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  1. /*
  2.  * Copyright (c) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericproc
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Task management.
  36.  */
  37.  
  38. #include <proc/thread.h>
  39. #include <proc/task.h>
  40. #include <mm/as.h>
  41. #include <mm/slab.h>
  42. #include <atomic.h>
  43. #include <synch/spinlock.h>
  44. #include <synch/waitq.h>
  45. #include <arch.h>
  46. #include <arch/barrier.h>
  47. #include <adt/avl.h>
  48. #include <adt/btree.h>
  49. #include <adt/list.h>
  50. #include <ipc/ipc.h>
  51. #include <ipc/ipcrsc.h>
  52. #include <print.h>
  53. #include <errno.h>
  54. #include <func.h>
  55. #include <syscall/copy.h>
  56.  
  57. /** Spinlock protecting the tasks_tree AVL tree. */
  58. SPINLOCK_INITIALIZE(tasks_lock);
  59.  
  60. /** AVL tree of active tasks.
  61.  *
  62.  * The task is guaranteed to exist after it was found in the tasks_tree as
  63.  * long as:
  64.  * @li the tasks_lock is held,
  65.  * @li the task's lock is held when task's lock is acquired before releasing
  66.  *     tasks_lock or
  67.  * @li the task's refcount is greater than 0
  68.  *
  69.  */
  70. avltree_t tasks_tree;
  71.  
  72. static task_id_t task_counter = 0;
  73.  
  74. /** Initialize kernel tasks support. */
  75. void task_init(void)
  76. {
  77.     TASK = NULL;
  78.     avltree_create(&tasks_tree);
  79. }
  80.  
  81. /*
  82.  * The idea behind this walker is to remember a single task different from
  83.  * TASK.
  84.  */
  85. static bool task_done_walker(avltree_node_t *node, void *arg)
  86. {
  87.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  88.     task_t **tp = (task_t **) arg;
  89.  
  90.     if (t != TASK) {
  91.         *tp = t;
  92.         return false;   /* stop walking */
  93.     }
  94.  
  95.     return true;    /* continue the walk */
  96. }
  97.  
  98. /** Kill all tasks except the current task. */
  99. void task_done(void)
  100. {
  101.     task_t *t;
  102.     do { /* Repeat until there are any tasks except TASK */
  103.        
  104.         /* Messing with task structures, avoid deadlock */
  105.         ipl_t ipl = interrupts_disable();
  106.         spinlock_lock(&tasks_lock);
  107.        
  108.         t = NULL;
  109.         avltree_walk(&tasks_tree, task_done_walker, &t);
  110.        
  111.         if (t != NULL) {
  112.             task_id_t id = t->taskid;
  113.            
  114.             spinlock_unlock(&tasks_lock);
  115.             interrupts_restore(ipl);
  116.            
  117. #ifdef CONFIG_DEBUG
  118.             printf("Killing task %" PRIu64 "\n", id);
  119. #endif         
  120.             task_kill(id);
  121.             thread_usleep(10000);
  122.         } else {
  123.             spinlock_unlock(&tasks_lock);
  124.             interrupts_restore(ipl);
  125.         }
  126.        
  127.     } while (t != NULL);
  128. }
  129.  
  130. /** Create new task with no threads.
  131.  *
  132.  * @param as        Task's address space.
  133.  * @param name      Symbolic name.
  134.  *
  135.  * @return      New task's structure.
  136.  *
  137.  */
  138. task_t *task_create(as_t *as, char *name)
  139. {
  140.     ipl_t ipl;
  141.     task_t *ta;
  142.     int i;
  143.    
  144.     ta = (task_t *) malloc(sizeof(task_t), 0);
  145.  
  146.     task_create_arch(ta);
  147.  
  148.     spinlock_initialize(&ta->lock, "task_ta_lock");
  149.     list_initialize(&ta->th_head);
  150.     ta->as = as;
  151.     ta->name = name;
  152.     atomic_set(&ta->refcount, 0);
  153.     atomic_set(&ta->lifecount, 0);
  154.     ta->context = CONTEXT;
  155.  
  156.     ta->capabilities = 0;
  157.     ta->cycles = 0;
  158.  
