src/simix/smx_synchro.cpp

   1 /* Copyright (c) 2007-2018. The SimGrid Team. All rights reserved.          */
   2
   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. */
   5
   6 #include "smx_private.hpp"
   7 #include "src/kernel/activity/ConditionVariableImpl.hpp"
   8 #include "src/kernel/activity/MutexImpl.hpp"
   9 #include "src/kernel/activity/SynchroRaw.hpp"
  10 #include "src/simix/smx_synchro_private.hpp"
  11 #include "src/surf/cpu_interface.hpp"
  12 #include <xbt/ex.hpp>
  13
  14 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_synchro, simix, "SIMIX Synchronization (mutex, semaphores and conditions)");
  15
  16 static void _SIMIX_cond_wait(smx_cond_t cond, smx_mutex_t mutex, double timeout,
  17                              smx_actor_t issuer, smx_simcall_t simcall);
  18 static void _SIMIX_sem_wait(smx_sem_t sem, double timeout, smx_actor_t issuer,
  19                             smx_simcall_t simcall);
  20
  21 /***************************** Raw synchronization *********************************/
  22
  23 smx_activity_t SIMIX_synchro_wait(sg_host_t smx_host, double timeout)
  24 {
  25   XBT_IN("(%p, %f)",smx_host,timeout);
  26
  27   simgrid::kernel::activity::RawImplPtr sync =
  28       simgrid::kernel::activity::RawImplPtr(new simgrid::kernel::activity::RawImpl());
  29   sync->sleep                          = smx_host->pimpl_cpu->sleep(timeout);
  30   sync->sleep->set_data(sync.get());
  31   XBT_OUT();
  32   return sync;
  33 }
  34
  35 void SIMIX_synchro_stop_waiting(smx_actor_t process, smx_simcall_t simcall)
  36 {
  37   XBT_IN("(%p, %p)",process,simcall);
  38   switch (simcall->call) {
  39
  40     case SIMCALL_MUTEX_LOCK:
  41       simgrid::xbt::intrusive_erase(simcall_mutex_lock__get__mutex(simcall)->sleeping, *process);
  42       break;
  43
  44     case SIMCALL_COND_WAIT:
  45       simgrid::xbt::intrusive_erase(simcall_cond_wait__get__cond(simcall)->sleeping, *process);
  46       break;
  47
  48     case SIMCALL_COND_WAIT_TIMEOUT:
  49       simgrid::xbt::intrusive_erase(simcall_cond_wait_timeout__get__cond(simcall)->sleeping, *process);
  50       break;
  51
  52     case SIMCALL_SEM_ACQUIRE:
  53       simgrid::xbt::intrusive_erase(simcall_sem_acquire__get__sem(simcall)->sleeping, *process);
  54       break;
  55
  56     case SIMCALL_SEM_ACQUIRE_TIMEOUT:
  57       simgrid::xbt::intrusive_erase(simcall_sem_acquire_timeout__get__sem(simcall)->sleeping, *process);
  58       break;
  59
  60     default:
  61       THROW_IMPOSSIBLE;
  62   }
  63   XBT_OUT();
  64 }
  65
  66 void SIMIX_synchro_finish(smx_activity_t synchro)
  67 {
  68   XBT_IN("(%p)", synchro.get());
  69   smx_simcall_t simcall = synchro->simcalls.front();
  70   synchro->simcalls.pop_front();
  71
  72   switch (synchro->state) {
  73
  74     case SIMIX_SRC_TIMEOUT:
  75       SMX_EXCEPTION(simcall->issuer, timeout_error, 0, "Synchro's wait timeout");
  76       break;
  77
  78     case SIMIX_FAILED:
  79         simcall->issuer->context->iwannadie = 1;
  80       break;
  81
  82     default:
  83       THROW_IMPOSSIBLE;
  84       break;
  85   }
  86
  87   SIMIX_synchro_stop_waiting(simcall->issuer, simcall);
  88   simcall->issuer->waiting_synchro = nullptr;
  89   SIMIX_simcall_answer(simcall);
  90   XBT_OUT();
  91 }
  92
  93 /******************************** Semaphores **********************************/
  94 /** @brief Initialize a semaphore */
  95 smx_sem_t SIMIX_sem_init(unsigned int value)
  96 {
  97   XBT_IN("(%u)",value);
  98   smx_sem_t sem = new s_smx_sem_t;
  99   sem->value = value;
 100   XBT_OUT();
 101   return sem;
 102 }
 103
 104 /** @brief Destroys a semaphore */
 105 void SIMIX_sem_destroy(smx_sem_t sem)
 106 {
 107   XBT_IN("(%p)",sem);
 108   XBT_DEBUG("Destroy semaphore %p", sem);
 109   if (sem != nullptr) {
 110     xbt_assert(sem->sleeping.empty(), "Cannot destroy semaphore since someone is still using it");
 111     delete sem;
 112   }
 113   XBT_OUT();
 114 }
 115
 116 /** @brief release the semaphore
 117  *
 118  * Unlock a process waiting on the semaphore.
