1 /* Copyright (c) 2004-2019. 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"
10 #include <simgrid/modelchecker.h>
11 #include <simgrid/s4u/Comm.hpp>
13 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_task, msg, "Logging specific to MSG (task)");
19 /* parallel tasks only */
21 delete[] flops_parallel_amount;
22 delete[] bytes_parallel_amount;
28 this->report_multiple_use();
32 void Task::report_multiple_use() const
34 if (msg_global->debug_multiple_use){
35 XBT_ERROR("This task is already used in there:");
37 XBT_ERROR("<missing backtrace>");
38 XBT_ERROR("And you try to reuse it from here:");
39 xbt_backtrace_display_current();
41 xbt_die("This task is still being used somewhere else. You cannot send it now. Go fix your code!"
42 "(use --cfg=msg/debug-multiple-use:on to get the backtrace of the other process)");
46 } // namespace simgrid
48 /********************************* Task **************************************/
49 /** @brief Creates a new task
51 * A constructor for msg_task_t taking four arguments.
53 * @param name a name for the object. It is for user-level information and can be nullptr.
54 * @param flop_amount a value of the processing amount (in flop) needed to process this new task.
55 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
56 * @param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
57 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
58 * @param data a pointer to any data may want to attach to the new object. It is for user-level information and can
59 * be nullptr. It can be retrieved with the function @ref MSG_task_get_data.
60 * @return The new corresponding object.
62 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
64 static std::atomic_ullong counter{0};
66 msg_task_t task = new s_msg_task_t;
68 task->simdata = new simgrid::msg::Task(name ? name : "", flop_amount, message_size);
72 task->counter = counter++;
75 MC_ignore_heap(&(task->counter), sizeof(task->counter));
80 /** @brief Creates a new parallel task
82 * A constructor for #msg_task_t taking six arguments.
85 * See :cpp:func:`void simgrid::s4u::this_actor::parallel_execute(int, s4u::Host**, double*, double*)` for
86 * the exact semantic of the parameters.
89 * @param name a name for the object. It is for user-level information and can be nullptr.
90 * @param host_nb the number of hosts implied in the parallel task.
91 * @param host_list an array of @p host_nb msg_host_t.
92 * @param flops_amount an array of @p host_nb doubles.
93 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
94 * @param bytes_amount an array of @p host_nb* @p host_nb doubles.
95 * @param data a pointer to any data may want to attach to the new object.
96 * It is for user-level information and can be nullptr.
97 * It can be retrieved with the function @ref MSG_task_get_data().
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 // Task's flops amount is set to an arbitrary value > 0.0 to be able to distinguish, in
103 // MSG_task_get_remaining_work_ratio(), a finished task and a task that has not started yet.
104 msg_task_t task = MSG_task_create(name, 1.0, 0, data);
105 simdata_task_t simdata = task->simdata;
107 /* Simulator Data specific to parallel tasks */
108 simdata->host_nb = host_nb;
109 simdata->host_list = new sg_host_t[host_nb];
110 std::copy_n(host_list, host_nb, simdata->host_list);
111 if (flops_amount != nullptr) {
112 simdata->flops_parallel_amount = new double[host_nb];
113 std::copy_n(flops_amount, host_nb, simdata->flops_parallel_amount);
115 if (bytes_amount != nullptr) {
116 simdata->bytes_parallel_amount = new double[host_nb * host_nb];
117 std::copy_n(bytes_amount, host_nb * host_nb, simdata->bytes_parallel_amount);
123 /** @brief Return the user data of the given task */
124 void *MSG_task_get_data(msg_task_t task)
129 /** @brief Sets the user data of a given task */
130 void MSG_task_set_data(msg_task_t task, void *data)
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 /** @brief Returns the sender of the given task */
150 msg_process_t MSG_task_get_sender(msg_task_t task)
152 return task->simdata->sender;
155 /** @brief Returns the source (the sender's host) of the given task */
156 msg_host_t MSG_task_get_source(msg_task_t task)
158 return task->simdata->sender->get_host();
161 /** @brief Returns the name of the given task. */
162 const char *MSG_task_get_name(msg_task_t task)
164 return task->simdata->get_cname();
167 /** @brief Sets the name of the given task. */
168 void MSG_task_set_name(msg_task_t task, const char *name)
170 task->simdata->set_name(name);
173 /** @brief Destroys the given task.
