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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 <string.h>
  56. #include <syscall/copy.h>
  57. #include <macros.h>
  58. #include <ipc/event.h>
  59.  
  60. /** Spinlock protecting the tasks_tree AVL tree. */
  61. SPINLOCK_INITIALIZE(tasks_lock);
  62.  
  63. /** AVL tree of active tasks.
  64.  *
  65.  * The task is guaranteed to exist after it was found in the tasks_tree as
  66.  * long as:
  67.  * @li the tasks_lock is held,
  68.  * @li the task's lock is held when task's lock is acquired before releasing
  69.  *     tasks_lock or
  70.  * @li the task's refcount is greater than 0
  71.  *
  72.  */
  73. avltree_t tasks_tree;
  74.  
  75. static task_id_t task_counter = 0;
  76.  
  77. /** Initialize kernel tasks support. */
  78. void task_init(void)
  79. {
  80.     TASK = NULL;
  81.     avltree_create(&tasks_tree);
  82. }
  83.  
  84. /*
  85.  * The idea behind this walker is to remember a single task different from
  86.  * TASK.
  87.  */
  88. static bool task_done_walker(avltree_node_t *node, void *arg)
  89. {
  90.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  91.     task_t **tp = (task_t **) arg;
  92.  
  93.     if (t != TASK) {
  94.         *tp = t;
  95.         return false;   /* stop walking */
  96.     }
  97.  
  98.     return true;    /* continue the walk */
  99. }
  100.  
  101. /** Kill all tasks except the current task. */
  102. void task_done(void)
  103. {
  104.     task_t *t;
  105.     do { /* Repeat until there are any tasks except TASK */
  106.        
  107.         /* Messing with task structures, avoid deadlock */
  108.         ipl_t ipl = interrupts_disable();
  109.         spinlock_lock(&tasks_lock);
  110.        
  111.         t = NULL;
  112.         avltree_walk(&tasks_tree, task_done_walker, &t);
  113.        
  114.         if (t != NULL) {
  115.             task_id_t id = t->taskid;
  116.            
  117.             spinlock_unlock(&tasks_lock);
  118.             interrupts_restore(ipl);
  119.            
  120. #ifdef CONFIG_DEBUG
  121.             printf("Killing task %" PRIu64 "\n", id);
  122. #endif         
  123.             task_kill(id);
  124.             thread_usleep(10000);
  125.         } else {
  126.             spinlock_unlock(&tasks_lock);
  127.             interrupts_restore(ipl);
  128.         }
  129.        
  130.     } while (t != NULL);
  131. }
  132.  
  133. /** Create new task with no threads.
  134.  *
  135.  * @param as        Task's address space.
  136.  * @param name      Symbolic name (a copy is made).
  137.  *
  138.  * @return      New task's structure.
  139.  *
  140.  */
  141. task_t *task_create(as_t *as, char *name)
  142. {
  143.     ipl_t ipl;
  144.     task_t *ta;
  145.     int i;
  146.    
  147.     ta = (task_t *) malloc(sizeof(task_t), 0);
  148.  
  149.     task_create_arch(ta);
  150.  
  151.     spinlock_initialize(&ta->lock, "task_ta_lock");
  152.     list_initialize(&ta->th_head);
  153.     ta->as = as;
  154.  
  155.     memcpy(ta->name, name, TASK_NAME_BUFLEN);
  156.     ta->name[TASK_NAME_BUFLEN - 1] = 0;
  157.  
  158.     atomic_set(&ta->refcount, 0);
  159.     atomic_set(&ta->lifecount, 0);
  160.     ta->context = CONTEXT;
  161.  
  162.     ta->capabilities = 0;
  163.     ta->cycles = 0;
  164.  
  165. #ifdef CONFIG_UDEBUG
  166.     /* Init debugging stuff */
  167.     udebug_task_init(&ta->udebug);
  168.  
  169.     /* Init kbox stuff */
  170.     ipc_answerbox_init(&ta->kb.box, ta);
  171.     ta->kb.thread = NULL;
  172.     mutex_initialize(&ta->kb.cleanup_lock, MUTEX_PASSIVE);
  173.     ta->kb.finished = false;
  174. #endif
  175.  
  176.     ipc_answerbox_init(&ta->answerbox, ta);
  177.     for (i = 0; i < IPC_MAX_PHONES; i++)
  178.         ipc_phone_init(&ta->phones[i]);
  179.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  180.         ta->context)))
  181.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  182.     atomic_set(&ta->active_calls, 0);
  183.  
  184.     mutex_initialize(&ta->futexes_lock, MUTEX_PASSIVE);
  185.     btree_create(&ta->futexes);
  186.    
