2 /* Copyright (c) 2007-2015. The SimGrid Team.
3 * All rights reserved. */
5 /* This program is free software; you can redistribute it and/or modify it
6 * under the terms of the license (GNU LGPL) which comes with this package. */
8 #include "smx_private.h"
9 #include "src/surf/cpu_interface.hpp"
10 #include "src/surf/surf_interface.hpp"
14 #include "src/kernel/activity/SynchroRaw.hpp"
16 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix, "SIMIX Synchronization (mutex, semaphores and conditions)");
18 static smx_activity_t SIMIX_synchro_wait(sg_host_t smx_host, double timeout);
19 static void _SIMIX_cond_wait(smx_cond_t cond, smx_mutex_t mutex, double timeout,
20 smx_actor_t issuer, smx_simcall_t simcall);
21 static void _SIMIX_sem_wait(smx_sem_t sem, double timeout, smx_actor_t issuer,
22 smx_simcall_t simcall);
24 /***************************** Raw synchronization *********************************/
26 static smx_activity_t SIMIX_synchro_wait(sg_host_t smx_host, double timeout)
28 XBT_IN("(%p, %f)",smx_host,timeout);
30 simgrid::kernel::activity::RawImplPtr sync =
31 simgrid::kernel::activity::RawImplPtr(new simgrid::kernel::activity::RawImpl());
32 sync->sleep = smx_host->pimpl_cpu->sleep(timeout);
33 sync->sleep->setData(&*sync);
38 void SIMIX_synchro_stop_waiting(smx_actor_t process, smx_simcall_t simcall)
40 XBT_IN("(%p, %p)",process,simcall);
41 switch (simcall->call) {
43 case SIMCALL_MUTEX_LOCK:
44 xbt_swag_remove(process, simcall_mutex_lock__get__mutex(simcall)->sleeping);
47 case SIMCALL_COND_WAIT:
48 xbt_swag_remove(process, simcall_cond_wait__get__cond(simcall)->sleeping);
51 case SIMCALL_COND_WAIT_TIMEOUT:
52 xbt_swag_remove(process, simcall_cond_wait_timeout__get__cond(simcall)->sleeping);
55 case SIMCALL_SEM_ACQUIRE:
56 xbt_swag_remove(process, simcall_sem_acquire__get__sem(simcall)->sleeping);
59 case SIMCALL_SEM_ACQUIRE_TIMEOUT:
60 xbt_swag_remove(process, simcall_sem_acquire_timeout__get__sem(simcall)->sleeping);
69 void SIMIX_synchro_finish(smx_activity_t synchro)
71 XBT_IN("(%p)", synchro.get());
72 smx_simcall_t simcall = synchro->simcalls.front();
73 synchro->simcalls.pop_front();
75 switch (synchro->state) {
77 case SIMIX_SRC_TIMEOUT:
78 SMX_EXCEPTION(simcall->issuer, timeout_error, 0, "Synchro's wait timeout");
82 simcall->issuer->context->iwannadie = 1;
83 // SMX_EXCEPTION(simcall->issuer, host_error, 0, "Host failed");
91 SIMIX_synchro_stop_waiting(simcall->issuer, simcall);
92 simcall->issuer->waiting_synchro = nullptr;
93 SIMIX_simcall_answer(simcall);
96 /*********************************** Mutex ************************************/
101 MutexImpl::MutexImpl() : mutex_(this)
103 XBT_IN("(%p)", this);
104 // Useful to initialize sleeping swag:
105 simgrid::simix::ActorImpl p;
106 this->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
110 MutexImpl::~MutexImpl()
112 XBT_IN("(%p)", this);
113 xbt_swag_free(this->sleeping);
117 void MutexImpl::lock(smx_actor_t issuer)
119 XBT_IN("(%p; %p)", this, issuer);
120 /* FIXME: check where to validate the arguments */
121 smx_activity_t synchro = nullptr;
124 /* FIXME: check if the host is active ? */
125 /* Somebody using the mutex, use a synchronization to get host failures */
126 synchro = SIMIX_synchro_wait(issuer->host, -1);
127 synchro->simcalls.push_back(&issuer->simcall);
128 issuer->waiting_synchro = synchro;
129 xbt_swag_insert(issuer, this->sleeping);
133 this->owner = issuer;
134 SIMIX_simcall_answer(&issuer->simcall);
139 /** Tries to lock the mutex for a process
141 * \param issuer the process that tries to acquire the mutex
142 * \return whether we managed to lock the mutex
144 bool MutexImpl::try_lock(smx_actor_t issuer)
146 XBT_IN("(%p, %p)", this, issuer);
153 this->owner = issuer;
158 /** Unlock a mutex for a process
160 * Unlocks the mutex and gives it to a process waiting for it.