  159. #ifdef CONFIG_UDEBUG
  160.     /* Init debugging stuff */
  161.     udebug_task_init(&ta->udebug);
  162.  
  163.     /* Init kbox stuff */
  164.     ipc_answerbox_init(&ta->kernel_box, ta);
  165.     ta->kb_thread = NULL;
  166.     mutex_initialize(&ta->kb_cleanup_lock, MUTEX_PASSIVE);
  167.     ta->kb_finished = false;
  168. #endif
  169.  
  170.     ipc_answerbox_init(&ta->answerbox, ta);
  171.     for (i = 0; i < IPC_MAX_PHONES; i++)
  172.         ipc_phone_init(&ta->phones[i]);
  173.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  174.         ta->context)))
  175.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  176.     atomic_set(&ta->active_calls, 0);
  177.  
  178.     mutex_initialize(&ta->futexes_lock, MUTEX_PASSIVE);
  179.     btree_create(&ta->futexes);
  180.    
  181.     ipl = interrupts_disable();
  182.  
  183.     /*
  184.      * Increment address space reference count.
  185.      */
  186.     atomic_inc(&as->refcount);
  187.  
  188.     spinlock_lock(&tasks_lock);
  189.     ta->taskid = ++task_counter;
  190.     avltree_node_initialize(&ta->tasks_tree_node);
  191.     ta->tasks_tree_node.key = ta->taskid;
  192.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  193.     spinlock_unlock(&tasks_lock);
  194.     interrupts_restore(ipl);
  195.  
  196.     return ta;
  197. }
  198.  
  199. /** Destroy task.
  200.  *
  201.  * @param t     Task to be destroyed.
  202.  */
  203. void task_destroy(task_t *t)
  204. {
  205.     /*
  206.      * Remove the task from the task B+tree.
  207.      */
  208.     spinlock_lock(&tasks_lock);
  209.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  210.     spinlock_unlock(&tasks_lock);
  211.  
  212.     /*
  213.      * Perform architecture specific task destruction.
  214.      */
  215.     task_destroy_arch(t);
  216.  
  217.     /*
  218.      * Free up dynamically allocated state.
  219.      */
  220.     btree_destroy(&t->futexes);
  221.  
  222.     /*
  223.      * Drop our reference to the address space.
  224.      */
  225.     if (atomic_predec(&t->as->refcount) == 0)
  226.         as_destroy(t->as);
  227.    
  228.     free(t);
  229.     TASK = NULL;
  230. }
  231.  
  232. /** Syscall for reading task ID from userspace.
  233.  *
  234.  * @param       uspace_task_id userspace address of 8-byte buffer
  235.  *          where to store current task ID.
  236.  *
  237.  * @return      Zero on success or an error code from @ref errno.h.
  238.  */
  239. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  240. {
  241.     /*
  242.      * No need to acquire lock on TASK because taskid remains constant for
  243.      * the lifespan of the task.
  244.      */
  245.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  246.         sizeof(TASK->taskid));
  247. }
  248.  
  249. /** Find task structure corresponding to task ID.
  250.  *
  251.  * The tasks_lock must be already held by the caller of this function and
  252.  * interrupts must be disabled.
  253.  *
  254.  * @param id        Task ID.
  255.  *
  256.  * @return      Task structure address or NULL if there is no such task
  257.  *          ID.
  258.  */
  259. task_t *task_find_by_id(task_id_t id) { avltree_node_t *node;
  260.    
  261.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  262.  
  263.     if (node)
  264.         return avltree_get_instance(node, task_t, tasks_tree_node);
  265.     return NULL;
  266. }
  267.  
  268. /** Get accounting data of given task.
  269.  *
  270.  * Note that task lock of 't' must be already held and interrupts must be
  271.  * already disabled.
  272.  *
  273.  * @param t     Pointer to thread.
  274.  *
  275.  * @return      Number of cycles used by the task and all its threads
  276.  *          so far.
  277.  */
  278. uint64_t task_get_accounting(task_t *t)
  279. {
  280.     /* Accumulated value of task */
  281.     uint64_t ret = t->cycles;
  282.    
