- /*
- * Start with one reference for the caller and one for the
- * act being alive.
- */
- act_lock_init(thr_act);
- thr_act->ref_count = 2;
-
- /* Latch onto the task. */
- thr_act->task = task;
- task_reference(task);
-
- /* special_handler will always be last on the returnhandlers list. */
- thr_act->special_handler.next = 0;
- thr_act->special_handler.handler = special_handler;
-
-#if MACH_PROF
- thr_act->act_profiled = FALSE;
- thr_act->act_profiled_own = FALSE;
- thr_act->profil_buffer = NULLPROFDATA;
-#endif
-
- /* Initialize the held_ulocks queue as empty */
- queue_init(&thr_act->held_ulocks);
-
- /* Inherit the profiling status of the parent task */
- act_prof_init(thr_act, task);
-
- ipc_thr_act_init(task, thr_act);
- act_machine_create(task, thr_act);
-
- /*
- * If thr_act created in kernel-loaded task, alter its saved
- * state to so indicate
- */
- if (task->kernel_loaded) {
- act_user_to_kernel(thr_act);
- }
-
- /* Cache the task's map and take a reference to it */
- map = task->map;
- thr_act->map = map;
-
- /* Inline vm_map_reference cause we don't want to increment res_count */
- mutex_lock(&map->s_lock);
- map->ref_count++;
- mutex_unlock(&map->s_lock);
-
- *new_act = thr_act;
- return KERN_SUCCESS;
-}
-
-/*
- * act_free - called when an thr_act's ref_count drops to zero.
- *
- * This can only happen after the activation has been reaped, and
- * all other references to it have gone away. We can now release
- * the last critical resources, unlink the activation from the
- * task, and release the reference on the thread shuttle itself.
- *
- * Called with activation locked.
- */
-#if MACH_ASSERT
-int dangerous_bzero = 1; /* paranoia & safety */
-#endif
-
-void
-act_free(thread_act_t thr_act)
-{
- task_t task;
- thread_t thr;
- vm_map_t map;
- unsigned int ref;
- void * task_proc;
-
-#if MACH_ASSERT
- if (watchacts & WA_EXIT)
- printf("act_free(%x(%d)) thr=%x tsk=%x(%d) %sactive\n",
- thr_act, thr_act->ref_count, thr_act->thread,
- thr_act->task,
- thr_act->task ? thr_act->task->ref_count : 0,
- thr_act->active ? " " : " !");
-#endif /* MACH_ASSERT */
-
- assert(!thr_act->active);
-
- task = thr_act->task;
- task_lock(task);
-
- task_proc = task->bsd_info;
- if (thr = thr_act->thread) {
- time_value_t user_time, system_time;
-
- thread_read_times(thr, &user_time, &system_time);
- time_value_add(&task->total_user_time, &user_time);
- time_value_add(&task->total_system_time, &system_time);
-
- /* Unlink the thr_act from the task's thr_act list,
- * so it doesn't appear in calls to task_threads and such.
- * The thr_act still keeps its ref on the task, however.
- */
- queue_remove(&task->thr_acts, thr_act, thread_act_t, thr_acts);
- thr_act->thr_acts.next = NULL;
- task->thr_act_count--;
- task->res_act_count--;
- task_unlock(task);
- task_deallocate(task);
- thread_deallocate(thr);
- act_machine_destroy(thr_act);
- } else {
- /*
- * Must have never really gotten started
- * no unlinking from the task and no need
- * to free the shuttle.
- */
- task_unlock(task);
- task_deallocate(task);
- }
-
- act_prof_deallocate(thr_act);
- ipc_thr_act_terminate(thr_act);
-
- /*
- * Drop the cached map reference.
- * Inline version of vm_map_deallocate() because we
- * don't want to decrement the map's residence count here.
- */
- map = thr_act->map;
- mutex_lock(&map->s_lock);
- ref = --map->ref_count;
- mutex_unlock(&map->s_lock);
- if (ref == 0)
- vm_map_destroy(map);
-
-#ifdef MACH_BSD
- {
- /*
- * Free uthread BEFORE the bzero.
- * Not doing so will result in a leak.
- */
- extern void uthread_free(task_t, void *, void *);
-
- void *ut = thr_act->uthread;
- thr_act->uthread = 0;
- uthread_free(task, ut, task_proc);
- }
-#endif /* MACH_BSD */
-
-#if MACH_ASSERT
- if (dangerous_bzero) /* dangerous if we're still using it! */
- bzero((char *)thr_act, sizeof(*thr_act));
-#endif /* MACH_ASSERT */
- /* Put the thr_act back on the thr_act zone */
- zfree(thr_act_zone, (vm_offset_t)thr_act);
-}
-
-
-/*
- * act_attach - Attach an thr_act to the top of a thread ("push the stack").
- *
- * The thread_shuttle must be either the current one or a brand-new one.
- * Assumes the thr_act is active but not in use.
- *
- * Already locked: thr_act plus "appropriate" thread-related locks
- * (see act_lock_thread()).
- */
-void
-act_attach(
- thread_act_t thr_act,
- thread_t thread,
- unsigned init_alert_mask)
-{
- thread_act_t lower;
-
-#if MACH_ASSERT
- assert(thread == current_thread() || thread->top_act == THR_ACT_NULL);
- if (watchacts & WA_ACT_LNK)
- printf("act_attach(thr_act %x(%d) thread %x(%d) mask %d)\n",
- thr_act, thr_act->ref_count, thread, thread->ref_count,
- init_alert_mask);
-#endif /* MACH_ASSERT */
-
- /*
- * Chain the thr_act onto the thread's thr_act stack.
- * Set mask and auto-propagate alerts from below.
- */
- thr_act->ref_count++;
- thr_act->thread = thread;
- thr_act->higher = THR_ACT_NULL; /*safety*/
- thr_act->alerts = 0;
- thr_act->alert_mask = init_alert_mask;
- lower = thr_act->lower = thread->top_act;
-
- if (lower != THR_ACT_NULL) {
- lower->higher = thr_act;
- thr_act->alerts = (lower->alerts & init_alert_mask);
- }
-
- thread->top_act = thr_act;
-}
-
-/*
- * act_detach
- *
- * Remove the current thr_act from the top of the current thread, i.e.
- * "pop the stack". Assumes already locked: thr_act plus "appropriate"
- * thread-related locks (see act_lock_thread).
- */
-void
-act_detach(
- thread_act_t cur_act)
-{
- thread_t cur_thread = cur_act->thread;
-
-#if MACH_ASSERT
- if (watchacts & (WA_EXIT|WA_ACT_LNK))
- printf("act_detach: thr_act %x(%d), thrd %x(%d) task=%x(%d)\n",
- cur_act, cur_act->ref_count,
- cur_thread, cur_thread->ref_count,
- cur_act->task,
- cur_act->task ? cur_act->task->ref_count : 0);
-#endif /* MACH_ASSERT */
-
- /* Unlink the thr_act from the thread's thr_act stack */
- cur_thread->top_act = cur_act->lower;
- cur_act->thread = 0;
- cur_act->ref_count--;
- assert(cur_act->ref_count > 0);
-
-#if MACH_ASSERT
- cur_act->lower = cur_act->higher = THR_ACT_NULL;
- if (cur_thread->top_act)
- cur_thread->top_act->higher = THR_ACT_NULL;
-#endif /* MACH_ASSERT */
-
- return;
-}
projects / apple / xnu.git / blobdiff