+
+/* We have two mailboxes. mbox is used to transfer migration data between
+ * source and destination PMs. mbox_ctl is used to detect the completion of a
+ * migration. The names of these mailboxes must not conflict with others. */
+static inline char *get_mig_mbox_src_dst(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm)
+{
+ char *vm_name = sg_host_name(vm);
+ char *src_pm_name = sg_host_name(src_pm);
+ char *dst_pm_name = sg_host_name(dst_pm);
+
+ return bprintf("__mbox_mig_src_dst:%s(%s-%s)", vm_name, src_pm_name, dst_pm_name);
+}
+
+static inline char *get_mig_mbox_ctl(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm)
+{
+ char *vm_name = sg_host_name(vm);
+ char *src_pm_name = sg_host_name(src_pm);
+ char *dst_pm_name = sg_host_name(dst_pm);
+
+ return bprintf("__mbox_mig_ctl:%s(%s-%s)", vm_name, src_pm_name, dst_pm_name);
+}
+
+static inline char *get_mig_process_tx_name(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm)
+{
+ char *vm_name = sg_host_name(vm);
+ char *src_pm_name = sg_host_name(src_pm);
+ char *dst_pm_name = sg_host_name(dst_pm);
+
+ return bprintf("__pr_mig_tx:%s(%s-%s)", vm_name, src_pm_name, dst_pm_name);
+}
+
+static inline char *get_mig_process_rx_name(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm)
+{
+ char *vm_name = sg_host_name(vm);
+ char *src_pm_name = sg_host_name(src_pm);
+ char *dst_pm_name = sg_host_name(dst_pm);
+
+ return bprintf("__pr_mig_rx:%s(%s-%s)", vm_name, src_pm_name, dst_pm_name);
+}
+
+static inline char *get_mig_task_name(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm, int stage)
+{
+ char *vm_name = sg_host_name(vm);
+ char *src_pm_name = sg_host_name(src_pm);
+ char *dst_pm_name = sg_host_name(dst_pm);
+
+ return bprintf("__task_mig_stage%d:%s(%s-%s)", stage, vm_name, src_pm_name, dst_pm_name);
+}
+
+
+struct migration_session {
+ msg_vm_t vm;
+ msg_host_t src_pm;
+ msg_host_t dst_pm;
+
+ /* The miration_rx process uses mbox_ctl to let the caller of do_migration()
+ * know the completion of the migration. */
+ char *mbox_ctl;
+ /* The migration_rx and migration_tx processes use mbox to transfer migration
+ * data. */
+ char *mbox;
+};
+
+
+static int migration_rx_fun(int argc, char *argv[])
+{
+ XBT_DEBUG("mig: rx_start");
+
+ // The structure has been created in the do_migration function and should only be freed in the same place ;)
+ struct migration_session *ms = MSG_process_get_data(MSG_process_self());
+
+ s_ws_params_t params;
+ simcall_host_get_params(ms->vm, ¶ms);
+
+ int need_exit = 0;
+
+ char *finalize_task_name = get_mig_task_name(ms->vm, ms->src_pm, ms->dst_pm, 3);
+
+ int ret = 0;
+ for (;;) {
+ msg_task_t task = NULL;
+ ret = MSG_task_recv(&task, ms->mbox);
+ {
+ if (ret != MSG_OK) {
+ // An error occured, clean the code and return
+ // The owner did not change, hence the task should be only destroyed on the other side
+ xbt_free(finalize_task_name);
+ return 0;
+ }
+ }
+
+ if (strcmp(task->name, finalize_task_name) == 0)
+ need_exit = 1;
+
+ MSG_task_destroy(task);
+
+ if (need_exit)
+ break;
+ }
+
+ // Here Stage 1, 2 and 3 have been performed.
