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;
71 simdata->affinity_mask_db = xbt_dict_new_homogeneous(nullptr);
76 simdata->host_list = nullptr;
77 simdata->flops_parallel_amount = nullptr;
78 simdata->bytes_parallel_amount = nullptr;
79 TRACE_msg_task_create(task);
84 /** \ingroup m_task_management
85 * \brief Creates a new #msg_task_t (a parallel one....).
87 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
88 * \param name a name for the object. It is for user-level information and can be nullptr.
89 * \param host_nb the number of hosts implied in the parallel task.
90 * \param host_list an array of \p host_nb msg_host_t.
91 * \param flops_amount an array of \p host_nb doubles.
92 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
93 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
94 * \param data a pointer to any data may want to attach to the new object.
95 * It is for user-level information and can be nullptr.
96 * It can be retrieved with the function \ref MSG_task_get_data.
98 * \return The new corresponding object.
100 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
101 double *flops_amount, double *bytes_amount, void *data)
103 msg_task_t task = MSG_task_create(name, 0, 0, data);
104 simdata_task_t simdata = task->simdata;
107 /* Simulator Data specific to parallel tasks */
108 simdata->host_nb = host_nb;
109 simdata->host_list = xbt_new0(sg_host_t, host_nb);
110 simdata->flops_parallel_amount = flops_amount;
111 simdata->bytes_parallel_amount = bytes_amount;
113 for (i = 0; i < host_nb; i++)
114 simdata->host_list[i] = host_list[i];
119 /** \ingroup m_task_management
120 * \brief Return the user data of a #msg_task_t.
122 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
124 void *MSG_task_get_data(msg_task_t task)
126 xbt_assert((task != nullptr), "Invalid parameter");
130 /** \ingroup m_task_management
131 * \brief Sets the user data of a #msg_task_t.
133 * This function allows to associate a new pointer to the user data associated of \a task.
135 void MSG_task_set_data(msg_task_t task, void *data)
137 xbt_assert((task != nullptr), "Invalid parameter");
141 /** \ingroup m_task_management
142 * \brief Sets a function to be called when a task has just been copied.
143 * \param callback a callback function
145 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
147 msg_global->task_copy_callback = callback;
150 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
152 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
156 /** \ingroup m_task_management
157 * \brief Return the sender of a #msg_task_t.
159 * This functions returns the #msg_process_t which sent this task
161 msg_process_t MSG_task_get_sender(msg_task_t task)
163 xbt_assert(task, "Invalid parameters");
164 return (static_cast<simdata_task_t> (task->simdata)->sender);
167 /** \ingroup m_task_management
168 * \brief Return the source of a #msg_task_t.
170 * This functions returns the #msg_host_t from which this task was sent
172 msg_host_t MSG_task_get_source(msg_task_t task)
174 xbt_assert(task, "Invalid parameters");
175 return (static_cast<simdata_task_t> (task->simdata)->source);
178 /** \ingroup m_task_management
179 * \brief Return the name of a #msg_task_t.
181 * This functions returns the name of a #msg_task_t as specified on creation
183 const char *MSG_task_get_name(msg_task_t task)
185 xbt_assert(task, "Invalid parameters");
189 /** \ingroup m_task_management
190 * \brief Sets the name of a #msg_task_t.
192 * This functions allows to associate a name to a task
194 void MSG_task_set_name(msg_task_t task, const char *name)
196 xbt_assert(task, "Invalid parameters");
197 task->name = xbt_strdup(name);
200 /** \ingroup m_task_management
201 * \brief Destroy a #msg_task_t.
203 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
205 * Only the process that owns the task can destroy it.
206 * The owner changes after a successful send.
207 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
209 * If the task failed to be sent, the sender remains the owner of the task.
211 msg_error_t MSG_task_destroy(msg_task_t task)
213 xbt_assert((task != nullptr), "Invalid parameter");
215 if (task->simdata->isused) {
216 /* the task is being sent or executed: cancel it first */
217 MSG_task_cancel(task);
219 TRACE_msg_task_destroy(task);
221 xbt_free(task->name);
223 /* free main structures */
224 delete task->simdata;
230 /** \ingroup m_task_usage
231 * \brief Cancel a #msg_task_t.
232 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
234 msg_error_t MSG_task_cancel(msg_task_t task)
236 xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
238 if (task->simdata->compute) {
239 simcall_execution_cancel(task->simdata->compute);
241 else if (task->simdata->comm) {
242 simdata_task_t simdata = task->simdata;
243 simcall_comm_cancel(simdata->comm);
244 simdata->setNotUsed();
249 /** \ingroup m_task_management
250 * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
252 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
253 * #MSG_task_set_flops_amount before restarting the task.
255 double MSG_task_get_flops_amount(msg_task_t task) {
256 if (task->simdata->compute) {
257 return task->simdata->compute->remains();
259 return task->simdata->flops_amount;
263 /** \ingroup m_task_management
264 * \brief set the computation amount needed to process a task #msg_task_t.
266 * \warning If the computation is ongoing (already started and not finished),
267 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
268 * zero, overriding any value set during the execution.
