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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 (a copy is made).
  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.  
  152.     memcpy(ta->name, name, TASK_NAME_BUFLEN);
  153.     ta->name[TASK_NAME_BUFLEN - 1] = '\0';
  154.  
  155.     atomic_set(&ta->refcount, 0);
  156.     atomic_set(&ta->lifecount, 0);
  157.     ta->context = CONTEXT;
  158.  
  159.     ta->capabilities = 0;
  160.     ta->cycles = 0;
  161.  
  162. #ifdef CONFIG_UDEBUG
  163.     /* Init debugging stuff */
  164.     udebug_task_init(&ta->udebug);
  165.  
  166.     /* Init kbox stuff */
  167.     ipc_answerbox_init(&ta->kb.box, ta);
  168.     ta->kb.thread = NULL;
  169.     mutex_initialize(&ta->kb.cleanup_lock, MUTEX_PASSIVE);
  170.     ta->kb.finished = false;
  171. #endif
  172.  
  173.     ipc_answerbox_init(&ta->answerbox, ta);
  174.     for (i = 0; i < IPC_MAX_PHONES; i++)
  175.         ipc_phone_init(&ta->phones[i]);
  176.     if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context,
  177.         ta->context)))
  178.         ipc_phone_connect(&ta->phones[0], ipc_phone_0);
  179.     atomic_set(&ta->active_calls, 0);
  180.  
  181.     mutex_initialize(&ta->futexes_lock, MUTEX_PASSIVE);
  182.     btree_create(&ta->futexes);
  183.    
  184.     ipl = interrupts_disable();
  185.  
  186.     /*
  187.      * Increment address space reference count.
  188.      */
  189.     atomic_inc(&as->refcount);
  190.  
  191.     spinlock_lock(&tasks_lock);
  192.     ta->taskid = ++task_counter;
  193.     avltree_node_initialize(&ta->tasks_tree_node);
  194.     ta->tasks_tree_node.key = ta->taskid;
  195.     avltree_insert(&tasks_tree, &ta->tasks_tree_node);
  196.     spinlock_unlock(&tasks_lock);
  197.     interrupts_restore(ipl);
  198.  
  199.     return ta;
  200. }
  201.  
  202. /** Destroy task.
  203.  *
  204.  * @param t     Task to be destroyed.
  205.  */
  206. void task_destroy(task_t *t)
  207. {
  208.     /*
  209.      * Remove the task from the task B+tree.
  210.      */
  211.     spinlock_lock(&tasks_lock);
  212.     avltree_delete(&tasks_tree, &t->tasks_tree_node);
  213.     spinlock_unlock(&tasks_lock);
  214.  
  215.     /*
  216.      * Perform architecture specific task destruction.
  217.      */
  218.     task_destroy_arch(t);
  219.  
  220.     /*
  221.      * Free up dynamically allocated state.
  222.      */
  223.     btree_destroy(&t->futexes);
  224.  
  225.     /*
  226.      * Drop our reference to the address space.
  227.      */
  228.     if (atomic_predec(&t->as->refcount) == 0)
  229.         as_destroy(t->as);
  230.    
  231.     free(t);
  232.     TASK = NULL;
  233. }
  234.  
  235. /** Syscall for reading task ID from userspace.
  236.  *
  237.  * @param       uspace_task_id userspace address of 8-byte buffer
  238.  *          where to store current task ID.
  239.  *
  240.  * @return      Zero on success or an error code from @ref errno.h.
  241.  */
  242. unative_t sys_task_get_id(task_id_t *uspace_task_id)
  243. {
  244.     /*
  245.      * No need to acquire lock on TASK because taskid remains constant for
  246.      * the lifespan of the task.
  247.      */
  248.     return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid,
  249.         sizeof(TASK->taskid));
  250. }
  251.  
  252. /** Find task structure corresponding to task ID.
  253.  *
  254.  * The tasks_lock must be already held by the caller of this function and
  255.  * interrupts must be disabled.
  256.  *
  257.  * @param id        Task ID.
  258.  *
  259.  * @return      Task structure address or NULL if there is no such task
  260.  *          ID.
  261.  */
  262. task_t *task_find_by_id(task_id_t id) { avltree_node_t *node;
  263.    
  264.     node = avltree_search(&tasks_tree, (avltree_key_t) id);
  265.  
  266.     if (node)
  267.         return avltree_get_instance(node, task_t, tasks_tree_node);
  268.     return NULL;
  269. }
  270.  
  271. /** Get accounting data of given task.
  272.  *
  273.  * Note that task lock of 't' must be already held and interrupts must be
  274.  * already disabled.
  275.  *
  276.  * @param t     Pointer to thread.
  277.  *
  278.  * @return      Number of cycles used by the task and all its threads
  279.  *          so far.