 119  * If no one was blocked, the semaphore capacity is increased by 1.
 120  */
 121 void SIMIX_sem_release(smx_sem_t sem)
 122 {
 123   XBT_IN("(%p)",sem);
 124   XBT_DEBUG("Sem release semaphore %p", sem);
 125   if (not sem->sleeping.empty()) {
 126     auto& proc = sem->sleeping.front();
 127     sem->sleeping.pop_front();
 128     proc.waiting_synchro = nullptr;
 129     SIMIX_simcall_answer(&proc.simcall);
 130   } else {
 131     sem->value++;
 132   }
 133   XBT_OUT();
 134 }
 135
 136 /** @brief Returns true if acquiring this semaphore would block */
 137 int SIMIX_sem_would_block(smx_sem_t sem)
 138 {
 139   XBT_IN("(%p)",sem);
 140   XBT_OUT();
 141   return (sem->value <= 0);
 142 }
 143
 144 /** @brief Returns the current capacity of the semaphore */
 145 int SIMIX_sem_get_capacity(smx_sem_t sem)
 146 {
 147   XBT_IN("(%p)",sem);
 148   XBT_OUT();
 149   return sem->value;
 150 }
 151
 152 static void _SIMIX_sem_wait(smx_sem_t sem, double timeout, smx_actor_t issuer,
 153                             smx_simcall_t simcall)
 154 {
 155   XBT_IN("(%p, %f, %p, %p)",sem,timeout,issuer,simcall);
 156   smx_activity_t synchro = nullptr;
 157
 158   XBT_DEBUG("Wait semaphore %p (timeout:%f)", sem, timeout);
 159   if (sem->value <= 0) {
 160     synchro = SIMIX_synchro_wait(issuer->host, timeout);
 161     synchro->simcalls.push_front(simcall);
 162     issuer->waiting_synchro = synchro;
 163     sem->sleeping.push_back(*issuer);
 164   } else {
 165     sem->value--;
 166     SIMIX_simcall_answer(simcall);
 167   }
 168   XBT_OUT();
 169 }
 170
 171 /**
 172  * \brief Handles a sem acquire simcall without timeout.
 173  * \param simcall the simcall
 174  */
 175 void simcall_HANDLER_sem_acquire(smx_simcall_t simcall, smx_sem_t sem)
 176 {
 177   XBT_IN("(%p)",simcall);
 178   _SIMIX_sem_wait(sem, -1, simcall->issuer, simcall);
 179   XBT_OUT();
 180 }
 181
 182 /**
 183  * \brief Handles a sem acquire simcall with timeout.
 184  * \param simcall the simcall
 185  */
 186 void simcall_HANDLER_sem_acquire_timeout(smx_simcall_t simcall, smx_sem_t sem, double timeout)
 187 {
 188   XBT_IN("(%p)",simcall);
 189   _SIMIX_sem_wait(sem, timeout, simcall->issuer, simcall);
 190   XBT_OUT();
 191 }