+ // Hence complete the migration
+
+ // Copy the reference to the vm (if SRC crashes now, do_migration will free ms)
+ // This is clearly ugly but I (Adrien) need more time to do something cleaner (actually we should copy the whole ms structure at the begining and free it at the end of each function)
+ msg_vm_t vm = ms->vm;
+ msg_host_t src_pm = ms->src_pm;
+ msg_host_t dst_pm = ms-> dst_pm;
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+
+// TODO: we have an issue, if the DST node is turning off during the three next calls, then the VM is in an inconsistent state
+// I should check with Takahiro in order to make this portion of code atomic
+ /* deinstall the current affinity setting for the CPU */
+ simcall_vm_set_affinity(vm, src_pm, 0);
+
+ /* Update the vm location */
+ simcall_vm_migrate(vm, dst_pm);
+
+ /* Resume the VM */
+ simcall_vm_resume(vm);
+
+ /* install the affinity setting of the VM on the destination pm */
+ {
+
+ unsigned long affinity_mask = (unsigned long) xbt_dict_get_or_null_ext(priv->affinity_mask_db, (char *)dst_pm, sizeof(msg_host_t));
+ simcall_vm_set_affinity(vm, dst_pm, affinity_mask);
+ XBT_DEBUG("set affinity(0x%04lx@%s) for %s", affinity_mask, MSG_host_get_name(dst_pm), MSG_host_get_name(vm));
+ }
+
+ {
+
+ // Now the VM is running on the new host (the migration is completed) (even if the SRC crash)
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+ priv->is_migrating = 0;
+ XBT_DEBUG("VM(%s) moved from PM(%s) to PM(%s)", ms->vm->key, ms->src_pm->key, ms->dst_pm->key);
+ #ifdef HAVE_TRACING
+ TRACE_msg_vm_change_host(ms->vm, ms->src_pm, ms->dst_pm);
+ #endif
+
+ }
+ // Inform the SRC that the migration has been correctly performed
+ {
+ char *task_name = get_mig_task_name(ms->vm, ms->src_pm, ms->dst_pm, 4);
+ msg_task_t task = MSG_task_create(task_name, 0, 0, NULL);
+ msg_error_t ret = MSG_task_send(task, ms->mbox_ctl);
+ // xbt_assert(ret == MSG_OK);
+ if(ret == MSG_HOST_FAILURE){
+ // The DST has crashed, this is a problem has the VM since we are not sure whether SRC is considering that the VM has been correctly migrated on the DST node
+ // TODO What does it mean ? What should we do ?
+ MSG_task_destroy(task);
+ } else if(ret == MSG_TRANSFER_FAILURE){
+ // The SRC has crashed, this is not a problem has the VM has been correctly migrated on the DST node
+ MSG_task_destroy(task);
+ }
+
+ xbt_free(task_name);
+ }
+
+
+ xbt_free(finalize_task_name);
+
+ XBT_DEBUG("mig: rx_done");
+
+ return 0;
+}
+
+static void reset_dirty_pages(msg_vm_t vm)
+{
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+
+ char *key = NULL;
+ xbt_dict_cursor_t cursor = NULL;
+ dirty_page_t dp = NULL;
+ xbt_dict_foreach(priv->dp_objs, cursor, key, dp) {
+ double remaining = MSG_task_get_remaining_computation(dp->task);
+ dp->prev_clock = MSG_get_clock();
+ dp->prev_remaining = remaining;
+
+ // XBT_INFO("%s@%s remaining %f", key, sg_host_name(vm), remaining);
+ }
+}
+
+static void start_dirty_page_tracking(msg_vm_t vm)
+{
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+ priv->dp_enabled = 1;
+
+ reset_dirty_pages(vm);
+}
+
+static void stop_dirty_page_tracking(msg_vm_t vm)
+{
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+ priv->dp_enabled = 0;
+}
+
+#if 0
+/* It might be natural that we define dp_rate for each task. But, we will also
+ * have to care about how each task behavior affects the memory update behavior
+ * at the operating system level. It may not be easy to model it with a simple algorithm. */
+double calc_updated_pages(char *key, msg_vm_t vm, dirty_page_t dp, double remaining, double clock)
+{
+ double computed = dp->prev_remaining - remaining;
