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 /********************************* Task **************************************/
23 /** \ingroup m_task_management
24 * \brief Creates a new #msg_task_t.
26 * A constructor for #msg_task_t taking four arguments and returning the corresponding object.
27 * \param name a name for the object. It is for user-level information and can be NULL.
28 * \param flop_amount a value of the processing amount (in flop) needed to process this new task.
29 * If 0, then it cannot be executed with MSG_task_execute(). This value has to be >=0.
30 * \param message_size a value of the amount of data (in bytes) needed to transfer this new task. If 0, then it cannot
31 * be transfered with MSG_task_send() and MSG_task_recv(). This value has to be >=0.
32 * \param data a pointer to any data may want to attach to the new object. It is for user-level information and can
33 * be NULL. It can be retrieved with the function \ref MSG_task_get_data.
35 * \return The new corresponding object.
37 msg_task_t MSG_task_create(const char *name, double flop_amount, double message_size, void *data)
39 msg_task_t task = xbt_new(s_msg_task_t, 1);
40 simdata_task_t simdata = xbt_new(s_simdata_task_t, 1);
41 task->simdata = simdata;
44 task->name = xbt_strdup(name);
48 simdata->compute = NULL;
50 simdata->bytes_amount = message_size;
51 simdata->flops_amount = flop_amount;
52 simdata->sender = NULL;
53 simdata->receiver = NULL;
54 simdata->source = NULL;
55 simdata->priority = 1.0;
57 simdata->affinity_mask_db = xbt_dict_new_homogeneous(NULL);
62 simdata->host_list = NULL;
63 simdata->flops_parallel_amount = NULL;
64 simdata->bytes_parallel_amount = NULL;
65 TRACE_msg_task_create(task);
70 /** \ingroup m_task_management
71 * \brief Creates a new #msg_task_t (a parallel one....).
73 * A constructor for #msg_task_t taking six arguments and returning the corresponding object.
74 * \param name a name for the object. It is for user-level information and can be NULL.
75 * \param host_nb the number of hosts implied in the parallel task.
76 * \param host_list an array of \p host_nb msg_host_t.
77 * \param flops_amount an array of \p host_nb doubles.
78 * flops_amount[i] is the total number of operations that have to be performed on host_list[i].
79 * \param bytes_amount an array of \p host_nb* \p host_nb doubles.
80 * \param data a pointer to any data may want to attach to the new object.
81 * It is for user-level information and can be NULL.
82 * It can be retrieved with the function \ref MSG_task_get_data.
84 * \return The new corresponding object.
86 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
87 double *flops_amount, double *bytes_amount, void *data)
89 msg_task_t task = MSG_task_create(name, 0, 0, data);
90 simdata_task_t simdata = task->simdata;
93 /* Simulator Data specific to parallel tasks */
94 simdata->host_nb = host_nb;
95 simdata->host_list = xbt_new0(sg_host_t, host_nb);
96 simdata->flops_parallel_amount = flops_amount;
97 simdata->bytes_parallel_amount = bytes_amount;
99 for (i = 0; i < host_nb; i++)
100 simdata->host_list[i] = host_list[i];
105 /** \ingroup m_task_management
106 * \brief Return the user data of a #msg_task_t.
108 * This function checks whether \a task is a valid pointer and return the user data associated to \a task if possible.
110 void *MSG_task_get_data(msg_task_t task)
112 xbt_assert((task != NULL), "Invalid parameter");
116 /** \ingroup m_task_management
117 * \brief Sets the user data of a #msg_task_t.
119 * This function allows to associate a new pointer to the user data associated of \a task.
121 void MSG_task_set_data(msg_task_t task, void *data)
123 xbt_assert((task != NULL), "Invalid parameter");
127 /** \ingroup m_task_management
128 * \brief Sets a function to be called when a task has just been copied.
129 * \param callback a callback function
131 void MSG_task_set_copy_callback(void (*callback) (msg_task_t task, msg_process_t sender, msg_process_t receiver)) {
133 msg_global->task_copy_callback = callback;
136 SIMIX_comm_set_copy_data_callback(MSG_comm_copy_data_from_SIMIX);
138 SIMIX_comm_set_copy_data_callback(SIMIX_comm_copy_pointer_callback);
142 /** \ingroup m_task_management
143 * \brief Return the sender of a #msg_task_t.
