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