+ double duration = clock - dp->prev_clock;
+ double updated = dp->task->dp_rate * computed;
+
+ XBT_INFO("%s@%s: computated %f ops (remaining %f -> %f) in %f secs (%f -> %f)",
+ key, sg_host_name(vm), computed, dp->prev_remaining, remaining, duration, dp->prev_clock, clock);
+ XBT_INFO("%s@%s: updated %f bytes, %f Mbytes/s",
+ key, sg_host_name(vm), updated, updated / duration / 1000 / 1000);
+
+ return updated;
+}
+#endif
+
+static double get_computed(char *key, msg_vm_t vm, dirty_page_t dp, double remaining, double clock)
+{
+ double computed = dp->prev_remaining - remaining;
+ double duration = clock - dp->prev_clock;
+
+ XBT_DEBUG("%s@%s: computed %f ops (remaining %f -> %f) in %f secs (%f -> %f)",
+ key, sg_host_name(vm), computed, dp->prev_remaining, remaining, duration, dp->prev_clock, clock);
+
+ return computed;
+}
+
+static double lookup_computed_flop_counts(msg_vm_t vm, int stage_for_fancy_debug, int stage2_round_for_fancy_debug)
+{
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+ double total = 0;
+
+ char *key = NULL;
+ xbt_dict_cursor_t cursor = NULL;
+ dirty_page_t dp = NULL;
+ xbt_dict_foreach(priv->dp_objs, cursor, key, dp) {
+ double remaining = MSG_task_get_remaining_computation(dp->task);
+
+ double clock = MSG_get_clock();
+
+ // total += calc_updated_pages(key, vm, dp, remaining, clock);
+ total += get_computed(key, vm, dp, remaining, clock);
+
+ dp->prev_remaining = remaining;
+ dp->prev_clock = clock;
+ }
+
+ total += priv->dp_updated_by_deleted_tasks;
+
+ XBT_DEBUG("mig-stage%d.%d: computed %f flop_counts (including %f by deleted tasks)",
+ stage_for_fancy_debug,
+ stage2_round_for_fancy_debug,
+ total, priv->dp_updated_by_deleted_tasks);
+
+
+
+ priv->dp_updated_by_deleted_tasks = 0;
+
+
+ return total;
+}
+
+// TODO Is this code redundant with the information provided by
+// msg_process_t MSG_process_create(const char *name, xbt_main_func_t code, void *data, msg_host_t host)
+void MSG_host_add_task(msg_host_t host, msg_task_t task)
+{
+ msg_host_priv_t priv = msg_host_resource_priv(host);
+ double remaining = MSG_task_get_remaining_computation(task);
+ char *key = bprintf("%s-%p", task->name, task);
+
+ dirty_page_t dp = xbt_new0(s_dirty_page, 1);
+ dp->task = task;
+
+ /* It should be okay that we add a task onto a migrating VM. */
+ if (priv->dp_enabled) {
+ dp->prev_clock = MSG_get_clock();
+ dp->prev_remaining = remaining;
+ }
+
+ xbt_assert(xbt_dict_get_or_null(priv->dp_objs, key) == NULL);
+ xbt_dict_set(priv->dp_objs, key, dp, NULL);
+ XBT_DEBUG("add %s on %s (remaining %f, dp_enabled %d)", key, sg_host_name(host), remaining, priv->dp_enabled);
+
+ xbt_free(key);
+}
+
+void MSG_host_del_task(msg_host_t host, msg_task_t task)
+{
+ msg_host_priv_t priv = msg_host_resource_priv(host);
+
+ char *key = bprintf("%s-%p", task->name, task);
+
+ dirty_page_t dp = xbt_dict_get_or_null(priv->dp_objs, key);
+ xbt_assert(dp->task == task);
+
+ /* If we are in the middle of dirty page tracking, we record how much
+ * computation has been done until now, and keep the information for the
+ * lookup_() function that will called soon. */
+ if (priv->dp_enabled) {
+ double remaining = MSG_task_get_remaining_computation(task);
+ double clock = MSG_get_clock();
+ // double updated = calc_updated_pages(key, host, dp, remaining, clock);
+ double updated = get_computed(key, host, dp, remaining, clock);
+
+ priv->dp_updated_by_deleted_tasks += updated;
+ }
+
+ xbt_dict_remove(priv->dp_objs, key);
+ xbt_free(dp);
+
+ XBT_DEBUG("del %s on %s", key, sg_host_name(host));
+
+ xbt_free(key);
+}
+
+
+
+
+static sg_size_t send_migration_data(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm,
