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