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