+ sg_size_t size, char *mbox, int stage, int stage2_round, double mig_speed, double timeout)
+{
+ sg_size_t sent = 0;
+ char *task_name = get_mig_task_name(vm, src_pm, dst_pm, stage);
+ msg_task_t task = MSG_task_create(task_name, 0, size, NULL);
+
+ /* TODO: clean up */
+
+ double clock_sta = MSG_get_clock();
+
+ msg_error_t ret;
+ if (mig_speed > 0)
+ ret = MSG_task_send_with_timeout_bounded(task, mbox, timeout, mig_speed);
+ else
+ ret = MSG_task_send(task, mbox);
+
+ xbt_free(task_name);
+
+ if (ret == MSG_OK) {
+ sent = size;
+ } else if (ret == MSG_TIMEOUT) {
+ sg_size_t remaining = MSG_task_get_remaining_communication(task);
+ sent = size - remaining;
+ XBT_INFO("timeout (%lf s) in sending_migration_data, remaining %llu bytes of %llu",
+ timeout, remaining, size);
+ }
+
+ /* FIXME: why try-and-catch is used here? */
+ if(ret == MSG_HOST_FAILURE){
+ //XBT_INFO("SRC host failed during migration of %s (stage %d)", sg_host_name(vm), stage);
+ MSG_task_destroy(task);
+ THROWF(host_error, 0, "SRC host failed during migration of %s (stage %d)", sg_host_name(vm), stage);
+ }else if(ret == MSG_TRANSFER_FAILURE){
+ //XBT_INFO("DST host failed during migration of %s (stage %d)", sg_host_name(vm), stage);
+ MSG_task_destroy(task);
+ THROWF(host_error, 0, "DST host failed during migration of %s (stage %d)", sg_host_name(vm), stage);
+ }
+
+ double clock_end = MSG_get_clock();
+ double duration = clock_end - clock_sta;
+ double actual_speed = size / duration;
+
+ if (stage == 2)
+ XBT_DEBUG("mig-stage%d.%d: sent %llu duration %f actual_speed %f (target %f)", stage, stage2_round, size, duration, actual_speed, mig_speed);
+ else
+ XBT_DEBUG("mig-stage%d: sent %llu duration %f actual_speed %f (target %f)", stage, size, duration, actual_speed, mig_speed);
+
+ return sent;
+}
+
+static sg_size_t get_updated_size(double computed, double dp_rate, double dp_cap)
+{
+ double updated_size = computed * dp_rate;
+ XBT_DEBUG("updated_size %f dp_rate %f", updated_size, dp_rate);
+ if (updated_size > dp_cap) {
+ // XBT_INFO("mig-stage2.%d: %f bytes updated, but cap it with the working set size %f", stage2_round, updated_size, dp_cap);
+ updated_size = dp_cap;
+ }
+
+ return (sg_size_t) updated_size;
+}
+
+static double send_stage1(struct migration_session *ms,
+ sg_size_t ramsize, double mig_speed, double dp_rate, double dp_cap)
+{
+
+ // const long chunksize = (sg_size_t)1024 * 1024 * 100;
+ const sg_size_t chunksize = (sg_size_t)1024 * 1024 * 100000;
+ sg_size_t remaining = ramsize;
+ double computed_total = 0;
+
+ while (remaining > 0) {
+ sg_size_t datasize = chunksize;
+ if (remaining < chunksize)
+ datasize = remaining;
+
+ remaining -= datasize;
+ send_migration_data(ms->vm, ms->src_pm, ms->dst_pm, datasize, ms->mbox, 1, 0, mig_speed, -1);
+ double computed = lookup_computed_flop_counts(ms->vm, 1, 0);
+ computed_total += computed;
+ }
+
+ return computed_total;
+}
+
+
+
+static double get_threshold_value(double bandwidth, double max_downtime)
+{
+ return max_downtime * bandwidth;
+}
+
+static int migration_tx_fun(int argc, char *argv[])
+{
+ XBT_DEBUG("mig: tx_start");
+
+ // Note that the ms structure has been allocated in do_migration and hence should be freed in the same function ;)
+ struct migration_session *ms = MSG_process_get_data(MSG_process_self());
+
+ s_ws_params_t params;
+ simcall_host_get_params(ms->vm, ¶ms);
+ const sg_size_t ramsize = params.ramsize;
+ const sg_size_t devsize = params.devsize;
+ const int skip_stage1 = params.skip_stage1;
+ int skip_stage2 = params.skip_stage2;
+ const double dp_rate = params.dp_rate;