175 * You should free user data, if any, @b before calling this destructor.
177 * Only the process that owns the task can destroy it.
178 * The owner changes after a successful send.
179 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
181 * If the task failed to be sent, the sender remains the owner of the task.
183 msg_error_t MSG_task_destroy(msg_task_t task)
185 if (task->simdata->is_used) {
186 /* the task is being sent or executed: cancel it first */
187 MSG_task_cancel(task);
190 /* free main structures */
191 delete task->simdata;
197 /** @brief Cancel the given task
199 * If it was currently executed or transfered, the working process is stopped.
201 msg_error_t MSG_task_cancel(msg_task_t task)
203 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
205 simdata_task_t simdata = task->simdata;
206 if (simdata->compute) {
207 simgrid::simix::simcall([simdata] { simdata->compute->cancel(); });
208 } else if (simdata->comm) {
209 simdata->comm->cancel();
211 simdata->set_not_used();
215 /** @brief Returns a value in ]0,1[ that represent the task remaining work
216 * to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
218 * It works for either parallel or sequential tasks.
220 double MSG_task_get_remaining_work_ratio(msg_task_t task) {
222 xbt_assert((task != nullptr), "Cannot get information from a nullptr task");
223 if (task->simdata->compute) {
225 return task->simdata->compute->get_remaining_ratio();
227 // Task not started (flops_amount is > 0.0) or finished (flops_amount is set to 0.0)
228 return task->simdata->flops_amount > 0.0 ? 1.0 : 0.0;
232 /** @brief Returns the amount of flops that remain to be computed
234 * The returned value is initially the cost that you defined for the task, then it decreases until it reaches 0
236 * It works for sequential tasks, but the remaining amount of work is not a scalar value for parallel tasks.
237 * So you will get an exception if you call this function on parallel tasks. Just don't do it.
239 double MSG_task_get_flops_amount(msg_task_t task) {
240 if (task->simdata->compute != nullptr) {
241 return task->simdata->compute->get_remaining();
243 // Not started or already done.
244 // - Before starting, flops_amount is initially the task cost
245 // - After execution, flops_amount is set to 0 (until someone uses MSG_task_set_flops_amount, if any)
246 return task->simdata->flops_amount;
250 /** @brief set the computation amount needed to process the given task.
252 * @warning If the computation is ongoing (already started and not finished),
253 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
254 * zero, overriding any value set during the execution.
256 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
258 task->simdata->flops_amount = flops_amount;
261 /** @brief set the amount data attached with the given task.
263 * @warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
265 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
267 task->simdata->bytes_amount = data_size;
270 /** @brief Returns the total amount received by the given task
272 * If the communication does not exist it will return 0.
273 * So, if the communication has FINISHED or FAILED it returns zero.
275 double MSG_task_get_remaining_communication(msg_task_t task)
277 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm.get());
278 return task->simdata->comm->get_remaining();
281 /** @brief Returns the size of the data attached to the given task. */
282 double MSG_task_get_bytes_amount(msg_task_t task)
284 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
285 return task->simdata->bytes_amount;
288 /** @brief Changes the priority of a computation task.
290 * This priority doesn't affect the transfer rate. A priority of 2
291 * will make a task receive two times more cpu power than regular tasks.
293 void MSG_task_set_priority(msg_task_t task, double priority)
295 task->simdata->priority = 1 / priority;
296 xbt_assert(std::isfinite(task->simdata->priority), "priority is not finite!");
299 /** @brief Changes the maximum CPU utilization of a computation task (in flops/s).
301 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
303 void MSG_task_set_bound(msg_task_t task, double bound)
305 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
306 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
307 task->simdata->bound = bound;