
149 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
151 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
155 /** \ingroup m_task_management
156 * \brief Return the sender of a #msg_task_t.
158 * This functions returns the #msg_process_t which sent this task
160 msg_process_t MSG_task_get_sender(msg_task_t task)
162 xbt_assert(task, "Invalid parameters");
163 return (static_cast<simdata_task_t> (task->simdata)->sender);
166 /** \ingroup m_task_management
167 * \brief Return the source of a #msg_task_t.
169 * This functions returns the #msg_host_t from which this task was sent
171 msg_host_t MSG_task_get_source(msg_task_t task)
173 xbt_assert(task, "Invalid parameters");
174 return (static_cast<simdata_task_t> (task->simdata)->source);
177 /** \ingroup m_task_management
178 * \brief Return the name of a #msg_task_t.
180 * This functions returns the name of a #msg_task_t as specified on creation
182 const char *MSG_task_get_name(msg_task_t task)
184 xbt_assert(task, "Invalid parameters");
188 /** \ingroup m_task_management
189 * \brief Sets the name of a #msg_task_t.
191 * This functions allows to associate a name to a task
193 void MSG_task_set_name(msg_task_t task, const char *name)
195 xbt_assert(task, "Invalid parameters");
196 task->name = xbt_strdup(name);
199 /** \ingroup m_task_management
200 * \brief Destroy a #msg_task_t.
202 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
204 * Only the process that owns the task can destroy it.
205 * The owner changes after a successful send.
206 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
208 * If the task failed to be sent, the sender remains the owner of the task.
210 msg_error_t MSG_task_destroy(msg_task_t task)
212 xbt_assert((task != nullptr), "Invalid parameter");
214 if (task->simdata->isused) {
215 /* the task is being sent or executed: cancel it first */
216 MSG_task_cancel(task);
218 TRACE_msg_task_destroy(task);
220 xbt_free(task->name);
222 /* free main structures */
223 delete task->simdata;
229 /** \ingroup m_task_usage
230 * \brief Cancel a #msg_task_t.
231 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
233 msg_error_t MSG_task_cancel(msg_task_t task)
235 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
237 if (task->simdata->compute) {
238 simcall_execution_cancel(task->simdata->compute);
240 else if (task->simdata->comm) {
241 simdata_task_t simdata = task->simdata;
242 simcall_comm_cancel(simdata->comm);
243 simdata->setNotUsed();
248 /** \ingroup m_task_management
249 * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
251 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
252 * #MSG_task_set_flops_amount before restarting the task.
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 set the computation amount needed to process a task #msg_task_t.
265 * \warning If the computation is ongoing (already started and not finished),
266 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
267 * zero, overriding any value set during the execution.
269 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
271 task->simdata->flops_amount = flops_amount;
274 /** \ingroup m_task_management
275 * \brief set the amount data attached with a task #msg_task_t.
277 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
279 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
281 task->simdata->bytes_amount = data_size;
284 /** \ingroup m_task_management
285 * \brief Returns the total amount received by a task #msg_task_t.
286 * If the communication does not exist it will return 0.
287 * So, if the communication has FINISHED or FAILED it returns zero.
289 double MSG_task_get_remaining_communication(msg_task_t task)
291 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm);
292 return task->simdata->comm->remains();
295 /** \ingroup m_task_management
296 * \brief Returns the size of the data attached to a task #msg_task_t.
298 double MSG_task_get_bytes_amount(msg_task_t task)
300 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
301 return task->simdata->bytes_amount;
304 /** \ingroup m_task_management
305 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
306 * will make a task receive two times more cpu power than the other ones.
308 void MSG_task_set_priority(msg_task_t task, double priority)
310 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
311 task->simdata->priority = 1 / priority;
312 if (task->simdata->compute)
313 simcall_execution_set_priority(task->simdata->compute,
314 task->simdata->priority);
317 /** \ingroup m_task_management
318 * \brief Changes the maximum CPU utilization of a computation task.
321 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
323 void MSG_task_set_bound(msg_task_t task, double bound)
325 xbt_assert(task, "Invalid parameter");
326 xbt_assert(task->simdata, "Invalid parameter");
328 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
329 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
331 task->simdata->bound = bound;
332 if (task->simdata->compute)
333 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);