  187.     ipl = interrupts_disable();
  188.  
  189.     /*
  190.      * Increment address space reference count.
  191.      */
  192.     atomic_inc(&as->refcount);
  193.  
  194.     spinlock_lock(&tasks_lock);
  195.     ta->taskid = ++task_counter;
  196.     avltree_node_initialize(&ta->tasks_tree_node);
  197.     ta->tasks_tree_node.key = ta->taskid;
  198.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  199.     spinlock_unlock(&tasks_lock);
  200.     interrupts_restore(ipl);
  201.    
  202.     /*
  203.      * Notify about task creation.
  204.      */
  205.     if (event_is_subscribed(EVENT_WAIT))
  206.         event_notify_3(EVENT_WAIT, TASK_CREATE, LOWER32(ta->taskid),
  207.             UPPER32(ta->taskid));
  208.    
  209.     return ta;
  210. }
  211.  
  212. /** Destroy task.
  213.  *
  214.  * @param t     Task to be destroyed.
  215.  */
  216. void task_destroy(task_t *t)
  217. {
  218.     /*
  219.      * Remove the task from the task B+tree.
  220.      */
  221.     spinlock_lock(&tasks_lock);
  222.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  223.     spinlock_unlock(&tasks_lock);
  224.  
  225.     /*
  226.      * Perform architecture specific task destruction.
  227.      */
  228.     task_destroy_arch(t);
  229.  
  230.     /*
  231.      * Free up dynamically allocated state.
  232.      */
  233.     btree_destroy(&t->futexes);
  234.  
  235.     /*
  236.      * Drop our reference to the address space.
  237.      */
  238.     if (atomic_predec(&t->as->refcount) == 0)
  239.         as_destroy(t->as);
  240.    
  241.     /*
  242.      * Notify about task destruction.
  243.      */
  244.     if (event_is_subscribed(EVENT_WAIT))
  245.         event_notify_3(EVENT_WAIT, TASK_DESTROY, LOWER32(t->taskid),
  246.             UPPER32(t->taskid));
  247.    
  248.     free(t);
  249.     TASK = NULL;
  250. }
  251.  
  252. /** Syscall for reading task ID from userspace.
  253.  *
  254.  * @param       uspace_task_id userspace address of 8-byte buffer
  255.  *          where to store current task ID.
  256.  *
  257.  * @return      Zero on success or an error code from @ref errno.h.
  258.  */
  259. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  260. {
  261.     /*
  262.      * No need to acquire lock on TASK because taskid remains constant for
  263.      * the lifespan of the task.
  264.      */
  265.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  266.         sizeof(TASK->taskid));
  267. }
  268.  
  269. /** Syscall for setting the task name.
  270.  *
  271.  * The name simplifies identifying the task in the task list.
  272.  *
  273.  * @param name  The new name for the task. (typically the same
  274.  *      as the command used to execute it).
  275.  *
  276.  * @return 0 on success or an error code from @ref errno.h.
  277.  */
  278. unative_t sys_task_set_name(const char *uspace_name, size_t name_len)
  279. {
  280.     int rc;
  281.     char namebuf[TASK_NAME_BUFLEN];
  282.  
  283.     /* Cap length of name and copy it from userspace. */
  284.  
  285.     if (name_len > TASK_NAME_BUFLEN - 1)
  286.         name_len = TASK_NAME_BUFLEN - 1;
  287.  
  288.     rc = copy_from_uspace(namebuf, uspace_name, name_len);
  289.     if (rc != 0)
  290.         return (unative_t) rc;
  291.  
  292.     namebuf[name_len] = '\0';
  293.     str_cpy(TASK->name, TASK_NAME_BUFLEN, namebuf);
  294.  
  295.     return EOK;
  296. }
  297.  
  298. /** Find task structure corresponding to task ID.
  299.  *
  300.  * The tasks_lock must be already held by the caller of this function and
  301.  * interrupts must be disabled.
  302.  *
  303.  * @param id        Task ID.
  304.  *
  305.  * @return      Task structure address or NULL if there is no such task
  306.  *          ID.
  307.  */
  308. task_t *task_find_by_id(task_id_t id) { avltree_node_t *node;
  309.    
  310.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  311.  
  312.     if (node)
  313.         return avltree_get_instance(node, task_t, tasks_tree_node);
  314.     return NULL;
  315. }
  316.  
  317. /** Get accounting data of given task.
  318.  *
  319.  * Note that task lock of 't' must be already held and interrupts must be
  320.  * already disabled.
  321.  *
  322.  * @param t     Pointer to thread.