145 * This functions returns the #msg_process_t which sent this task
147 msg_process_t MSG_task_get_sender(msg_task_t task)
149 xbt_assert(task, "Invalid parameters");
150 return ((simdata_task_t) task->simdata)->sender;
153 /** \ingroup m_task_management
154 * \brief Return the source of a #msg_task_t.
156 * This functions returns the #msg_host_t from which this task was sent
158 msg_host_t MSG_task_get_source(msg_task_t task)
160 xbt_assert(task, "Invalid parameters");
161 return ((simdata_task_t) task->simdata)->source;
164 /** \ingroup m_task_management
165 * \brief Return the name of a #msg_task_t.
167 * This functions returns the name of a #msg_task_t as specified on creation
169 const char *MSG_task_get_name(msg_task_t task)
171 xbt_assert(task, "Invalid parameters");
175 /** \ingroup m_task_management
176 * \brief Sets the name of a #msg_task_t.
178 * This functions allows to associate a name to a task
180 void MSG_task_set_name(msg_task_t task, const char *name)
182 xbt_assert(task, "Invalid parameters");
183 task->name = xbt_strdup(name);
186 /** \ingroup m_task_management
187 * \brief Destroy a #msg_task_t.
189 * Destructor for #msg_task_t. Note that you should free user data, if any, \b before calling this function.
191 * Only the process that owns the task can destroy it.
192 * The owner changes after a successful send.
193 * If a task is successfully sent, the receiver becomes the owner and is supposed to destroy it. The sender should not
195 * If the task failed to be sent, the sender remains the owner of the task.
197 msg_error_t MSG_task_destroy(msg_task_t task)
199 xbt_assert((task != NULL), "Invalid parameter");
201 if (task->simdata->isused) {
202 /* the task is being sent or executed: cancel it first */
203 MSG_task_cancel(task);
205 TRACE_msg_task_destroy(task);
207 xbt_free(task->name);
209 if (task->simdata->compute)
210 task->simdata->compute->unref();
212 /* parallel tasks only */
213 xbt_free(task->simdata->host_list);
215 xbt_dict_free(&task->simdata->affinity_mask_db);
217 /* free main structures */
218 xbt_free(task->simdata);
224 /** \ingroup m_task_usage
225 * \brief Cancel a #msg_task_t.
226 * \param task the task to cancel. If it was executed or transfered, it stops the process that were working on it.
228 msg_error_t MSG_task_cancel(msg_task_t task)
230 xbt_assert((task != NULL), "Cannot cancel a NULL task");
232 if (task->simdata->compute) {
233 simcall_execution_cancel(task->simdata->compute);
235 else if (task->simdata->comm) {
236 simdata_task_t simdata = task->simdata;
237 simcall_comm_cancel(simdata->comm);
238 if (msg_global->debug_multiple_use && simdata->isused!=0)
239 xbt_ex_free(*(xbt_ex_t*)simdata->isused);
245 /** \ingroup m_task_management
246 * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
248 * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
249 * #MSG_task_set_flops_amount before restarting the task.
251 double MSG_task_get_flops_amount(msg_task_t task) {
252 if (task->simdata->compute) {
253 return task->simdata->compute->remains();
255 return task->simdata->flops_amount;
259 /** \ingroup m_task_management
260 * \brief set the computation amount needed to process a task #msg_task_t.
262 * \warning If the computation is ongoing (already started and not finished),
263 * it is not modified by this call. Moreover, after its completion, the ongoing execution with set the flops_amount to
264 * zero, overriding any value set during the execution.
266 void MSG_task_set_flops_amount(msg_task_t task, double flops_amount)
268 task->simdata->flops_amount = flops_amount;
271 /** \ingroup m_task_management
272 * \brief set the amount data attached with a task #msg_task_t.
274 * \warning If the transfer is ongoing (already started and not finished), it is not modified by this call.
276 void MSG_task_set_bytes_amount(msg_task_t task, double data_size)
278 task->simdata->bytes_amount = data_size;
281 /** \ingroup m_task_management
282 * \brief Returns the total amount received by a task #msg_task_t.
283 * If the communication does not exist it will return 0.
284 * So, if the communication has FINISHED or FAILED it returns zero.
286 double MSG_task_get_remaining_communication(msg_task_t task)
288 XBT_DEBUG("calling simcall_communication_get_remains(%p)", task->simdata->comm);
289 return task->simdata->comm->remains();
292 /** \ingroup m_task_management
293 * \brief Returns the size of the data attached to a task #msg_task_t.