  280.  */
  281. uint64_t task_get_accounting(task_t *t)
  282. {
  283.     /* Accumulated value of task */
  284.     uint64_t ret = t->cycles;
  285.    
  286.     /* Current values of threads */
  287.     link_t *cur;
  288.     for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
  289.         thread_t *thr = list_get_instance(cur, thread_t, th_link);
  290.        
  291.         spinlock_lock(&thr->lock);
  292.         /* Process only counted threads */
  293.         if (!thr->uncounted) {
  294.             if (thr == THREAD) {
  295.                 /* Update accounting of current thread */
  296.                 thread_update_accounting();
  297.             }
  298.             ret += thr->cycles;
  299.         }
  300.         spinlock_unlock(&thr->lock);
  301.     }
  302.    
  303.     return ret;
  304. }
  305.  
  306. /** Kill task.
  307.  *
  308.  * This function is idempotent.
  309.  * It signals all the task's threads to bail it out.
  310.  *
  311.  * @param id        ID of the task to be killed.
  312.  *
  313.  * @return      Zero on success or an error code from errno.h.
  314.  */
  315. int task_kill(task_id_t id)
  316. {
  317.     ipl_t ipl;
  318.     task_t *ta;
  319.     link_t *cur;
  320.  
  321.     if (id == 1)
  322.         return EPERM;
  323.    
  324.     ipl = interrupts_disable();
  325.     spinlock_lock(&tasks_lock);
  326.     if (!(ta = task_find_by_id(id))) {
  327.         spinlock_unlock(&tasks_lock);
  328.         interrupts_restore(ipl);
  329.         return ENOENT;
  330.     }
  331.     spinlock_unlock(&tasks_lock);
  332.    
  333.     /*
  334.      * Interrupt all threads.
  335.      */
  336.     spinlock_lock(&ta->lock);
  337.     for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
  338.         thread_t *thr;
  339.         bool sleeping = false;
  340.        
  341.         thr = list_get_instance(cur, thread_t, th_link);
  342.            
  343.         spinlock_lock(&thr->lock);
  344.         thr->interrupted = true;
  345.         if (thr->state == Sleeping)
  346.             sleeping = true;
  347.         spinlock_unlock(&thr->lock);
  348.        
  349.         if (sleeping)
  350.             waitq_interrupt_sleep(thr);
  351.     }
  352.     spinlock_unlock(&ta->lock);
  353.     interrupts_restore(ipl);
  354.    
  355.     return 0;
  356. }
  357.  
  358. static bool task_print_walker(avltree_node_t *node, void *arg)
  359. {
  360.     task_t *t = avltree_get_instance(node, task_t, tasks_tree_node);
  361.     int j;
  362.        
  363.     spinlock_lock(&t->lock);
  364.            
  365.     uint64_t cycles;
  366.     char suffix;
  367.     order(task_get_accounting(t), &cycles, &suffix);
  368.  
  369. #ifdef __32_BITS__ 
  370.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %10p %10p %9" PRIu64
  371.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  372.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  373. #endif
  374.  
  375. #ifdef __64_BITS__
  376.     printf("%-6" PRIu64 " %-10s %-3" PRIu32 " %18p %18p %9" PRIu64
  377.         "%c %7ld %6ld", t->taskid, t->name, t->context, t, t->as, cycles,
  378.         suffix, atomic_get(&t->refcount), atomic_get(&t->active_calls));
  379. #endif
  380.  
  381.     for (j = 0; j < IPC_MAX_PHONES; j++) {
  382.         if (t->phones[j].callee)
  383.             printf(" %d:%p", j, t->phones[j].callee);
  384.     }
  385.     printf("\n");
  386.            
  387.     spinlock_unlock(&t->lock);
  388.     return true;
  389. }
  390.  
  391. /** Print task list */
  392. void task_print_list(void)
  393. {
  394.     ipl_t ipl;
  395.    
  396.     /* Messing with task structures, avoid deadlock */
  397.     ipl = interrupts_disable();
  398.     spinlock_lock(&tasks_lock);
  399.  
  400. #ifdef __32_BITS__ 
  401.     printf("taskid name       ctx address    as         "
  402.         "cycles     threads calls  callee\n");
  403.     printf("------ ---------- --- ---------- ---------- "
  404.         "---------- ------- ------ ------>\n");
  405. #endif
  406.  
  407. #ifdef __64_BITS__
  408.     printf("taskid name       ctx address            as                 "
  409.         "cycles     threads calls  callee\n");
  410.     printf("------ ---------- --- ------------------ ------------------ "
  411.         "---------- ------- ------ ------>\n");
  412. #endif
  413.  
  414.     avltree_walk(&tasks_tree, task_print_walker, NULL);
  415.  
  416.     spinlock_unlock(&tasks_lock);
  417.     interrupts_restore(ipl);
  418. }
  419.  
  420. /** @}
  421.  */
  422.