  323.  *
  324.  * @return      Number of cycles used by the task and all its threads
  325.  *          so far.
  326.  */
  327. uint64_t task_get_accounting(task_t *t)
  328. {
  329.     /* Accumulated value of task */
  330.     uint64_t ret = t->cycles;
  331.    
  332.     /* Current values of threads */
  333.     link_t *cur;
  334.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  335.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  336.        
  337.         spinlock_lock(&thr->lock);
  338.         /* Process only counted threads */
  339.         if (!thr->uncounted) {
  340.             if (thr == THREAD) {
  341.                 /* Update accounting of current thread */
  342.                 thread_update_accounting();
  343.             }
  344.             ret += thr->cycles;
  345.         }
  346.         spinlock_unlock(&thr->lock);
  347.     }
  348.    
  349.     return ret;
  350. }
  351.  
  352. /** Kill task.
  353.  *
  354.  * This function is idempotent.
  355.  * It signals all the task's threads to bail it out.
  356.  *
  357.  * @param id        ID of the task to be killed.
  358.  *
  359.  * @return      Zero on success or an error code from errno.h.
  360.  */
  361. int task_kill(task_id_t id)
  362. {
  363.     ipl_t ipl;
  364.     task_t *ta;
  365.     link_t *cur;
  366.  
  367.     if (id == 1)
  368.         return EPERM;
  369.    
  370.     ipl = interrupts_disable();
  371.     spinlock_lock(&tasks_lock);
  372.     if (!(ta = task_find_by_id(id))) {
  373.         spinlock_unlock(&tasks_lock);
  374.         interrupts_restore(ipl);
  375.         return ENOENT;
  376.     }
  377.     spinlock_unlock(&tasks_lock);
  378.    
  379.     /*
  380.      * Interrupt all threads.
  381.      */
  382.     spinlock_lock(&ta->lock);
  383.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  384.         thread_t *thr;
  385.         bool sleeping = false;
  386.        
  387.         thr = list_get_instance(cur, thread_t, th_link);
  388.        
  389.         spinlock_lock(&thr->lock);
  390.         thr->interrupted = true;
  391.         if (thr->state == Sleeping)
  392.             sleeping = true;
  393.         spinlock_unlock(&thr->lock);
  394.        
  395.         if (sleeping)
  396.             waitq_interrupt_sleep(thr);
  397.     }
  398.     spinlock_unlock(&ta->lock);
  399.     interrupts_restore(ipl);
  400.    
  401.     return 0;
  402. }
  403.  
  404. static bool task_print_walker(avltree_node_t *node, void *arg)
  405. {
  406.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  407.     int j;
  408.        
  409.     spinlock_lock(&t->lock);
  410.            
  411.     uint64_t cycles;
  412.     char suffix;
  413.     order(task_get_accounting(t), &cycles, &suffix);
  414.  
  415. #ifdef __32_BITS__ 
  416.     printf("%-6" PRIu64 " %-12s %-3" PRIu32 " %10p %10p %9" PRIu64
  417.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  418.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  419. #endif
  420.  
  421. #ifdef __64_BITS__
  422.     printf("%-6" PRIu64 " %-12s %-3" PRIu32 " %18p %18p %9" PRIu64
  423.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  424.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  425. #endif
  426.  
  427.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  428.         if (t->phones[j].callee)
  429.             printf(" %d:%p", j, t->phones[j].callee);
  430.     }
  431.     printf("\n");
  432.            
  433.     spinlock_unlock(&t->lock);
  434.     return true;
  435. }
  436.  
  437. /** Print task list */
  438. void task_print_list(void)
  439. {
  440.     ipl_t ipl;
  441.    
  442.     /* Messing with task structures, avoid deadlock */
  443.     ipl = interrupts_disable();
  444.     spinlock_lock(&tasks_lock);
  445.  
  446. #ifdef __32_BITS__ 
  447.     printf("taskid name         ctx address    as         "
  448.         "cycles     threads calls  callee\n");
  449.     printf("------ ------------ --- ---------- ---------- "
  450.         "---------- ------- ------ ------>\n");
  451. #endif
  452.  
  453. #ifdef __64_BITS__
  454.     printf("taskid name         ctx address            as                 "
  455.         "cycles     threads calls  callee\n");
  456.     printf("------ ------------ --- ------------------ ------------------ "
  457.         "---------- ------- ------ ------>\n");
  458. #endif
  459.  
  460.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  461.  
  462.     spinlock_unlock(&tasks_lock);
  463.     interrupts_restore(ipl);
  464. }
  465.  
  466. /** @}
  467.  */
  468.