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