270 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
272 task->simdata->flops_amount = flops_amount;
275 /** \ingroup m_task_management
276 * \brief set the amount data attached with a task #msg_task_t.
278 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
280 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
282 task->simdata->bytes_amount = data_size;
285 /** \ingroup m_task_management
286 * \brief Returns the total amount received by a task #msg_task_t.
287 * If the communication does not exist it will return 0.
288 * So, if the communication has FINISHED or FAILED it returns zero.
290 double MSG_task_get_remaining_communication(msg_task_t task)
292 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm);
293 return task->simdata->comm->remains();
296 /** \ingroup m_task_management
297 * \brief Returns the size of the data attached to a task #msg_task_t.
299 double MSG_task_get_bytes_amount(msg_task_t task)
301 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
302 return task->simdata->bytes_amount;
305 /** \ingroup m_task_management
306 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
307 * will make a task receive two times more cpu power than the other ones.
309 void MSG_task_set_priority(msg_task_t task, double priority)
311 xbt_assert((task != nullptr) && (task->simdata != nullptr), "Invalid parameter");
312 task->simdata->priority = 1 / priority;
313 if (task->simdata->compute)
314 simcall_execution_set_priority(task->simdata->compute,
315 task->simdata->priority);
318 /** \ingroup m_task_management
319 * \brief Changes the maximum CPU utilization of a computation task.
322 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
324 void MSG_task_set_bound(msg_task_t task, double bound)
326 xbt_assert(task, "Invalid parameter");
327 xbt_assert(task->simdata, "Invalid parameter");
329 if (bound < 1e-12) /* close enough to 0 without any floating precision surprise */
330 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
332 task->simdata->bound = bound;
333 if (task->simdata->compute)
334 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);
337 /** \ingroup m_task_management
338 * \brief Changes the CPU affinity of a computation task.
340 * When pinning the given task to the first CPU core of the given host, use 0x01 for the mask value. Each bit of the
341 * mask value corresponds to each CPU core. See taskset(1) on Linux.
343 * \param task a target task
344 * \param host the host having a multi-core CPU
345 * \param mask the bit mask of a new CPU affinity setting for the task
348 * 0. Define a host with multiple cores.
349 * \<host id="PM0" power="1E8" core="2"/\>
351 * 1. Pin a given task to the first CPU core of a host.
352 * MSG_task_set_affinity(task, pm0, 0x01);
354 * 2. Pin a given task to the third CPU core of a host. Turn on the third bit of the mask.
355 * MSG_task_set_affinity(task, pm0, 0x04); // 0x04 == 100B
357 * 3. Pin a given VM to the first CPU core of a host.
358 * MSG_vm_set_affinity(vm, pm0, 0x01);
360 * See examples/msg/cloud/multicore.c for more information.
363 * 1. The current code does not allow an affinity of a task to multiple cores.
364 * The mask value 0x03 (i.e., a given task will be executed on the first core or the second core) is not allowed.
365 * The mask value 0x01 or 0x02 works. See cpu_cas01.c for details.
367 * 2. It is recommended to first compare simulation results in both the Lazy and Full calculation modes
368 * (using --cfg=cpu/optim:Full or not). Fix cpu_cas01.c if you find wrong results in the Lazy mode.
370 void MSG_task_set_affinity(msg_task_t task, msg_host_t host, unsigned long mask)
372 xbt_assert(task, "Invalid parameter");
373 xbt_assert(task->simdata, "Invalid parameter");
377 /* We need remove_ext() not throwing exception. */
378 void *ret = xbt_dict_get_or_null_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(msg_host_t));
380 xbt_dict_remove_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(host));
382 xbt_dict_set_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(host), (void *)(uintptr_t) mask, nullptr);
384 /* We set affinity data of this task. If the task is being executed, we actually change the affinity setting of the
385 * task. Otherwise, this change will be applied when the task is executed. */
386 if (!task->simdata->compute) {
387 /* task is not yet executed */
388 XBT_INFO("set affinity(0x%04lx@%s) for %s (not active now)", mask, MSG_host_get_name(host),
389 MSG_task_get_name(task));
393 simgrid::kernel::activity::Exec *compute = task->simdata->compute;
394 msg_host_t host_now = compute->host; // simix_private.h is necessary
395 if (host_now != host) {
396 /* task is not yet executed on this host */
397 XBT_INFO("set affinity(0x%04lx@%s) for %s (not active now)", mask, MSG_host_get_name(host),
398 MSG_task_get_name(task));
402 /* task is being executed on this host. so change the affinity now */
403 /* check it works. remove me if it works. */
404 xbt_assert(static_cast<unsigned long>((uintptr_t) xbt_dict_get_or_null_ext(task->simdata->affinity_mask_db,
405 (char*)(host), sizeof(msg_host_t))) == mask);
406 XBT_INFO("set affinity(0x%04lx@%s) for %s", mask, MSG_host_get_name(host), MSG_task_get_name(task));
407 simcall_execution_set_affinity(task->simdata->compute, host, mask);