295 double MSG_task_get_bytes_amount(msg_task_t task)
297 xbt_assert((task != NULL) && (task->simdata != NULL), "Invalid parameter");
298 return task->simdata->bytes_amount;
301 /** \ingroup m_task_management
302 * \brief Changes the priority of a computation task. This priority doesn't affect the transfer rate. A priority of 2
303 * will make a task receive two times more cpu power than the other ones.
305 void MSG_task_set_priority(msg_task_t task, double priority)
307 xbt_assert((task != NULL) && (task->simdata != NULL), "Invalid parameter");
308 task->simdata->priority = 1 / priority;
309 if (task->simdata->compute)
310 simcall_execution_set_priority(task->simdata->compute,
311 task->simdata->priority);
314 /** \ingroup m_task_management
315 * \brief Changes the maximum CPU utilization of a computation task.
318 * For VMs, there is a pitfall. Please see MSG_vm_set_bound().
320 void MSG_task_set_bound(msg_task_t task, double bound)
322 xbt_assert(task, "Invalid parameter");
323 xbt_assert(task->simdata, "Invalid parameter");
326 XBT_INFO("bound == 0 means no capping (i.e., unlimited).");
328 task->simdata->bound = bound;
329 if (task->simdata->compute)
330 simcall_execution_set_bound(task->simdata->compute, task->simdata->bound);
333 /** \ingroup m_task_management
334 * \brief Changes the CPU affinity of a computation task.
336 * When pinning the given task to the first CPU core of the given host, use 0x01 for the mask value. Each bit of the
337 * mask value corresponds to each CPU core. See taskset(1) on Linux.
339 * \param task a target task
340 * \param host the host having a multi-core CPU
341 * \param mask the bit mask of a new CPU affinity setting for the task
344 * 0. Define a host with multiple cores.
345 * \<host id="PM0" power="1E8" core="2"/\>
347 * 1. Pin a given task to the first CPU core of a host.
348 * MSG_task_set_affinity(task, pm0, 0x01);
350 * 2. Pin a given task to the third CPU core of a host. Turn on the third bit of the mask.
351 * MSG_task_set_affinity(task, pm0, 0x04); // 0x04 == 100B
353 * 3. Pin a given VM to the first CPU core of a host.
354 * MSG_vm_set_affinity(vm, pm0, 0x01);
356 * See examples/msg/cloud/multicore.c for more information.
359 * 1. The current code does not allow an affinity of a task to multiple cores.
360 * The mask value 0x03 (i.e., a given task will be executed on the first core or the second core) is not allowed.
361 * The mask value 0x01 or 0x02 works. See cpu_cas01.c for details.
363 * 2. It is recommended to first compare simulation results in both the Lazy and Full calculation modes
364 * (using --cfg=cpu/optim:Full or not). Fix cpu_cas01.c if you find wrong results in the Lazy mode.
366 void MSG_task_set_affinity(msg_task_t task, msg_host_t host, unsigned long mask)
368 xbt_assert(task, "Invalid parameter");
369 xbt_assert(task->simdata, "Invalid parameter");
373 /* We need remove_ext() not throwing exception. */
374 void *ret = xbt_dict_get_or_null_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(msg_host_t));
376 xbt_dict_remove_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(host));
378 xbt_dict_set_ext(task->simdata->affinity_mask_db, (char *) host, sizeof(host), (void *)(uintptr_t) mask, NULL);
380 /* We set affinity data of this task. If the task is being executed, we actually change the affinity setting of the
381 * task. Otherwise, this change will be applied when the task is executed. */
382 if (!task->simdata->compute) {
383 /* task is not yet executed */
384 XBT_INFO("set affinity(0x%04lx@%s) for %s (not active now)", mask, MSG_host_get_name(host),
385 MSG_task_get_name(task));
390 simgrid::simix::Exec *compute = task->simdata->compute;
391 msg_host_t host_now = compute->host; // simix_private.h is necessary
392 if (host_now != host) {
393 /* task is not yet executed on this host */
394 XBT_INFO("set affinity(0x%04lx@%s) for %s (not active now)", mask, MSG_host_get_name(host),
395 MSG_task_get_name(task));
399 /* task is being executed on this host. so change the affinity now */
401 /* check it works. remove me if it works. */
402 xbt_assert((unsigned long)(uintptr_t) xbt_dict_get_or_null_ext(task->simdata->affinity_mask_db,
403 (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);