  283.     /* Current values of threads */
  284.     link_t *cur;
  285.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  286.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  287.        
  288.         spinlock_lock(&thr->lock);
  289.         /* Process only counted threads */
  290.         if (!thr->uncounted) {
  291.             if (thr == THREAD) {
  292.                 /* Update accounting of current thread */
  293.                 thread_update_accounting();
  294.             }
  295.             ret += thr->cycles;
  296.         }
  297.         spinlock_unlock(&thr->lock);
  298.     }
  299.    
  300.     return ret;
  301. }
  302.  
  303. /** Kill task.
  304.  *
  305.  * This function is idempotent.
  306.  * It signals all the task's threads to bail it out.
  307.  *
  308.  * @param id        ID of the task to be killed.
  309.  *
  310.  * @return      Zero on success or an error code from errno.h.
  311.  */
  312. int task_kill(task_id_t id)
  313. {
  314.     ipl_t ipl;
  315.     task_t *ta;
  316.     link_t *cur;
  317.  
  318.     if (id == 1)
  319.         return EPERM;
  320.    
  321.     ipl = interrupts_disable();
  322.     spinlock_lock(&tasks_lock);
  323.     if (!(ta = task_find_by_id(id))) {
  324.         spinlock_unlock(&tasks_lock);
  325.         interrupts_restore(ipl);
  326.         return ENOENT;
  327.     }
  328.     spinlock_unlock(&tasks_lock);
  329.    
  330.     /*
  331.      * Interrupt all threads.
  332.      */
  333.     spinlock_lock(&ta->lock);
  334.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  335.         thread_t *thr;
  336.         bool sleeping = false;
  337.        
  338.         thr = list_get_instance(cur, thread_t, th_link);
  339.            
  340.         spinlock_lock(&thr->lock);
  341.         thr->interrupted = true;
  342.         if (thr->state == Sleeping)
  343.             sleeping = true;
  344.         spinlock_unlock(&thr->lock);
  345.        
  346.         if (sleeping)
  347.             waitq_interrupt_sleep(thr);
  348.     }
  349.     spinlock_unlock(&ta->lock);
  350.     interrupts_restore(ipl);
  351.    
  352.     return 0;
  353. }
  354.  
  355. static bool task_print_walker(avltree_node_t *node, void *arg)
  356. {
  357.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  358.     int j;
  359.        
  360.     spinlock_lock(&t->lock);
  361.            
  362.     uint64_t cycles;
  363.     char suffix;
  364.     order(task_get_accounting(t), &cycles, &suffix);
  365.  
  366. #ifdef __32_BITS__ 
  367.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %10p %10p %9" PRIu64
  368.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  369.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  370. #endif
  371.  
  372. #ifdef __64_BITS__
  373.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %18p %18p %9" PRIu64
  374.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  375.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  376. #endif
  377.  
  378.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  379.         if (t->phones[j].callee)
  380.             printf(" %d:%p", j, t->phones[j].callee);
  381.     }
  382.     printf("\n");
  383.            
  384.     spinlock_unlock(&t->lock);
  385.     return true;
  386. }
  387.  
  388. /** Print task list */
  389. void task_print_list(void)
  390. {
  391.     ipl_t ipl;
  392.    
  393.     /* Messing with task structures, avoid deadlock */
  394.     ipl = interrupts_disable();
  395.     spinlock_lock(&tasks_lock);
  396.  
  397. #ifdef __32_BITS__ 
  398.     printf("taskid name       ctx address    as         "
  399.         "cycles     threads calls  callee\n");
  400.     printf("------ ---------- --- ---------- ---------- "
  401.         "---------- ------- ------ ------>\n");
  402. #endif
  403.  
  404. #ifdef __64_BITS__
  405.     printf("taskid name       ctx address            as                 "
  406.         "cycles     threads calls  callee\n");
  407.     printf("------ ---------- --- ------------------ ------------------ "
  408.         "---------- ------- ------ ------>\n");
  409. #endif
  410.  
  411.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  412.  
  413.     spinlock_unlock(&tasks_lock);
  414.     interrupts_restore(ipl);
  415. }
  416.  
  417. /** @}
  418.  */
  419.