161 * If the unlocker is not the owner of the mutex nothing happens.
162 * If there are no process waiting, it sets the mutex as free.
164 void MutexImpl::unlock(smx_actor_t issuer)
166 XBT_IN("(%p, %p)", this, issuer);
167 if (not this->locked)
168 THROWF(mismatch_error, 0, "Cannot release that mutex: it was not locked.");
170 /* If the mutex is not owned by the issuer, that's not good */
171 if (issuer != this->owner)
172 THROWF(mismatch_error, 0, "Cannot release that mutex: it was locked by %s (pid:%ld), not by you.",
173 this->owner->cname(), this->owner->pid);
175 if (xbt_swag_size(this->sleeping) > 0) {
176 /*process to wake up */
177 smx_actor_t p = (smx_actor_t) xbt_swag_extract(this->sleeping);
178 p->waiting_synchro = nullptr;
180 SIMIX_simcall_answer(&p->simcall);
182 /* nobody to wake up */
183 this->locked = false;
184 this->owner = nullptr;
192 /** Increase the refcount for this mutex */
193 smx_mutex_t SIMIX_mutex_ref(smx_mutex_t mutex)
195 if (mutex != nullptr)
196 intrusive_ptr_add_ref(mutex);
200 /** Decrease the refcount for this mutex */
201 void SIMIX_mutex_unref(smx_mutex_t mutex)
203 if (mutex != nullptr)
204 intrusive_ptr_release(mutex);
209 void simcall_HANDLER_mutex_lock(smx_simcall_t simcall, smx_mutex_t mutex)
211 mutex->lock(simcall->issuer);
214 int simcall_HANDLER_mutex_trylock(smx_simcall_t simcall, smx_mutex_t mutex)
216 return mutex->try_lock(simcall->issuer);
219 void simcall_HANDLER_mutex_unlock(smx_simcall_t simcall, smx_mutex_t mutex)
221 mutex->unlock(simcall->issuer);
224 /********************************* Condition **********************************/
227 * \brief Initialize a condition.
229 * Allocates and creates the data for the condition.
230 * It have to be called before the use of the condition.
231 * \return A condition
233 smx_cond_t SIMIX_cond_init()
236 simgrid::simix::ActorImpl p;
237 smx_cond_t cond = new s_smx_cond();
238 cond->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
245 * \brief Handle a condition waiting simcall without timeouts
246 * \param simcall the simcall
248 void simcall_HANDLER_cond_wait(smx_simcall_t simcall, smx_cond_t cond, smx_mutex_t mutex)
250 XBT_IN("(%p)",simcall);
251 smx_actor_t issuer = simcall->issuer;
253 _SIMIX_cond_wait(cond, mutex, -1, issuer, simcall);
258 * \brief Handle a condition waiting simcall with timeouts
259 * \param simcall the simcall
261 void simcall_HANDLER_cond_wait_timeout(smx_simcall_t simcall, smx_cond_t cond,
262 smx_mutex_t mutex, double timeout)
264 XBT_IN("(%p)",simcall);
265 smx_actor_t issuer = simcall->issuer;
267 _SIMIX_cond_wait(cond, mutex, timeout, issuer, simcall);
272 static void _SIMIX_cond_wait(smx_cond_t cond, smx_mutex_t mutex, double timeout,
273 smx_actor_t issuer, smx_simcall_t simcall)
275 XBT_IN("(%p, %p, %f, %p,%p)",cond,mutex,timeout,issuer,simcall);
276 smx_activity_t synchro = nullptr;
278 XBT_DEBUG("Wait condition %p", cond);
280 /* If there is a mutex unlock it */
281 /* FIXME: what happens if the issuer is not the owner of the mutex? */
282 if (mutex != nullptr) {
284 mutex->unlock(issuer);
287 synchro = SIMIX_synchro_wait(issuer->host, timeout);
288 synchro->simcalls.push_front(simcall);
289 issuer->waiting_synchro = synchro;
290 xbt_swag_insert(simcall->issuer, cond->sleeping);
295 * \brief Signalizes a condition.
297 * Signalizes a condition and wakes up a sleeping process.
298 * If there are no process sleeping, no action is done.
299 * \param cond A condition
301 void SIMIX_cond_signal(smx_cond_t cond)
304 smx_actor_t proc = nullptr;
305 smx_mutex_t mutex = nullptr;
306 smx_simcall_t simcall = nullptr;
308 XBT_DEBUG("Signal condition %p", cond);
310 /* If there are processes waiting for the condition choose one and try
311 to make it acquire the mutex */
312 if ((proc = (smx_actor_t) xbt_swag_extract(cond->sleeping))) {
314 /* Destroy waiter's synchronization */
315 proc->waiting_synchro = nullptr;
317 /* Now transform the cond wait simcall into a mutex lock one */
318 simcall = &proc->simcall;
319 if(simcall->call == SIMCALL_COND_WAIT)
320 mutex = simcall_cond_wait__get__mutex(simcall);
322 mutex = simcall_cond_wait_timeout__get__mutex(simcall);
323 simcall->call = SIMCALL_MUTEX_LOCK;
325 simcall_HANDLER_mutex_lock(simcall, mutex);
331 * \brief Broadcasts a condition.