+ const double dp_cap = params.dp_cap;
+ const double mig_speed = params.mig_speed;
+ double max_downtime = params.max_downtime;
+
+ /* hard code it temporally. Fix Me */
+#define MIGRATION_TIMEOUT_DO_NOT_HARDCODE_ME 10000000.0
+ double mig_timeout = MIGRATION_TIMEOUT_DO_NOT_HARDCODE_ME;
+
+ double remaining_size = ramsize + devsize;
+ double threshold = 0.0;
+
+ /* check parameters */
+ if (ramsize == 0)
+ XBT_WARN("migrate a VM, but ramsize is zero");
+
+ if (max_downtime == 0) {
+ XBT_WARN("use the default max_downtime value 30ms");
+ max_downtime = 0.03;
+ }
+
+ /* Stage1: send all memory pages to the destination. */
+ XBT_DEBUG("mig-stage1: remaining_size %f", remaining_size);
+ start_dirty_page_tracking(ms->vm);
+
+ double computed_during_stage1 = 0;
+ if (!skip_stage1) {
+ double clock_prev_send = MSG_get_clock();
+
+ TRY {
+ /* At stage 1, we do not need timeout. We have to send all the memory
+ * pages even though the duration of this tranfer exceeds the timeout
+ * value. */
+ sg_size_t sent = send_migration_data(ms->vm, ms->src_pm, ms->dst_pm, ramsize, ms->mbox, 1, 0, mig_speed, -1);
+ remaining_size -= sent;
+ computed_during_stage1 = lookup_computed_flop_counts(ms->vm, 1, 0);
+
+ if (sent < ramsize) {
+ XBT_INFO("mig-stage1: timeout, force moving to stage 3");
+ skip_stage2 = 1;
+ } else if (sent > ramsize)
+ XBT_CRITICAL("bug");
+
+ } CATCH_ANONYMOUS {
+ //hostfailure (if you want to know whether this is the SRC or the DST please check directly in send_migration_data code)
+ // Stop the dirty page tracking an return (there is no memory space to release)
+ stop_dirty_page_tracking(ms->vm);
+ return 0;
+ }
+
+ double clock_post_send = MSG_get_clock();
+ mig_timeout -= (clock_post_send - clock_prev_send);
+ if (mig_timeout < 0) {
+ XBT_INFO("The duration of stage 1 exceeds the timeout value (%lf > %lf), skip stage 2",
+ (clock_post_send - clock_prev_send), MIGRATION_TIMEOUT_DO_NOT_HARDCODE_ME);
+ skip_stage2 = 1;
+ }
+
+ /* estimate bandwidth */
+ double bandwidth = ramsize / (clock_post_send - clock_prev_send);
+ threshold = get_threshold_value(bandwidth, max_downtime);
+ XBT_DEBUG("actual bandwidth %f (MB/s), threshold %f", bandwidth / 1024 / 1024, threshold);
+ }
+
+
+ /* Stage2: send update pages iteratively until the size of remaining states
+ * becomes smaller than the threshold value. */
+ if (skip_stage2)
+ goto stage3;
+
+
+ int stage2_round = 0;
+ for (;;) {
+
+ sg_size_t updated_size = 0;
+ if (stage2_round == 0) {
+ /* just after stage1, nothing has been updated. But, we have to send the
+ * data updated during stage1 */
+ updated_size = get_updated_size(computed_during_stage1, dp_rate, dp_cap);
+ } else {
+ double computed = lookup_computed_flop_counts(ms->vm, 2, stage2_round);
+ updated_size = get_updated_size(computed, dp_rate, dp_cap);
+ }
+
+ XBT_DEBUG("mig-stage 2:%d updated_size %llu computed_during_stage1 %f dp_rate %f dp_cap %f",
+ stage2_round, updated_size, computed_during_stage1, dp_rate, dp_cap);
+
+
+ /* Check whether the remaining size is below the threshold value. If so,
+ * move to stage 3. */
+ remaining_size += updated_size;
+ XBT_DEBUG("mig-stage2.%d: remaining_size %f (%s threshold %f)", stage2_round,
+ remaining_size, (remaining_size < threshold) ? "<" : ">", threshold);
+ if (remaining_size < threshold)
+ break;
+
+
+ sg_size_t sent = 0;
+ double clock_prev_send = MSG_get_clock();
+ TRY {
+ sent = send_migration_data(ms->vm, ms->src_pm, ms->dst_pm, updated_size, ms->mbox, 2, stage2_round, mig_speed, mig_timeout);
+ } CATCH_ANONYMOUS {
+ //hostfailure (if you want to know whether this is the SRC or the DST please check directly in send_migration_data code)