333 * Signal ALL processes waiting on a condition.
334 * If there are no process waiting, no action is done.
335 * \param cond A condition
337 void SIMIX_cond_broadcast(smx_cond_t cond)
340 XBT_DEBUG("Broadcast condition %p", cond);
342 /* Signal the condition until nobody is waiting on it */
343 while (xbt_swag_size(cond->sleeping)) {
344 SIMIX_cond_signal(cond);
349 smx_cond_t SIMIX_cond_ref(smx_cond_t cond)
352 intrusive_ptr_add_ref(cond);
356 void SIMIX_cond_unref(smx_cond_t cond)
359 XBT_DEBUG("Destroy condition %p", cond);
360 if (cond != nullptr) {
361 intrusive_ptr_release(cond);
367 void intrusive_ptr_add_ref(s_smx_cond_t *cond)
369 auto previous = (cond->refcount_)++;
370 xbt_assert(previous != 0);
373 void intrusive_ptr_release(s_smx_cond_t *cond)
375 auto count = --(cond->refcount_);
377 xbt_assert(xbt_swag_size(cond->sleeping) == 0,
378 "Cannot destroy conditional since someone is still using it");
379 xbt_swag_free(cond->sleeping);
384 /******************************** Semaphores **********************************/
385 /** @brief Initialize a semaphore */
386 smx_sem_t SIMIX_sem_init(unsigned int value)
388 XBT_IN("(%u)",value);
389 simgrid::simix::ActorImpl p;
391 smx_sem_t sem = xbt_new0(s_smx_sem_t, 1);
392 sem->sleeping = xbt_swag_new(xbt_swag_offset(p, synchro_hookup));
398 /** @brief Destroys a semaphore */
399 void SIMIX_sem_destroy(smx_sem_t sem)
402 XBT_DEBUG("Destroy semaphore %p", sem);
403 if (sem != nullptr) {
404 xbt_assert(xbt_swag_size(sem->sleeping) == 0,
405 "Cannot destroy semaphore since someone is still using it");
406 xbt_swag_free(sem->sleeping);
412 /** @brief release the semaphore
414 * Unlock a process waiting on the semaphore.
415 * If no one was blocked, the semaphore capacity is increased by 1.
417 void SIMIX_sem_release(smx_sem_t sem)
422 XBT_DEBUG("Sem release semaphore %p", sem);
423 if ((proc = (smx_actor_t) xbt_swag_extract(sem->sleeping))) {
424 proc->waiting_synchro = nullptr;
425 SIMIX_simcall_answer(&proc->simcall);
432 /** @brief Returns true if acquiring this semaphore would block */
433 int SIMIX_sem_would_block(smx_sem_t sem)
437 return (sem->value <= 0);
440 /** @brief Returns the current capacity of the semaphore */
441 int SIMIX_sem_get_capacity(smx_sem_t sem)
448 static void _SIMIX_sem_wait(smx_sem_t sem, double timeout, smx_actor_t issuer,
449 smx_simcall_t simcall)
451 XBT_IN("(%p, %f, %p, %p)",sem,timeout,issuer,simcall);
452 smx_activity_t synchro = nullptr;
454 XBT_DEBUG("Wait semaphore %p (timeout:%f)", sem, timeout);
455 if (sem->value <= 0) {
456 synchro = SIMIX_synchro_wait(issuer->host, timeout);
457 synchro->simcalls.push_front(simcall);
458 issuer->waiting_synchro = synchro;
459 xbt_swag_insert(issuer, sem->sleeping);
462 SIMIX_simcall_answer(simcall);
468 * \brief Handles a sem acquire simcall without timeout.
469 * \param simcall the simcall
471 void simcall_HANDLER_sem_acquire(smx_simcall_t simcall, smx_sem_t sem)
473 XBT_IN("(%p)",simcall);
474 _SIMIX_sem_wait(sem, -1, simcall->issuer, simcall);
479 * \brief Handles a sem acquire simcall with timeout.
480 * \param simcall the simcall
482 void simcall_HANDLER_sem_acquire_timeout(smx_simcall_t simcall, smx_sem_t sem, double timeout)
484 XBT_IN("(%p)",simcall);
485 _SIMIX_sem_wait(sem, timeout, simcall->issuer, simcall);