+ // Stop the dirty page tracking an return (there is no memory space to release)
+ stop_dirty_page_tracking(ms->vm);
+ return 0;
+ }
+ double clock_post_send = MSG_get_clock();
+
+ if (sent == updated_size) {
+ /* timeout did not happen */
+ double bandwidth = updated_size / (clock_post_send - clock_prev_send);
+ threshold = get_threshold_value(bandwidth, max_downtime);
+ XBT_DEBUG("actual bandwidth %f, threshold %f", bandwidth / 1024 / 1024, threshold);
+ remaining_size -= sent;
+ stage2_round += 1;
+ mig_timeout -= (clock_post_send - clock_prev_send);
+ xbt_assert(mig_timeout > 0);
+
+ } else if (sent < updated_size) {
+ /* When timeout happens, we move to stage 3. The size of memory pages
+ * updated before timeout must be added to the remaining size. */
+ XBT_INFO("mig-stage2.%d: timeout, force moving to stage 3. sent %llu / %llu, eta %lf",
+ stage2_round, sent, updated_size, (clock_post_send - clock_prev_send));
+ remaining_size -= sent;
+
+ double computed = lookup_computed_flop_counts(ms->vm, 2, stage2_round);
+ updated_size = get_updated_size(computed, dp_rate, dp_cap);
+ remaining_size += updated_size;
+ break;
+
+ } else
+ XBT_CRITICAL("bug");
+ }
+
+
+stage3:
+ /* Stage3: stop the VM and copy the rest of states. */
+ XBT_DEBUG("mig-stage3: remaining_size %f", remaining_size);
+ simcall_vm_suspend(ms->vm);
+ stop_dirty_page_tracking(ms->vm);
+
+ TRY {
+ send_migration_data(ms->vm, ms->src_pm, ms->dst_pm, remaining_size, ms->mbox, 3, 0, mig_speed, -1);
+ } CATCH_ANONYMOUS {
+ //hostfailure (if you want to know whether this is the SRC or the DST please check directly in send_migration_data code)
+ // Stop the dirty page tracking an return (there is no memory space to release)
+ simcall_vm_resume(ms->vm);
+ return 0;
+ }
+
+ // At that point the Migration is considered valid for the SRC node but remind that the DST side should relocate effectively the VM on the DST node.
+ XBT_INFO("mig: tx_done");
+
+ return 0;
+}
+
+
+
+static int do_migration(msg_vm_t vm, msg_host_t src_pm, msg_host_t dst_pm)
+{
+ struct migration_session *ms = xbt_new(struct migration_session, 1);
+ ms->vm = vm;
+ ms->src_pm = src_pm;
+ ms->dst_pm = dst_pm;
+ ms->mbox_ctl = get_mig_mbox_ctl(vm, src_pm, dst_pm);
+ ms->mbox = get_mig_mbox_src_dst(vm, src_pm, dst_pm);
+
+
+ char *pr_rx_name = get_mig_process_rx_name(vm, src_pm, dst_pm);
+ char *pr_tx_name = get_mig_process_tx_name(vm, src_pm, dst_pm);
+
+ msg_process_t tx_process, rx_process;
+// MSG_process_create(pr_rx_name, migration_rx_fun, ms, dst_pm);
+// MSG_process_create(pr_tx_name, migration_tx_fun, ms, src_pm);
+#if 1
+ {
+ char **argv = xbt_new(char *, 2);
+ argv[0] = pr_rx_name;
+ argv[1] = NULL;
+ rx_process = MSG_process_create_with_arguments(pr_rx_name, migration_rx_fun, ms, dst_pm, 1, argv);
+ }
+ {
+ char **argv = xbt_new(char *, 2);
+ argv[0] = pr_tx_name;
+ argv[1] = NULL;
+ tx_process = MSG_process_create_with_arguments(pr_tx_name, migration_tx_fun, ms, src_pm, 1, argv);
+ }
+#endif
+
+ /* wait until the migration have finished or on error has occured */
+ {
+ XBT_DEBUG("wait for reception of the final ACK (i.e. migration has been correctly performed");
+ msg_task_t task = NULL;
+ msg_error_t ret = MSG_TIMEOUT;
+ while (ret == MSG_TIMEOUT && MSG_host_is_on(dst_pm)) //Wait while you receive the message o
+ ret = MSG_task_receive_with_timeout(&task, ms->mbox_ctl, 3);
+
+ xbt_free(ms->mbox_ctl);
+ xbt_free(ms->mbox);
+ xbt_free(ms);
+
+ //xbt_assert(ret == MSG_OK);
+ if(ret == MSG_HOST_FAILURE){
+ // Note that since the communication failed, the owner did not change and the task should be destroyed on the other side.
+ // Hence, just throw the execption
+ XBT_INFO("SRC crashes, throw an exception (m-control)");
+ MSG_process_kill(tx_process); // Adrien, I made a merge on Nov 28th 2014, I'm not sure whether this line is required or not
+ return -1;
+ }
+ else if((ret == MSG_TRANSFER_FAILURE) || (ret == MSG_TIMEOUT)){ // MSG_TIMEOUT here means that MSG_host_is_avail() returned false.
+ XBT_INFO("DST crashes, throw an exception (m-control)");
+ return -2;
+ }
+
+
+ char *expected_task_name = get_mig_task_name(vm, src_pm, dst_pm, 4);
+ xbt_assert(strcmp(task->name, expected_task_name) == 0);
+ xbt_free(expected_task_name);
+ MSG_task_destroy(task);
+ return 0;
+ }
+}
+
+
+
+
+/** @brief Migrate the VM to the given host.
+ * @ingroup msg_VMs
+ *
+ * FIXME: No migration cost occurs. If you want to simulate this too, you want to use a
+ * MSG_task_send() before or after, depending on whether you want to do cold or hot
+ * migration.
+ */
+void MSG_vm_migrate(msg_vm_t vm, msg_host_t new_pm)
+{
+ /* some thoughts:
+ * - One approach is ...
+ * We first create a new VM (i.e., destination VM) on the destination
+ * physical host. The destination VM will receive the state of the source
+ * VM over network. We will finally destroy the source VM.
+ * - This behavior is similar to the way of migration in the real world.
+ * Even before a migration is completed, we will see a destination VM,
+ * consuming resources.
+ * - We have to relocate all processes. The existing process migraion code
+ * will work for this?
+ * - The name of the VM is a somewhat unique ID in the code. It is tricky
+ * for the destination VM?
+ *
+ * - Another one is ...
+ * We update the information of the given VM to place it to the destination
+ * physical host.
+ *
+ * The second one would be easier.
+ *
+ */
+
+ msg_host_t old_pm = simcall_vm_get_pm(vm);
+
+ if (!MSG_vm_is_running(vm))
+ THROWF(vm_error, 0, "VM(%s) is not running", sg_host_name(vm));
+
+ if (MSG_vm_is_migrating(vm))
+ THROWF(vm_error, 0, "VM(%s) is already migrating", sg_host_name(vm));
+
+ msg_host_priv_t priv = msg_host_resource_priv(vm);
+ priv->is_migrating = 1;
+
+ {
+
+ int ret = do_migration(vm, old_pm, new_pm);
+ if (ret == -1){
+ priv->is_migrating = 0;
+ THROWF(host_error, 0, "SRC host failed during migration");
+ }
+ else if(ret == -2){
+ priv->is_migrating = 0;
+ THROWF(host_error, 0, "DST host failed during migration");
+ }
+ }
+
+ // This part is done in the RX code, to handle the corner case where SRC can crash just at the end of the migration process
+ // In that case, the VM has been already assigned to the DST node.
+ //XBT_DEBUG("VM(%s) moved from PM(%s) to PM(%s)", vm->key, old_pm->key, new_pm->key);
+ //#ifdef HAVE_TRACING
+ //TRACE_msg_vm_change_host(vm, old_pm, new_pm);
+ //#endif
+}
+